Prognostic impact of young age on stage IV prostate cancer treated with primary androgen deprivation therapy

Objectives: To elucidate whether the disease characteristics and prognosis of stageIV prostate cancer treated with primary androgen deprivation therapy differ between young and elderly patients. Methods: A total of 3006 patients identified from the database of the Japan Study Group of Prostate Cancer were included in the analysis according to the following entry criteria: age of 75 years or less and stageIV disease. These patients were stratified into three groups: young (aged ≤55 years); middle-aged (aged ≧56 and ≤65 years); and elderly (aged ≧66 and ≤75 years). Their prognoses were analyzed both within age groups and according to whether or not there was metastasis. Results: The proportion of lymph node metastasis was significantly higher in the young group than in the elderly group (P=0.007), and there were no significant differences in other factors among age groups. The overall survival rate at 5 years in the young group was significantly worse than that in the middle-aged and elderly groups (26.6%, 59.7% and 55.3%, respectively) in patients with stageIV disease with metastasis, although there was no difference among age groups in patients with stageIV disease without metastasis. Multivariate analysis showed that younger age was an independent strong prognostic factor in stageIV disease with metastasis. Conclusions: Young men with metastatic prostate cancer have a poor prognosis. Young age is an independent prognostic factor in stageIV metastatic prostate cancer patients treated with primary androgen deprivation therapy.