Liquid Biopsy In Stage Iv Non-Small Cell Lung And Prostate Cancers And Prevalence Of Ethnicity And Risk Factors: A Va Medcial Center Experience

Abstract

Abstract Introduction/Objective The advent of Liquid biopsy (LB) is a milestone in precision oncology. This minimally invasive revolutionary technique analyses circulating tumor DNA and detects signature genomic alterations. Advanced-stage prostate cancers are more common in African Americans both in general and veteran patient population, while general cohort Caucasians are more prone to advanced/metastatic NSCLC. Risk factor for these cancers is smoking; agent orange exposure and its relationship with aggressiveness/ethnicity for veterans is sparse in the literature. We performed a QA study for advanced lung/prostate cancers of veteran patients on LB. Methods QA documentation from Foundation One (Cambridge MA, NGS) on LB performed for the regional Veteran Affairs Medical Center (VAMC) from May 2019 to April 2020 were reviewed. The testing was performed on advanced NSCLC/prostate cancer cases with evidence of advanced tumor progression. Data for ethnicity, risk factors, post therapy PSA, Gleason score and genetic mutations noted. Results A total of 30 LBs were performed over this time period. Of 30 LBs, 23 were prostate and 7 were lung cancers. 2/30 had unknown ethnic background. 19/28 (67.8%) were of African American origin, 18 of which had advanced prostate cancers. 11/28 were white, of which 3/30 were advanced NSCLC. One patient declined to reveal risk factor exposure, hence 17/29 (58.6%) had smoking, 15/29 (51.7%) had a risk of herbicide, agent orange exposure; and, 10/29 (34.4%) had both risk factor exposures. 6/29 (20.6%) African American veterans had combined risk factors. 9/10 (90%) veterans which had dual exposure presented with either Gleason score of 9 or as metastasis. Post therapy PSA ranged from 0.5 to 1870 ng/ml and did not corelate with the aggressiveness of the cancer or therapy response. Conclusion Veteran patient population has slightly higher incidence of ethnic African Americans presenting with advanced NSCLC/prostate cancers compared to general patient cohort. Although incidence of smoking is similar, combined exposure with agent orange, increases the aggressiveness of the disease three-fold. Real-time monitoring of the therapy response and multimodal benefits by LB is of immense help in morbidly ill veterans, compared to post- therapy PSA monitoring or invasive tissue biopsy. Role of LB should also be explored for early screening/triaging the veterans.