biostudies-literatureUnknown113(4)Zaanan AAnti-epidermal growth factor receptor (EGFR) efficacy in patients with microsatellite instability (MSI) metastatic colorectal cancer (mCRC) according to sporadic vs familial origin is unknown. We retrospectively analyzed 128 patients with MSI mCRC treated with first-line chemotherapy ± anti-EGFR. Among them, 61 and 67 patients were respectively categorized as familial and sporadic based on mismatch repair protein immunostaining, BRAF mutational status, and MLH1 promoter methylation status. We observed that addition of anti-EGFR to chemotherapy was associated with a statistically significant improvement of progression-free survival for familial (median = 5.0 vs 10.2 months, hazard ratio [HR] = 0.47, 95% confidence interval [CI] = 0.23 to 0.94; P = .03) but not for sporadic (median = 4.4 vs Journal of the National Cancer Institute496-500https://www.ebi.ac.uk/biostudies/studies/S-EPMC8023852biostudies-literatureEfficacy of Anti-EGFR in Microsatellite Instability Metastatic Colorectal Cancer Depending on Sporadic or Familial Origin.PMC8023852Cohen Rde la Fouchardiere CZaanan AAparicio TTaieb JSvrcek MEvrard CSefrioui DAssociation des Gastro-entérologues Oncologues (AGEO)Tougeron DLecomte TAndre TVernerey DHenriques JfalseEfficacy of Anti-EGFR in Microsatellite Instability Metastatic Colorectal Cancer Depending on Sporadic or Familial Origin.Anti-epidermal growth factor receptor (EGFR) efficacy in patients with microsatellite instability (MSI) metastatic colorectal cancer (mCRC) according to sporadic vs familial origin is unknown. We retrospectively analyzed 128 patients with MSI mCRC treated with first-line chemotherapy ± anti-EGFR. Among them, 61 and 67 patients were respectively categorized as familial and sporadic based on mismatch repair protein immunostaining, BRAF mutational status, and MLH1 promoter methylation status. We observed that addition of anti-EGFR to chemotherapy was associated with a statistically significant improvement of progression-free survival for familial (median = 5.0 vs 10.2 months, hazard ratio [HR] = 0.47, 95% confidence interval [CI] = 0.23 to 0.94; P = .03) but not for sporadic (median = 4.4 vs 2021-01-01T00:00:00Z2021 Apr2025-04-06T23:24:11.55Z2025-04-04T11:29:14.495ZS-EPMC80238523241597310.1093/jnci/djaa072