Characteristics of recurrence in patients who underwent lymphatic mapping for vulvar cancer

Objective. To evaluate patients with vulvar cancer who experienced a recurrence after undergoing lymphatic mapping and sentinel lymph node (SLN) biopsy. Methods. We reviewed the records of 52 patients who underwent vulvectomy and lymphatic mapping with blue dye for treatment of vulvar cancer at our institution from 1993 to 1999 and identified patients who experienced recurrent disease. Results. Fourteen (27%) of 52 patients experienced a recurrence. The patients' median age was 60 years (range 35-84 years). Nine patients had squamous lesions, four patients had melanoma, and one patient had Paget's disease with stromal invasion. Four tumors were stage T1, seven were T2, and three were T3. Eight lesions were located at the midline and six were lateral. Thirteen patients underwent superficial inguinal lymphadenectomy while one patient underwent SLN biopsy only. Postoperatively, seven patients underwent no further treatment, six underwent radiation therapy, and one patient underwent chemotherapy. The median follow-up was 46 months and the median disease-free interval was 21 months. Primary recurrence was in the vulva in eight patients (57%), in the groin in three patients (21%), and distant in three patients (21%). Nine of 32 (22%) squamous lesions recurred, four (57%) of seven melanomas recurred, and the sole patient with invasive Paget's recurred. Patient weight was found to be significantly different between patients who experienced a recurrence and those who did not (P = 0.05). At least one SLN was identified in 46 (88%) of the 52 patients. One (17%) of six patients in whom no SLN was identified experienced a recurrence, and 13 (28%) of 46 patients in whom a SLN was identified experienced a recurrence (P = 0.5). In the 41 patients with negative SLNs and negative non-SLNs, the recurrence rate was 24%; in the six patients with positive SLNs and negative non-SLNs, the recurrence rate was 40%; and in the five patients with positive SLNs and positive non-SLNs, the recurrence rate was 40% (P = 0.6). No patients had a negative SLN and positive non-SLN. Of the three patients who experienced a recurrence in the groin, one had a negative SLN and negative non-SLN, one had a positive SLN and positive non-SLN, and one had no SLN identified and a negative non-SLN. Conclusions. This heterogeneous group of patients who underwent lymphatic mapping with blue dye had similar patterns of recurrence to reported series of patients who did not undergo lymphatic mapping. Groin relapse following a negative SLN biopsy is of concern and suggests that long-term follow-up data are required before lymphatic mapping and SLN biopsy alone can be considered standard treatment for patients with vulvar cancer.