Validation of models predicting lymph node involvement probability in patients with prostate cancer

Analysis of biopsy pathology and risk factors of lymph node metastasis in prostate cancer

OBJECTIVE

To explore the relationship between biopsy pathology and lymph node metastasis in patients with prostate cancer (PCa), and to identify risk factors of lymph node metastasis (LNM).

PATIENTS AND METHODS

Patients diagnosed with prostate cancer were respective screened between Jan 2015 and May 2022. Patients diagnosed PCa via 13-core ultrasound-guided biopsies and underwent radical prostatectomy and lymph node dissection were identified. The clinicopathological characteristics of the patients were recorded. Relationships between LNM and non-LNM were analyzed using chi-square and independent samples t-test. Logistic regression model was fitted to analyze the risk factors of lymph node metastases.

RESULTS

Two hundreds and fifteen patients were included, sixty-seven patients had lymph node metastasis. Gleason scores in LNM group were higher than that in non-LNM group (8.5 ± 0.9 VS 7.5 ± 1.5, p < 0.001), positive biopsy in non-LNM group was significantly lower than that in LNM group (p < 0.001), Binary logistic regression analysis indicated number of positive biopsy and number of removed lymph nodes increased the risks of LNM (odds ratio, OR = 1.28, 95% confidence interval, CI = 1.16-1.42, p < 0.001; OR = 1.11, 95% CI = 1.06-1.17, p < 0.001; respectively). Number of positive biopsy in internal gland but not external gland was significant associated with LNM (OR = 1.66, 95% CI = 1.34-2.06, p < 0.001; OR = 1.19, 95% CI = 0.88-1.61, p = 0.262; respectively). The patients with lymph nodes dissection more than 13 were about four times more likely to detect lymph node metastasis than those fewer than 13 (OR = 3.92, 95% CI = 2.10-7.33, p < 0.001).

CONCLUSIONS

The risk of lymph node metastasis increased with the number of positive prostate biopsy cores, and tumors in the internal gland were more likely to cause lymph node metastasis. In addition, lymph node metastasis was more likely to be found when the number of lymph nodes dissection was greater than 13.

Prognostication in Lymph Node-Positive Prostate Cancer with No PSA Persistence After Radical Prostatectomy

BACKGROUND

This study aimed to create a prognostic model to predict disease recurrence among patients with lymph node involvement but no prostate-specific antigen (PSA) persistence and to explore its clinical utility.

METHODS

The study analyzed patients with lymph node involvement after pelvic lymph node dissection with radical prostatectomy in whom no PSA persistence was observed between 2006 and 2019 at 33 institutions. Prognostic factors for recurrence-free survival (RFS) were analyzed by the Cox proportional hazards model.

RESULTS

Among 231 patients, 127 experienced disease recurrence. The factors prognostic for RFS were PSA level at diagnosis (≥ 20 vs. < 20 ng/mL: hazard ratio [HR], 1.66; 95% confidence interval [CI], 1.09-2.52; P = 0.017), International Society of Urological Pathology grade group at radical prostatectomy (RP) specimen (group ≥ 4 vs. ≤ 3: HR, 1.63; 95% CI 1.12-2.37; P = 0.010), pathologic T-stage (pT3b/4 vs. pT2/3a: HR, 1.70; 95% CI 1.20-2.42; P = 0.0031), and surgical margin status (positive vs. negative: HR, 1.60; 95% CI 1.13-2.28; P = 0.0086). The prognostic model using four parameters were associated with RFS and metastasis-free survival.

CONCLUSION

The prognostic model in combination with postoperative PSA value and number of lymph nodes is clinically useful for discussing treatment choice with patients.

Validation of schedules for optimal prostate-specific antigen monitoring after radical prostatectomy

BACKGROUND

Early detection of biochemical recurrence (BCR) after radical prostatectomy (RP) is crucial for early treatment and improving survival outcomes. The optimal prostate-specific antigen (PSA) monitoring remains unclear, and several models have been proposed. We aimed to externally validate four models for optimal PSA monitoring after RP and propose modifications to improve them.

METHODS

We reviewed the clinicopathological data of 896 patients who underwent robot-assisted RP between 2009 and 2022. We examined all PSA values and estimated the PSA value for four monitoring schedules at each time point in the virtual follow-up. We defined the ideal PSA for BCR detection between 0.2 and 0.4 ng/mL.

RESULTS

During the median follow-up of 21.4 months, 128 (14.3%) patients presented BCR. The original and modified Keio models, National Cancer Center Hospital model, and American Urological Association/American Society for Radiation Oncology model detected BCR in 14 (10.9%), three (2.3%), 12 (9.4%), and 11 (8.6%) patients with PSA >0.4 ng/mL. Most patients experienced BCR detected with PSA >0.4 ng/mL during the first year postoperative. The modification of interval within 6 months postoperative avoided BCR detection with PSA >0.4 ng/mL within the first year postoperative in 8/9 (88.9%), 1/2 (50.0%), 5/6 (83.3%), and 4/4 (100%) for the original and modified Keio models, National Cancer Center Hospital model, and American Urological Association/American Society for Radiation Oncology model, respectively.

CONCLUSION

We validated four models for PSA monitoring after RP to detect BCR and suggested modifications to avoid detections out of the desired range of PSA. These modifications could help to establish an optimal PSA monitoring schedule after RP.

Improved urinary continence recovery after robot-assisted radical prostatectomy with lateral pelvic fascia preservation

The novel technique of lateral pelvic fascia preservation (LPFP) in robot-assisted radical prostatectomy (RARP) has been reported to improve urinary continence recovery. We aimed to investigate surgical and oncological outcomes after RARP using the LPFP technique and compare them with conventional RARP. This study included patients who underwent RARP with and without the LPFP technique. Time to urinary continence recovery was compared between the LPFP and non-LPFP groups using univariate, multivariate, and propensity-score matched analysis. Perioperative and postoperative outcomes were compared between the two groups using univariate analysis. We included 139 patients who underwent RARP, 68 in the LPFP group and 71 in the non-LPFP group. The LPFP technique was associated with a shorter time to urinary continence recovery, a shorter operative time and lower estimated blood loss. Surgical and oncological outcomes, including complications, pathological T-stage, surgical margin status, and biochemical recurrence-free survival, were comparable between the two groups. This study demonstrated that the LPFP technique improves urinary continence recovery and operative times without compromising surgical and oncological outcomes. The use of this technique in patients with clinically localized prostate cancer is recommended.

Comparison of neoadjuvant chemohormonal therapy vs. extended pelvic lymph-node dissection in high-risk prostate cancer treated with robot-assisted radical prostatectomy

We compared the impact of treatment strategies on postoperative complications and prognosis between robot-assisted radical prostatectomy (RARP) plus extended pelvic lymph-node dissection (ePLND) and RARP plus neoadjuvant chemohormonal therapy (NCHT) without ePLND. We retrospectively evaluated 452 patients with high-risk prostate cancer (defined as any one of prostate-specific antigen ≥ 20 ng/mL, Gleason score 8-10, or cT2c-3) who were treated with RARP between January 2012 and February 2021. The patients were divided into two groups: RARP with ePLND (ePLND group) and NCHT plus RARP without ePLND (NCHT group). We compared the complication rate (Clavien-Dindo classification), biochemical recurrence-free survival, and castration-resistant prostate cancer (CRPC)-free survival between the groups. We performed multivariable Cox regression analysis using inverse probability weighting (IPTW) methods to assess the impact of the different treatments on prognosis. There were 150 and 302 patients in the ePLND and NCHT groups, respectively. The postoperative complication rate was significantly higher in the ePLND group than in the NCHT group (P < 0.001). IPTW-adjusted biochemical recurrence-free survival and CRPC-free survival were significantly higher in the NCHT group than in the ePLND group (hazard ratio [HR] 0.29, P < 0.001, and HR 0.29, P = 0.010, respectively). NCHT plus RARP without ePLND may reduce the risk of postoperative complications compared with ePLND during RARP. The impact of treatment strategies on oncological outcomes needs further studies.

Correlation between extended pelvic lymph node dissection and urinary incontinence at early phase after robot‐assisted radical prostatectomy

OBJECTIVES

To investigate the impact of extended pelvic lymph node dissection (ePLND) on urinary incontinence (UI) at early post-surgery robot-assisted radical prostatectomy (RARP).

METHODS

Patients who underwent RARP without cavernous nerve sparing were included between 2014 and 2019. Patient data were obtained prospectively. The associations between ePLND and postoperative urinary continence were defined as a maximum of one daily pad use. International prostate symptom score (IPSS) was examined. Expression of synaptophysin and tyrosine hydroxylase (TH) in perilymph node adipose tissue (PLA) was evaluated by immunohistochemistry.

RESULTS

In total, 186 and 163 patients underwent RARP with and without ePLND. Urinary continence rate at 1 month postoperatively among patients with ePLND was lower than those without ePLND (24.1% vs. 35.1%, p < 0.05), however, not significantly different at 3, 6, and 12 months after RARP (57.4 vs. 62.6%, 73.1 vs. 74.2%, and 83.0 vs. 81.2%, respectively). Total and voiding plus postvoiding IPSS scores at 1 month were higher in patients with ePLND than in those without ePLND (14.5 ± 0.5 vs. 13.6 ± 0.6, 7.0 ± 0.3 vs. 6.2 ± 0.4, respectively, p < 0.05). In univariate and multivariate analyses, larger prostate volume and ePLND were factors associated with an increased UI rate. Among patients who underwent ePLND, synaptophysin and TH-positive nerve fibers were detected in PLA.

CONCLUSIONS

Detection of synaptophysin and TH-immunopositive nerves suggested denervation of sympathetic and peripheral nerves caused by ePLND might be associated with a higher UI rate and poor urinary symptoms at an early stage after RARP.