Can reducing chemotherapy duration from 6 to 3 months reduce side effects in patients with colorectal cancer and still be effective?

This study investigated if reducing therapy duration could reduce side effects in patients but still be effective in patients with stage II colorectal cancer (CRC). This study showed that in certain patients a 3-month treatment duration can be considered. 

Patients with colorectal cancer (CRC) can be treated with surgery to remove the tumor. Add-on chemotherapy (CT) is often given to ensure that any remaining cancer cells are destroyed. 

Studies have shown that adding oxaliplatin (Eloxatin) can improve this add-on chemotherapy. FOLFOX (folinic acid, fluorouracil, and oxaliplatin) and CAPOX (capecitabine and oxaliplatin) are two CT regimens that contain oxaliplatin commonly used for the treatment of CRC. However, patients treated with oxaliplatin report high levels of nerve damage as side effects. It is not known if reducing treatment duration from 6 to 3 months improves patient side effects without impacting the therapeutic effect.

This study evaluated data from 4 phase III clinical trials. All patients were diagnosed with high-risk CRC. 3,273 patients were included in the study. 38% of patients were given FOLFOX and 62% of patients were given CAPOX, as decided by their doctor. Group 1 (1,639 patients) received therapy for the standard 6 months. Group 2 (1,634 patients) received therapy for 3 months. The average follow up was 60.2 months. 

Patients in group 1 reported more nerve damage compared to group 2 (36% vs 13%). 5-year survival without signs of cancer was 80.7% in group 2 and 83.9% in group 1. The 3-month duration of treatment benefited more patients treated with CAPOX than those treated with FOLFOX.

This study found that a 3-month duration of CAPOX therapy could be considered in certain patients with stage II CRC.

This study was based on results from different clinical trials with different protocols. The definition of high-risk disease was not similar in all studies. More research is needed to establish the right duration for add-on CT in these patients.