Thapa, Ram

ImportanceWhile the incidence of early-onset metastatic colorectal cancer (mCRC) has been increasing, studies on the age-related disparity in this group of patients are limited.ObjectiveTo evaluate the association of age with treatment-related adverse events and survival in patients with mCRC and explore the potential underlying factors.Design, Setting, and ParticipantsThis cohort study included 1959 individuals. Individual data on 1223 patients with mCRC who received first-line fluorouracil and oxaliplatin therapy in 3 clinical trials, and clinical and genomic data of 736 patients with mCRC from Moffitt Cancer Center were used to assess genomic alterations and serve as an external validation cohort. All statistical analyses were conducted from October 1, 2021, through November 12, 2022.ExposuresMetastatic colorectal cancer.Main Outcomes and MeasuresSurvival outcomes and treatment-related adverse events were compared among patients in 3 age groups: younger than 50 (early onset), 50 to 65, and older than 65 years.ResultsIn the total population of 1959 individuals, 1145 (58.4%) were men. Among 1223 patients from previous clinical trials, 179 (14.6%) in the younger than 50 years group, 582 (47.6%) in the 50 to 65 years group, and 462 (37.8%) in the older than 65 years group had similar baseline characteristics except for sex and race. The younger than 50 years group had significantly shorter progression-free survival (PFS) (hazard ratio [HR], 1.46; 95% CI, 1.22-1.76; P < .001) and overall survival (OS) (HR, 1.48; 95% CI, 1.19-1.84; P < .001) compared with the 50 to 65 years group after adjustment for sex, race, and performance status. Significantly shorter OS in the younger than 50 years group was confirmed in the Moffitt cohort. The younger than 50 years group had a significantly higher incidence of nausea and vomiting (69.3% vs 57.6% [50-65 years] vs 60.4% [>65 years]; P = .02), severe abdominal pain (8.4% vs 3.4% vs 3.5%; P = .02), severe anemia (6.1% vs 1.0% vs 1.5%; P < .001), and severe rash (2.8% vs 1.2% vs 0.4% P = .047). The younger than 50 years group also had earlier onset of nausea and vomiting (1.0 vs 2.1 vs 2.6 weeks; P = .01), mucositis (3.6 vs 5.1 vs 5.7 weeks; P = .05), and neutropenia (8.0 vs 9.4 vs 8.4 weeks; P = .04), and shorter duration of mucositis (0.6 vs 0.9 vs 1.0 weeks; P = .006). In the younger than 50 years group, severe abdominal pain and severe liver toxic effects were associated with shorter survival. The Moffitt genomic data showed that the younger than 50 years group had a higher prevalence of CTNNB1 mutation (6.6% vs 3.1% vs 2.3%; P = .047), ERBB2 amplification (5.1% vs 0.6% vs 2.3%; P = .005), and CREBBP mutation (3.1% vs 0.9% vs 0.5%; P = .05), but lower prevalence of BRAF mutation (7.7% vs 8.5% vs 16.7%; P = .002).Conclusions and RelevanceIn this cohort study of 1959 patients, those with early-onset mCRC showed worse survival outcomes and unique adverse event patterns, which could be partially attributed to distinct genomic profiles. These findings may inform individualized management approaches in patients with early-onset mCRC.

e21016 Background: BRAF mutations are grouped (class I, II or III) according to kinase activity, dependence on RAS, and dimerization. BRAF class I mutations are targeted with BRAF/MEK inhibitors. The management of class II/III mutations has not been fully elucidated. We aimed to further characterize BRAF-mutant NSCLC. Methods: Moffitt patients with BRAF-mutant NSCLC were identified through retrospective review of a clinical molecular database and electronic health record from 1/1/2012 - 03/31/2020. Demographics, PD-L1 expression, responses to chemotherapy/immunotherapy, and overall survival were collected. The correlation between BRAF mutation classes and these variables was determined using a pairwise comparison of p-values and corrected for testing using the Benjamini-Hochberg method. For survival analysis, we used the Kaplan-Meier method with log-rank test. Results: 153 patients were included. Table summarizes the demographic data. 14 evaluable patients with class I mutations received anti-BRAF therapy. The DCR was 79% (11/14) and 83% when PD-L1 ≥1% (5/6). 36 response-evaluable patients received immunotherapy. The DCR was 79% (11/14) for patients with class I, 69% (9/13) for class II, and 78% (7/9) for class III mutations (p=0.89). The DCR was 73% in those with PD-L1 ≥1% (22/30) and 44% in those with PD-L1 <1% (7/16; p= 0.02). 43 response-evaluable patients received chemotherapy. The DCR was 86% (18/21) for patients with class I, 69% (9/13) for class II, and 78% (7/9) for class III mutations (p=0.49). The mOS was 26.2 months for all patients. The mOS was 31.2 months for class I, 15.6 months for class II, 28.8 months for class III, 34.8 months for AMP, and 24 months for VUS (p=0.6). Conclusions: To our knowledge, this is the largest retrospective study of patients with BRAF-mutant NSCLC. BRAFmutations were more common in patients with adenocarcinoma and those with a smoking history. PD-L1 levels ≥1% were seen more frequently in all BRAF-mutant patients. Class I mutations were significantly more common than other mutations and responded well to BRAF-targeted therapy, particularly when PD-L1 ≥1%. All BRAF-mutant classes responded similarly to immunotherapy and better responses were seen among those with PD-L1 ≥1%. Responses to chemotherapy were similar across all classes. Improved OS in class I-mutant disease was seen. These findings were not statistically significant. Additional research is needed to better characterize these patients to individualize management and improve outcomes.[Table: see text]