Three versus six months of adjuvant chemotherapy in colorectal cancer

The international SCOT study, recenlty published on the Journal of Clinical Oncology, proved the non-inferiority of a three months adjuvant chemotherapy with oxaliplatin and a fluopyrimidine versus six months of treatment in patients with colorectal cancer.

The SCOT trial is an international, randomized, phase III, non-inferiority trial involving over 6000 patients with colorectal cancer. In this tumor, 6 months of adjuvant chemotherapy with oxaliplatin and a fluoropyrimidine has been an international standard for over 20 years but is associated with cumulative peripheral neuropathy; authors thus investigated a treatment reduction from 6 to 3 months. The new paper shows additional results after the report of non-inferiority in disease-free survival and an improved quality of life, at the first follow-up; after a median follow-up of 113 months, the 5-year overall survival for 3 versus 6 months of treatment was 82.4% in both groups. Non-inferiority of 3 months of treatment for overall survival was also shown in 1087 patients with rectal cancer. The duration effect is regimen-dependent, with non-inferiority shown for capecitabine and oxaliplatin but not for infusional fluorouracil, leucovorin, and oxaliplatin. As authors note, «These final SCOT trial results provide further evidence that 3 months of adjuvant chemotherapy can be recommended for most localized colon or rectal cancers, with no statistically significant overall survival advantage of 6 months of treatment in any cohort, even for patients with high-risk stage III disease. When deciding on treatment duration for high-risk stage III disease, it is important to emphasize that there is no significant overall survival advantage for 6 months of therapy, and to highlight the additional toxicities (particularly cumulative neuropathy) and hospital visits. Extended treatment duration should be the exception, and only agreed after careful shared decision making between clinician and patient», they conclude.