SURVIVAL PATTERNS AMONG CLINICALLY NODE POSITIVE PROSTATE CANCER TREATED WITH RADICAL PROSTATECTOMY

Abstract

Introduction

Recent advancements in prostate cancer diagnostics and the strategic use of advanced imaging have enhanced our ability to accurately stage patients. The 8^th edition of the American Joint Committee on Cancer (AJCC) classification system indicates that the extent of lymph node involvement is associated with more advanced disease stages. This study aims to compare cancer specific survival (CSS) and distant metastasis free survival (MFS) for patients with PCa staged as cN1 or cM1a according to the AJCC classification and treated at a single institution.

Methods

A total of 207 Patients diagnosed with PCa and clinically suspicious lymphadenopathy treated with radical prostatectomy and extended lymph node dissection (eLND) with or without neoadjuvant androgen deprivation therapy (NADT) between October 2007 and September 2022 were retrospectively identified. Patients were classified as either cN1 or cM1a based on the initial staging. The true positivity of the suspected nodes was confirmed either clinically, through pre-operative re-staging after NADT, or through the final pathological examination. The exact extent of the eLND was based on the location of the positive nodes. Exclusion criteria were the presence of bone and/or visceral metastases, salvage prostatectomy, the use of chemotherapy prior to surgery, and false positive cN1 or cM1a patients. Kaplan-Meyer curves and Cox proportional hazard ratios were estimated to compare CSS and MFS. The date of surgery was considered the time 0 for all the endpoints. Distant metastases were defined as the detection of at least one metastasis outside the pelvic lymph nodes and/or the prostate bed.

Results

150 men were classified as cN1, and 57 had at least one retroperitoneal node involved (cM1a). The median age at surgery was 63 years (IQR 58-67). There were no differences between ASA score (p 0.61). Median initial PSA was comparable between the two groups (15.6 ng/ml, IQR 8.35-34.3, p 0.07). Patients in the cM1a group had a higher number of clinically positive nodes (p < 0.001), with a larger median diameter (15 versus 11 mm, p 0.01). Among the cM1a PCa, 26 presented with involvement of common iliac nodes only, while 31 had also other positive retroperitoneal nodes. Most of the patients had a pT ≥ 3b (65.6%), there were no differences in terms of pT stage (p 0.08), pN stage (p 0.79) and final Gleason score (p 0.09) between the two groups. On Cox regression analysis, clinical nodal status was not a statistically significant predictor of MFS even after adjusting for pathological T-stage (HR 1.07, 95%CI 0.66, 1.72, p 0.78). Nodal stage was not a statistically significant predictor of CSS after adjusting for statistically significant predictors (HR1.06, 95%CI 0.46, 2.45, p 0.90).

Conclusions

Radical prostatectomy remains a viable primary treatment option for patients with positive lymph nodes, irrespective of the N stage or the extent of lymph node involvement. Our study shows that radical prostatectomy does not negatively affect distant metastasis-free survival (MFS) or cancer-specific survival (CSS) in patients with cM1a disease.