[When to introduce hormone therapy after total prostatectomy with positive lymph nodes? Study of the factors influencing the time of introduction of hormone therapy].

INTRODUCTION: Adjuvant hormone therapy is the standard treatment after total prostatectomy with positive lymph node. However, this treatment has side effects and at the time of the PSA era and extensive lymph node dissection, this principle is questioned. The aim of this study is to describe the oncological characteristics of patients that may explain the delay in introducing hormone therapy in patients with positive lymph node.

METHODS: Monocentric, retrospective study of 161 patients from November 1988 to February 2018 in a single French University Hospital, having undergone radical prostatectomy with positive lymph nodes on pathology. For each patient, preoperative data (age, clinical stage, biopsy results, d'Amico classification) and postoperative data (pathological results, number of lymph nodes removed, number of positive lympnodes, recurrence free survival, specific survival and overall survival) were collected. The date of introduction of hormone therapy was noted and survival without hormonal therapy was established according to the Kaplan Meier curve. The pre- and post-operative oncological factors that could influence hormone therapy introduction were investigated with Chi2 and Student tests (statistically significant when P<0.05).

RESULTS: The mean number of lymph nodes removed was 12 [1-40]. The mean number of positive lymph nodes was 2.5 [1-24], the mean percentage of positive lymph nodes was 25% (2.5-100). After a mean follow-up of 95 months (3-354), 88 patients (54.6%) had no hormonal treatment. The average time to hormonal treatment was 40 months [0-310]. At 3 years, survival without hormone therapy was 52% and 51% at 5 years. Only the percentage of positive lymphnodes appeared to be a significant predictor of the introduction of hormone therapy. (29.32% vs. 21.99%, P=0.047). Hormone-free survival was significantly higher in patients with lymph node involvement less than 25% (P<0.0001) or with less than 2 positive lymph nodes (P=0.0294).

CONCLUSION: Lymph node invasion is a factor of poor prognosis after total prostatectomy and leads to introduce hormone therapy. Our study identified the percentage and number of positive lymph nodes as factors that identify patients who may be delayed in introducing this hormone therapy.

LEVEL OF PROOF: 3.