SIU 2017:Use of Radiation for Positive Surgical Margins in Prostate Cancer – argument for adjuvant radiotherapy

Lisbon, Portugal ( Dr. Briganti presented his support for adjuvant radiation therapy for patients with positive surgical margins (PSM) after radical prostatectomy. He began his interesting discussion by pointing out the difficult choice surgeons must face between adjuvant radiotherapy and salvage radiotherapy, for patients after radical prostatectomy exhibiting adverse pathology.

There has been 3 randomized prospective trials trying to answer the question whether adjuvant radiation therapy should be given to patients with PSM or pT3 N0 disease. These include the SWOG 8794, EORTC 22911, and ARO 96-02. A meta-analysis of these studies showed that the data favors giving radiation therapy to these patients with a clear benefit in biochemical recurrence free survival. This is now also incorporated in most ur-oncological guidelines. However, aside from the Bolla trial (EORTC 22911), the other 2 studies did not show a clinical progression free survival benefit or an overall survival benefit from adjuvant radiotherapy. Dr. Briganti thinks this is due to the inclusion of patients with favorable cancer features, and over treatment of healthy men in this studies.

Both the ARO and EORTC trials shows that patients with PSM benefitted the most from adjuvant radiotherapy. But Dr. Brignati argues that this does not mean that all patients with all types of PSM should receive adjuvant radiation, as not all PSM are equal. It has been shown that the anterior and base PSM are the worst with a 5 year BCR of 80% and 100% respectively. Moreover, multifocality of PSM is also a significant risk factor. Additionally, it has been shown that the margin length and the Gleason score of the tissue at the PSM are also considerable risk factors. Studies have shown that if a patient has 2 of the 3 following pathological risk factors: seminal vesicle invasion, lymph node invasion or Gleason score of 8 and above, adjuvant radiotherapy will significantly improve cancer specific survival.

Dr. Briganti also mentions the novel genetic tests that are currently available to identify adverse pathology after radical prostatectomy in order to find which patients would benefit from adjuvant radiation therapy, namely the Decipher test.

Dr. Briganti concluded his excellent talk recommending that administration of adjuvant radiotherapy is critical to the appropriate patients with the proper pathological adverse features. 

Presented by: Alberto Briganti

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre.Twitter: @GoldbergHanan at the 37th Congress of Société Internationale d’Urologie - October 19-22, 2017- Lisbon, Portugal