Hematological Changes Associated With Prostate Radiotherapy And Androgen Deprivation Therapy

Abstract

Prostate cancer (PCa) is often managed with prostate radiotherapy (PRT), pelvic nodal radiotherapy (PNRT), and androgen deprivation therapy (ADT). Both PNRT and ADT are thought to place patients at risk for myelosuppression. The interaction and duration of PRT, PNRT, ADT, and RT technique (3D-CRT versus IMRT) on myelosuppression is not well characterized in PCa patients. This study sought to address this uncertainty. A single-institution retrospective analysis of 600 PCa patients treated with PRT (between 2007-2017) was conducted. Patients were stratified into four groups: PRT alone (group-1), PRT and PNRT (group-2), PRT and ADT (group-3), and PRT, PNRT, and ADT (group-4). Hemoglobin (HGB), white blood cells (WBC), neutrophils, and platelets (PLTs) were extracted from baseline (prior to RT), mid-RT, at RT end, one-month post-RT, and one-year post-RT. Chi-Square tests were performed to test differences between groups. Additionally, hematologic values were stratified by the RT technique. A total of 600 patients were identified in this study for the final analysis. Although bone marrow suppression (BMS) was associated with Group 2, 3, and 4. Only Group 4 (N = 321) showed persistent decreased HGB one-month post-treatment. The addition of ADT was associated with an Odds-Ratio (OR) of 2.43 (CI:1.33-4.35, P<0.004) and that of PNRT with an OR of 3.24 (CI:1.76-5.74, P<0.001). Decreased WBCs were observed in all groups, with PNRT carrying the highest impact with an OR of 2.23 (CI:1.12-4.50, P<0.023). Neutrophil counts were decreased in all groups, with PNRT carrying an OR of 4.69 (CI:3.02-7.27, P<0.001). Both WBC and neutrophil recuperated at four weeks post-PRT in all groups. IMRT was associated with lower BMS than 3DCRT. Our analysis did not identify a statistically significant decrease in platelet count in all groups. Importantly, no patient required intervention for the myelosuppression. Our study suggests that prostate RT, ADT, and the use of 3D-CRT vs. IMRT is associated with mild myelosuppression. The myelosuppression is mild and transient with most patients recuperating to their baseline at four weeks post-radiation therapy. Longer follow up, and patient-reported outcomes should be considered in future studies to determine if these changes are clinically significant.