Is the Recommendation of a Pelvic Lymphadenectomy in Conjunction with Radical Prostatectomy in Prostate Cancer Patients Justified? Report from a Multidisciplinary Expert Panel Meeting

Diagnostic capability of 18F-PSMA PET-MRI and pelvic MRI plus bone scan in treatment-naive prostate cancer: a single-center paired validating confirmatory study

BACKGROUND

Radical prostatectomy with pelvic lymph node dissection for the treatment of high-risk localized prostate cancer (PCa) results in long-term benefits in selected patients. But insufficient sensitivity of conventional examinations which are pelvic MRI and bone scan, limits the diagnosis of bone and lymph node metastasis of PCa. This affects the surgical management strategy of a large number of patients. The purpose of this study was to investigate whether 18F-prostate-specific membrane antigen (PSMA) PET-MRI could improve the clinical detection of PCa metastases compared with the conventional pelvic MRI plus bone scan.

MATERIALS AND METHODS

From April 2020 to April 2023, we prospectively enroled 472 patients with histologically proven PCa in our centre, and 120 patients underwent 18F-PSMA PET-MRI, multiparametric MRI, and bone scan before laparoscopic radical prostatectomy plus lymph node dissection. The accuracy of imaging results in detecting lymph node and bone metastatic lesions was compared between PSMA PET-MRI and MRI plus bone scan.

RESULTS

In diagnosing lymph node metastasis, PSMA PET-MRI had an area under the curve (AUC) of 0.844 (95% CI: 0.738-0.949, P < 0.001), sensitivity and specificity of 75% and 96%, which performed apparently better than MRI [AUC=0.615 (95% CI: 0.480-0.750, P =0.073)]. PSMA PET-MRI showed excellent expression in the diagnosis of bone metastases, with an AUC of 0.910 (95% CI: 0.840-0.981, P <0.001) compared to 0.700 (95% CI: 0.577-0.823, P =0.001) in bone scanning. PSMA PET-MRI also had higher sensitivity than bone scanning (90% vs. 43%), while lower specificity (92% vs. 97%).

CONCLUSION

PSMA PET-MRI is superior to conventional imaging at diagnosing metastases in lymph nodes and bones in PCa and can provide a more accurate stagement.

Pelvic lymph node dissection in prostate and bladder cancers

Prostate cancer and bladder cancer accounts for approximately 13.5% and 3% of all male cancers and all newly diagnosed cancers (regardless sex), respectively. Thus, these cancers represent a major health and economic burden globally. The knowledge of lymph node status is an integral part of the management of any solid tumor. In the urological field, pelvic lymph node dissection (PLND) is of paramount importance in the diagnosis, management, and prognosis of prostate and bladder cancers. However, PLND may be associated with several comorbidities. In this narrative review, the most recent updates concerning the patterns and incidence of lymph node metastasis, the role of different imaging studies and nomograms in determining patients' eligibility for PLND, and the anatomical templates of PLND in urologic patients with bladder or prostate cancer will be discussed.

Association of lymph node yield with overall survival in patients with pathologically node negative prostate cancer

We investigated the association between lymph node yield (LNY) with overall survival (OS) and post-radical prostatectomy (RP) secondary treatments among men with pathologically node negative (pN0) prostate cancer. We reviewed the National Cancer Database for men with Gleason Grade Group 2 or higher prostate cancer treated with RP and had pathologically node-negative disease. LNY was modeled as a continuous and categorical variable grouped by quartiles of LNY. Secondary treatment was defined as the use of radiation or systemic therapy post-RP. Multivariable Cox proportional hazards and logistic regression models were used to test for an association of LNY with OS and secondary treatments, respectively. We identified 89,416 men with pN0 prostate cancer treated with RP from 2010-2015. LNY was associated with improved OS when modeled as a categorical and continuous variable. The third (6-9 nodes) and fourth (≥10 nodes) quartiles of LNY were associated with improved OS (HR 0.87, 95% CI 0.79-0.96, P = 0.006 and HR 0.88, 95% CI 0.79-0.98, P= 0.017, respectively) when compared with the lowest quartile of LNY (≤3 nodes) and the hazard of death decreased by 1% for each benign lymph node removed (HR 0.99, 95% CI 0.98-0.99, P= 0.022). Additionally, categorical and continuous LNY was associated with significantly less use of post-RP secondary treatments. Removal of additional negative lymph nodes was associated with improved OS and less secondary treatments in patients with pN0 prostate cancer. These data suggest that removing a higher quantity of lymph nodes provides more accurate staging and prognosis.

Cribriform architecture prostatic adenocarcinoma in needle biopsies is a strong independent predictor for lymph node metastases in radical prostatectomy

AIM

Lymph node metastases (pN1) at prostatectomy are infrequent but impact prognosis. Traditional prostate nomograms assess age, serum prostatic-specific antigen (PSA), clinical stage, and biopsy parameters to inform decisions on pelvic lymph node dissection. The impact of intraductal carcinoma (IDC) and cribriform pattern 4 (CC) on nodal metastases has yet to be explored.

METHODS

Five hundred forty three radical prostatectomy cases were reviewed for International Society of Urological Pathology (ISUP) grade, CC/IDC, T- and N-stage. Two hundred seventy five cases had matched biopsies with age, serum PSA, CC/IDC and ISUP grade recorded. The association of CC/IDC with pN1 in both prostatectomy and biopsy settings was assessed using Fisher's exact test, as well as univariable (UVA) and multivariable (MVA) logistic regression.

RESULTS

In 543 men in whom a prostatectomy was performed, a nodal dissection was also available in 340 (63%), and 37 (10.9%) of them had pN1 disease. ISUP grade, stage and CC/IDC were significantly associated with pN1 (p < 0.001). UVA regression showed grade (p < 0.001, odds ratio [OR]: 5.85), CC/IDC (p = 0.003, OR: 14.06) and T stage (p = 0.004, OR: 61.94) associated with pN1 as did MVA regression: grade (p = 0.010, OR: 2.81), CC/IDC (p = 0.015, OR: 5.12) and T stage (p = 0.016, OR: 30.38). In 275 patients with matched biopsies, a nodal dissection was performed in 197 (71.6%) and 20 (10.2%) patients had pN1 disease. On UVA regression, grade (p < 0.001, OR: 6.33), CC/IDC (p = 0.013, OR: 3.28), serum PSA (p = 0.001, OR: 1.08) and age (p = 0.047, OR: 1.07) were significant for pN1 at prostatectomy. All parameters including specifically grade (p = 0.007, OR: 5.35) and CC/IDC (p = 0.018, OR: 4.42) on biopsies predicted for pN1 by multivariate analysis.

CONCLUSION

CC/IDC in prostatectomy and biopsy significantly associates with pN1. Incorporation of CC/IDC status into preoperative nomograms may optimize patient selection for pelvic nodal dissection.