Patients with prostate cancer who have pelvic lymph node metastases visualized on preoperative PSMA PET/CT staging (prostate-specific membrane antigen positron emission tomography/computed tomography) have a significantly higher risk for biochemical disease progression after robot-assisted radical prostatectomy (RARP) compared with those without pelvic lymph node metastases on imaging, recent study findings suggest.
The retrospective study included 145 patients who underwent PSMA PET/CT lymph node staging prior to RARP and had pelvic lymph node metastases found on extended pelvic lymph node dissection. The median biochemical progression-free survival was 7.9 months among the 49 patients (34%) whose preoperative imaging revealed pelvic lymph node metastases compared with 13.7 months for the 96 patients (66%) whose preoperative imaging did not, Dennie Meijer, MD, of Amsterdam University Medical Center in The Netherlands, and colleagues reported in BJU International.
In addition, the presence of more than 2 tumor-positive lymph nodes, compared with 1-2, was significantly associated with a nearly 2-fold increased risk for biochemical progression, after adjustment for multiple variables. A larger diameter of the largest nodal metastasis was significantly associated with a 12% increased risk.Today’s top picks on the Haymarket Medical NetworkNew Machine Learning Tool to Predict Pneumonia Progression Outperforms PSIAI Can Help Identify Incidental PE on Conventional Chest CT ExamsArtificial Intelligence and the Hunt for Neuroprotection in Glaucoma
The investigators defined biochemical progression as a PSA level of 0.2 ng/mL or higher during follow-up or the initiation of additional treatment.
The median diameter of the largest nodal metastasis was significantly larger among the patients with vs without nodal metastases found on preoperative PSMA PET/CT lymph node staging (6 vs 3 mm).
At final histopathologic evaluation, the median biochemical progression-free survival for patients with 1 or 2 tumor-positive lymph nodes was 14.9 months compared with only 3.9 months for patients who had more than 2 tumor-positive lymph nodes, Dr Meijer’s team reported.
Among patients with nodal metastases visualized on preoperative PSMA PET/CT, only the diameter of the largest nodal metastasis was significantly associated with biochemical progression; the number of tumor-positive lymph nodes was not. Among patients with no nodal metastases seen on PSMA PET/CT, both the presence of more than 2 positive lymph nodes and the diameter of the largest nodal metastasis were significantly associated with biochemical progression.
Meijer D, Ettema RH, van Leeuwen PJ et al. The prognostic value of lymph node staging with prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) and extended pelvic lymph node dissection in node-positive patients with prostate cancer. BJU Int. Published online September 7, 2022. doi:10.1111/bju.15881
The evidence continues to grow that PSMA PET/CT used pre-operatively can predict which patients will relapse and which will not. In this study, investigators looked at a group of 145 patients who had scans and then went on to get surgery. Patients with as few as only 1 or 2 positive lymph nodes on the scan were more likely to have a rising PSA in the future, even when those nodes were removed at surgery. One role of PSMA PET/CT is to spare patients from potentially disabling surgery who are unlikely to have a long term benefit.