Factors related to early castration resistance in metastatic prostate cancer. Results from the National Prostate Cancer Registry in Spain

Abstract

Introduction: The objective of the study was to determine the factors independently related with the development of castration resistance (CR) in prostate cancer (PC) in the medium term.

Material and methods: 155 patients diagnosed with metastatic PC with a follow-up of up to 39 months. Data taken from the National PC Registry. The evaluated variables were age, PSA, nadir PSA, Gleason, perineural invasion, TNM stages, and ADT type (intermittent/continuous).

Results: Mean follow-up 26,2±13,4 months. 47.1% developed early CR, with mean time until onset of 12,2±8,7 months. Univariate analysis the mean PSA was correlated with CR (290±905,1 ng/mL in non CR, 519,1±1437,2 ng/mL in CR, P<.001), mean age (73,3±8,3 years in non CR, 69,1±9,3 in CR P=.01), mean PSA nadir (15,5±57,3ng/mL in non CR, 15,9±23,7 ng/mL in CR, p<0,001), Gleason (in ≥8, HR:2,11. 95% CI: 1.22-3.65, p=0.006), and T stage (in T3-T4, HR: 2.85. 95% CI: 1.57-5.19, P<.001). Multivariate analysis the independent variables associated to CR are age (HR: 0.96. 95% CI: 0.94-0.99, P=.01), PSA nadir (HR: 1.65. 95% CI: 1,43-1,91, P<.001), and T3-T4 stage (HR: 2.11. 95% CI: 1.10-4.04, P=.02).

Conclusions: PSA nadir and T3-T4 tumor stage at diagnosis are associated to an increased risk of developing CR. In addition, age at diagnosis is shown as a variable that decreases risk. Therefore, an older age would be associated with lower risk probability of CR in the medium term.

Keywords: Castration resistance; Cáncer de próstata; Factores pronósticos; Prognostic factors; Prostate cancer; Resistencia a la castración.