Sobrevida e fatores prognósticos em uma coorte hospitalar de pacientes com câncer de próstata localizado

Abstract

Prostate cancer is the most incident malignant neoplasia among Brazilian men. Currently, great part of these tumors is confined to the prostate at the moment of the diagnosis. However, many tumors is clinically classified as local diseases, actually has already extra-prostatic extension, making the curative therapies ineffective. On the other hand, many patients with cancer without clinical significance are unnecessarily treated, because of the limited prognostic ability of the clinical stage. To determine the 5 and 10 years survival and to evaluate the clinical prognostic factors (pre-treatment) for patients with histologic diagnosis of adenocarcinoma of the prostate, in early clinical stages (I and II), in a hospital cohort of patients treated in the National Institute of Cancer, Rio de Janeiro, registered from 1990 to 1999. Kaplan-Meier survival functions were estimated, using the date of the histologic diagnosis as the initial time of follow-up and, as events, the deaths due to prostate cancer . To evaluate the prognostic factors, the hazard ratios (HR) were calculated, with confidence intervals of 95%, following the Cox s proportional hazards model. The following variables were analyzed as independent prognostic factors: age, color, degree of instruction, year of first treatment, histologic differentiation grade of the biopsy specimens (Gleason), clinical stage and pretreatment PSA. The assumption of proportionality of risks was assessed using Schoenfeld s residuals analysis and, the influence of outliers in the model fitness, was addressed using martingale and score residuals. The study s cohort included 258 patients with the study s eligibility criteria, of which 46 had died during the follow-up time. The overall survival rate was of 88% for 5 years and 71% for 10 years. Age of 80 years or more, Gleason score higher than 6, PSA levels higher than 40ng/ml, B2 stage and white race were independent makers of bad prognosis. Classics prognostic factors were useful in the estimate of the prognostic in this cohort. The study s results showed that, for patients diagnosed in early stages, the socio-economic factors analyzed did not influence the prognostic. Other studies must be carried out, in the country, in order to investigate the differences in the prognostic in relation to the ethnicity.