Impact of age at diagnosis on prostate cancer treatment and survival

Abstract

Purpose: Older men are more likely to be diagnosed with high-risk prostate cancer and to have lower overall survival. As a result, age often plays a role in treatment choice. However, the relationships among age, disease risk, and prostate cancer-specific survival have not been well established.

Patients and methods: We studied men in the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) database with complete risk, treatment, and follow-up information. High-risk patients were identified by using the validated Cancer of the Prostate Risk Assessment (CAPRA) score. Competing risks regression was used to identify the independent impact of age on cancer-specific survival. We also analyzed the effect of local treatment on survival among older men with high-risk disease.

Results: In all, 26% of men age ≥ 75 years presented with high-risk disease (CAPRA score 6 to 10). Treatment varied markedly with age across risk strata; older men were more likely to receive androgen deprivation monotherapy. Controlling for treatment modality alone, or for treatment and risk, age did not independently predict cancer-specific survival. Furthermore, controlling for age, comorbidity, and risk, older men with high-risk tumors receiving local therapy had a 46% reduction in mortality compared with those treated conservatively.

Conclusion: Older patients are more likely to have high-risk prostate cancer at diagnosis and less likely to receive local therapy. Indeed, underuse of potentially curative local therapy among older men with high-risk disease may in part explain observed differences in cancer-specific survival across age strata. These findings support making decisions regarding treatment on the basis of disease risk and life expectancy rather than on chronologic age.

Fig 1.

Distribution of disease risk by age at diagnosis. Proportion of patients in each risk category are given by age stratum; risk is defined by validated groupings of the Cancer of the Prostate Risk Assessment (CAPRA) scores 0 to 2, 3 to 5, or 6 to 10.

Fig 2.

Distribution of treatment modality by Cancer of the Prostate Risk Assessment (CAPRA) risk score and by age cohort. For patients in each age stratum within each risk group (defined by CAPRA scores 0 to 2, 3 to 5, or 6 to 10), distribution among treatments is given. WW, watchful waiting; RP, radical prostatectomy; Brachy, brachytherapy; EBRT, external-beam radiation therapy; Cryo, cryotherapy; PADT, primary androgen deprivation therapy.

Fig 3.

Unadjusted Kaplan-Meier plots of cancer-specific and overall survival by age stratum.