Because lymph node metastasis is the single most important prognostic factor for vulvar carcinoma, standard treatment consists of radical tumor removal along with unilateral or bilateral inguino-femoral lymphadenectomy. Biopsy of the sentinel lymph node (SLN) holds promise for identifying the estimated 70% to 80% of patients with early-stage disease in whom lymphadenectomy, with its attendant surgical risks, may not be necessary. This study prospectively compared outcomes in 28 women with early-stage vulvar cancer who had vulvectomy and lymphadenectomy as well as identification of the SLN, and 27 other women in whom no attempt was made to identify the SLN. Women in the SLN group had lymphoscintigraphy in which technetium-99 colloid albumin was injected around the tumor, and also were mapped during surgery using isosulfan blue dye.
This series included 52 patients with squamous-cell carcinoma of the vulva and 3 with malignant melanoma. Sentinel node identification failed in one instance. There was a single false-negative SLN; the procedure was 86% sensitive. There were 9 T1 and 19 T2 tumors in the SLN group. Forty groins were dissected, and 9 positive lymph nodes were found in 7 patients. The number of sentinel nodes detected per patient was 2.2. In the non-SLN group there were 7 T1 and 20 T2 tumors. Forty-nine groins were dissected, and 9 positive nodes were found in 6 patients. Recurrence rates in the SLN and non-SLN groups were 29% and 27%, respectively, during median follow-up intervals of 22.5 months for the SLN group and 60 months for the non-SLN group. There were no recurrences in nondissected groins. Between 25% and 30% of women in both groups had recurrent vulvar cancer.
The authors conclude that an attempt to detect and biopsy the SLN in women with invasive but early-stage vulvar cancer is a helpful way of identifying those in whom disease has not involved the inguinal lymph nodes. It is an appropriate alternative to complete inguino-femoral lymphadenectomy in patients with histologically negative nodes.