The Role of Adjuvant Radiation Therapy in Women 70 Years of Age and Older With Node-Positive Vulvar Cancer: A NCDB Analysis

Abstract

Prior studies have demonstrated a survival benefit with the addition of adjuvant radiation therapy in patients with node-positive vulvar cancer after surgery. We sought to evaluate whether the survival benefit of adjuvant radiation therapy after surgery is maintained in elderly patients, who make up a large subgroup of patients with vulvar cancer.The National Cancer Database was queried for patients 70 years of age or older, who were diagnosed with vulvar squamous cell carcinoma from 2004-2017 and underwent surgery with confirmed node-positive disease. Patients with unknown last follow-up date were excluded. Statistical analysis was performed with chi-square test, logistic regression analysis, log-rank test Kaplan-Meier, and multivariable Cox proportional regression modeling.A total of 1,992 patients were analyzed, of which 1,216 (61.0%) received adjuvant radiotherapy with or without chemotherapy. Median follow-up was 73.0 months. Median age at diagnosis was 79 years (range 70-90). Five-year overall survival (OS) for the entire cohort was 28.0%. Five-year OS was 30.9% in patients who received adjuvant radiation and 23.4% in patients who did not receive adjuvant therapy (P < 0.0001). Multivariate analysis demonstrated a survival benefit associated with the addition of adjuvant radiotherapy (HR 0.77 [95% CI 0.69-00.86], P < 0.001) and chemotherapy (HR 0.86 [95% CI 0.77-0.96], P = 0.006). Among patients aged 70-84 years (N = 1555), adjuvant radiotherapy remained associated with improved overall survival (5-year OS 33.6% vs. 25.8%, P < 0.0001). However, in patients aged 85 years and older (N = 437), there was no significant difference in overall survival between patients who received adjuvant radiation versus those who did not receive adjuvant therapy (HR 0.91 [95% CI 0.74-1.12], P = 0.37), (5-year OS 16.8% vs. 18.3%, P = 0.36).The results of this study suggest there is still a survival benefit associated with the addition of adjuvant radiotherapy in older patients with node-positive vulvar cancer treated with surgery. However, this benefit may be limited to patients under 85 years of age, and de-escalating therapy may be appropriate for a subset of elderly patients.L. Ni: None. S. Sinha: None. C. Phuong: None. L. Chen: None. I.J. Hsu: None. E.J. Yoshida: None.