An Odyssey into the Land of Deleterious Rare Mutations in Colorectal Liver Metastases

Excerpt

In this issue, Kobayashi et al. present the survival of patients with BRAF V600E mutations who underwent initial hepatectomy for colorectal liver metastases (CLM) from 2005 to 2016 at six high-volume institutions in Japan.1 Among a total of 33 patients in this multicenter, retrospective, cohort study, only 21.2% received preoperative chemotherapy, and 51.5% received adjuvant chemotherapy. The authors reported 1- and 3-year recurrence-free survival (RFS) rates of 24.2% and 6.1%, respectively, after median post-hepatectomy follow-up of 49.2 months. The majority of patients (93.9%) developed recurrence at a median of 5.3 months, with 42.4% recurring in multiple sites and 87.9% in an unresectable pattern. Median overall survival (OS) for the study cohort was 31.1 months, including six patients who survived 5 years. The Japanese approach to patients with resectable CLM does not typically include the use of preoperative chemotherapy outside of a clinical trial, as noted by the authors. Thus, this small cohort reflects the natural history of BRAF V600E mutations for patients who undergo CLM resection without patient selection based on response to preoperative chemotherapy as a surrogate marker for tumor biology. …