Causes of death in intermediate- and high-risk prostate cancer treated with radiotherapy with or without androgen deprivation therapy: Analysis from two phase III trials.

Abstract

34 Background: The purpose of this analysis was to establish causes of death in a population of intermediate-risk (IR) and high-risk (HR) prostate cancer treated on two phase III trials. Methods: From October 2000 to September 2010, 1,230 patients were randomized: 630 with HR (ClinicalTrials.gov, #NCT00223171) and 600 with IR (#NCT00223145). HR was defined as T3-4, PSA >20 g/ml, Gleason >7 (with at least one of these 3 factors). IR was defined as T1-T2, Gleason < 6 and PSA 10-20 ng/ml or T1-T2, Gleason 7 and PSA < 20 ng/ml. Causes of death were compiled until July 2015 and were established from data sent by the different investigators and centrally reviewed. Causes of death were mainly based on data from clinical records, then by family members, obituaries, death certificates and family physicians. Results: The median follow-up for the 1,230 patients was 7.5 years (HR 8 vs. IR 6.8 years, p<0.001). 30.2% (372/1,230) patients had died: (HR 37% vs. IR 23.2%, p<0.001). A total of 8% (99/1,230) patients developed local, regional, and metastatic prostate cancer recurrences: (HR 11.6% vs. IR 4.3%, p<0.001) and 4.4% (54/1,230) died from prostate cancer: (HR 7.3% vs. IR 1.3%, p<0.001). The most frequent cause of death was a second cancer (120/1,230, 9.8%): (HR 10.6% vs. IR 8.8%, p=NS). Cardiovascular deaths occurred in 6.3% (78/1,230) (HR 7.1% vs. IR 5.5%, p=NS) with no statistical difference between the different durations of androgen deprivation therapy (ADT) 0, 6, 18, or 36 months. Other causes of death were pulmonary (3.7%), digestive (1.1%), others (3.3%), and unknown (1.7%). Majority of deaths occurred between 3 and 9 years after randomization (HR 70% and IR 73%). Prostate cancer deaths were distributed over all the follow-up period. The 5/10 year overall survival between HR and IR were 88.6%, 91.8%, and 61.6%, 69.8%, respectively with significant differences (p=0.045 and p=0.016). Conclusions: In patients with localized HR and IR prostate cancer, the first cause of death was a second cancer and prostate cancer came as the third one after cardiovascular disease. There was no statistical difference in the incidence of cardiovascular deaths in patients treated with different durations of ADT. Clinical trial information: Clinical Trials, gov. #NCT00223145 - Clinical Trials, gov. #NCT00223171.