No benefit was found in low-risk patients who underwent pelvic lymph node dissection (PLND).
The extent of pelvic lymph node dissection (PLND) in patients undergoing radical prostatectomy (RP) for prostate cancer does not affect the risk that low-risk patients will experience biochemical recurrence, but it may provide a small benefit in high-risk patients, according to a new report.
Writing in BMC Urology, study authors explained that the therapeutic value of PLND in radical prostatectomy is controversial. Current recommendations suggest performing PLND in high-risk patients if the estimated risk of lymph node involvement is above 5% on preoperative nomograms, the authors noted. In patients with less than 5% risk, PLND is not recommended. Recent studies have offered conflicting insights about PLND, the study authors added. One study found the procedure increased the risk of intra- and postoperative complications, and another study suggested the procedure could reduce micro-metastatic disease. Studies of longer-term outcomes have likewise found mixed results.
The investigators wanted to assess whether the completeness of PNLD reduces biochemical recurrence using their own prospectively collected institutional database. The database yielded 3724 men who underwent RP between 1995 and 2015, all of whom had a minimum of 5 years of follow-up. Patients were excluded if they had been given androgen deprivation therapy or radiotherapy prior to biochemical recurrence.
Sixty-five percent of the patients in the study underwent PLND. Patients were analyzed based on their risk of lymph node invasion using the Briganti Nomogram. A total of 2402 patients were categorized as low-risk (risk below 5%) and 1322 were categorized as high-risk.
At a median follow-up of 79.7 months, a multivariate analysis showed 4 factors were independently associated with biochemical recurrence, which was defined as prostate-specific antigen levels (PSA) above 0.2 ng/mL. Those factors were PSA level, extracapsular extension at RP, positive surgical margin, and positive lymph node on pathology.
In high-risk patients, an increased nodal yield at PLND was linked with a small reduction in biochemical recurrence risk (HR, 0.97; 95% CI, 0.95-1.00; P = .05), but no correlation was found in the low-risk group.
“Previous studies and meta-analyses have reported conflicting results regarding the oncologic benefit of performing PLND, but the weight of evidence is consistent with the findings from our study, demonstrating a consistent lack of benefit in low-risk men and conflicting evidence regarding a weak benefit for ePLND (extended PLND) in high-risk men,” the authors wrote.
They noted some limitations to their study, such as the fact that it was not a randomized controlled trial and that only 12.8% of the men in their dataset who were reported to have undergone ePLND had 10 or more lymph nodes removed, which they said is fewer than would be expected.
“This may at least partially explain our modest (although still statistically significant) reduction in biochemical recurrence) in the high-risk group,” they noted.
The marginal level of benefit from ePLND needs to be weighed against the potential risks associated with the procedure, the authors added. They said earlier research has suggested an increased risk of complications, and they noted that ePLND also adds 60 to 75 minutes to the overall operating time. In addition, there is an “urgent need” for an adequately powered, noninferiority randomized controlled trial comparing ePLND to no PLND in patients with high-risk prostate cancer undergoing radical prostatectomy.
Doan P, Katelaris A, Scheltema MJ, et al. The relationship between biochemical recurrence and number of lymph nodes removed during surgery for localized prostate cancer. BMC Urol. Published online April 28, 2023. doi:10.1186/s12894-023-01228-3