In an issue of ONCOLOGY, there was a review of the literature provides us with a comprehensive review of the limited literature on management of men with prostate cancer who have pelvic lymph node involvement but no known distant metastatic disease at diagnosis.
Common folklore has been that these men, with limited pelvic lymph node involvement, are considered “incurable” and managed solely with androgen deprivation therapy. However, there are several reasons to consider local treatment of men with lymph node positive prostate cancer with prostatectomy, radiation therapy, or both prostatectomy and radiation.
Based on the literature we need to change our way of thinking and consider local primary treatment as a standard of care as it can prevent symptomatic local progression. The literature shows that multiple retrospective studies demonstrate that in men with lymph node–positive prostate cancer (LN+ PCa) who have had a prostatectomy (surgery) decreased their risk of developing local symptoms, including urinary obstruction, hematuria, and pain.
They found that there are less data for men with LN+ PCa who receive radiation therapy as opposed to surgery. But they did determine that the administration of prostate radiation therapy to men with LN+ PCa improved local control, thereby decreasing the risk of developing local symptoms.
They also determined that the administration of local therapy might delay disease progression. Retrospective studies suggest that both prostatectomy and radiation therapy improve both freedom from the development of metastatic disease and disease-free survival in men with LN+ PCa. They felt that targeting the bulk of the disease in the gland with local therapy might reduce cancer clonogens, extend the androgen deprivation therapy–free interval, and potentially prolong the time to development of castrate-resistant prostate cancer.
In a prospective study evaluating systemic therapy, men who received prior definitive local therapy had a longer time to development of castrate-resistant disease than men who had not received local therapy. Therefore, local therapy may make systemic therapy more effective.
The other important conclusion was that for selected men, administration of local therapy may actually lengthen their survival, a goal we all are interested in achieving.
Many retrospective studies suggest that both prostatectomy and radiation therapy may improve overall survival in men with LN+ PCa, however in order for local therapy to confer a survival benefit, either the man must have no micro-metastatic disease outside the treatment field and the micro-metastatic disease must be controlled by systemic therapy. They found that in those men with uncontrolled micro-metastatic disease their distant metastasis drive their clinical course and their survival.
We are still lacking in high-level evidence, however the existing literature does indicate that select men with lymph node–positive prostate cancer will benefit from local therapy. Local therapy has the potential to prevent symptomatic local progression, extend androgen deprivation therapy–free intervals, prolong the time to the development of castrate-resistant disease, delay the development of metastatic disease, and lengthen disease survival.
We now have to hope that there will be new systemic agents developed that better address micro-metastatic prostate cancer as it can have a very significant effect on the course of some men’s lives.
Oncology Journal,Prostate Cancer, Genitourinary Cancers, July 15, 2013,Hoffman, Kuban