LAUSR

1502Background: Triple negative breast and ovarian cancer are known to have a high frequency of homologous recombination deficiencies (HRDef). The prevalence of HRDef among all tumors is unknown. Methods: Molecular profiles of 48,733 tumors obtained from pts with bladder, breast, ovarian, pancreas, prostate, thyroid, cervical, hepatobiliary, colorectal (CRC), endometrial, gastric/esophageal (GE), head/neck, renal, non-small cell lung (NSCLC), small cell lung (SCLC), GIST, glioma, melanoma, sarcoma and unknown 1° cancers were reviewed to identify somatic pathogenic mutations (mut) in HR genes ATM, ATRX, BARD1, BLM, BRCA1/2, BRIP1, FANCA/C/D2/E/F/G/L, MRE11A, NBN, PALB2, PTEN, RAD50, RAD51, RAD51B, or WRN. Molecular profiles were generated from tumors submitted to Caris Life Sciences using multiple technologies including next generation sequencing (average read depth 500X). Results: Overall frequency of HR mut among all tumors is 11.61% (5658/48733). Cancer lineages with highest frequency of HR mut are endo...