A Focus on the Epidemiology of Colon Cancers

In France, the incidence of colon cancers, which had increased up to 2000, has since seen a reduction. A more detailed analysis of data shows that time-related trends in the incidence of colon cancers varies based on its sub-location. The incidence of both right and left colon cancers has increased. It has remained stable for cancers found in the sigmoid colon in men and has decreased in women. A male born around 1900 was more than three times more likely to have sigmoid cancer than cancer in any other section of the colon. The risk of developing right colon cancer increased from 0.5% for males born around 1900 to 1.2% for those born around 1950. For more recent cohorts, the risk of getting right colon cancer became greater than the risk of getting cancer in the sigmoid colon. The net survival rate was 57% at 5 years and 50% at 10 years for males. These rates were 57 and 52% respectively for the same time scales in females. The prognosis for colon cancers has improved over the last two decades in France: the survival rate at 5 years has risen from 53% for cancers diagnosed between 1989 and 1991 to 58% for those diagnosed between 2001 and 2004. The greatest increase in survival rates at 10 years has been seen for cancer of the left colon and the rectosigmoid junction (+19%). The increase is slightly lower for cancer of the right colon (+11%). Significant progress has been made in the treatment of colon cancer. Developments in adjuvant chemo-therapies and more effective palliative care, greater inclusion of patients in therapeutic studies and the development of a screening strategy, based in the short-term on immunological tests, should enable further progress to be made.