Comparison of the Prognostic Utility of the Cell Cycle Progression Score for Predicting Clinical Outcomes in African American and Non-African American Men with Localized Prostate Cancer.

BACKGROUND

Better prostate cancer risk stratification is necessary to inform medical management, especially for African American (AA) men, for whom outcomes are particularly uncertain.

OBJECTIVE

To evaluate the utility of both a cell cycle progression (CCP) score and a clinical cell-cycle risk (CCR) score to predict clinical outcomes in a large cohort of men with prostate cancer highly enriched in an AA patient population.

DESIGN, SETTING, AND PARTICIPANTS: Patients were diagnosed with clinically localized adenocarcinoma of the prostate and treated at The Ochsner Clinic (New Orleans, LA, USA) from January 2006 to December 2011. CCP scores were derived from archival formalin-fixed, paraffin-embedded biopsy tissue. CCR scores were calculated as the combination of molecular (CCP score) and clinical (Cancer of the Prostate Risk Assessment [CAPRA] score) components.

INTERVENTION

Active treatment (radical prostatectomy, radiation therapy alone, or radiation and hormone therapy) or watchful waiting.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was progression to metastatic disease. Association with outcomes was evaluated via Cox proportional hazards survival analysis and likelihood ratio tests.

RESULTS AND LIMITATIONS

The final cohort included 767 men, of whom 281 (36.6%) were AA. After accounting for ancestry, treatment, and CAPRA in multivariable analysis, the CCP score remained a significant predictor of metastatic disease (hazard ratio [HR] 2.04; p<0.001), and there was no interaction with ancestry (p=0.20) or treatment (p=0.09). The CCR score was highly prognostic (HR 3.86; p<0.001), and as with the CCP score, there was no interaction with ancestry (p=0.24) or treatment (p=0.32). Limitations include the retrospective study design and the use of self-reported ancestry information.

CONCLUSIONS

A CCR score provided significant prognostic information regardless of ancestry. The findings demonstrate that AA men in this study cohort appear to have similar prostate cancer outcomes to non-AA patients after accounting for all available molecular and clinicopathologic variables.

PATIENT SUMMARY

In this study we evaluated the ability of a combined molecular and clinical score to predict the progression of localized prostate cancer. We found that the combined molecular and clinical score predicted progression to metastasis regardless of patient ancestry or treatment. This suggests that the combined molecular and clinical score may be a valuable tool for determining the risk of metastasis in men with newly diagnosed prostate cancer in order to make appropriate treatment decisions.