The success rates of clinical cancer next-generation sequencing based on pathologic diagnosis: Experience from a single academic laboratory

Abstract Objectives This article aims to establish the relationship between pathologic diagnosis and the rate of success in cancer next-generation sequencing testing. Methods Clinical next-generation sequencing results performed for solid tumors were reviewed. The rate of success was analyzed in the context of tumor type and accompanying variables. Results Out of 683 total specimens, 533 (78.0%) underwent successful sequencing. The rate of success was 91.8% for ovarian carcinomas, 87.5% for lung non–small cell carcinomas, 82.0% for colorectal adenocarcinomas, 78.3% for melanomas, 75.9% for breast carcinomas, and 64.7% for pancreatic adenocarcinomas. For specimens that successfully underwent sequencing, pancreatic adenocarcinomas had the lowest median tumor proportion and somatic RAS and TP53 mutation allele fractions compared with other tumor types. Cytology specimens had a 33.3% success rate for pancreatic adenocarcinomas (5 of 15) and a 93.3% success rate for lung carcinomas (14 of 15). Compared with tissue from primary sites, tissue from metastatic sites showed a higher success rate for pancreatic adenocarcinomas and lower success rates for colorectal adenocarcinomas and melanomas. Conclusions The success rate of cancer next-generation sequencing testing is dependent on pathologic diagnosis, tissue site, and diagnostic procedure. Understanding which specimens are at higher risk for failing molecular testing may help pathologists and clinical care teams optimize tissue acquisition and usage for patient care.