Login to Access Video or Poster Abstract: MP80-05
Sources of Funding: None

Introduction

Due to the rarity of penile cancer, there are no randomized studies evaluating the different treatment modalities for high stage disease. We used the National Cancer Database (NCDB) to determine factors associated with receiving adjuvant radiation and the influence on prognosis in men with Stage III (T1-3, N1-2) penile cancer who underwent inguinal lymph node dissection (ILND)._x000D_

Methods

The National Cancer Database (NCDB) was queried from 1998-2012 to identify men with penile cancer who had pathologic nodal status available. Clinical and pathologic variables associated with adjuvant radiation therapy were examined using chi square testing. Univariate and multivariate logistic regression was used to evaluate odds of receiving adjuvant radiation therapy, while Cox regression analysis evaluated whether adjuvant radiation influenced overall survival._x000D_

Results

A total of 589 patients with stage III disease (T1-3, N1-2) underwent ILND. Adjuvant radiation was given in 23% of patients (N=136). Mean age was 61.8 +/-13.7 years (median age 63, IQR 52-72). Patient age, year of diagnosis, Charlson comorbidity index, insurance status, income, education, stage, grade, tumor size, histology, LVI, extra-nodal extension (ENE), and primary surgery (partial vs. total penectomy) were not associated with receiving adjuvant radiation therapy. Factors associated with adjuvant radiation were higher pathologic nodal stage (OR 1.9, 95%CI 1.1-3.1), greater distance of travel (OR 0.5, 95%CI 0.3-0.9), and treatment in an academic setting (OR 0.5, 95%CI 0.3-0.8). Those receiving adjuvant radiation had a significant improvement in overall survival (HR 0.65, 95%CI 0.43-0.96) in the multivariate Cox regression analysis adjusting for year of diagnosis, age, race, Charlson comorbidity index, stage, grade, nodal status, and primary surgery. This benefit was notably attenuated when limited to N1 disease only (HR 0.86, 95%CI 0.36-2.06) versus to N2 disease only (HR 0.71, 95%CI 0.43-1.18)._x000D_ _x000D_

Conclusions

Use of adjuvant radiation for stage III penile cancer is relatively common in the United States. The primary determinants of adjuvant radiation therapy are related to the proximity to cancer centers and greater nodal burden. We find evidence of a benefit with the use of adjuvant radiation, particularly in those with higher nodal disease burden (N2 vs. N1). As penile cancer remains a rare disease, multi-institutional studies are needed to improve treatment algorithms for high-stage disease._x000D_

Funding

None