Recently there have been a number of conversations in the prostate media around the topic of treating oligometastatic prostate cancer with a curative goal. Oligometastatic prostate cancer describes the disease state where primary treatment has failed as evidenced by an increasing PSA along with scanning evidence of a limited number of lymph nodes involved in and near to the prostate bed.
Because of the development of better scanning technology and scanning contrasts more oligometastatic disease has been identified and so the conversation escalated about their treatment.
The most commonly discussed treatments have involved radiation therapy. In a presentation at the recent meeting of the Society of Urologic Oncology (SUO) Dr. Jeffrey Karnes discussed the possible role of surgery to treat men with oligometastatic disease.
Dr. Carnes confirmed the well-known fact that 33% of men who have primary treatment will ultimately experience a biochemical recurrence, which can be indicative of local or distant relapse. He said that the recently approved scanning technology, C-Choline PET is a useful tool in identifying the specific location of disease and that it has been incorporated in NCCN’s 2014 guidelines. He also confirmed that men with nodal-only metastases have a more favorable prognosis than those with bony or visceral metastases, the hallmark of oligometastatic disease.
Historically, the standard of care for men with oligometastatic disease is hormone therapy (ADT). ADT is not curative and comes with a host of significant side effects. Dr. Karnes pointed out that ADT is associated with much toxicity, negative quality of life changes and the risk that nodal metastases may harbor castration resistant disease.
He posed the fundamental question, can we cure metastatic prostate cancer? Toujer and colleagues demonstrated good survival outcomes in men with oligometastatic disease without hormones, with those having Gleason that is less than 8, negative margins, and fewer than 2 lymph nodes positive having the longest biochemical recurrence-free survival.
Dr. Karnes then reported his initial use of salvage lymph node dissection (surgery not radiation) performed in 2007 on a 60-year-old man who had received as his primary treatment high-dose brachytherapy, with recurrence in a single obturator lymph node. He reported that this man is alive today and has PSA less than 0.2, to date.
This launched the Mayo Clinic series of salvage lymph node dissections, which includes 52 cases, where all men had a radical prostatectomy in the past.
At a median follow-up of 20 months, 24 men had no further therapy, 18 did start ADT, and 10 had multimodal therapy. Twenty-nine patients had PSA less than 0.2, while 8 had biochemical recurrence after PSA originally became less than 0.2. Median time to biochemical recurrence after salvage node dissection was 438 days.
Dr. Karnes acknowledged that there are limitations to his study which include a heterogeneous treatment sample, a short follow-up, selection bias, along with the lack of a comparable control group. However, he concluded that at this time, salvage node dissection remains a valid treatment option in well-selected patients, and that this novel treatment deserves further study. Optimal patients have not been defined, but likely include those with low PSA, pelvic-only lesions, Gleason score less than 8, and longer interval to a recurrence.
Joel T. Nowak, M.A., M.S.W.