Comorbidity and competing risks for mortality in men with prostate cancer

Accurate estimation of life expectancy is essential for men deciding between aggressive and conservative treatment of prostate cancer. The authors sought to assess the competing risks of nonprostate cancer and prostate cancer mortality among men with differing Charlson comorbidity index scores and tumor risks.

The authors conducted a retrospective study of 1482 men with nonmetastatic prostate cancer diagnosed from 1997 to 2004 at the Greater Los Angeles and Long Beach Veterans Affairs Medical Centers. They performed Kaplan-Meier and competing risks regression analyses to assess survival outcomes.

After a mean follow-up of 6.0 years, 370 (25%) men died from other causes, whereas 44 (3%) died of prostate cancer. At 10 years after diagnosis, men with Charlson scores 0, 1, 2, and 3+ had nonprostate cancer mortality rates of 17%, 34%, 52%, and 74%, respectively. In competing risks regression analysis, each point increase in Charlson score was associated with a 2-fold increase in hazard of nonprostate mortality. Men with Charlson 3+ had 8.5× the hazard of death from other causes, compared with men with the lowest scores (subhazard ratio, 8.5; 95% confidence interval, 6.2-11.7). After stratification by tumor risk, nonprostate mortality rates remained markedly elevated among men with higher Charlson scores, whereas prostate cancer mortality was rare, especially among low-risk and intermediate-risk groups (0.4%, 3%, and 8% for low, intermediate, and high risk, respectively).

Men with the highest Charlson scores should consider conservative management of low-risk and intermediate-risk tumors, given their exceedingly high risk of death from other causes and low risk of prostate cancer mortality.