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Comparing Radiotherapy With Inguinofemoral Lymphadenectomy in Patients With Vulvar Cancer Who Have Micrometastases in the Sentinel Node
Inguinofemoral radiotherapy is considered a safer treatment option than inguinofemoral lymphadenectomy in patients with vulvar cancer who have sentinel node micrometastases (J Clin Oncol. 2021; JCO2100006. doi:10.1200/JCO.21.00006).
Maaike Oonk, PhD, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands, and colleagues conducted the Groningen International Study on Sentinel nodes in Vulvar cancer (GROINSS-V)-II, which aimed to determine whether inguinofemoral radiotherapy was a safe alternative to inguinofemoral lymphadenectomy in vulvar cancer patients with a metastatic sentinel node.
In the GROINSS-V-II Study, a prospective multicenter phase-II single-arm treatment trial, analyzed patients with early-stage vulvar cancer (diameter < 4 cm) without signs of lymph node involvement at imaging, who had primary surgical treatment (local excision with sentinel node biopsy.
Inguinofemoral radiotherapy was administered (50 Gy) where the metastatic sentinel node (of any size) was involved. Isolated groin recurrence rate at 24 months was the primary end point. Stopping rules were the for the occurrence of groin recurrences.
A total of 1,535 eligible patients were registered between December 2005, and October 2016, with metastasis in 322 of the patients (21%).
The stopping rule was initiated in June 2010 for 91 sentinel node-positive patients due to the isolated groin recurrence rate in this group surpassing the predefined threshold. Nine of the 10 patients with an isolated groin recurrence had sentinel node metastases >2 mm and/or extracapsular spread. Patients with sentinel node macrometastases (>2 mm) received inguinofemoral lymphadenectomy, while the patients with sentinel node micrometastases (≤2 mm) received inguinofemoral radiotherapy.
In the sentinel node micrometastases group, 79% of patients (126 of 160 patients) underwent inguinofemoral radiotherapy, with an ipsilateral isolated groin recurrence rate at 2 years of 1.6%. In the sentinel node macrometastases group, the isolated groin recurrence rate at 2 years was 22% in those who received radiotherapy, and 6.9% in those who received inguinofemoral lymphadenectomy (P = .011). Compared to inguinofemoral lymphadenectomy, treatment-morbidity occurred less often in patients undergoing radiotherapy.
“Inguinofemoral radiotherapy is a safe alternative for IFL [inguinofemoral lymphadenectomy] in patients with SN [sentinel node] micrometastases, with minimal morbidity,” wrote Dr Oonk and colleagues, adding, “For patients with SN [sentinel node] macrometastasis, radiotherapy with a total dose of 50 Gy resulted in more isolated groin recurrences compared with IFL [inguinofemoral lymphadenectomy].”—Marta Rybczynski
