HELICOBACTER PYLORI AND GASTRIC CANCER: IS THERE A LINK? Lt Col AC ANAND, VSM * , Lt Col M ANAND +, Col PS REDDY, Brig JR BHARDWAJ ** ABSTRACT This paper examines the correlation between prevalence of H pylori, gastritis and the histological type of gastric cancer. 50 gastrectomy specimens from the patients with gastric cancers were studied for the prevalence of H pylori, type of gastritis as dassified by the Sydney system, presence of intestinal metaplasia, and the histological type of gastric cancer. H pylori was detected in 27 (54%) stomachs. The common site for finding this bacterium was either antrum or body of stomach (16 and 17 sections respectively), Gastritis was found in 48/50 specimen (96%) from non-neoplastic areas. However, 15 ofthe 18 patients with atrophic gastritis had H pylori in their stomach specimens either in the body or in antrum. Intestinal metaplasia was detected in 19 (38%) specimen. Of these, 14(73.7%) specimens had type I and remaining 5 (26.3%) had type 2 metaplasia. The distribution of metaplasia was significantly more in H pylori positive patients. Prevalence of H pylori positivity was highest in intestinal type of cancer (66.7%) and lowest in diffuse variety (45.8%). In two third specimens of intestinal type of cancer, gastritis was related to H pylori while such association with H pylori was seen in approximately half (45.8% & 57.1%, respectively) the specimens of other types of cancers. There is strong association between the prevalence of H pylori and gastritis on one hand and the intestinal metaplasia on the other, in patients with gastric cancer. These findings, indirectly support Correa's hypothesis that H pylori is a causal fador in the intestinal form of gastric cancer. MJAF11998; 54: 297-301 KEY WORDS: Gastric carcinoma; Gastritis; H pylori; Intestinal metaplasia.
Introduction
E
nvironmental influences play a significant role in the causation of gastric cancer, as is indicated by several epidemiological studies [1]. To date, most investigators have emphasised the role of diet in gastric carcinogenesis [2]. Atrophic gastritis with intestinal metaplasia has been identified as a precursor lesion for the commoner intestinal form of gastric carcinoma [3,4]. Helicobacter pylori has now been found to be the causative oerganism of non-immune type B gastritis [5]. A few case controlled studies have also hinted at the association between H. pylori infection and subsequent development of gastric cancer [6-8]. The possibility that H pylori is involved in gastric carcinogenesis has therefore been raised [4]. This study was carried out to examine the relationship between H pylori, histological gastritis, and intestinal metaplasia in gastric cancers of different histological types. Material and Methods A total of 50 gastrectomy specimens from the patients with gastric cancers received by Department of Pathology. from June 92 to May 94 were studied. The specimens were fixed in too/o butTered formalin. Multiple blocks were taken from the tumour. antrum, and body of stomach. The sections of antral and body mucosa were taken as far from the tumour site as possible. Paraffin
embedded histological sections were cut at 4 J.Lm thickness and stained with haematoxylin and eosin, Giemsa. Periodic acid SehitT reaction with and without diastase digestion and mucicarmine stains when required. Histological Classification olGastric Carcinoma
All the sections from tumour were meticulously reviewed to determine the histological type of cancer as per modified Lauren classification [9J : (i) Intestinal type: characterised by cohesive cell clusters showing distinct glandular elements with well-defined lamina lined with polarised epithelial cells. Papillary structures. solid componenets, brush borders and pools of extracellular mucin may be present (ii) Diffuse type: characterised by dissociated malignant cells infiltrating surrounding tissue as single or small cluster of cells. Glandular lamina is lacking. Intracellular or extracellular mucin production is variable. (iii) Mixed type is one that includes the features of both intestinal and diffuse subtypes.
Histological Assessment
All tissue blocks of antral and body mucosa and of the tumour areas were re-cut and stained by the Giemsa method (2% Giemsa prepared in buffered distilled water) and Harris's haematoxylin and 1% eosin solution for the identification of H pylori [IOJ. The sections were also reviewed for occurrence of gastric and intestinal metaplasia. Gastritis was classified as per Sydney system of classification (II]. Intestinal metaplasia was classified as described by Filipe [12]:
• Reader (Medicine). Armed Forces Medical College. Pune. + Graded Specialist (Pathology), Command Hospital (SC), Pune-40, Advisor (Pathology), Army Hospital (R&R), Delhi Cantt, •• Cmmandant. AFMSD. Delhi Cantt.
#
Senior
298
Anand, Reddy and Bhardwaj
Type I: Presence of goblet cells secreting sialomucins and sometimes sulfomucins. Paneth cells and mature non-mucus secreting absorptive cells present. Type II : Goblet cells as above and complete absence of Paneth cells. Replacement of absorptive cells by columnar mucous cells secreting non-sulphated mucins. Type III: As above but columnar cells secrete predominantly sulphomucins. H pylori colonisation was classified as 'severe'when large groups of organisms were present on surface and upper pits of more than two thirds of mucosal surface examined; 'mild' colonisation, when individual organisms or small groups were covering less than one third of mucosal surface; 'moderate' colonisation being in between these two.
gastric cancer patients and another 300 blocks from the controls were studied. From the gastric cancer specimen, 2 biopsies from tumor area, and 2 each from antral, body and fundal mucosa of each case were studied. In small proportion of cases, it was not possible to take all the 8 blocks due to extensive tumor infiltration. Thus total of 100 blocks were examined from the tumour, 92 from antral mucosa, 94 from body mucosa and 84 from fundal mucosa. TABLE I Histopathological type of cancer stomach compartd to the age and sex of patients and the anatomical location of the cancer Histopathological type Number 12(24%) Mean age (years) 55.2± 12.6 Male: Female ratio II: I Location oftumour Fundus 3 Body 2 Antrum 7
Controls
Fifty consecutive patients that underwent upper gastrointestinal endoscopy biopsy for dyspeptic symptoms and did not have gastric malignancy. The biopsies were studied in a similar manner to determine the prevalence ofH pylori, gastritis, atrophy and intestinal metaplasia.
24(48%) 51.7±9.5 3: I
14(28%) 51.9 ± 10.8 9:5
50 52.6± 11.3 19: 6
4 15 9-
4 5 5
11 22 21-
-Note: Four cases were involving both body and antrum extensively so that the site ofpredominent involvement/origin could not be determined. These have been grouped under both areas
Statistical Analysis
Frequency of H pylori prevalence, atrophic gastritis and intestinal metaplasia was compared for statistical significance by chi square test and ANOVA (equivalent to student's test). Probability values < 0.05 were taken as significant.
Majority of tumours were of diffuse type. (Table I). The mean age of patients presenting with these three types of histological cancer was not statistically different from each other (p > 0.05). Most of the tumours were situated in body and antrum (78%). Prevalence of H pylori, gastritis, atrophy and metaplasia were more common in the gastric cancer patients in comparison to controls (Table 2). Gastritis was found in most of stomach specimens
Results A total of 50 cases of carcinoma stomach seen during the study period from June 92 to May 94 were included in the study. Age and sex distribution of patients included in the study group is summarized in Table I. A total of 370 tissue blocks from these
TABLE 2 Histological type of cancer stomach compared to the prevalence and type ofgastritis in stomach mucosa
Number Gastritis (a) Aetiolog}' i. H pylori ii. Other (H pylori negative) iii. Distribution of H pylori Tumour area Fundus Body Antrum (b) Topography i. Antral ii. Corpus iii. Pan-gastritis (c) Morphology i. Acute ii. Chronic iii. Atrophic (d) Miscellaneous i. Lymphoid follicles ii. Eosinophilic infiltrate iii. Granulomas
Intestinal
Histological type Diffuse
12 12 ( 100"A.)
24 24 (IOO"A.)
Mixed 14 12
(86%)
Total 50 48
(96%) (54%) (46%)
8 4
II 13
8 6
27 23
0 0 4 7
0 0 7 6
0 0 5 4
0 0 16 17
2 6 4
5 10 9
3 8 3
10 24 16
(20%) (48%) (32%)
0 6 6
3 10 II
I 5 8
4 21 25
(8%) (42%) (50%)
4 0 0
5 0 0
5 0 0
14 0 0
(28%)
WAH. Vol. 54. No.4. 1998
Helicobacter pylori and Gastric Cancer
299
examined from non-neoplastic areas (48/50 spccimen; 96%). Antral gastritis alone was present in 10 (20%). corpus or body gastritis alone was noted in 22 (44%) while remaining stomachs (16 or 32%) had pan-gastritis. Morphologically the gastritis was found to be acute in 3 (6%). chronic in 20(40010) and atrophic in 25 (50%). Lymphoid follicles were detected in 14 (28%) patients while none of the patients showed presence of granulomas or eosiniophilic infiltrate in stomach sections. Intestinal metaplasia was detected in only 19(38%) specimen. Of these, 14 (73.7%) specimens had type I metaplasia and remaining 5 (26.3%) had type 2 metaplasia. Type 3 metaplasia was not seen in this study.
had H pyloriin their stomach specimens (though not on the atrophic epithelium) either in the body or in antrum. This difference in prevalence of H pylori was also not found to be statistically significant. Lymphoid follicles were detected in 12 patients and of these 9 were H pylori positive. Here again the difference was not statistically significant. Intestinal metaplasia was present in 19 patients and of these 14 were positive for H pylori Difference is more marked when we see type 2 metaplasia where 8 of the 9 patients were positive for H pylori. Thus, distribution of metaplasia was significantly more in H pylori positive patients.
Correlation of histological type of gastric cancer with H pylori. positivity is summarised in Table 3. Prevalence of H pylori positivity was highest in intestinal type of cancer (66.7%) and lowest in diffuse variety (45.8%). However, difference in H pylori prevalence was not statistically significant. In patients with intestinal type of cancer. H pylori. was detected predominantly in antrum while in remaining specimens, it was equally distributed in antral and body sections. Correlation of histological type of gastric cancer with prevalence and type of gastritis is summarised in Table 2 Gastritis was present in stomach specimens of all patients with intestinal as well as diffuse type of cancers but was seen in only 85% specimens of mixed type of gastric cancer. This difference in prevalence is however not significant (p=O.05). In two third specimens of intestinal type of cancer. gastritis was related to H pylori while such association with H pylori was seen in approximately half (45.8% & 57.1 % respectively) the specimens of other types of cancers. Sections from the body of the stomach showed maximum prevalence of gastritis in all the types of cancers. Lymphoid follicles were detected in 4 specimens of intestinal type of cancer (33.3%). 5 specimens of diffuse type of cancer (20.8%) and 5 of mixed type of cancer (35.7%).
TABLE 4 Prevalenee and morphology orgastritis as well as intestinal metaplasia Is eorrelated with presenee or H pylori in patients with gastrie eaneer
TABLE 3 Histologieal type or eaneer stomaeh eompared to the prevalenee and loeation orintestinal metaplasia in stomaeh mueosa Intestinal Number
12 8 (67%) Intestinal metaplasia· 9 (a) Type I 5 (b) Type II 4 (c) Type III 0 H Pylori positivity
Histological type Diffuse Mixed 24 11(46%) 6 5 I 0
14 8(57%) 4 4 0 0
Total 50 27(54%) 19(38%) 14(28%) 5 (10"10) 0
·Statistical significance in respect of intestinal metaplasia: Chi square =
8.62, P = 0.0134 (significant)
Correlation of histological type of gastric cancer with prevalence and type of intestinal metaplasia is summarised in Table 3. Nine gastric specimens from patients with intestinal type of cancer (75%), 6 from diffuse type of gastric cancer (25%) and 4(28.6%) from mixed type of gastric cancer showed intestinal mataplasia. The difference between prevalence of intestinal metaplasia in various histological types of gastric cancer is statistically significant. In majority of cases the metaplasia was of type I variety and the type 3 metaplasia was not seen in this study. Correlation of intestinal metaplasia, and gastritis with prevalence of H pylori in stomach specimens of gastric cancer is summarised in Table 4. Since almost all patients had gastritis(96%). it is not possible to relate presence of H pylori with presence of gastritis. However, 15 of the 18 patients with atrophic gastritis WAFI. Vol. $./. No. ./, 1998
Gastritis features
Prevalence ofgastritis (a) Present (b) Absent Morphology of gastritis (a) Acute (b) Chronic (c) Atrophic Presence oflymphoid follicles (a) Present (b) Absent
H pYlori status H pylori Hpylori
positive
negative
27 0
21 2
I 11
3 6 12
p value >0.05
15
(not significant) >0.05
(not significant)
>0.05
14 13
(not significant) 5 18
Discussion The profile of gastric cancer seen by us differs significantly from that reported in literature. Very few cases have been reported below the age of 30 years and the incidence of gastric cancer has been reported to increase sharply after the age of SO [13]. In our study 32% patients were below the age SO years and youngest patient was 13 years old. At Tata Memorial Hospital, Bombay, 36.2% patients were below the age of SO years and fundal growths were found to be more common than body (27.7% against 17.3%) and antral growths were the commonest (43.9%) [14]. In our study antral growth was present in 42% cases and body growth was equally, if not more common [IS]. this difference in prevalence may be related to our sample selection or it may suggest that intestinal type of cancer predominates in the high risk areas and its incidence falls in a population showing lower incidence of gastric cancer. India definitely has much lower prevalence of gastric cancer in comparison to countries like Japan and Chile [16]. In our study, gastritis was found in most of stomach specimens. Antral gastritis alone was present in 20%, body gastritis alone was noted in 44% while remaining positive specimen (32%) had pan-gastritis. Morphologically the gastritis was found to be acute in 6%,
300
chronic in 40% and atrophic in 50%. Lymphoid follicles were detected in 28% patients. Gastritis was earlier sub-classified into environmental, auto-immune and hypersecretory [17]. Of these, environmental type of chronic gastritis has been found to be most closely related to gastric cancer, and corresponds to type B gastritis of Strickland and Mackay classification [19]. Relatively lower incidence of atrophic gastritis in our study may be attributed to the fact that we had relatively higher proportion of patients with diffusel mixed types of tumour. An intestinal type of gastric cancer is thought to originate from cancer precursor lesions mainly chronic atrophic gastritis and intestinal metaplasia [19]. Tumour location had no influence on the occurrence or type of gastritis either in our study or in the study reported from Singapore [20]. We found Intestinal metaplasia in only 38% of specimen studied. Nine gastric specimens from patients with intestinal type of cancer (75%),6 from diffuse type of gastric cancer (25%) and 4 (28.6%) from mixed type of gastric cancer showed intestinal metaplasia in our study. Of these, 14 (73.7%) specimens had type 1 metaplasia and remaining 5 (26.3%) had type 2 metaplasia. Type 3 metaplasia was not seen in this study. Other workers have found metaplasia to be present in 16 to 70% cases [20]. Wee et al found higher prevalence of atrophic gastritis in intestinal types of gastric cancer though frequency of metaplasia was not significantly higher than this type of cancer [20]. Correlation between metaplasia and histological type of carcinoma noted in our study supports the view that intestinal variety of cancer may be more frequently related to pre-cancerous lesions as reported by some other workers [21]. In our study, H pylori was detected in 54% stomach specimens. Wee et al found prevalence of H pylori to be much higher i.e.74% [20]. In our study, in two third specimens of intestinal type of cancer, gastritis was associated with H pylori while such association with H pylori was seen in approximately half (45.8% & 57.1 % respectively) the specimens of other types of cancers. Wee et al have also reported similar results [20]. In addition, three case control studies using serological tests found that H pylori infection was significantly more common in cases with gastric cancer as compared to matched controls. Prevalence of H pylori in gastric cancer patients varied from 63 to 100% [6-8]. Our study found that prevalence of H pylori positivity was highest in intestinal type of cancer (66.7%) and lowest in diffuse variety (45.8%). However, difference in H pylori prevalence was not statistically siginificant. In patients with intestinal type of
Anand, Reddy and Bhardwaj
cancer, H pylori was detected predominantly in antrum while in remaining specimens, it was equally distributed in antral and body sections. Our results concur with those from two recent studies, which found no difference in the occurrence of H pylori between intestinal and diffuse type gastric carcinoma [20,22] though an American study found H pylori more commonly in intestinal type gastric carcinoma than in the diffuse type [23]. The reason for these discrepancies is unclear though it is quite possible that H pylori dissapears from areas showing atrophy of glands and/or intestinal metaplasia. It is known that patients with severe gastric atrophy or intestinal metaplasia rarely have demonstrable H pylori in the stomaach , but they have H pylori antibodies in the serum indicating past infection [24]. Correa has hypothesised that H pylori may be a cause of multifocal chronic atrophic gastritis, dysplasia and hence gastric cancer [4]. Infection with H pylori was found to increase the risk of subsequent development of gastric cancer [6]. In different countries within China, the frequency of gastric cancer corelated significantly with the prevalence of antibody .Igainst H pylori [7]. In our study, since almost all . patients had gastritis (96%), it is not possible to relate presence of H pylori with presence of gastritis. However, 15 of the 18 patients with atrophic gastritis had H pylori in their stomach specimens either in the body or in antrum. Populations at high risk of gastric cancer have high prevalence rates of H pylori infection and acquisition of infection occurs at younger ages than in low risk population [25]. Subjects from lower socioeconomic backgrounds have the highest rates of infections again conforming to their increased gastric cancer risk [26]. an anecdotal report suggested relationship between H pylori, gastric dysplasia, the occurrence of intestinal metaplasia at a young age and familial gastric cancer [27]. Our findings like those of Wee et al [20] therefore, only indirectly support Correa's hypothesis [4] that H pylori is a causal factor in the atrophic gastritis-intestinal metaplasia-intestinal form of gastric cancer sequence. Wee et al have pointed out the limitations of retrospective studies and have suggested two possible reasons for lack of clear support for the hypothesis. Firstly, the association between H pylori and gastric cancer may be a fortuitous one, secondary to separate association with gastritis. It is also possible that H pylori may be causally related to both forms of gastric cancer via an unknown mechanism [20]. H Pylori does not colonise metaplastic epiethlium. This is a potential confounding factor in the present study since MJAI'l, Vol. 5-1. No. -I, 1'J911
He/lcobacler pylori and Gastric Cancer
301
even if H pylori infection was the cause of atrophic gastritis and intestinal metaplasia initially, it might not be demonstrable subsequently in metaplastic tissue. Another possible confounding factor is that the histological identification of H pylori in fixed resection specimens may not be optimal although Ormand et at reported otherwise [23]. Both of these confounding factors are expected to affect tumours of different histological types equally and will probably not influence the conclusions ofthe present study.
Red. Gastrointestinal and esophagcal pathology, 1st edition. Edinburg Churchill Livingstone 1989:71. 13. Dupont JB Jr. Lee JR, Burton GR. Cohn I Jr. Adenocarcinoma of the stomach: a review of 1497 cascs. Cancer 1978;41: 941-47.
REFERENCES
16. warren JR, Marshall BJ. Unidentified curved bacilli on gastric epithelium in active chronic gastritis. Lancet 1983;i: 1273-5.
I. Coggon 0, Acheson ED. The geogmphy of cancer of the stomach. Br Med Bull 1984; 40: 335-44. 2. Joossens JV, Goboers J. Diet and environment in the etiology of gastric cancer. In: Levin B, Riddell RH. eds. Frontiers in gastrointestinal cancer. New York: Elsevier. 1986: 167-83. 3. Correa P. A human model of gastric carcinogenesis. Cancer Res 1988; 48: 3554-60. 4. Correa P, Ruiz B. Campylobacter pylori and gastric cancer. In: Rathbone BJ, Heatley RV, cds. Campylobacter pylori and gastroduodenal disease. Oxford: Blackwell, 1989: 139-45. 5. Axon AR. Duodenal ulcer: the villain unasked. Brit Mcd J 1991; 302: 919-20. 6. Forman D. Newell DG. Fullerton F. Yarnell JWG, Stacey AR, Wald N. et al. Association between infection with Helicobacter pylori and risk of gastric cancer. BMJ 1991; 302: 1302-5. 7. Parsonnet J. Friedman GO, Vandersteen DP. et al. Helicobac-. ter pylori infection and risk of gastric carcinoma. N Engl J Med 1991; 325: 1127-31. 8. Nomum A, Stemmermann GN. Chvou PH. Kato I. PerezPerez 01, Blaser MJ. Helicobacter pylori infection and gastric carcinoma among Japanese Americans in Hawaii. N Engl J Mcd 1991;325: 1132-6. 9. Munoz N, Matro I. Histological types ofgastric cancer and its relationship with intesteinal metaplasia. Cancer Res 1972;39:99-105. 10. Stevens A. The haematoxylins. In Bancroft JD, Stevens A eds. Second edition. Edinbourgh Churchill Livingstone 1982:109-121 11. Misiewiez JJ. Tyigai FNJ, Goodwin CS, et al. the Sydney System: A new classification of gastritis. Working Party Reports. World Congress of Gastroenterology 1990: 1-10. 12. Fillipe MI. Histochemistry of intestinal mucin. In Whitehead
Wit /01. ro/.
5~.
Nil.
~.
/9'JH
14. Desai PB. Rao On, shroff po: Hospital Based Cancer Registry-Annual Report 1988. Bombay, Tala Memorial Hospital. 1988: 79. 15. Lauren P. The two histological types of gastric carcinoma diffuse and so called intestinal type carcinoma. Acta Pathol Microbjol Scand 1965;64:31-49.
17. Stemmermann GN, Samloff 1M. Hayashi T. Pepsinogen I & II in carcinoma of stomach: an immunohistochemical study. Appl Path 1985;3: 159-63. 18. Goodwin CS. Armstrong JA, Marshall BJ. compylobacter pyloridis. gastritis, and peptic ulcemtion. J Clin Pathol 1986; 39: 353-65. 19. Rosai J. Ackerman's surgical Pathology. 7th edition VolumeI. new Delhi, JayPee Brothers. 1989: 487-521. 20. Wee A, Kang JY, The M. H pylori and gastric cancer: correlation with gastritis intestinal metaplasia and tumour histology. Gut 1992; 33: 1029-32. 21. Blazer MJ, Hypothesis on the pathogenesis and natuml history of H pylori-induced inflammation. Gastroenterology 1992;102:720-7 22. Loffeld RJLF, Williams I, Flendrig JA Arends JW. H pylori and gastric carcinoma. Histopathology 1990;17: 537-41. 23. Ormand JE, Talley NJ. Shorter RG. et al. Prevalence of H pylori in specific forms of gastritis. Dig Dis Sci 1991; 36: 142-5. 24. Kernes Jr WE. Samloff 1M. Siumla M, et al. Positive serum antibody and negative tissue staining for H pylori in subjects with atrophic body gastritis. Gastroenterology 1991; 101: 167-74. 25. Borch GMA. Clinical significance of Compylobacter pylori. Eur J Gastroenterol Hepatol 1989;1:27-33. 26. Sitas F, Forman 0, Yarnell JWG. et al. H pylori infection mtes in relation to age and social class in a population of Welsh men. Gut 1991;32:25-8. 27. scott N, Lansdown M, Diament R, et al. Helicobacter gastritis and intestinal metaplasia in a gastric cancer family (Lettter). Lancet 1990; i:728.
Introduction
E
nvironmental influences play a significant role in the causation of gastric cancer, as is indicated by several epidemiological studies [1]. To date, most investigators have emphasised the role of diet in gastric carcinogenesis [2]. Atrophic gastritis with intestinal metaplasia has been identified as a precursor lesion for the commoner intestinal form of gastric carcinoma [3,4]. Helicobacter pylori has now been found to be the causative oerganism of non-immune type B gastritis [5]. A few case controlled studies have also hinted at the association between H. pylori infection and subsequent development of gastric cancer [6-8]. The possibility that H pylori is involved in gastric carcinogenesis has therefore been raised [4]. This study was carried out to examine the relationship between H pylori, histological gastritis, and intestinal metaplasia in gastric cancers of different histological types. Material and Methods A total of 50 gastrectomy specimens from the patients with gastric cancers received by Department of Pathology. from June 92 to May 94 were studied. The specimens were fixed in too/o butTered formalin. Multiple blocks were taken from the tumour. antrum, and body of stomach. The sections of antral and body mucosa were taken as far from the tumour site as possible. Paraffin
embedded histological sections were cut at 4 J.Lm thickness and stained with haematoxylin and eosin, Giemsa. Periodic acid SehitT reaction with and without diastase digestion and mucicarmine stains when required. Histological Classification olGastric Carcinoma
All the sections from tumour were meticulously reviewed to determine the histological type of cancer as per modified Lauren classification [9J : (i) Intestinal type: characterised by cohesive cell clusters showing distinct glandular elements with well-defined lamina lined with polarised epithelial cells. Papillary structures. solid componenets, brush borders and pools of extracellular mucin may be present (ii) Diffuse type: characterised by dissociated malignant cells infiltrating surrounding tissue as single or small cluster of cells. Glandular lamina is lacking. Intracellular or extracellular mucin production is variable. (iii) Mixed type is one that includes the features of both intestinal and diffuse subtypes.
Histological Assessment
All tissue blocks of antral and body mucosa and of the tumour areas were re-cut and stained by the Giemsa method (2% Giemsa prepared in buffered distilled water) and Harris's haematoxylin and 1% eosin solution for the identification of H pylori [IOJ. The sections were also reviewed for occurrence of gastric and intestinal metaplasia. Gastritis was classified as per Sydney system of classification (II]. Intestinal metaplasia was classified as described by Filipe [12]:
• Reader (Medicine). Armed Forces Medical College. Pune. + Graded Specialist (Pathology), Command Hospital (SC), Pune-40, Advisor (Pathology), Army Hospital (R&R), Delhi Cantt, •• Cmmandant. AFMSD. Delhi Cantt.
#
Senior
298
Anand, Reddy and Bhardwaj
Type I: Presence of goblet cells secreting sialomucins and sometimes sulfomucins. Paneth cells and mature non-mucus secreting absorptive cells present. Type II : Goblet cells as above and complete absence of Paneth cells. Replacement of absorptive cells by columnar mucous cells secreting non-sulphated mucins. Type III: As above but columnar cells secrete predominantly sulphomucins. H pylori colonisation was classified as 'severe'when large groups of organisms were present on surface and upper pits of more than two thirds of mucosal surface examined; 'mild' colonisation, when individual organisms or small groups were covering less than one third of mucosal surface; 'moderate' colonisation being in between these two.
gastric cancer patients and another 300 blocks from the controls were studied. From the gastric cancer specimen, 2 biopsies from tumor area, and 2 each from antral, body and fundal mucosa of each case were studied. In small proportion of cases, it was not possible to take all the 8 blocks due to extensive tumor infiltration. Thus total of 100 blocks were examined from the tumour, 92 from antral mucosa, 94 from body mucosa and 84 from fundal mucosa. TABLE I Histopathological type of cancer stomach compartd to the age and sex of patients and the anatomical location of the cancer Histopathological type Number 12(24%) Mean age (years) 55.2± 12.6 Male: Female ratio II: I Location oftumour Fundus 3 Body 2 Antrum 7
Controls
Fifty consecutive patients that underwent upper gastrointestinal endoscopy biopsy for dyspeptic symptoms and did not have gastric malignancy. The biopsies were studied in a similar manner to determine the prevalence ofH pylori, gastritis, atrophy and intestinal metaplasia.
24(48%) 51.7±9.5 3: I
14(28%) 51.9 ± 10.8 9:5
50 52.6± 11.3 19: 6
4 15 9-
4 5 5
11 22 21-
-Note: Four cases were involving both body and antrum extensively so that the site ofpredominent involvement/origin could not be determined. These have been grouped under both areas
Statistical Analysis
Frequency of H pylori prevalence, atrophic gastritis and intestinal metaplasia was compared for statistical significance by chi square test and ANOVA (equivalent to student's test). Probability values < 0.05 were taken as significant.
Majority of tumours were of diffuse type. (Table I). The mean age of patients presenting with these three types of histological cancer was not statistically different from each other (p > 0.05). Most of the tumours were situated in body and antrum (78%). Prevalence of H pylori, gastritis, atrophy and metaplasia were more common in the gastric cancer patients in comparison to controls (Table 2). Gastritis was found in most of stomach specimens
Results A total of 50 cases of carcinoma stomach seen during the study period from June 92 to May 94 were included in the study. Age and sex distribution of patients included in the study group is summarized in Table I. A total of 370 tissue blocks from these
TABLE 2 Histological type of cancer stomach compared to the prevalence and type ofgastritis in stomach mucosa
Number Gastritis (a) Aetiolog}' i. H pylori ii. Other (H pylori negative) iii. Distribution of H pylori Tumour area Fundus Body Antrum (b) Topography i. Antral ii. Corpus iii. Pan-gastritis (c) Morphology i. Acute ii. Chronic iii. Atrophic (d) Miscellaneous i. Lymphoid follicles ii. Eosinophilic infiltrate iii. Granulomas
Intestinal
Histological type Diffuse
12 12 ( 100"A.)
24 24 (IOO"A.)
Mixed 14 12
(86%)
Total 50 48
(96%) (54%) (46%)
8 4
II 13
8 6
27 23
0 0 4 7
0 0 7 6
0 0 5 4
0 0 16 17
2 6 4
5 10 9
3 8 3
10 24 16
(20%) (48%) (32%)
0 6 6
3 10 II
I 5 8
4 21 25
(8%) (42%) (50%)
4 0 0
5 0 0
5 0 0
14 0 0
(28%)
WAH. Vol. 54. No.4. 1998
Helicobacter pylori and Gastric Cancer
299
examined from non-neoplastic areas (48/50 spccimen; 96%). Antral gastritis alone was present in 10 (20%). corpus or body gastritis alone was noted in 22 (44%) while remaining stomachs (16 or 32%) had pan-gastritis. Morphologically the gastritis was found to be acute in 3 (6%). chronic in 20(40010) and atrophic in 25 (50%). Lymphoid follicles were detected in 14 (28%) patients while none of the patients showed presence of granulomas or eosiniophilic infiltrate in stomach sections. Intestinal metaplasia was detected in only 19(38%) specimen. Of these, 14 (73.7%) specimens had type I metaplasia and remaining 5 (26.3%) had type 2 metaplasia. Type 3 metaplasia was not seen in this study.
had H pyloriin their stomach specimens (though not on the atrophic epithelium) either in the body or in antrum. This difference in prevalence of H pylori was also not found to be statistically significant. Lymphoid follicles were detected in 12 patients and of these 9 were H pylori positive. Here again the difference was not statistically significant. Intestinal metaplasia was present in 19 patients and of these 14 were positive for H pylori Difference is more marked when we see type 2 metaplasia where 8 of the 9 patients were positive for H pylori. Thus, distribution of metaplasia was significantly more in H pylori positive patients.
Correlation of histological type of gastric cancer with H pylori. positivity is summarised in Table 3. Prevalence of H pylori positivity was highest in intestinal type of cancer (66.7%) and lowest in diffuse variety (45.8%). However, difference in H pylori prevalence was not statistically significant. In patients with intestinal type of cancer. H pylori. was detected predominantly in antrum while in remaining specimens, it was equally distributed in antral and body sections. Correlation of histological type of gastric cancer with prevalence and type of gastritis is summarised in Table 2 Gastritis was present in stomach specimens of all patients with intestinal as well as diffuse type of cancers but was seen in only 85% specimens of mixed type of gastric cancer. This difference in prevalence is however not significant (p=O.05). In two third specimens of intestinal type of cancer. gastritis was related to H pylori while such association with H pylori was seen in approximately half (45.8% & 57.1 % respectively) the specimens of other types of cancers. Sections from the body of the stomach showed maximum prevalence of gastritis in all the types of cancers. Lymphoid follicles were detected in 4 specimens of intestinal type of cancer (33.3%). 5 specimens of diffuse type of cancer (20.8%) and 5 of mixed type of cancer (35.7%).
TABLE 4 Prevalenee and morphology orgastritis as well as intestinal metaplasia Is eorrelated with presenee or H pylori in patients with gastrie eaneer
TABLE 3 Histologieal type or eaneer stomaeh eompared to the prevalenee and loeation orintestinal metaplasia in stomaeh mueosa Intestinal Number
12 8 (67%) Intestinal metaplasia· 9 (a) Type I 5 (b) Type II 4 (c) Type III 0 H Pylori positivity
Histological type Diffuse Mixed 24 11(46%) 6 5 I 0
14 8(57%) 4 4 0 0
Total 50 27(54%) 19(38%) 14(28%) 5 (10"10) 0
·Statistical significance in respect of intestinal metaplasia: Chi square =
8.62, P = 0.0134 (significant)
Correlation of histological type of gastric cancer with prevalence and type of intestinal metaplasia is summarised in Table 3. Nine gastric specimens from patients with intestinal type of cancer (75%), 6 from diffuse type of gastric cancer (25%) and 4(28.6%) from mixed type of gastric cancer showed intestinal mataplasia. The difference between prevalence of intestinal metaplasia in various histological types of gastric cancer is statistically significant. In majority of cases the metaplasia was of type I variety and the type 3 metaplasia was not seen in this study. Correlation of intestinal metaplasia, and gastritis with prevalence of H pylori in stomach specimens of gastric cancer is summarised in Table 4. Since almost all patients had gastritis(96%). it is not possible to relate presence of H pylori with presence of gastritis. However, 15 of the 18 patients with atrophic gastritis WAFI. Vol. $./. No. ./, 1998
Gastritis features
Prevalence ofgastritis (a) Present (b) Absent Morphology of gastritis (a) Acute (b) Chronic (c) Atrophic Presence oflymphoid follicles (a) Present (b) Absent
H pYlori status H pylori Hpylori
positive
negative
27 0
21 2
I 11
3 6 12
p value >0.05
15
(not significant) >0.05
(not significant)
>0.05
14 13
(not significant) 5 18
Discussion The profile of gastric cancer seen by us differs significantly from that reported in literature. Very few cases have been reported below the age of 30 years and the incidence of gastric cancer has been reported to increase sharply after the age of SO [13]. In our study 32% patients were below the age SO years and youngest patient was 13 years old. At Tata Memorial Hospital, Bombay, 36.2% patients were below the age of SO years and fundal growths were found to be more common than body (27.7% against 17.3%) and antral growths were the commonest (43.9%) [14]. In our study antral growth was present in 42% cases and body growth was equally, if not more common [IS]. this difference in prevalence may be related to our sample selection or it may suggest that intestinal type of cancer predominates in the high risk areas and its incidence falls in a population showing lower incidence of gastric cancer. India definitely has much lower prevalence of gastric cancer in comparison to countries like Japan and Chile [16]. In our study, gastritis was found in most of stomach specimens. Antral gastritis alone was present in 20%, body gastritis alone was noted in 44% while remaining positive specimen (32%) had pan-gastritis. Morphologically the gastritis was found to be acute in 6%,
300
chronic in 40% and atrophic in 50%. Lymphoid follicles were detected in 28% patients. Gastritis was earlier sub-classified into environmental, auto-immune and hypersecretory [17]. Of these, environmental type of chronic gastritis has been found to be most closely related to gastric cancer, and corresponds to type B gastritis of Strickland and Mackay classification [19]. Relatively lower incidence of atrophic gastritis in our study may be attributed to the fact that we had relatively higher proportion of patients with diffusel mixed types of tumour. An intestinal type of gastric cancer is thought to originate from cancer precursor lesions mainly chronic atrophic gastritis and intestinal metaplasia [19]. Tumour location had no influence on the occurrence or type of gastritis either in our study or in the study reported from Singapore [20]. We found Intestinal metaplasia in only 38% of specimen studied. Nine gastric specimens from patients with intestinal type of cancer (75%),6 from diffuse type of gastric cancer (25%) and 4 (28.6%) from mixed type of gastric cancer showed intestinal metaplasia in our study. Of these, 14 (73.7%) specimens had type 1 metaplasia and remaining 5 (26.3%) had type 2 metaplasia. Type 3 metaplasia was not seen in this study. Other workers have found metaplasia to be present in 16 to 70% cases [20]. Wee et al found higher prevalence of atrophic gastritis in intestinal types of gastric cancer though frequency of metaplasia was not significantly higher than this type of cancer [20]. Correlation between metaplasia and histological type of carcinoma noted in our study supports the view that intestinal variety of cancer may be more frequently related to pre-cancerous lesions as reported by some other workers [21]. In our study, H pylori was detected in 54% stomach specimens. Wee et al found prevalence of H pylori to be much higher i.e.74% [20]. In our study, in two third specimens of intestinal type of cancer, gastritis was associated with H pylori while such association with H pylori was seen in approximately half (45.8% & 57.1 % respectively) the specimens of other types of cancers. Wee et al have also reported similar results [20]. In addition, three case control studies using serological tests found that H pylori infection was significantly more common in cases with gastric cancer as compared to matched controls. Prevalence of H pylori in gastric cancer patients varied from 63 to 100% [6-8]. Our study found that prevalence of H pylori positivity was highest in intestinal type of cancer (66.7%) and lowest in diffuse variety (45.8%). However, difference in H pylori prevalence was not statistically siginificant. In patients with intestinal type of
Anand, Reddy and Bhardwaj
cancer, H pylori was detected predominantly in antrum while in remaining specimens, it was equally distributed in antral and body sections. Our results concur with those from two recent studies, which found no difference in the occurrence of H pylori between intestinal and diffuse type gastric carcinoma [20,22] though an American study found H pylori more commonly in intestinal type gastric carcinoma than in the diffuse type [23]. The reason for these discrepancies is unclear though it is quite possible that H pylori dissapears from areas showing atrophy of glands and/or intestinal metaplasia. It is known that patients with severe gastric atrophy or intestinal metaplasia rarely have demonstrable H pylori in the stomaach , but they have H pylori antibodies in the serum indicating past infection [24]. Correa has hypothesised that H pylori may be a cause of multifocal chronic atrophic gastritis, dysplasia and hence gastric cancer [4]. Infection with H pylori was found to increase the risk of subsequent development of gastric cancer [6]. In different countries within China, the frequency of gastric cancer corelated significantly with the prevalence of antibody .Igainst H pylori [7]. In our study, since almost all . patients had gastritis (96%), it is not possible to relate presence of H pylori with presence of gastritis. However, 15 of the 18 patients with atrophic gastritis had H pylori in their stomach specimens either in the body or in antrum. Populations at high risk of gastric cancer have high prevalence rates of H pylori infection and acquisition of infection occurs at younger ages than in low risk population [25]. Subjects from lower socioeconomic backgrounds have the highest rates of infections again conforming to their increased gastric cancer risk [26]. an anecdotal report suggested relationship between H pylori, gastric dysplasia, the occurrence of intestinal metaplasia at a young age and familial gastric cancer [27]. Our findings like those of Wee et al [20] therefore, only indirectly support Correa's hypothesis [4] that H pylori is a causal factor in the atrophic gastritis-intestinal metaplasia-intestinal form of gastric cancer sequence. Wee et al have pointed out the limitations of retrospective studies and have suggested two possible reasons for lack of clear support for the hypothesis. Firstly, the association between H pylori and gastric cancer may be a fortuitous one, secondary to separate association with gastritis. It is also possible that H pylori may be causally related to both forms of gastric cancer via an unknown mechanism [20]. H Pylori does not colonise metaplastic epiethlium. This is a potential confounding factor in the present study since MJAI'l, Vol. 5-1. No. -I, 1'J911
He/lcobacler pylori and Gastric Cancer
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even if H pylori infection was the cause of atrophic gastritis and intestinal metaplasia initially, it might not be demonstrable subsequently in metaplastic tissue. Another possible confounding factor is that the histological identification of H pylori in fixed resection specimens may not be optimal although Ormand et at reported otherwise [23]. Both of these confounding factors are expected to affect tumours of different histological types equally and will probably not influence the conclusions ofthe present study.
Red. Gastrointestinal and esophagcal pathology, 1st edition. Edinburg Churchill Livingstone 1989:71. 13. Dupont JB Jr. Lee JR, Burton GR. Cohn I Jr. Adenocarcinoma of the stomach: a review of 1497 cascs. Cancer 1978;41: 941-47.
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