ASPO Abstracts
Definitive treatment and risk of death among men diagnosed with metastatic prostate cancer at the Veteran’s Health Administration
Category: Survivorship & Health Outcomes/Comparative Effectiveness Research, Survivorship & Health Outcomes/Comparative Effectiveness Research
Conference Year: 2018
Abstract Body:
PURPOSE: Traditional treatments for men with metastatic prostate cancer include hormone therapy or chemotherapy; here we investigate the potential survival benefit associated with receipt of definitive treatment (i.e. radical prostatectomy or radiation) in men with metastatic prostate cancer. METHODS: Our cohort consisted with 3926 men that received treatment for metastatic prostate cancer at the Veteran’s Health Administration between 1997 and 2009. Metastatic disease was defined as cancer that had spread regionally (T4), metastasized to the lymph nodes (N1), or metastasized distantly (M1). Definitive treatment was defined as primary treatment with radical prostatectomy or radiation and determined using VA medical records. Cox proportional hazards models were used to assess the association between receipt of definitive treatment and (1) prostate cancer-specific death and (2) all-cause death. Multivariable models were adjusted for age, race, PSA, locale (rural vs. urban), and prostate cancer grade at diagnosis. In a sensitivity analysis, we used a more restrictive definition of metastatic prostate cancer (T4 or M1 only). RESULTS: 38.9% of the cohort received definitive treatment. Men were least likely to receive definitive treatment if they were diagnosed after 70 years of age, had grade 4 prostate cancer, or a PSA > 20 ng/ml at diagnosis. During follow-up there were 1106 prostate cancer-specific and 1754 all-cause deaths with a mean survival time of 7.6 and 6.0 years, respectively. Receipt of definitive treatment was associated with a reduced risk of prostate cancer death in both models adjusted for grade (HR: 0.27; 95% CI: 0.23, 0.31) and fully adjusted models (HR: 0.37; 95% CI: 0.31, 0.44). Definitive treatment was also associated with a reduced risk of all-cause death [grade-adjusted (HR: 0.35; 95% CI: 0.31, 0.39), fully-adjusted (HR: 0.47; 95% CI: 0.42, 0.53)]. In a sensitivity analysis using a more restrictive definition of metastatic disease (T4 or MI), definitive treatment remained associated with a reduced risk of prostate-cancer specific (HR: 0.48; 95% CI: 0.39, 0.59) and all-cause (HR: 0.59; 95% CI: 0.51, 0.68) death in fully adjusted models. CONCLUSION: Definitive treatment may improve survival in men with metastatic prostate cancer.
Keywords: prostate cancer metastatic definitive treatment Veteran's Health