APMIS 98: 173-178, 1990
Tumours in Iceland. 13. Malignant tumours of the testis A histological classification, epidemiological considerations and survival EINAR GUDLAUGSSON, BJARKI MAGNUSSON and JONAS HALLGRIMSSON Department of Pathology, University of Iceland, Reykjavik, Iceland
Gudlaugsson, E., Magnusson, B. & Hallgrimsson, J.: Tumours in Iceland. 13. Malignant tumours of the testis. A histological classification, survival and epidemiological considerations. APMIS 98: 173- 178, 1990. Data from 76 patients with malignant tumours of the testis registered with the Icelandic Cancer Registry during the period 1955-1984were analyzed and classified histologically according to the WHO criteria. In 55 patients the tumours were of one histological type (72%of total). In the order of frequency, seminoma was diagnosed in 35 (46%), embryonal carcinoma in 14 (18%) and teratoma in 6 patients (8%). Twenty patients had tumours of more than one histological type (26%),i.e. a combination of embryonal carcinoma and teratoma (teratocarcinoma) in nine ( 12%)and combined tumours (seminoma component with other tumours) in seven (9%). Two patients had choriocarcinomas and three had yolk sac (endodermal sinus) tumours, both of them in combination with other neoplasms. Embryonal rhabdomyosarcoma was the only malignant non-germ cell tumour diagnosed. The age-adjusted incidence of malignant testis tumours increased by 48% from 1.6 per 100,000 per annum in 1955-1964 to 3.1 per 100,000 in 1975-1984. The increase affected both seminoma and non-seminomatous tumours (NSGCT). There has been an improvement in survival with time. Sixteen deaths were related to testis tumours and all occurred within four years of diagnosis. The incidence of testicular tumours in Iceland is intermediate between “high risk” and “low risk” countries. Key words: Testis tumours; histological typing; epidemiology. Jonas Hallw’msson, Dept. of Pathology, P.O. Box 1465, IS-121 Reykjavik, Iceland.
Malignant tumours of the testis were typed according to the WHO International Histological Classification of testis tumours published in 1977 (1 1). This is part of a planned series of population studies involving the histological classification of tumours occumng in Icelanders during the years 1955-1974 and later extending the interval to thirty years, 1955-1984,(1,2,3,4,6,7,8,9, 13, 14, 16, 18). We also include some epidemiological observations and data on survival.
Received July 10, 1989. Accepted August 3 1, 1989.
MATERIAL AND METHODS Information on patients with testicular tumours was obtained from the files of the Icelandic Cancer Registry. This included names, age, date at original histological diagnosis and date of death of deceased patients. Death certificates and autopsy reports were also reviewed. The histologicalmaterial was obtained from the Department of Pathology at the University of Iceland, which was responsible for all histological diagnostic work in the country during the survey period. Classificationof all the testicular tumours was done jointly by the first two authors according to the criteria proposed by the World Health Organization in 1977 (1 1). Parafin blocks were recut when necessary. In most cases a hematoxylin and eosin stain was sufficient for diagnosis, but occasionally
I73
GUDLAUGSSON el al.
a Periodic Acid Schiff (PAS) reagent stain was used. In selected cases immunohistochemical techniques were used (peroxidase-anti-peroxidase method) to demonstrate the presence of Beta Human Chorionic Gonadotropins (HCG), Alpha Fetoprotein (AFP) and Placental Alkaline Phosphatase (PLAP). Data on survival were obtained from the Icelandic Cancer Registry and death certificates from the Statistical Bureau of Iceland.
RESULTS According to the Icelandic Cancer Registry 79 malignant testicular tumours were diagnosed in Iceland during the period 1955-1984. For one patient no histological material was available for review and after our review a further two tumours were excluded (one was a primary prostatic carcinoma and the other an extragonadal germ cell tumour). This left 76 primary malignant testicular tumours, 47 of which were in the right testicle and 29 in the left. Table 1 shows the results of the histological typing according to the WHO classification and also age standardized incidence rates and mean age at diagnosis. Seminomas were most frequent or 35
tumours (46Yo). Of these, seven tumours or 20% were anaplastic seminomas ( 12). Choriocarcinoma in combination with other tumours (one with a teratoma and the other with a combination of teratoma, seminoma and embryonal carcinoma) occurred twice or in 2.6Y0 of the patients. Yolk sac elementswere found in combination with other tumours in three patients (one with an embryonal carcinoma, another with a mixed teratoma and embryonal carcinoma and the third with a mixed seminoma, embryonal carcinoma and teratoma). All these tumours occurred in adults. The only non-germ cell tumour diagnosed was an embryonal rhabdomyosarcoma in a five-yearold boy. The mean age at diagnosis for all the patients as a group was 32.8 years. Non-seminomatous germ cell tumours (NSGCT) and combined tumours affected the younger members of the group, with a mean age of 26 years at diagnosis, but for the seminoma group the mean age at diagnosis was about 40 years. Fig. 1 shows the age specific incidence, and reflects the younger age trends for NSGCT and combined tumours (peak at 20-29
TABLE 1. Malignant testis tumours in Iceland 1955-1984. Morphology, number of cases, age standardized rates adjusted to the world population and mean age at diagnosis Morphology type
ICD-OM number
Number of cases
%
Age standardized Meanageat rates per 100,000 diagnosis per annum (years)
906 113 907013 908013
35 14 6 (3) (3)
46.0 18.4 7.9
1.2 0.5 0.2
40.4 28.6 24.7
908 113 910113
9 2 9
11.8 2.6 11.8
0.3 0.1 0.3
25.1 32.5 26.8
891013
1
1.3
2.5
32.8
Germ cell tumours
I:
A. Tumours of one histological type: Seminoma Embryonal carcinoma Teratoma - immature - mature B. Tumours of more than one histological type: Embryonal carcinoma and teratoma Chonocarcinoma and other Other combinations' VII: Tumours of collecting ducts, rete, epididymis, spermatic cord, capsule, supporting structures and appendices Embryonal rhabdomyosarcoma Total 174
76
100
TESTIS TUMOURS IN ICELAND
+ Serninorna
Fig. 1. Incidence rates of germ cell tumours of the testis in Iceland 1955-1984.
+ Other turnours
-
0-9
10119
20-29 30-39 40-49 50-59
years) and older age trends for pure seminoma tumours (peak at 30-39 years). Fig. 2 shows that the incidence of malignant testicular tumours increased during the study period. In the first l 0-year period, 1955-1964, the age
4
-
".
1955-59
Olhertumurs Semima All turnours
196Ii64
Total
1965-69
1970.74
1975-79
1980-84
YEAR
Fig. 2. Age standardized incidence per 100,000 of malignant testis tumours in Iceland in six 5-year periods from 1955-1984.
standardized incidence was 1.6 while in the third 10-year period, 1975-1984, it was 3.1, or a 48% increase. The increase was more obvious in the NSGCT group and combined tumours (50%)than the pure seminoma group (4290). Crude survival was higher for seminoma (97%in the first year and 86%after five years), than for the NSGCT group (87%in the first year and 75%after five years) (Fig. 3). The best survival was clearly achieved in the last ten-year period 1975-1984 (Fig. 4). By examining the death certificates of the 25 patientswhodiedduringtheperiod 1955-1988,16 patients were considered to have died of their testicular tumours. Autopsy reports were available for six of the patients, confirming the clinical diagnosis at death. The mean survival time for the 16 patients was 12 months. Embryonal carcinoma (6 patients) and tumours of more than one histological type (6 patients) were the most frequent causes of death, with a mean survival of 15 and 1 1 months, respectively. Seminoma of the anaplastic subtype and pure teratoma were the cause of death in two patients each, with a mean survival of 8 and 9 months, respectively. Cryptorchidism was observed in four patients. Two of them had bilateral uncorrected cryp175
GUDLAUGSSON ef al.
DISCUSSION
0
1
2
3
4
5
6
7 8 9 10 YEAR AFTER DIAGNOSIS
Fig. 3. Annual survival rates of malignant tumours of the testis 1955-1984.
torchidism and developed classical seminomas. The other two had unilateral cryptorchidism and developed embryonal carcinoma in the cryptorchid testicle, 4 and 14 years respectively after corrective surgery.
-
1955-64 1965-74 -+ 1975-84 4-
According to most reports in the literature, testicular tumours constitute less than 2% of all malignant tumours in males (20). In Iceland, these tumours account for 1% of malignant tumours in males ( 17). The relative frequencies of the different histological types in our Icelandic series correspond roughly to those observed in many other countries, with seminomas constituting approximately 509/0. Greater variation is observed between countries regarding the different types within the group of NSGCT tumours ( 19). For some unknown reason, there is a slight overall preponderance of tumours in the right testis ( 5 ) , in our series in the ratio 5:3 (47/29). Incidence curves in Iceland for age specific rates peaked at 20-29 years for NSGCT and combined tumours on the one hand, with a mean age of 27 years at diagnosis, whilst on the other hand the peak for pure seminoma was 30-39 years with a mean age of 40 years at diagnosis. This gap of more than ten years is similar to that found by others (10). In the time-period 1955-1984 the annual incidence of malignant tumours of the testis in Iceland was 2.5 per 100,000.Compared with the incidence rates in other countries for the time-period 19781982 (Table 2), it becomes evident that Iceland, with an annual incidence of 2.6 per 100,000,occupies a medium position with nations such as Sweden and the United Kingdom (Birmingham). Various factors such as age, trauma, repeated infection, and endocrine abnormalities have been suspected of being involved in the etiologyof testicular tumours. Information on these factorsin our series of patients is not available. The incidence of
TABLE 2. Adjusted* incidence ratesper 100,000per year of testis cancerfor selected registries**(cirka 1978-1982) \
\ 8-m-m-m--8-m-m-•
*”60 ‘ 0
1
2
3
4
5
6
7
8
9
10
YEAR AFTER DIAGNOSIS
Fig. 4. Crude survival rates of malignant testis tumours in Iceland in three 10-year periods.
176
Denmark Norway USA - Detroit (white) Sweden UK - Birmingham Iceland Finland USA - Detroit (black)
7.8 5.9 4.1 3.3 3.1 2.6 1.5 1.1
*Standardized to the “world” population **Census for 1980- 198 1
TESTIS TUMOURS IN ICELAND
testiculartumours has been reported to be higher in cryptorchidism than in scrota1 testis ( 15). We observed cryptorchidismin four patients out of 76, or about 5%. It has been proposed that the variation in incidence between the Nordic countries is due in part to variation in genetical background. The incidence in Iceland has been rising. It nearly doubled from 1.6 per 100,000per year from 1955-1964 to 3.1 per 100,000 from 1975-1984. Such trends have been seen in most developed countries in the world (20). The increase was in all types of germ cell tumours, slightly more so for the NSGCT group than for seminoma in the latter half of the period. We observed the best prognosis in the last 10-year period of our study ( 1975-1984).It is likely that this reflects more concise staging approaches and more effective treatment regimens for disseminated germ cell tumours, especially with chemotheurapeuticals introduced in the early 1970s and with radiation therapy. CONCLUSION 1. The incidence of testicular tumours in Iceland is intermediate between that found in “highrisk“ and “low-risk” countries. 2. The age distribution for all testicular tumours and separately for individual histological types as well as the proportion of various histological types is similar to that found in other countries. 3. The survival in Iceland is improving and for the individual histological types it is the same as in other countries of Western Europe and North America.
REFERENCES Agnarsson, B. A , , Olafsdottir, K. & Benediktsson, H.: Tumours in Iceland. 8. Hodgkin’s disease and nonHodgkin’s malignant lymphomas. A histological classification and epidemiological considerations. Acta path. rnicrobiol. immunol. scand. Sect. A, 95: 23-28, 1987. Benediktsdottir, K. R., Jonasson, J. G. & Hallgrimsson, J.: Tumours in Iceland. 12. Malignant tumours of the body of the uterus. A histological classification, epidemiological considerations and survival. APMIS 97: 78 1-786,1989. Bjarnason, 0. & Tulinius, H.: Tumours in Iceland. 9. Malignant tumours of the ovary. A histological classification, epidemiological considerations and
survival. Acta path. microbiol. immunol. scand. Sect. A, 95: 185-192, 1987. 4. Cooper, M. A. & Hallgrimsson, J.: Tumours in Iceland. 4. Tumours of the upper respiratory tract and ear. A histological classification and some etiological and epidemiological considerations. Acta path. rnicrobiol. scand. Sect. A, 89: 377-387, 1981. 5. Fraumeni, Jr., F. & Schottenfeld, D. (Eds): Schottenfeld, D. & Warshauer, E. M . , in: Cancer epidemiology and preventation, Ch.: 56, Testis. W. B. Saunders Comp., 1982, pp. 947-957. 6. Geirsson, G., Johannesson, G. & Tulinius, H.: Tumours in Iceland. 5. Malignant tumours of the cervix uteri. Histological types, clinical stages and the effect of mass screening. Acta path. rnicrobiol. immunol, scand. Sect. A, 90: 139-143, 1982. 7. Hallgrimsson, J., Thorarinsson, H. & Tulinius, H.: Tumours in Iceland. 7. Malignant epithelial tumours of the lung. A histological classification, epidemiological considerations and relation to smoking. Acta path. rnicrobiol. immunol. scand. Sect. A, 91: 203-207, 1983. 8. Jonasson, J. G., Hrafnkelsson, J. & Bjornsson, J.: Tumours in Iceland. 1 1. Malignant tumours of the thyroid gland. A histological classification and epidemiological considerations. APMIS 97: 625-630, 1989. 9. McKnight, C. K. & Magnusson, B.: Tumours in Iceland. 1. Malignant tumours of skin. A histological classification. Acta path. microbiol. scand. Sect. A, 87: 37-44, 1979. 10. Mostofi, F. K.: Testicular tumors. Epidemiologic, etiologic, and pathologic features. Cancer 32: 1 1861201, 1973. 1 1. Mostofi, F. K . & Sobin, L. H.: Histological typing of testis tumors. No 16. WHO, Geneva 1977. 12. Mostofi, F. K.: Pathology of germ cell tumors of the testis. A progress report. Cancer 45: 1735-1754, 1980. 13. Perry, S. B., Thorhallsson, P. & Hallgrimsson, J.: Tumours in Iceland. 6. Tumours of the urinary bladder, ureter and urethra. A histological classification and some epidemiological and environmental factors. Acta path. microbiol. immunol. scand. Sect. A, 90: 175-183, 1982. 14. Sigurjonsson, S. V., Hallgrimsson, J., Brekkan, A . & Haraldsson, S.: Tumours in Iceland. 2. Tumours and tumour-like lesions of bone. Histological types and clinical course. Acta path. rnicrobiol. scand. Sect. A, 87: 403-409, 1979. 15. Swerdlow, A. J., Huttly, S. R. A. & Smith, P. G.: Testicular cancer and antecedent diseases. Br. J. Cancer 55: 97-103, 1987. 16. Thorhallsson, P. & Tulinius, H.: Tumours in Iceland. 3. Malignant tumours of kidney. A histological classification. Acta path. rnicrobiol. scand. Sect. A, 89: 403-410, 1981. 17. Tulinius, H. & Ragnarsson, J.: Cancer incidence in Iceland. Icelandic Cancer Association & Director General of Health, 1987, p. 12.
177
GUDLAUGSSON el al.
18. Tulinius, H., Bjarnason, O., Sigvaldason, H., Bjarnadottir, G. & Olafsdottir, G.: Tumours in Iceland. 10. Malignant tumours of the female breast. A histological classification, laterality, survival and epidemiological considerations. APMIS. 96: 229238, 1988.
178
19. Waterhouse, J. A . H., Muir, C. S., Shanmugaratnam, K. &Powell, I. (Eds):Cancer incidence in five continents. Vol. IV. IARC Sci. Publ. No 42, Lyon, 1982. 20. Waterhouse, J. A . H.: Epidemiology of testicular tumours.J. R. SOC.Med., 78:Suppl. 6,1985, pp. 3-7.
Tumours in Iceland. 13. Malignant tumours of the testis A histological classification, epidemiological considerations and survival EINAR GUDLAUGSSON, BJARKI MAGNUSSON and JONAS HALLGRIMSSON Department of Pathology, University of Iceland, Reykjavik, Iceland
Gudlaugsson, E., Magnusson, B. & Hallgrimsson, J.: Tumours in Iceland. 13. Malignant tumours of the testis. A histological classification, survival and epidemiological considerations. APMIS 98: 173- 178, 1990. Data from 76 patients with malignant tumours of the testis registered with the Icelandic Cancer Registry during the period 1955-1984were analyzed and classified histologically according to the WHO criteria. In 55 patients the tumours were of one histological type (72%of total). In the order of frequency, seminoma was diagnosed in 35 (46%), embryonal carcinoma in 14 (18%) and teratoma in 6 patients (8%). Twenty patients had tumours of more than one histological type (26%),i.e. a combination of embryonal carcinoma and teratoma (teratocarcinoma) in nine ( 12%)and combined tumours (seminoma component with other tumours) in seven (9%). Two patients had choriocarcinomas and three had yolk sac (endodermal sinus) tumours, both of them in combination with other neoplasms. Embryonal rhabdomyosarcoma was the only malignant non-germ cell tumour diagnosed. The age-adjusted incidence of malignant testis tumours increased by 48% from 1.6 per 100,000 per annum in 1955-1964 to 3.1 per 100,000 in 1975-1984. The increase affected both seminoma and non-seminomatous tumours (NSGCT). There has been an improvement in survival with time. Sixteen deaths were related to testis tumours and all occurred within four years of diagnosis. The incidence of testicular tumours in Iceland is intermediate between “high risk” and “low risk” countries. Key words: Testis tumours; histological typing; epidemiology. Jonas Hallw’msson, Dept. of Pathology, P.O. Box 1465, IS-121 Reykjavik, Iceland.
Malignant tumours of the testis were typed according to the WHO International Histological Classification of testis tumours published in 1977 (1 1). This is part of a planned series of population studies involving the histological classification of tumours occumng in Icelanders during the years 1955-1974 and later extending the interval to thirty years, 1955-1984,(1,2,3,4,6,7,8,9, 13, 14, 16, 18). We also include some epidemiological observations and data on survival.
Received July 10, 1989. Accepted August 3 1, 1989.
MATERIAL AND METHODS Information on patients with testicular tumours was obtained from the files of the Icelandic Cancer Registry. This included names, age, date at original histological diagnosis and date of death of deceased patients. Death certificates and autopsy reports were also reviewed. The histologicalmaterial was obtained from the Department of Pathology at the University of Iceland, which was responsible for all histological diagnostic work in the country during the survey period. Classificationof all the testicular tumours was done jointly by the first two authors according to the criteria proposed by the World Health Organization in 1977 (1 1). Parafin blocks were recut when necessary. In most cases a hematoxylin and eosin stain was sufficient for diagnosis, but occasionally
I73
GUDLAUGSSON el al.
a Periodic Acid Schiff (PAS) reagent stain was used. In selected cases immunohistochemical techniques were used (peroxidase-anti-peroxidase method) to demonstrate the presence of Beta Human Chorionic Gonadotropins (HCG), Alpha Fetoprotein (AFP) and Placental Alkaline Phosphatase (PLAP). Data on survival were obtained from the Icelandic Cancer Registry and death certificates from the Statistical Bureau of Iceland.
RESULTS According to the Icelandic Cancer Registry 79 malignant testicular tumours were diagnosed in Iceland during the period 1955-1984. For one patient no histological material was available for review and after our review a further two tumours were excluded (one was a primary prostatic carcinoma and the other an extragonadal germ cell tumour). This left 76 primary malignant testicular tumours, 47 of which were in the right testicle and 29 in the left. Table 1 shows the results of the histological typing according to the WHO classification and also age standardized incidence rates and mean age at diagnosis. Seminomas were most frequent or 35
tumours (46Yo). Of these, seven tumours or 20% were anaplastic seminomas ( 12). Choriocarcinoma in combination with other tumours (one with a teratoma and the other with a combination of teratoma, seminoma and embryonal carcinoma) occurred twice or in 2.6Y0 of the patients. Yolk sac elementswere found in combination with other tumours in three patients (one with an embryonal carcinoma, another with a mixed teratoma and embryonal carcinoma and the third with a mixed seminoma, embryonal carcinoma and teratoma). All these tumours occurred in adults. The only non-germ cell tumour diagnosed was an embryonal rhabdomyosarcoma in a five-yearold boy. The mean age at diagnosis for all the patients as a group was 32.8 years. Non-seminomatous germ cell tumours (NSGCT) and combined tumours affected the younger members of the group, with a mean age of 26 years at diagnosis, but for the seminoma group the mean age at diagnosis was about 40 years. Fig. 1 shows the age specific incidence, and reflects the younger age trends for NSGCT and combined tumours (peak at 20-29
TABLE 1. Malignant testis tumours in Iceland 1955-1984. Morphology, number of cases, age standardized rates adjusted to the world population and mean age at diagnosis Morphology type
ICD-OM number
Number of cases
%
Age standardized Meanageat rates per 100,000 diagnosis per annum (years)
906 113 907013 908013
35 14 6 (3) (3)
46.0 18.4 7.9
1.2 0.5 0.2
40.4 28.6 24.7
908 113 910113
9 2 9
11.8 2.6 11.8
0.3 0.1 0.3
25.1 32.5 26.8
891013
1
1.3
2.5
32.8
Germ cell tumours
I:
A. Tumours of one histological type: Seminoma Embryonal carcinoma Teratoma - immature - mature B. Tumours of more than one histological type: Embryonal carcinoma and teratoma Chonocarcinoma and other Other combinations' VII: Tumours of collecting ducts, rete, epididymis, spermatic cord, capsule, supporting structures and appendices Embryonal rhabdomyosarcoma Total 174
76
100
TESTIS TUMOURS IN ICELAND
+ Serninorna
Fig. 1. Incidence rates of germ cell tumours of the testis in Iceland 1955-1984.
+ Other turnours
-
0-9
10119
20-29 30-39 40-49 50-59
years) and older age trends for pure seminoma tumours (peak at 30-39 years). Fig. 2 shows that the incidence of malignant testicular tumours increased during the study period. In the first l 0-year period, 1955-1964, the age
4
-
".
1955-59
Olhertumurs Semima All turnours
196Ii64
Total
1965-69
1970.74
1975-79
1980-84
YEAR
Fig. 2. Age standardized incidence per 100,000 of malignant testis tumours in Iceland in six 5-year periods from 1955-1984.
standardized incidence was 1.6 while in the third 10-year period, 1975-1984, it was 3.1, or a 48% increase. The increase was more obvious in the NSGCT group and combined tumours (50%)than the pure seminoma group (4290). Crude survival was higher for seminoma (97%in the first year and 86%after five years), than for the NSGCT group (87%in the first year and 75%after five years) (Fig. 3). The best survival was clearly achieved in the last ten-year period 1975-1984 (Fig. 4). By examining the death certificates of the 25 patientswhodiedduringtheperiod 1955-1988,16 patients were considered to have died of their testicular tumours. Autopsy reports were available for six of the patients, confirming the clinical diagnosis at death. The mean survival time for the 16 patients was 12 months. Embryonal carcinoma (6 patients) and tumours of more than one histological type (6 patients) were the most frequent causes of death, with a mean survival of 15 and 1 1 months, respectively. Seminoma of the anaplastic subtype and pure teratoma were the cause of death in two patients each, with a mean survival of 8 and 9 months, respectively. Cryptorchidism was observed in four patients. Two of them had bilateral uncorrected cryp175
GUDLAUGSSON ef al.
DISCUSSION
0
1
2
3
4
5
6
7 8 9 10 YEAR AFTER DIAGNOSIS
Fig. 3. Annual survival rates of malignant tumours of the testis 1955-1984.
torchidism and developed classical seminomas. The other two had unilateral cryptorchidism and developed embryonal carcinoma in the cryptorchid testicle, 4 and 14 years respectively after corrective surgery.
-
1955-64 1965-74 -+ 1975-84 4-
According to most reports in the literature, testicular tumours constitute less than 2% of all malignant tumours in males (20). In Iceland, these tumours account for 1% of malignant tumours in males ( 17). The relative frequencies of the different histological types in our Icelandic series correspond roughly to those observed in many other countries, with seminomas constituting approximately 509/0. Greater variation is observed between countries regarding the different types within the group of NSGCT tumours ( 19). For some unknown reason, there is a slight overall preponderance of tumours in the right testis ( 5 ) , in our series in the ratio 5:3 (47/29). Incidence curves in Iceland for age specific rates peaked at 20-29 years for NSGCT and combined tumours on the one hand, with a mean age of 27 years at diagnosis, whilst on the other hand the peak for pure seminoma was 30-39 years with a mean age of 40 years at diagnosis. This gap of more than ten years is similar to that found by others (10). In the time-period 1955-1984 the annual incidence of malignant tumours of the testis in Iceland was 2.5 per 100,000.Compared with the incidence rates in other countries for the time-period 19781982 (Table 2), it becomes evident that Iceland, with an annual incidence of 2.6 per 100,000,occupies a medium position with nations such as Sweden and the United Kingdom (Birmingham). Various factors such as age, trauma, repeated infection, and endocrine abnormalities have been suspected of being involved in the etiologyof testicular tumours. Information on these factorsin our series of patients is not available. The incidence of
TABLE 2. Adjusted* incidence ratesper 100,000per year of testis cancerfor selected registries**(cirka 1978-1982) \
\ 8-m-m-m--8-m-m-•
*”60 ‘ 0
1
2
3
4
5
6
7
8
9
10
YEAR AFTER DIAGNOSIS
Fig. 4. Crude survival rates of malignant testis tumours in Iceland in three 10-year periods.
176
Denmark Norway USA - Detroit (white) Sweden UK - Birmingham Iceland Finland USA - Detroit (black)
7.8 5.9 4.1 3.3 3.1 2.6 1.5 1.1
*Standardized to the “world” population **Census for 1980- 198 1
TESTIS TUMOURS IN ICELAND
testiculartumours has been reported to be higher in cryptorchidism than in scrota1 testis ( 15). We observed cryptorchidismin four patients out of 76, or about 5%. It has been proposed that the variation in incidence between the Nordic countries is due in part to variation in genetical background. The incidence in Iceland has been rising. It nearly doubled from 1.6 per 100,000per year from 1955-1964 to 3.1 per 100,000 from 1975-1984. Such trends have been seen in most developed countries in the world (20). The increase was in all types of germ cell tumours, slightly more so for the NSGCT group than for seminoma in the latter half of the period. We observed the best prognosis in the last 10-year period of our study ( 1975-1984).It is likely that this reflects more concise staging approaches and more effective treatment regimens for disseminated germ cell tumours, especially with chemotheurapeuticals introduced in the early 1970s and with radiation therapy. CONCLUSION 1. The incidence of testicular tumours in Iceland is intermediate between that found in “highrisk“ and “low-risk” countries. 2. The age distribution for all testicular tumours and separately for individual histological types as well as the proportion of various histological types is similar to that found in other countries. 3. The survival in Iceland is improving and for the individual histological types it is the same as in other countries of Western Europe and North America.
REFERENCES Agnarsson, B. A , , Olafsdottir, K. & Benediktsson, H.: Tumours in Iceland. 8. Hodgkin’s disease and nonHodgkin’s malignant lymphomas. A histological classification and epidemiological considerations. Acta path. rnicrobiol. immunol. scand. Sect. A, 95: 23-28, 1987. Benediktsdottir, K. R., Jonasson, J. G. & Hallgrimsson, J.: Tumours in Iceland. 12. Malignant tumours of the body of the uterus. A histological classification, epidemiological considerations and survival. APMIS 97: 78 1-786,1989. Bjarnason, 0. & Tulinius, H.: Tumours in Iceland. 9. Malignant tumours of the ovary. A histological classification, epidemiological considerations and
survival. Acta path. microbiol. immunol. scand. Sect. A, 95: 185-192, 1987. 4. Cooper, M. A. & Hallgrimsson, J.: Tumours in Iceland. 4. Tumours of the upper respiratory tract and ear. A histological classification and some etiological and epidemiological considerations. Acta path. rnicrobiol. scand. Sect. A, 89: 377-387, 1981. 5. Fraumeni, Jr., F. & Schottenfeld, D. (Eds): Schottenfeld, D. & Warshauer, E. M . , in: Cancer epidemiology and preventation, Ch.: 56, Testis. W. B. Saunders Comp., 1982, pp. 947-957. 6. Geirsson, G., Johannesson, G. & Tulinius, H.: Tumours in Iceland. 5. Malignant tumours of the cervix uteri. Histological types, clinical stages and the effect of mass screening. Acta path. rnicrobiol. immunol, scand. Sect. A, 90: 139-143, 1982. 7. Hallgrimsson, J., Thorarinsson, H. & Tulinius, H.: Tumours in Iceland. 7. Malignant epithelial tumours of the lung. A histological classification, epidemiological considerations and relation to smoking. Acta path. rnicrobiol. immunol. scand. Sect. A, 91: 203-207, 1983. 8. Jonasson, J. G., Hrafnkelsson, J. & Bjornsson, J.: Tumours in Iceland. 1 1. Malignant tumours of the thyroid gland. A histological classification and epidemiological considerations. APMIS 97: 625-630, 1989. 9. McKnight, C. K. & Magnusson, B.: Tumours in Iceland. 1. Malignant tumours of skin. A histological classification. Acta path. microbiol. scand. Sect. A, 87: 37-44, 1979. 10. Mostofi, F. K.: Testicular tumors. Epidemiologic, etiologic, and pathologic features. Cancer 32: 1 1861201, 1973. 1 1. Mostofi, F. K . & Sobin, L. H.: Histological typing of testis tumors. No 16. WHO, Geneva 1977. 12. Mostofi, F. K.: Pathology of germ cell tumors of the testis. A progress report. Cancer 45: 1735-1754, 1980. 13. Perry, S. B., Thorhallsson, P. & Hallgrimsson, J.: Tumours in Iceland. 6. Tumours of the urinary bladder, ureter and urethra. A histological classification and some epidemiological and environmental factors. Acta path. microbiol. immunol. scand. Sect. A, 90: 175-183, 1982. 14. Sigurjonsson, S. V., Hallgrimsson, J., Brekkan, A . & Haraldsson, S.: Tumours in Iceland. 2. Tumours and tumour-like lesions of bone. Histological types and clinical course. Acta path. rnicrobiol. scand. Sect. A, 87: 403-409, 1979. 15. Swerdlow, A. J., Huttly, S. R. A. & Smith, P. G.: Testicular cancer and antecedent diseases. Br. J. Cancer 55: 97-103, 1987. 16. Thorhallsson, P. & Tulinius, H.: Tumours in Iceland. 3. Malignant tumours of kidney. A histological classification. Acta path. rnicrobiol. scand. Sect. A, 89: 403-410, 1981. 17. Tulinius, H. & Ragnarsson, J.: Cancer incidence in Iceland. Icelandic Cancer Association & Director General of Health, 1987, p. 12.
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GUDLAUGSSON el al.
18. Tulinius, H., Bjarnason, O., Sigvaldason, H., Bjarnadottir, G. & Olafsdottir, G.: Tumours in Iceland. 10. Malignant tumours of the female breast. A histological classification, laterality, survival and epidemiological considerations. APMIS. 96: 229238, 1988.
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19. Waterhouse, J. A . H., Muir, C. S., Shanmugaratnam, K. &Powell, I. (Eds):Cancer incidence in five continents. Vol. IV. IARC Sci. Publ. No 42, Lyon, 1982. 20. Waterhouse, J. A . H.: Epidemiology of testicular tumours.J. R. SOC.Med., 78:Suppl. 6,1985, pp. 3-7.
