Lymphatic mapping and sentinel lymph node dissection compared to complete lymphadenectomy in the management of early-stage vulvar cancer: A cost-utility analysis

Objective. Sentinel lymph node biopsy (SLNB) is an acceptable method of evaluating groin lymph nodes in women with vulvar cancer. The purpose of this study is to assess the cost and effectiveness of SLNB compared to universal inguinofemoral lymphadenectomy (LND) for vulvar cancer. Methods. A modified Markov decision model was generated to compare two surgical approaches for newly diagnosed, early-stage vulvar cancer: (1) radical vulvectomy + LND and (2) radical vulvectomy + SLNB. Published data were used to estimate survival outcomes, probability of positive lymph nodes and lymphedema. Costs of surgery and radiation and lymphedema therapies were estimated from published data. Lymphedema's effect on quality of life (QOL) was extrapolated from other disease sites and assigned a utility score of 0.84. Multiple sensitivity analyses were performed. Results. SLNB was less costly ($13,449 versus $14,261) and more effective (4.16 quality-adjusted life years (QALYs) versus 4.00 QALYs) than LND. The model was sensitive to the impact of lymphedema on QOL. Unless the impact of lymphedema on QOL was minimal (utility score > 0.975) SLNB dominated LND. Variations in the rate of positive SLNB and probability of lymphedema over clinically reasonable ranges did not alter the results. Conclusions. SLNB is a cost-effective strategy for the treatment of newly diagnosed vulvar cancer, mainly due to the impact of lymphedema on QOL.