Molecular analysis of advanced colorectal cancer in a patient cohort of Hispanics, African Americans, and Caucasians within a diverse single institution.

Abstract

e15121 Background: CRC survival and treatment response differences have been noted across racial and ethnic groups, particularly between Hispanics (HA), non-Hispanic AA (AA), and non-Hispanic Caucasian (CA). We examined if there are differences in molecular drivers between these groups that could explain such differences in our diverse medical center. Methods: We retrospectively examined 361 HA, AA, CA patients at Montefiore Medical Center diagnosed with metastatic CRC (mCRC) from 2007 to 2018. Mismatch repair proficiency (MMR-P), deficiency (MMR-D) was determined by immunohistochemistry. KRAS, NRAS, BRAF were determined by polymerase chain reaction or next generation sequencing. Mutations were then correlated with overall survival (OS). Results: Across subgroups, there was no differences in MMR, KRAS, NRAS, BRAF incidence (Table). Using a univariate analysis, the median survival for RAS mutated (M) patients was 33 months (ms), compared to 69 ms for RAS wild-type (WT, p = 0.01). The median OS for RAS mutated HA patients was 41 ms, compared to 41 ms and 33 ms for CA and AA respectively (p = 0.14). There was also no statistically significant difference between median OS for RAS WT HA patients (69 ms), compared to AA patients (51 ms) and CA (not reached, p = 0.75). Conclusions: In our single institution study, we found no difference in incidence of RAS (KRAS and NRAS), BRAF, MMR amongst HA, AA, and CA. Delivery of uniform care may account for similar OS outcomes in our patient population. RAS WT and M disease had improved OS compared to previously established rates in the literature. Additional studies are needed to evaluate known differences in treatment response and survival in minority populations.[Table: see text]