Effectiveness of definitive radiotherapy for squamous cell carcinoma of the vulva with gross inguinal lymphadenopathy

Objective: To evaluate the effectiveness and long-term side effects of definitive groin radiotherapy for vulvar cancer with grossly involved inguinal lymph nodes. Methods: The records of 407 women with vulvar squamous cell carcinoma treated with radiotherapy at one institution during 1992–2014 were reviewed to identify patients who had radiographic or histologic evidence of grossly involved inguinal lymph nodes. Patients with lymphadenectomy before radiotherapy and patients treated for recurrent disease were excluded. Actuarial incidences of vulvar, inguinal, and distant recurrences, the relationship between vulvar recurrence and inguinal recurrence, and overall survival were analyzed using the Kaplan–Meier method. Results: Thirty-three patients were identified. The median age at diagnosis was 64 years. The median long-axis radiographic diameter of the largest inguinal lymph node or lymph node mass was 2.5 cm (range, 1.4–8.7). Sixteen patients (48%) also had evidence of pelvic lymph node metastasis. The median radiation dose delivered to grossly involved nodes was 66.0 Gy (range, 60.0–70.0). The 3-year actuarial incidences of vulvar, groin, and distant recurrences were 24.2%, 17.7%, and 30.3%, respectively. With a median follow-up time of 28 months (range, 2–196), four patients (12%) had groin recurrence, of whom three also had vulvar recurrence. There were few major late adverse effects of regional radiotherapy. The 3-year overall survival rate was 51%. Conclusions: High-dose volume-directed radiotherapy achieves a high rate of local control with low risk of serious long-term toxic effects in patients with vulvar squamous cell carcinoma and grossly involved inguinal lymph nodes.