Changing survival prospects in rectal and colonic cancer.

Cancer specific survival analysis in a series of 2204 patients managed by one of the authors for large-intestinal cancer shows a worsened outcome for patients treated operatively for rectal cancer from 1970 to 1979 in comparison with the two previous decades (p less than 0.05). Cancer specific survival after curative resection has also worsened (p less than 0.001). These changes are partly explained by an increase in Dukes' stage C tumours (p = 0.01). Paradoxically, the deterioration has been paralleled by earlier diagnosis (p less than 0.01). The worsened outcome cannot be accounted for by changes in sex or age distribution, tumour site, patient referral pattern or by an increase in sphincter-saving operations. The hypothesis advanced that a real change has occurred in the behaviour of rectal cancer in the Australian community requires further testing. There has been no significant change in survival prospects between the last two decades for colonic cancer patients treated operatively. A national cancer registry should be established to monitor changes in the epidemiology and survival prospects of large-intestinal cancer and other malignancies.