Does chemotherapy after surgery improve survival in older patients with colon cancer?

This study investigated the use of chemotherapy after surgery in elderly patients with stage 2 and 3 colon cancer. Researchers suggested that chemotherapy after surgery improves outcomes in patients with stage 3 colon cancer.

Life expectancy in the Western countries has increased. Colorectal cancer is diagnosed most commonly in people over the age of 65. Therefore, it is expected that more people will be diagnosed with colon cancer in the coming years.

Chemotherapy is used after surgery to kill any remaining cancer cells. However, this treatment also targets normal, healthy tissues. Older patients frequently have other medical conditions. This makes them more vulnerable to the side effects of chemotherapy. There is evidence that chemotherapy after surgery improves the outcomes of older patients with colon cancer. However, there is limited information on how chemotherapy is being used in this population.  

This study included 31,990 patients aged 66 or older with stage 2 and 3 colon cancer. These patients were divided into different age groups. The number of patients receiving chemotherapy decreased by each age groups. Patients with stage 3 disease were most likely to receive chemotherapy.

In patients with stage 2 cancer, chemotherapy after surgery increased the risk of mortality by 32%. In stage 3 patients, chemotherapy after surgery decreased the risk of mortality by 27%. However, in patients aged 90 or older chemotherapy appeared to increase mortality.

This study showed that chemotherapy after surgery improved outcomes only in patients with stage 3 colon cancer under the age of 90.

This study was based on information from an insurance database. Information on some patients may have been missing. This could have changed the results. Patients received chemotherapy between 1991 and 2007. Some chemotherapy drugs used nowadays were not approved during that period.