Incidence of initial local therapy among men with lower-risk prostate cancer in the United States. Miller DC, Gruber SB, Hollenbeck BK, Montie JE, Wei JT, Department of Urology, University of Michigan, Ann Arbor, MI

Background: The frequently indolent nature of early-stage prostate cancer in older men and in men with low- or moderate-grade tumors and the demonstration that the survival benefits of radical prostatectomy are primarily among men younger than 65 years have led to concerns about prostate cancer overtreatment. Methods: Using data from 13 Surveillance, Epidemiology, and End Results registries, we performed a retrospective cohort study of 71,602 men who were diagnosed with localized or regional prostate cancer between 2000 and 2002. We quantified the incidence of initial curative therapy (i.e., surgery or radiation therapy) among men with lower-risk cancers as defined by their limited likelihood of either dying from expectantly managed prostate cancer or achieving a survival benefit from local therapy. Stratified analyses and multinomial logistic regression models were used to quantify the absolute and relative rates of curative therapy among men in various age-grade strata. All statistical tests were two-sided. Results: We identified 24,405 men with lower-risk prostate cancers and complete data for the first course of treatment. Initial curative therapy was undertaken in 13,537 of these men (55%); 81% of treated men received radiation therapy. The likelihood of curative therapy, relative to expectant management, varied statistically significantly among lower-risk age-grade strata (all P < .05). Assuming that initial expectant management is appropriate for all lower-risk cancers, 2564 men (10%) in this population-based sample were overtreated with radical prostatectomy and 10,973 (45%) with radiation therapy. Conclusions: These data quantify a target population for whom greater use of expectant approaches may reduce overtreatment and improve the quality of localized prostate cancer care.