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Background: Outcomes after metastasectomy for metastatic colorectal cancer (mCRC) vary with RAS and BRAF mutational status, but their effects on resectability and conversion rates have not been extensively studied. Methods: This substudy of the prospective RAXO trial included 906 patients recruited between 2011 and 2018. We evaluated repeated centralised resectability assessment, conversion/resection rates and overall survival (OS), according to RAS and BRAF status. Results: Patients included 289 with RAS and BRAF wild-type (RAS and BRAFwt), 529 with RAS mutated (RASmt) and 88 with BRAF mutated (BRAFmt) mCRC. Metastatic prevalence varied between the RAS and BRAFwt/RASmt/BRAFmt groups, for liver (78%/74%/61%), lung (24%/35%/28%) and peritoneal (15%/15%/32%) metastases, respectively. Upfront resectability (32%/29%/15%), conversion (16%/13%/7%) and resection/local ablative therapy (LAT) rates (45%/37%/17%) varied for RASa and BRAFwt/RASmt/BRAFmt, respectively. Median OS for patients treated with resection/LAT (n = 342) was 83/69/30 months, with 5-year OS-rates of 67%/60%/24%, while systemic therapy-only patients (n = 564) had OS of 29/21/15 months with 5-year OS-rates of 11%/6%/2% in RAS and BRAFwt/RASmt/BRAFmt, respectively. Resection/LAT was associated with improved OS in all subgroups. Conclusions: There were significant differences in resectability, conversion and resection/LAT rates according to RAS and BRAF status. OS was also significantly longer for RAS and BRAFwt versus either mutant. Patients only receiving systemic therapy had poorer long-term survival, with variation according to molecular status.

Metastasectomy and/or local ablative therapy in metastatic colorectal cancer (mCRC) patients often provide long-term survival. Health-related quality of life (HRQoL) data in curatively treated mCRC are limited. In the RAXO-study that evaluated repeated resectability, a multi-cross-sectional HRQoL substudy with 15D, EQ-5D-3L, QLQ-C30, and QLQ-CR29 questionnaires was conducted. Mean values of patients in different treatment groups were compared with age- and gender-standardized general Finnish populations. The questionnaire completion rate was 444/477 patients (93%, 1751 questionnaires). Mean HRQoL was 0.89–0.91 with the 15D, 0.85–0.87 with the EQ-5D, 68–80 with the EQ-5D-VAS, and 68–79 for global health status during curative treatment phases, with improvements in the remission phase (disease-free >18 months). In the remission phase, mean EQ-5D and 15D scores were similar to the general population. HRQoL remained stable during first- to later-line treatments, when the aim was no longer cure, and declined notably when tumour-controlling therapy was no longer meaningful. The symptom burden affecting mCRC survivors’ well-being included insomnia, impotence, urinary frequency, and fatigue. Symptom burden was lower after treatment and slightly higher, though stable, through all phases of systemic therapy. HRQoL was high in curative treatment phases, further emphasizing the strategy of metastasectomy in mCRC when clinically meaningful.

Background: KRAS mutations, present in over 40% of metastatic colorectal cancer (mCRC), are negative predictive factors for anti-EGFR therapy. Mutations in KRAS-G12C have a cysteine residue for which drugs have been developed. Published data on this specific mutation are conflicting; thus, we studied the frequency and clinical characteristics in a real-world and population-based setting. Methods: Patients from three Nordic population-based cohorts and the real-life RAXO-study were combined. RAS and BRAF tests were performed in routine healthcare, except for one cohort. The dataset consisted of 2,559 patients, of which 1,871 could be accurately classified as KRAS, NRAS, and BRAF-V600E. Demographics, treatments, and outcomes were compared using logistic regression. Overall survival (OS) was estimated with Kaplan–Meier, and differences were compared using Cox regression, adjusted for baseline factors. Results: The KRAS-G12C frequency was 2%–4% of all tested in the seven cohorts (mean 3%) and 4%–8% of KRAS mutated tumors in the cohorts (mean 7%). Metastasectomies and ablations were performed more often (38% vs. 28%, p = 0.040), and bevacizumab was added more often (any line 74% vs. 59%, p = 0.007) for patients with KRAS-G12C- vs. other KRAS-mutated tumors, whereas chemotherapy was given to similar proportions. OS did not differ according to KRAS mutation, neither overall (adjusted hazard ratio (HR) 1.03; 95% CI 0.74–1.42, reference KRAS-G12C) nor within treatment groups defined as “systemic chemotherapy, alone or with biologics”, “metastasectomy and/or ablations”, or “best supportive care”, RAS and BRAF wild-type tumors (n = 548) differed similarly to KRAS-G12C, as to other KRAS- or NRAS-mutated (n = 66) tumors. Conclusions: In these real-life and population-based cohorts, there were no significant differences in patient characteristics and outcomes between patients with KRAS-G12C tumors and those with other KRAS mutations. This contrasts with the results of mo