Radiation Therapy Compared With Pelvic Node Resection for Node-Positive Vulvar Cancer

Abstract

To report long-term survival and toxicity of radiation compared with pelvic node resection for patients with groin node-positive vulvar cancer. A Gynecologic Oncology Group protocol enrolled 114 patients randomly allocated to postoperative pelvic and groin radiation (45-50 Gy, n=59) or to ipsilateral pelvic node resection (n=55) after radical vulvectomy and inguinal lymphadenectomy. Retrospective analyses for 114 enrolled patients included both risk of progression and death after treatment and assessment of toxicity. Median age was 70 years. Median survivor follow-up was 74 months. The relative risk of progression was 39% in radiation patients (95% confidence interval [CI] 0.17-0.88, P=.02). Fourteen intercurrent deaths occurred after radiation as compared with only two after pelvic node resection, narrowing 6-year overall survival (51% compared with 41%, hazard ratio 0.61 [95% CI 0.30-1.3], P=.18). However, the cancer-related death rate was significantly higher for pelvic node resection compared with radiation (51% compared with 29% at 6 years, hazard ratio 0.49 [95% CI 0.28-0.87], P=.015). Six-year overall survival benefit for radiation in patients with clinically suspected or fixed ulcerated groin nodes (P=.004) and two or more positive groin nodes (P<.001) persisted. A ratio of more than 20% positive ipsilateral groin nodes (number positive/number resected) was significantly associated with contralateral lymph node metastasis, relapse, and cancer-related death. Late chronic lymphedema (16% compared with 22%) and cutaneous desquamation (19% compared with 15%) were balanced after radiation and pelvic node resection. Radiation after radical vulvectomy and inguinal lymphadenectomy significantly reduces local relapses and decreases cancer-related deaths. Late toxicities remained similar after radiation or pelvic node resection. I.