ASCO 2017: Impact of perioperative chemotherapy and radiation for locally advanced penile squamous cell carcinoma

Chicago, IL ( Since penile squamous cell carcinoma (PSCC) is typically equated with orphan tumor status, there are a lack of clinical trials providing definitive evidence for treatment algorithms, particularly in the advanced state. Dr. Hathaway and colleagues presented the results of their study assessing perioperative chemotherapy and radiation for locally advanced PSCC at the genitourinary cancer poster session at the 2017 ASCO annual meeting in Chicago.

The authors used the National Cancer Database (NCDB) to identify patients with locally advanced PSCC from 1998-2011. Inclusion criteria included patients that underwent surgery for PSCC pathologic stage ≥1 with data for receipt of perioperative chemotherapy and/or XRT. There were 418 patients fitting inclusion criteria among which there were 132 patients in the surgery + XRT group, 166 patients in the surgery + chemotherapy group and 120 patients in the surgery + chemotherapy + XRT group. The breakdown by stage included 26 stage I, 78 stage II, 146 stage III, and 137 stage IV. Using multivariable survival analysis, the authors noted that stage was an independent prognostic factor associated with OS (p=0.002), while age (p=0.056) and Charlson comorbidity index (p=0.057) trended towards significance. Importantly, surgery + chemotherapy + XRT was not statistically better than surgery + XRT (HR 1.37, 95%CI 0.94 -2.01) or surgery + chemotherapy (HR 0.83 95%CI 0.59-1.18). Furthermore, surgery + chemotherapy was not associated with significantly different OS compared to surgery + XRT (HR 1.14, 95%CI 0.79-1.65). The strength of this study is that population-level data allow these comparisons to be made despite the rarity of the disease, however limitations include the retrospective nature of study and the inherent selection bias associated with observational studies.

In summary, the authors conclude that with this large study assessing perioperative therapy for locally advanced PSCC, trimodal therapy (surgery + chemotherapy + XRT) did not extend OS compared to dual modality therapy (surgery + chemotherapy or surgery + XRT). Secondarily, the analysis did not confirm whether chemotherapy or radiation should be used for patients undergoing dual modality therapy. We eagerly await the results of the phase II International Penile Cancer Adjuvant Trial (InPACT) to attempt to delineate appropriate concomitant therapy with surgical resection.

Presented By: Amanda Redden Hathaway, University of Alabama at Birmingham Comprehensive Cancer Center, Birmingham, AL, USA

Co-Authors: Charity Morgan, Eddy Shih-Hsin Yang, Gregory Diorio, Philippe E. Spiess, Guru Sonpavde

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

at the 2017 ASCO Annual Meeting - June 2 - 6, 2017 – Chicago, Illinois, USA