- The quality of evidence supporting such an approach is very poor.
- The morbidity of such treatment is increased.
- There is clinical and experimental evidence that local therapy may promote new metastases and the growth of micrometastases.
- Local progression is problematic in a relatively low number of patients with M1 PCa.
- Lessons from breast cancer.
Highlighting her recently published review article, she reviewed that there are no randomized data supporting a survival benefit of local therapy and that the available data are drawn from very small numbers of highly selected patients. In general, these studies have found that <3% of eligible patients receive local therapy. In population-based registries, conclusions have differed on the basis of the inclusion of baseline PSA data. In single institution reports, numbers are so low as to preclude multivariable analyses to account for baseline differences between patients who received local therapy and those who did not. Given the powerful influence of selection bias, she argued that differences in the overall fitness of the patients, the burden of metastatic disease, and response to systemic therapy are likely to confound any association between local therapy and survival outcomes.
She then switched focus to the parallel of breast cancer. Similar to the data currently available in metastatic prostate cancer, early observational research suggested a benefit of surgical resection of the primary tumor in patients with stage IV breast cancer. However, when this hypothesis was submitted to a randomized controlled trial, no benefit to such an approach was demonstrated.
The first trial comparing local therapy to no local therapy in metastatic prostate cancer, HORRAD, presented first at the AUA this year, was then summarized. This was a multicenter trial looking at the role of radiotherapy to the primary tumor in addition to ADT in patients with metastatic prostate cancer. This was a convincingly negative study (HR 0.90, 95% CI 0.70-1.14).
Tilki then closed by concluding that local, radical therapy in patients with metastatic disease should be reserved for clinical trials and highlighted the g-RAMPP study that is being run at her institution.
Presented by: Derya Tilki, MD, University Hospital Hamburg-Eppendorf
Read the Opposing Debate: Treatment of High Risk Advanced and M1 Disease: Is There a Role for Treatment of the Primary? (PRO)
Written by: Christopher J.D. Wallis, Urology Resident, University of Toronto @WallisCJD at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA