A preliminary study showed that along with systemic therapies, salvage lymph node dissection (removal) in men with non-metastatic (M0) castration-resistant prostate cancer might delay cancer recurrence.
More research is still needed to confirm this result says Luca Boeri, MD, of Mayo Clinic, Rochester, MN, who presented the results at the 2019 AUA annual meeting in Chicago.
This result is significant because non-metastatic, castration-resistant prostate cancer is a relatively indolent disease, and there is no high-quality evidence to guide clinical decision-making. Currently, the standard of care for men who do not exhibit evidence of bone or visceral metastases are typically managed with observation or ADT.
The retrospective study conducted by Dr. Boeri, working with R. Jeffrey Karnes, MD, and colleagues at Mayo Clinic analyzed men with node-only recurrence who were treated with salvage lymph node dissection or systemic therapies from January 1990 through January 2016. These men underwent a positron emission tomography/computed tomography scan and conventional imaging to detect possible metastases (detected at 11C-choline PET/CT).
Among the men in this cohort, 23 (51%) underwent salvage lymph node dissection for lymph node-only recurrence of castration-resistant prostate cancer, and 22 (48.9%) received systemic therapies (ADT or chemotherapy) for lymph node-only recurrence of castration-resistant prostate cancer.
ADT patients were treated with a different medication—either alone or in combination with the previous ADT drug used—based on the physician’s discretion. All salvage lymph node dissection procedures were performed by a single surgeon between Nov. 1, 2009, and Dec. 31, 2016.
Biochemical recurrence was defined as a PSA greater than 0.2 ng/mL with an increased trend, while radiologic recurrence was described as a positive imaging study or biopsy-proven metastasis after salvage lymph node dissection or systemic therapies.
Median follow-up for the entire cohort was 49.3 months
The results point to the potential for salvage lymph node dissection to be used as a treatment option in men with node-only recurrence of castration-resistant prostate cancer:
• Mean PSA reduction was significantly higher after salvage lymph node dissection than after ADT (62.8% vs. 17.4%).
• Time to PSA nadir was significantly lower in the salvage lymph node dissection group than the ADT group (1.6 months vs. 7.3 months).
• The 5-year cancer-specific mortality rates were 72.7% and 72.3% for salvage lymph node dissection and ADT patients, respectively.
• There was a trend toward a longer time to biochemical recurrence (13.3 months vs. six months) and radiologic recurrence (21.1 months vs. 14.2 months) in salvage lymph node dissection patients than ADT patients.
• The median time to standard systemic therapy was longer in the salvage lymph node dissection group than that ADT group (66.1 months vs. 43.3 months)
However, one limitation of the study—in addition to the small sample size—is that the results are based on traditional imaging techniques.
