Impact of marital status and race on outcomes of patients enrolled in Radiation Therapy Oncology Group prostate cancer trials.

INTRODUCTION: Previous studies by our group and others have demonstrated the importance of sociodemographic factors in cancer-related outcomes. The identification of these factors has led to novel approaches to the care of the high-risk cancer patient, specifically in the adoption of clinical interventions that convey similar benefits as favorable sociodemographic characteristics. This study examined the importance of marital status and race as prognostic indicators in men with prostate cancer.
METHODS: This report is a meta-analysis of 3,570 patients with prostate cancer treated in three prospective RTOG clinical trials. The Kaplan-Meier method was used to estimate the survival rate and the cumulative incidence method was used to analyze biochemical failure rate. Hazard ratios were calculated for all covariates using either the Cox or Fine and Gray's proportional hazards model or logistic regression model with associated 95% confidence intervals and p values.
RESULTS: Hazard ratio (HR) for overall survival (OS) for single status compared to married status was 1.36 (95% CI, 1.2 to 1.53). OS HR for non-White compared to White patients was 1.05 (CI 0.92 to 1.21). In contrast, the disease-free survival (DFS) HR and biochemical failure (BF) HR were both not significantly different neither between single and married patients nor between White patients and non-White patients. Median time to death for married men was 5.68 years and for single men was 4.73 years. Median time for DFS for married men was 7.25 years and for single men was 6.56 years. Median time for BF for married men was 7.81 years and for single men was 7.05 years.
CONCLUSIONS: Race was not associated with statistically significant differences in this analysis. Congruent with our previous work in other cancer sites, marital status predicted improved prostate cancer outcomes including overall survival. IMPLICATIONS FOR CANCER SURVIVORS: Prostate cancer is the most common visceral cancer in men in the USA. The stratification of prostate cancer risk is currently modeled solely on pathologic prognostic factors including PSA and Gleason Score. Independent of these pathologic prognostic factors, our paper describes the central sociodemographic factor of being single as a negative prognostic indicator. Single men are at high risk of poorer outcomes after prostate cancer treatment. Intriguingly, in our group of patients, race was not a significant prognostic factor. The findings in this paper add to the body of work that describes important sociodemographic prognostic factors that are currently underappreciated in patients with cancer. Future steps will include the validation of these findings in prospective studies, and the incorporation of clinical strategies that identify and compensate for sociodemographic factors that predict for poorer cancer outcomes.