1101
PLASMA GLUCOSE AND INSULIN CONCENTRATIONS BEFORE AND AFTER GLUCOSE CHALLENGE (MEAN, SD)
behave differently in different populations is often advocated. This argument is difficult to confirm or refute since malignant disease runs a variable course within any population, and rectal cancer is no exception. However, attributing the impressive results of another group of surgeons who are obtaining consistently better results than ourselves as being due to the more benign nature of the disease is complacent if not arrogant, and is also likely to become a self-fulfilling prophesy. We have studied the techniques and results of radical surgery for rectal cancer at the National Cancer Center in Tokyo to assess the role of radical surgery in rectal cancer.
RVO=re2nal
vein
occlusion.
OAG= open -angle glaucoma
glucose challenge. Impaired glucose metabolism is the result of insensitivity to insulin-stimulated glucose uptake6 principally in muscle. Initially compensatory hyperinsulinaemia, due to augmented secretion, offsets hyperglycaemia but if insulin secretion declines, glucose intolerance and eventually diabetes develop.6,8 This sequence may explain why previous studies1 have failed to show abnormalities in glucose metabolism underlying central retinal vein occlusion and open-angle glaucoma. Euglycaemic insulin clamp studies9 have shown insulin resistance in non-diabetic first-degree relatives of non-insulin dependent diabetics, suggesting a genetic aetiology. Obesity in non-diabetics decreases tissue sensitivity to insulin, producing insulin tissue
resistance.6,10 Because BMI was similar in all three groups, this mechanism appears unlikely here. Although these results should be interpreted cautiously, they suggest an association between insulin resistance and both open-angle glaucoma and central retinal vein occlusion, which might explain the frequent association of these conditions. We thank Lederle Laboratories, Alcon (UK), and IOLAB for funding this study. We also thank Dr E. Horsfield and Mrs M. Thompson, Department of Chemical Pathology, Barnsley District General Hospital, for assays.
A. LOCKWOOD L. G. CLEARKIN
Arrowe Park Hospital,
Upton, Wirral, Merseyside L49 5PE, UK
1. Cole MD, Dodson PM, Hendeles S. Medical conditions underlying retinal vein occlusion in patients with glaucoma or ocular hypertension. Br J Ophthalmol 1989; 73: 693-98. 2. McGrath MA, Weschler F, Huynor ABL. Systemic factors contributory to retinal vein occlusion. Arch Intern Med 1978; 138: 216-20. 3. Mapstone R, Clark CV. Prevelance of diabetes in glaucoma. BMJ 1985; 291: 93-95. 4. Walker W, Walton K, Magnani H. Glaucoma and ischaemic vascular disease risk factors. Trans Ophthal Soc UK 1976; 96: 237-40. 5. Khan HA, Leibowitz HM, Gahley JP. Association of ophthalmic pathology with single variables previously measured in the Framingham heart study. Am J Epidemiol 1977; 106: 33-75. 6. DeFronzo R, Ferrannini E. Insulin resistance: a multifaceted syndrome. Diabetes Care 1991; 14: 173-94. 7 WHO expert committee on diabetes mellitus (2nd report). WHO report series, 1980: 646. 8. Felber J, Jallut D, Golay A, Frascarolo P, Jequier E Obesity to diabetes: a longitudinal study of glucose metabolism in man. Diabetes 1989; 38 (suppl 1): 221A. 9. Eriksson J, Franssila-Kallunki A, Ekstrand A, et al. Early metabolic defects in persons at increased risk for non-insulin dependent diabetes mellitus. N Engl J Med 1989; 321: 337-43. 10. Golay A, Felber JP, Jequier E. Metabolic basis of obesity and non-insulin diabetes mellitus. Diabetes Metab Rev 1988; 4: 727-47.
Surgery for rectal
cancer
in
Japan
SIR,-Neoplastic disease is the commonest cause of adult death in Japan, and gastric, hepatic, and colorectal cancers are the most common. Whereas in Europe current trends in cancer therapy are away from radical surgery towards adjuvant therapy for gastrointestinal tumours, a different path is being followed in Japan, where the approach is more reliant on radical surgical resection, not only for the primary disease but also for recurrent and metastatic disease. The results for both gastric and rectal cancer are impressive (hepatocellular carcinoma is rare in Europe, making comparisons difficult), with local recurrence and disease-free survival lower than those seen in European centres for surgical treatment alone. When discussing results of therapy for a malignant disease across international boundaries, the argument that malignant diseases
The basic tenet of Japanese cancer surgery is that potential cure necessitates wide excision of the tumour together with its associated lymphatic tissues to an anatomical plane beyond which the cancer has spread. Though this idea ignores the possibility of occult metastasis at the time of operation, the approach keeps to a minimum the risk of local recurrence. Subsequent metastatic disease is also likely to be treated surgically when possible, and chemotherapy is reserved for metastatic disease that is unresectable. The Japanese hold the medical profession in high esteem and the attitude of Japanese patients towards cancer treatment is similar to that of their doctors-namely, that they believe the best way to treat cancer is radical surgery. As a result of this belief, postoperative complications, such as urinary retention and sexual dysfunction, which commonly follow pelvic lymphadenectomy for rectal cancer, are accepted as a price to be paid. The techniques of Japanese cancer surgery are anatomically accurate to ensure complete lymphadenectomy, and meticulous haemostasis is a prerequisite for this kind of dissection. Such surgery tends to be protracted and an anterior resection often takes 5 hours. The morbidity associated with radical pelvic lymphadenectomy, especially urinary and sexual dysfunction, has led to the development of a pelvic-nerve-sparing operation, which seems to reduce the occurrence of these complications. However, nerve sparing is regarded as a lower priority than lymphadenectomy, and radical surgery supervenes over preservation of urinary and sexual function. Although the age of presentation with gastric and colorectal cancer in Japan is similar to that seen in Europe, the lower incidence of cardiovascular disease in Japan may account for the rare occurrence of cardiovascular and thromboembolic complications after such protracted operations. The results of radical pelvic lymphadenectomy are probably unsurpassed, with a local recurrence of 5% and an overall disease-free 5-year survival approaching 70%/ but despite large series (over 500 radical pelvic lymphadenectomies have been performed at the National Cancer Center), no controlled trials have been done. Unfortunately Japanese surgeons dislike randomised controlled studies and as a result of their large experience, local surgeons are convinced that their techniques are effective and they are reluctant to do controlled studies. This has resulted in scepticism among surgeons in Europe and frustration in Japan. We probably cannot assess whether the benefits of radical surgery are real without randomised controlled studies. Goligher2 first made this suggestion in 1984 and although results have since improved, trials still have not been done. Perhaps international pressure will persuade Japanese surgeons of the necessity of such studies, since ideally the trials would be in Japan where the technique is already established; if not a European group should take up the challenge. The precedent has already been set in trials of lymphadenectomy for gastric cancer in the UK and in the Netherlands. Department of Surgery, Northern General Hospital, Sheffield S5 7AU, UK
J.
Department of Surgery, Leiden University, Leiden, Netherlands
W. H. STEUP
H. SCHOLEFIELD
1.
Monya Y, Hojo K, Sawada T, Koyama Y. Significance of lateral node dissection for advanced rectal carcinoma at or below the peritoneal reflection. Dis Colon Rectum
2.
Goligher J. Tindall,
1989; 32: 307-15. In: Diseases of the 1984.
anus colon
and rectum. 5th ed. London: Baillière
PLASMA GLUCOSE AND INSULIN CONCENTRATIONS BEFORE AND AFTER GLUCOSE CHALLENGE (MEAN, SD)
behave differently in different populations is often advocated. This argument is difficult to confirm or refute since malignant disease runs a variable course within any population, and rectal cancer is no exception. However, attributing the impressive results of another group of surgeons who are obtaining consistently better results than ourselves as being due to the more benign nature of the disease is complacent if not arrogant, and is also likely to become a self-fulfilling prophesy. We have studied the techniques and results of radical surgery for rectal cancer at the National Cancer Center in Tokyo to assess the role of radical surgery in rectal cancer.
RVO=re2nal
vein
occlusion.
OAG= open -angle glaucoma
glucose challenge. Impaired glucose metabolism is the result of insensitivity to insulin-stimulated glucose uptake6 principally in muscle. Initially compensatory hyperinsulinaemia, due to augmented secretion, offsets hyperglycaemia but if insulin secretion declines, glucose intolerance and eventually diabetes develop.6,8 This sequence may explain why previous studies1 have failed to show abnormalities in glucose metabolism underlying central retinal vein occlusion and open-angle glaucoma. Euglycaemic insulin clamp studies9 have shown insulin resistance in non-diabetic first-degree relatives of non-insulin dependent diabetics, suggesting a genetic aetiology. Obesity in non-diabetics decreases tissue sensitivity to insulin, producing insulin tissue
resistance.6,10 Because BMI was similar in all three groups, this mechanism appears unlikely here. Although these results should be interpreted cautiously, they suggest an association between insulin resistance and both open-angle glaucoma and central retinal vein occlusion, which might explain the frequent association of these conditions. We thank Lederle Laboratories, Alcon (UK), and IOLAB for funding this study. We also thank Dr E. Horsfield and Mrs M. Thompson, Department of Chemical Pathology, Barnsley District General Hospital, for assays.
A. LOCKWOOD L. G. CLEARKIN
Arrowe Park Hospital,
Upton, Wirral, Merseyside L49 5PE, UK
1. Cole MD, Dodson PM, Hendeles S. Medical conditions underlying retinal vein occlusion in patients with glaucoma or ocular hypertension. Br J Ophthalmol 1989; 73: 693-98. 2. McGrath MA, Weschler F, Huynor ABL. Systemic factors contributory to retinal vein occlusion. Arch Intern Med 1978; 138: 216-20. 3. Mapstone R, Clark CV. Prevelance of diabetes in glaucoma. BMJ 1985; 291: 93-95. 4. Walker W, Walton K, Magnani H. Glaucoma and ischaemic vascular disease risk factors. Trans Ophthal Soc UK 1976; 96: 237-40. 5. Khan HA, Leibowitz HM, Gahley JP. Association of ophthalmic pathology with single variables previously measured in the Framingham heart study. Am J Epidemiol 1977; 106: 33-75. 6. DeFronzo R, Ferrannini E. Insulin resistance: a multifaceted syndrome. Diabetes Care 1991; 14: 173-94. 7 WHO expert committee on diabetes mellitus (2nd report). WHO report series, 1980: 646. 8. Felber J, Jallut D, Golay A, Frascarolo P, Jequier E Obesity to diabetes: a longitudinal study of glucose metabolism in man. Diabetes 1989; 38 (suppl 1): 221A. 9. Eriksson J, Franssila-Kallunki A, Ekstrand A, et al. Early metabolic defects in persons at increased risk for non-insulin dependent diabetes mellitus. N Engl J Med 1989; 321: 337-43. 10. Golay A, Felber JP, Jequier E. Metabolic basis of obesity and non-insulin diabetes mellitus. Diabetes Metab Rev 1988; 4: 727-47.
Surgery for rectal
cancer
in
Japan
SIR,-Neoplastic disease is the commonest cause of adult death in Japan, and gastric, hepatic, and colorectal cancers are the most common. Whereas in Europe current trends in cancer therapy are away from radical surgery towards adjuvant therapy for gastrointestinal tumours, a different path is being followed in Japan, where the approach is more reliant on radical surgical resection, not only for the primary disease but also for recurrent and metastatic disease. The results for both gastric and rectal cancer are impressive (hepatocellular carcinoma is rare in Europe, making comparisons difficult), with local recurrence and disease-free survival lower than those seen in European centres for surgical treatment alone. When discussing results of therapy for a malignant disease across international boundaries, the argument that malignant diseases
The basic tenet of Japanese cancer surgery is that potential cure necessitates wide excision of the tumour together with its associated lymphatic tissues to an anatomical plane beyond which the cancer has spread. Though this idea ignores the possibility of occult metastasis at the time of operation, the approach keeps to a minimum the risk of local recurrence. Subsequent metastatic disease is also likely to be treated surgically when possible, and chemotherapy is reserved for metastatic disease that is unresectable. The Japanese hold the medical profession in high esteem and the attitude of Japanese patients towards cancer treatment is similar to that of their doctors-namely, that they believe the best way to treat cancer is radical surgery. As a result of this belief, postoperative complications, such as urinary retention and sexual dysfunction, which commonly follow pelvic lymphadenectomy for rectal cancer, are accepted as a price to be paid. The techniques of Japanese cancer surgery are anatomically accurate to ensure complete lymphadenectomy, and meticulous haemostasis is a prerequisite for this kind of dissection. Such surgery tends to be protracted and an anterior resection often takes 5 hours. The morbidity associated with radical pelvic lymphadenectomy, especially urinary and sexual dysfunction, has led to the development of a pelvic-nerve-sparing operation, which seems to reduce the occurrence of these complications. However, nerve sparing is regarded as a lower priority than lymphadenectomy, and radical surgery supervenes over preservation of urinary and sexual function. Although the age of presentation with gastric and colorectal cancer in Japan is similar to that seen in Europe, the lower incidence of cardiovascular disease in Japan may account for the rare occurrence of cardiovascular and thromboembolic complications after such protracted operations. The results of radical pelvic lymphadenectomy are probably unsurpassed, with a local recurrence of 5% and an overall disease-free 5-year survival approaching 70%/ but despite large series (over 500 radical pelvic lymphadenectomies have been performed at the National Cancer Center), no controlled trials have been done. Unfortunately Japanese surgeons dislike randomised controlled studies and as a result of their large experience, local surgeons are convinced that their techniques are effective and they are reluctant to do controlled studies. This has resulted in scepticism among surgeons in Europe and frustration in Japan. We probably cannot assess whether the benefits of radical surgery are real without randomised controlled studies. Goligher2 first made this suggestion in 1984 and although results have since improved, trials still have not been done. Perhaps international pressure will persuade Japanese surgeons of the necessity of such studies, since ideally the trials would be in Japan where the technique is already established; if not a European group should take up the challenge. The precedent has already been set in trials of lymphadenectomy for gastric cancer in the UK and in the Netherlands. Department of Surgery, Northern General Hospital, Sheffield S5 7AU, UK
J.
Department of Surgery, Leiden University, Leiden, Netherlands
W. H. STEUP
H. SCHOLEFIELD
1.
Monya Y, Hojo K, Sawada T, Koyama Y. Significance of lateral node dissection for advanced rectal carcinoma at or below the peritoneal reflection. Dis Colon Rectum
2.
Goligher J. Tindall,
1989; 32: 307-15. In: Diseases of the 1984.
anus colon
and rectum. 5th ed. London: Baillière
