Definitive radiation therapy with or without chemotherapy for vulvar cancer with positive sentinel lymph node

Purpose: To evaluate the patterns of failure and impact of adjuvant radiation therapy with or without chemotherapy on oncologic outcomes for vulvar cancer patients with one or more positive inguinal lymph nodes, without an inguinal-femoral lymphadenectomy.

Methodology: We retrospectively reviewed patients with invasive vulva carcinoma who underwent vulvectomy and sentinel lymph biopsy. We identified patients who were found to have one or more positive inguinal lymph node and received adjuvant radiation therapy, with or without chemotherapy. Patients who received adjuvant therapy at an outside institution were included. The vulva was treated if high risk local features were present. Independent prognostic factors for local recurrence, groin recurrence, and distant metastases including tumor size, depth of invasion, lymphovascular invasion, extranodal extension, and radiation dose were assessed.

Results: From January 2000 to April 2021, 26 patients with invasive vulvar carcinoma and positive sentinel inguinal lymph node(s) received adjuvant radiation therapy at our institution. Median age at diagnosis was 69.5. The most common histology was squamous cell carcinoma (96%) with one of adenocarcinoma. Radiologically suspicious lymph nodes were found in 65% of patients preoperatively, although 23% of patients did not have preoperative imaging. Lymphovascular invasion was present in 5 patients (19%) and extranodal extension was present in 8 of 26 patients (31%). Lymph node size < 5 mm was seen in 8 of 26 patients (31%). Intensity modulated radiation therapy (IMRT) was utilized in 86% of patients. 14 of 26 patients (54%) received chemotherapy concurrently with radiation therapy. Most who received chemotherapy (80%) received weekly cisplatin. With a median follow-up of 21 months, there were 17 of 26 patients (65%) without disease recurrence. 6 patients had local recurrence (23%), 5 had groin recurrence (19%), and 6 had distant metastases (23%). 2 patients (8%) had local recurrence only. Out of the 5 groin recurrences, 3 were contralateral and 2 ipsilateral. One patient had only groin recurrence, as other groin recurrences occurred synchronously with local and distant disease. Of the 12 patients who did not receive chemotherapy, 1 had local recurrence only and 3 had local and groin recurrence synchronously with distant metastases. No ≥ grade 3 toxicity was reported. 76% of patients experienced maximum grade 2 acute toxicities including skin, upper or lower gastrointestinal, genitourinary, and hematologic toxicities.

Conclusions: Adjuvant radiation therapy with or without chemotherapy is a reasonable treatment paradigm for patients with invasive vulva carcinoma with positive sentinel lymph node biopsy without inguinofemoral nodal dissection.

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