Background
Phase III RCT (GOG 37). 114 patients with T2–T3 squamous cell carcinoma of the vulva who had positive inguinal lymph nodes after radical vulvectomy and bilateral inguinal-femoral lymphadenectomy. Randomized to adjuvant pelvic lymph node resection vs bilateral groin and pelvic irradiation. This trial established the standard approach to management of lymph node-positive vulvar cancer after radical surgery.
Interventions and follow up
Arm A: Pelvic lymph node resection (ipsilateral pelvic lymphadenectomy)
Arm B: Bilateral groin and pelvic irradiation (47.5 Gy to bilateral groins and pelvis)
Primary endpoint: Overall survival
mFollow up: Initial report (Homesley 1986): median ~34 months; Long-term update (Kunos 2009): median ~74 month
Arm B: Bilateral groin and pelvic irradiation (47.5 Gy to bilateral groins and pelvis)
Primary endpoint: Overall survival
mFollow up: Initial report (Homesley 1986): median ~34 months; Long-term update (Kunos 2009): median ~74 month
Results
2-year OS: 68% RT vs 54% surgery, P=.03
OS benefit greatest in bilateral LN+ patients: 72% RT vs 37% surgery
Groin recurrence: 5% RT vs 24% surgery arm
5-year OS (Kunos 2009 update): ~41% RT vs ~32% surgery
OS benefit greatest in bilateral LN+ patients: 72% RT vs 37% surgery
Groin recurrence: 5% RT vs 24% surgery arm
5-year OS (Kunos 2009 update): ~41% RT vs ~32% surgery
Adverse events
Main adverse events: RT arm: significant short-term skin reactions and bowel effects during treatment. Long-term: leg edema in both arms (lymphadenectomy-related in surgery arm, radiation-related in RT arm). No significant difference in long-term toxicity between arms. Wound morbidity was a major concern in the surgery arm.
Conclusions
Adjuvant inguinofemoral and pelvic radiation therapy significantly improves overall survival compared with pelvic lymph node dissection in patients with lymph node-positive vulvar cancer after radical vulvectomy. The benefit is most pronounced in patients with bilateral nodal involvement or ≥2 positive nodes. This trial established adjuvant RT to the groins and pelvis as the standard of care for node-positive vulvar cancer.
Key Limitations
Key Limitations: Small trial (n=114); patients with only 1 micrometastatic positive node may not benefit equally. Modern surgical techniques (sentinel node biopsy) and RT fields have changed since this trial. Pelvic lymph node resection is no longer the standard surgical comparator — this comparison was based on the practice at the time. IMRT techniques now allow improved normal tissue sparing in adjuvant RT vs the 4-field technique used in this trial. Quality-of-life data not reported.
Clinical Context
GOG 37 remains the foundational trial establishing inguinofemoral-pelvic adjuvant RT as standard of care for LN-positive vulvar cancer. Current NCCN guidelines recommend adjuvant RT (with concurrent cisplatin in most cases) to bilateral groins and pelvis for patients with ≥2 involved lymph nodes, extracapsular extension, or positive margins after surgery. For 1 microscopically positive node without ECE, the benefit is less certain and management is individualized. GROINSS-V II has now demonstrated that inguinofemoral RT alone (without dissection) can also manage sentinel node-positive patients.
References