2022 Volume 55 Issue 8 Pages 473-482
Purpose: Patients with metastatic colorectal cancer (mCRC) with BRAF V600E mutation have a poor response to standard cytotoxic agents and extremely poor outcomes. Thus, the optimal indication for metastasectomy remains debatable, even when the metastatic region is resectable. The aims of this retrospective study were to examine the outcomes of BRAF V600E mCRC, identify risk factors for poor survival, and establish the optimal surgical indication for resection. Materials and Methods: The subjects were 14 patients with BRAF V600E mCRC who started treatment in our department between December 2016 and April 2020. No patients underwent surgery prior to introduction of systemic chemotherapy. Patients were divided into two groups based on the initial response to first-line chemotherapy: controlled disease (CD, n=8) for tumors that shrunk or stabilized from baseline, and uncontrolled disease (UD, n=6) for tumors that increased in size. Results: The median follow-up period was 39.7 months. The 2-year overall survival rate was 35.7% in all patients, and was higher in the CD group than in the UD group (50.0% vs. 16.7%, P=0.051). Six patients (42.9%) underwent curative metastasectomy, of whom 4 developed recurrence and one underwent re-resection. In the CD group, 2 of 3 patients who underwent metastasectomy were alive without cancer, while all 3 patients in the UD group developed recurrence after metastasectomy and 2 had early recurrence within 3 months. Conclusion: This study suggests that evaluation of the initial response to first-line chemotherapy may be a useful prognostic factor in BRAF V600E mCRC. Even if a tumor is resectable, the indication for metastasectomy should be carefully considered in cases with poor disease control in the initial response.
