Assessing the Efficacy and Safety of Shorter versus Extended Adjuvant Treatment Duration for Stage III Low-Risk Colon...

In recent years, reducing adjuvant treatment period from 6 months to 3 months in low-risk stage 3 colon cancer has shown no decline in efficiency and fewer adverse effects, particularly neuropathy.

We examined the efficacy and side effects of 3- and 6-month adjuvant chemotherapy regimens in low-risk stage 3 colon cancer patients.

Twelve oncology centers retrospectively scanned operated, low-risk, stage 3 (T1-3, N1) colon cancer patients. Capecitabine and oxaliplatin (CAPOX) were given to all 3-month adjuvant chemotherapy patients, while 6-month patients received FOLFOX orCAPOX. Two adjuvant treatment groups compared DFS (disease-free survival) and side effects.

In total, 204 patients were included in our study and the patients' median age was 56 years. Regarding treatment duration, 40.6% of patients (n:83) were treated for 3 months and 59.4% (n:121) were treated for 6 months. The 24-month DFS was numerically high in the 6-month treatment arm, but the difference was not statistically significant (91% vs 84%, respectively; HR: 0.7 95 CI% 0.3-1.58, p: 0.38). During the treatment time, both in all grades (30% vs 54.5%) and in grade 3 (6% vs 15%), neuropathy was significantly higher in the 6-month treatment arm. After the end of the treatment, the average persistent neuropathy frequency after 12 months of follow-up was significantly higher in the 6-month treatment arm, and all of them were at grade 1-2 (12% vs 31%, respectively).

In adjuvant treatment of low-risk stage 3 colon cancer, 3-month CAPOX and 6-month FOLFOX/CAPOX had similar 2-year DFS. The neuropathy was significantly lower in the 3-month treatment arm.