The Significance Of Local Treatment Of Primary Lesion In Oligometastatic Prostate Cancer

Objective:To detect the clinical significance of local treatment of primary lesion in oligometastatic patients with prostate cancer.Methods:Clinical data were retrospectively collected and analyzed among 66 patients with metastatic prostate cancer which were initially diagnosed between 2010.01 and 2016.09 in First Affiliated Hospital of Soochow University.These patients were divided into oligometastatic group and multi-metastatic group.Patients with no more than 5 lesions of bone metastases were included in oligometastatic group,others were included in multi-metastatic group.Kaplan-Meier plot was used to evaluate overall survival and Log-rank test was used to evaluate the statistical significance of overall survival between oligometastatic group and multi-metastatic group.Prognostic effects were studied among patients treated with hormone therapy only and patients treated with hormone therapy and local treatment of primary lesion.Results:The median overall survival was 67 months in oligometastatic group and 27 months in multip-metastatic group(P=0.004).During the follow-up period,22 patients were dead(6 in oligometastatic group and 16 in multiple group,20% vs 44%).32 patients progressed to castration resistant prostate cancer,13 in oligometastatic group(43.3%)and 19 in multi-metastatic group(52.8%).In oligometastatic group,the median time of the PSA decreased to the lowest level was 8.5 months in patients treated with androgen deprivation therapy(ADT)only while it was 3.5 months in patients treated with ADT combined with local tremtment of the primary tumor(P=0.024).The median PSA progression-free survivalwas15 months in ADT only group and 25 months in combined tremtment group(P=0.049).The median overall survival was 46.4 months and 69.7 months in the ADT only group and combined treatment group respectively(P=0.181).In multi-metastatic group,the median time of the PSA decreased to the lowest level was 7 months in ADT only group and 5 months in combined treatment group(P=0.118).The median PSA progression-free survival was 9 months in ADT only group and 13.5 months in combined tremtmentgroup(P=0.374).The median overall survival was 19 months and 37 months among ADT only group and combined treatment grop respectively(P=0.560).Conclusions:The oligometastatic prostate cancer patients have longer overall survival than the multi-metastatic prostate cancer patients.Among oligometastatic patients,local treatment of the primary tumor with radical prostatectomy or radiation therapy in addition to androgen deprivation has the effect of fastening PSA decreasing and prolonging PSA progression free survival and may have the overall survival benefit.