Improvement in survival following surgery for colorectal cancer.

BACKGROUND: Recent reports based on registry data have shown that survival after surgery for colorectal cancer is improving in the UK. It is not clear whether these improvements are due to earlier presentation or more effective treatment.

METHODS: Outcome for 645 patients with colorectal cancer admitted to Glasgow Royal Infirmary between 1974 and 1979 was compared with that for 354 patients admitted between 1991 and 1994.

RESULTS: More patients in the later period had Dukes' A or B tumours and fewer had evidence of metastatic spread (P < 0.001); more underwent potentially curative resection (57.6 versus 49.9 per cent; P < 0.001) and fewer underwent palliative diversion. The overall postoperative mortality rate fell from 14.1 to 8.5 per cent (P = 0.017). Overall and cancer-specific 5-year survival after potentially curative resection increased from 40.1 to 60.5 per cent and from 47.3 to 71.7 per cent respectively (both P < 0.001). Compared with the earlier period, the adjusted hazard ratio for cancer-specific survival following potentially curative resection was 0.452 (95 per cent confidence interval 0.329 to 0.622; P < 0.001).

CONCLUSION: The observed improvement in survival was mainly due to improvements in the quality of surgery and in perioperative care rather than earlier presentation.