Due to uncertainties regarding clinically meaningful gains from adjuvant chemotherapy after colorectal cancer surgery, several Nordic Groups in the early 1990s initiated randomised trials to prove or reject such gains. This report gives the joint analyses after a minimum 5-year follow-up. Between October 1991 and December 1997, 2 224 patients under 76 years of age with colorectal cancer stages II and III were randomised to surgery alone (n = 1 121) or adjuvant chemotherapy (n = 1 103) which varied between trials (5FU/levamisole for 12 months, n = 444; 5FU/leucovorin for 4-5 months according to either a modified Mayo Clinic schedule (n = 262) or the Nordic schedule (n = 397). Some centres also randomised patients treated with 5FU/leucovorin to+/-levamisole). A total of 812 patients had colon cancer stage II, 708 colon cancer stage III, 323 rectal cancer stage II and 368 rectal cancer stage III. All analyses were according to intention-to-treat. No statistically significant difference in overall survival, stratified for country or region, could be found in any group of patients according to stage or site. In colon cancer stage III, an absolute difference of 7% (p = 0.15), favouring chemotherapy, was seen. The present analyses corroborate a small but clinically meaningful survival gain from adjuvant chemotherapy in colon cancer stage III, but not in the other presentations.
BACKGROUND. Genetic polymorphisms and expression of steroid receptors may explain why some individuals are more at risk of developing prostate cancer. Some risk factors often discussed are androgen stimulation, and vitamin A and D deficiency. Long CAG-repeats in exon 1 of the androgen receptor (AR) gene on the X chromosome seem to have a protective role against androgen overstimulation. Likewise, long vitamin D receptor alleles in the poly-A tract may prevent vitamin D stimulation. METHODS. Blood samples from 59 Swedish patients with sporadic prostate cancers, 59 with hereditary prostate cancer, and 34 Japanese prostate cancer patients were compared with benign controls. Tissue specimens from 37 Swedish and 23 Japanese prostate cancer patients with matching blood samples were investigated by immunohistochemical techniques. RESULTS. The number of CAG-repeats was identical in sporadic and hereditary prostate cancer patients, but the repeats were significantly shorter than in benign controls. Benign Japanese controls were similar to Swedish controls, but Japanese prostate cancers had longer repeats than did controls. Both the vitamin D and A receptor staining was stronger in Japanese than in Swedish prostate cancer specimens. Prostate cancer occurs approximately 5 years later in Japanese compared with Swedish men. CONCLUSIONS. Varying lengths of CAG-repeats of the androgen receptor cannot fully explain racial differences in clinical prostate cancer incidence. A larger content of vitamin A and D receptors may be linked to a delayed onset of clinical prostate cancer in Japanese men.
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