Surgery for lymph node-positive prostate cancer: a second look
Posted Feb 10 2010 12:00am
For many years, the urology group at the Mayo Clinic has argued that surgery is a viable form of treatment for at least some patients with TxN+M0 prostate cancer. A retrospective analysis of data from the Munich Cancer Registry in Germany now seems to confirm this argument.
Engel et al. sought to compare the overall survival (OS) and the relative survival (RS) of lymph node-positive patients who did or did not receive a completed radical prostatectomy (RP). RS was used as an estimate of cancer-specific survival in this study.
The Munich Cancer Registry was able to provide data on 35,629 patients treated for prostate cancer between 1988 and 2007, of whom 1,413 had positive lymph nodes (LNs):
Prostatectomy was abandoned in 456/1,413 of these LN-positive patients.
957/1,413 of these patients underwent RP despite the LN-positive finding.
Detailed analysis was possible based on data from 938 of the LN-positive patients (688 of whom received an RP and 250 of whom did not). For these patients, complete data included their age at the time of surgery, clinical stage, cancer grade, PSA levels, number of positive LNs, and length of surgery.
The results of the analysis on these 938 patients showed the following:
Median follow-up was 5.6 years.
For the patients in whom RP was completed,
For the patients in whom RP was not completed,
There was an imbalance in the numbers of positive LNs:
Despite the imbalance in the propostions of patients with 4 or more LNs, however, multivariate analysis clearly showed that completion of RP was a strong independent predictor of survival (hazard ratio = 2.04), and the authors conclude that “the abandonment of RP in node-positive cases may not be justified.”
Historically, positive LN status has been considered by most urologic surgeons to be a “systemic” disease state, implying the presence of micrometastases throughout the patient’s body. This may well have been the case for many patients in the pre-PSA era. However, in the PSA era it may now be the case that positive lymph nodes are, in many cases, an advanced form of localized disease that is amenable to surgical treatment for many patients. The question today is perhaps more about exactly how many positive lymph nodes the surgeon would need to find before he decided to abort an operation.