What is the optimal duration of chemotherapy after surgery for patients with stage III colon cancer?

This trial looked at the length of adjuvant chemotherapy (AC; chemotherapy after surgery) for patients with stage III colon cancer. The authors found that 3 months of AC resulted in similar survival with reduced levels of toxicity, and cost compared to 6 months. 

AC has been standard care for patients with stage III colon cancer for nearly 30 years. AC is usually given after surgery to reduce the risk of a cancer coming back. Common AC regimens include FOLFOX (folinic acid, fluorouracil, and oxaliplatin) and CAPOX (capecitabine and oxaliplatin). Patients with colon cancer experienced a longer survival with these AC regimens. However, these AC regimens also increase the risk of side effects such as sensory nerve damage which can affect a patient’s quality of life. This often continues after the treatment has been stopped.

Therefore, the optimal duration of AC for improved outcomes and minimal side effects in patients with stage III colon cancer remains under investigation. 

The results of 6 trials that were examined for this study. Overall, 12835 patients with stage III colon cancer were included. 5064 patients received CAPOX for 3 or 6 months as AC. 7771 patients received FOLFOX for 3 months or 6 months as AC. The average follow-up was 72.3 months.

For all patients, the 5-year overall survival (OS) rate was 82.4% with 3 months of therapy and 82.8% with 6 months of AC. For patients treated with CAPOX, the 5-year OS was 82.1% in the 3-month group and 81.2% for the 6-month group. For patients treated with FOLFOX, the 5-year OS 82.6% in the 3-month group and 83.8% in the 6-month group. 

The authors concluded that a 3-month course of AC was beneficial in terms of OS for most patients. The authors suggest that compared to the 6-month course, this can reduce the cost and toxicity. 

This study did not directly compare the outcomes of patients treated with 3 months or 6 months of AC. More studies are needed.