Objective: To determine if adjuvant radiotherapy improves the survival of women with invasive squamous cell carcinoma of the vulva involving one inguinal node.
Methods: Demographic, pathologic, and treatment information was obtained on patients with vulvar cancers from the Surveillance, Epidemiology, and End Results database between 1988 and 2001. Kaplan-Meier estimates and Cox-proportional hazards model were used for analyses.
Results: Of the 490 patients with stage III, node-positive vulvar cancers, 208 had a single positive inguinal node. The median age of this group was 71 years (range: 29-100). 82.2% of patients were White, 7.2% were Hispanic, 7.7% were Black, 1.4% were Asian, and 1.4% were Others. 91.8% of patients underwent a radical vulvectomy with a unilateral or bilateral inguinal lymphadenectomy. The median number of lymph nodes resected was 13 (range: 1-34). 102 women underwent adjuvant radiotherapy, while 106 did not receive any radiation treatment. Women who received adjuvant radiotherapy had a 5-year disease-specific survival of 77.0% compared to 61.2% in those without radiotherapy (p=0.02). After stratifying the study group based on the extent of lymphadenectomy, we found that radiation treatment improved the survival of those with <or=12 lymph nodes removed (76.6% versus 55.1%, p=0.035). In those with more than 12 nodes resected, radiotherapy increased the survival from 66.7% to 77.3%, though this difference was not statistically significant (p=0.23). In multivariate analysis, younger age (p=0.01) remained as a significant prognostic factor for improved survival; however, adjuvant radiotherapy had a borderline significance (p=0.06).
Conclusion: Our data suggest that adjuvant radiotherapy may improve the disease-specific survival of patients with single-node-positive vulvar cancer who underwent a less extensive lymph node resection (<or=12 nodes removed).