Year: 2017
Type: dissertation
Study design: Observational Study
Abstract: Despite long-term research efforts to identify a cohesive explanation of racial disparities in cancer outcomes, evidence remains mixed.Disparities persist in randomized clinical trials, suggesting that inherited factors contribute to differential outcomes.Hemoglobin variants represent a heretofore unstudied inherited prognostic factor, the most prevalent of which is sickle cell trait (SCT).SCT is disproportionally prevalent in African American/Blacks (AA/Bs) (~8%) compared to non-Hispanic whites (NHWs) (<0.1%).Case report evidence suggests SCT interacts with the tumor microenvironment and rigors of cancer treatment, inducing adverse outcomes.We identified 162,357 older cancer patients (75,633 breast; 86,904 prostate) diagnosed 2007-2013 using the SEER-Medicare linked database.AA/B and NHW patients were grouped by hemoglobinopathy status (AA/B+, AA/B-, NHW-) and three-way propensity score weighting was performed to evaluate treatment completion, occurrence of adverse events, and survival.A total of 371 AA/B+ patients were analyzed, compared to 17,303 AA/B-and 144,863 NHW-.At diagnosis, AA/B+ were more likely than AA/B-and NHW-to have multiple comorbidities including cerebrovascular disease, diabetes, and chronic renal failure.After propensity score weighting, no significant association was observed in treatment completion status between AA/B+ and AA/B-.Among treated patients, however, AA/B+ status was associated with increased risk of experiencing one or more adverse event compared to both AA/B-(HR: 1.15, 95% CI: 1.07 -1.24) and NHW-(HR: 1.18, 95% CI: 1.10 -1.26).While hazards models failed to reveal significant differences across study groups, the magnitude of the associations with Jessica R Hoag -University of Connecticut, 2017 mortality in relation to either treatment completion or adverse events varied by hemoglobinopathy status.Among AA/B+ who completed treatment, those who experienced one or more adverse events had more than five times the mortality risk compared to those with no adverse events (HR: 5.56, 95% CI: 4.70 -6.58) whereas the estimated mortality risk among AA/B-and NHW-patients were approximately three-fold.Among patients who failed to complete treatment, however, the adverse event-mortality relationship was similar across groups.
Author: Jessica R. Hoag
Language: English
Subfield: Genetics (clinical)
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2737062629