Predictors of secondary cancer treatment in patients receiving local therapy for prostate cancer: data from cancer of the prostate strategic urologic research endeavor

Abstract

Purpose: Secondary cancer treatment is common after definitive local therapy for prostate cancer and it may be an indicator of the efficacy and cost of primary local treatment. We determined predictors of secondary cancer treatment in patients initially treated with radical prostatectomy or external beam radiation.

Materials and methods: We examined 2,336 patients in Cancer of the Prostate Strategic Urologic Research Endeavor, a longitudinal registry of patients with prostate cancer, who underwent initial treatment with radical prostatectomy (1,744) or external beam radiation (592). Patients had at least 1 month of followup and all pretreatment information was available. The percent of patients receiving secondary cancer treatment, time to secondary treatment and type of secondary treatment delivered was determined. Multivariate analysis was done to determine independent predictors of secondary cancer treatment. In patients initially treated with prostatectomy a similar analysis was performed to identify predictors of receiving androgen deprivation versus radiation.

Results: A total of 590 patients (25%) received secondary cancer treatment, including prostatectomy in 391 (22%) and radiation in 199 (34%). Secondary cancer treatment was equally divided between radiation and androgen deprivation in 52% and 47%, respectively, of those initially treated with prostatectomy, while 92% initially treated with radiation received androgen deprivation. Predictors of any secondary treatment included patient age, biopsy Gleason score and prostate specific antigen at diagnosis. There was a trend toward increased secondary treatment more than 6 months after local therapy in patients initially treated with radiation. Increased age and lymph node metastases were independent predictors of receiving androgen deprivation after prostatectomy, while there was increased use of radiation in patients with positive surgical margins or extracapsular disease extension.

Conclusions: Secondary treatment differs in patients initially treated with radical prostatectomy and radiation. Pretreatment factors can be used to counsel patients regarding the likelihood of secondary treatment, while age and prostatectomy results appear to determine the type of secondary treatment in those initially treated with prostatectomy.