Disease-Specific Survival in Prostate Cancer Patients : Results from the Scandinavian Prostate Cancer Group (SPCG) Trial No. 5 and Regional Cancer Register Data

Abstract

Introduction Prostate cancer (PCa) is the most common cancer among men in Sweden. The clinical course varies considerably, which makes it difficult to predict the prognosis in the individual case. In order to explore the early as well as the late course of the disease, large study groups and population-based cohorts are necessary. Aims To explore factors that influence the long-term outcome of men with low-risk tumours in a population-based register, to predict the long-term course, and to assess the mortality rate for men with prostate cancer (Paper I) To analyse long-term outcome and to investigate factors associated with long-term survival in patients with metastases to the skeleton (Paper II) To analyse early androgen deprivation treatment (ADT) failure and to define clinical predictors associated with short survival due to early ADT failure in prostate cancer patients with bone metastases (Paper III) To analyse the prognostic significance of the extent of bone metastases in relation to other pretreatment variables in prostate cancer patients, and to explore the impact of bone metastases on quality-of-life (Paper IV) Material and methods The study groups were assembled from The South East Region Prostate Cancer Register (SERPCR), and The Scandinavian Prostate Cancer Group (SPCG) Trial No. 5. In the first study, prognostic factors and long-term disease-specific mortality rates of low-risk prostate cancer patients from the early PSA era were analysed. In the second study, patient-related factors, quality-of-life (QoL) and long-term survival in 915 PCa patients with bone metastases (M1b) under ADT, were analysed. In Study III factors predicting primary failure to respond to ADT were identified. Study IV explored the impact of the extent of bone metastases on survival and QoL for these men. Result and conclusions The long-term disease-specific mortality of low-risk localised PCa is low, but the annual mortality rate gradually increases. This indicates that some tumours slowly develop into lethal cancer, particularly in men 70 years or older and with a PSA level ≥ 4 μg/L. From the SPCG Trial No. 5, a subgroup of patients with M1b disease and favourable set of predictive factors survived more than 10 years under ADT with an acceptable QoL. Independent predictors of long-term survival were identified as performance status (PS) < 2, limited extent of bone metastases, and a PSA level < 231 μg/L at the time of enrolment in the trial. However, four independent clinical predictors of early ADT failure could be defined. Men exhibiting these features should be considered for an alternative treatment. Patient grouping based on three categories of extent of bone metastases related to PS, haemoglobin, and QoL at presentation, as independent predictors of mortality, may provide improved accuracy of prognosis