EAU 2017: Is There a Role for Local Treatment of Oligometastatic Disease? Yes

London, England (UroToday.com) Following Dr. Tombal’s introductory talk at the EAU 2017’s “Controversies in Metastatic Prostate Cancer” stating that there was no role for local treatment in the oligometastatic setting, Dr. Martin Spahn from Switzerland provided the rebuttal argument. At a recent meeting in St. Gallen, Switzerland, the Advanced Prostate Cancer Consensus Conference, world experts were asked “In a patient with newly diagnosed oligometastatic disease, do you recommend local treatment of the primary tumor and all metastases instead of systemic treatment?” Interestingly, 61.8% of respondents said that they would recommend this treatment strategy, while 38.2% stated they would do so only in a minority of patients. There were no respondents that said they would never consider this aggressive approach. Certainly, there appears to be a shift in philosophy among prostate cancer thought leaders regarding immediate systemic therapy in these high-risk patients.

Specifically for patients with low volume metastatic disease, Dr. Spahn cites that among patients from three studies (SWOG, MDACC, GETUG15) with mature follow-up, these patients do better with androgen deprivation therapy (ADT) alone, however there are outliers (20-30%) of patients that will die within 3-4 years. In these patients imaging has allowed more sophisticated staging, however as Dr. Spahn notes, for a patient with cT3b disease, PSA >20 and an oligometastatic bone metastases on MRI, several potential treatment strategies may be feasible: (i) local treatment (radical prostatectomy (RP) or radiation therapy + ADT), ignoring the MRI findings of possible bone metastasis, (ii) local therapy + stereotactic RT to the bone lesion + 6 months of ADT, or (iii) ADT + docetaxel. Many patients with de novo metastatic disease may suffer from locoregional symptoms. A recent study assessing 263 men with newly diagnosed metastatic disease, included 82% of men with bone metastases and median PSA at diagnosis of 118 ng/mL [1]. There were 77.9% of patients that had disease-specific locoregional symptoms, most commonly dysuria (51.3%), pelvic pain (46.8%), and acute urinary retention (35.7%). Ultimately, the goal for these patients is to improve survival and quality of life – treatment decisions should be guided accordingly.

Data assessing the role of treatment of the primary tumor in the metastatic setting are largely based on population/registry retrospective cohort studies. The Munich cancer registry experience reported that among 1,538 patients with M1 disease, 74 (4.8%) men underwent RP, conferring a survival advantage comparing to men that did not RP (RP 5-year OS rate 55% vs non-RP 21%, p<0.01) [2]. These results have also been assessed in the SEER-database, with similar findings.

In summary, we have seen hypothesis generating retrospective studies regarding outcomes in treatment of oligometastatic lesions, as well as treatment of the primary tumor in the metastatic setting. Some patients may experience a durable treatment response with minimal side effects, however patient selection is challenging but of the utmost importance. This will be an exciting area of research and debate moving forward.

1. Patrikidou A, Brureau L, Casenave J, et al. Locoregional symptoms in patients with de novo metastatic prostate cancer: Morbidity, management, and disease outcome. Urologic Oncology 2015;33:e9-e17.
2. Gratzke C, Engel J, Stief CG. Role of radical prostatectomy in metastatic prostate cancer: data from the Munich Cancer Registry. Eur Urol 2014;66(3):602-603.

Speaker(s): Martin Spahn, University of Bern, Bern, Switzerland

Written By: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto
Twitter: @zklaassen_md

at the #EAU17 - March 24-28, 2017- London, England