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

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.

Three-year interim results of overall and progression-free survival in a cohort of patients with prostate cancer (GESCAP group)

AIMS

To describe the 3-year progression-free survival (PFS), overall survival (OS) and disease-specific mortality in the prospective prostate cancer GESCAP cohort, as well as the progression to castration resistance in patients on hormone therapy.

MATERIAL AND METHODS

Prospective, observational, epidemiological, multicentre study. Of the 4087 patients recruited, 3843 were evaluable. The variables analysed were the risk group (localized, locally advanced, lymph involvement, metastatic), age, prostate-specific antigen (PSA) levels, Gleason score and initial treatment. Kaplan Meier survival analysis, the log-rank test and the Cox model were used to evaluate the survival data.

RESULTS

Three-year PFS was 81.4% and OS was 92.4%. During the 3 years of follow-up, 303 patients died (7.9%), 110 of them (36.3%) due to disease-related causes. The probability of castration resistance for all patients on hormone therapy (n=715) was 14.2%: 5%, 9.9%, 26.1% and 44.4% in localized, locally advanced, lymph involvement and metastatic cancer, respectively (log-rank P<.0001). Patients with metastases had poorer outcomes with respect to PFS, OS, disease-specific mortality and castration resistance. In the multivariate analysis, the Gleason score, PSA and presence of metastases were associated with shorter OS and PFS.

CONCLUSIONS

Our study showed stratification of risk, with a more unfavourable prognosis for patients with metastases. Patients with locally advanced disease differed with respect to those with localized disease due to their higher risk as regards disease-specific mortality. (Controlled-trials.com ISRCTN19893319).