Benefit of operative mortality reduction on colorectal cancer survival

Background: The aim of this study was to determine trends in operative mortality after colorectal cancer surgery over a 20-year period in a well defined population, and consequences on overall survival. Methods: Some 4745 new cases of colorectal adenocarcinoma were registered between 1976 and 1995 in a French region containing 500 000 people. Among these, 84.3 per cent were operated on, of whom 78.1 per cent were resected. Results: The overall operative mortality rate decreased from 17.7 to 8.1 per cent between 1976-1979 and 1992-1995. Corresponding rates after curative surgery were 12.6 and 6.2 per cent respectively. Period of diagnosis, age and subsite were factors independently associated with operative mortality. Applying the operative mortality rates for the interval 1976-1979 to the 1992-1995 cohort, the expected 5-year survival rate after curative surgery would have been 40.0 per cent, compared with an observed rate of 51.0 per cent. This corresponds to a 27.5 per cent improvement in 5-year overall survival. Applying this result to the French population as a whole, it was estimated that almost 3000 deaths are avoided each year in France as a result of the reduction in operative mortality. Conclusion: Operative mortality decreased dramatically over the 20 years of the study. It was associated with a significant improvement in survival after surgery for cure.