SUO 2017: National Trends in the Management of Patients with Positive Surgical Margin at the Time of Radical Prostatectomy
The authors of this study examine time trends and determinants of adjuvant therapy of men with prostate cancer (PCa) treated with primary definitive RP (2010-2014) using the National Cancer Database (NCDB) – however, the primary survival outcome is overall survival, and others such as biochemical recurrence and cancer-specific survival cannot be captured. Subsequent management strategies were stratified as the following: no adjuvant therapy as part of the initial planned course of management, receipt of adjuvant radiation therapy (RT), and receipt of adjuvant RT in combination with androgen deprivation therapy (ADT). Adjuvant was defined as therapy within 12 months of RP.
They identified 44,523 patients with PSM after RP. Of those, 5,179 (11.6%) men received any adjuvant RT (+/- ADT), while only 1,380 (3%) received adjuvant RT with ADT. The remainder received no adjuvant therapy. Use of adjuvant RT did not change over the study period (p=0.61), so it was quite steady over this 5-year period. However, there was a slight trend upward over this short time frame.
On multivariable analysis, men of uninsured status (p=0.003), Medicaid insurance (p=0.001), and patients treated in non-academic facilities (p<0.001) were more likely to receive adjuvant RT. This is surprising! In addition, use of adjuvant RT was associated with higher pre-treatment PSA (p<0.001), pathologic stage (p<0.001) and Gleason grade group (p<0.001), decreasing distance from the treatment center (p<0.001), and shorter duration between diagnosis and RP (p<0.001). Receipt of adjuvant ADT with RT was associated with clinical and pathologic features; however, not with sociodemographic factors.
It is unclear why the association above was noted. However, it should be noted that they only utilized variables significant on univariate analysis in the multivariable model. Pathologic factors were much more significant (HR 2-4) compared to patient characteristics (HR 0.8-1.2). Hence, it may be a result of the model rather than a true finding.
Limitations / Discussion Points:
1. NCDB - the primary survival outcome is overall survival, and others such as biochemical recurrence and cancer-specific survival cannot be captured. These would be more relevant in the setting of positive surgical margins.
2. Intent of therapy unclear. As they used a 12-month cutoff for defining adjuvant, some of these patients may have actually been salvage.
Presented by: Kamyar Ghabili Amirkhiz, MD
Co-Authors: Kevin A. Nguyen BS¹, Walter Hsiang ¹, Jamil S. Syed MD¹, Alfredo Suarez-Sarmiento MD¹, Brian M. Shuch MD¹, Henry S. Park MD, MPH², James B. Yu MD, MHS² and Michael S. Leapman MD¹
Affiliation: ¹Department of Urology, Yale University School of Medicine, New Haven, CT; ²Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT
Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, twitter: @tchandra_uromd at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC