GOG 173 Study
Lymphatic Mapping and Sentinel Lymph Node Biopsy in Women With Squamous Cell Carcinoma of the Vulva: A Gynecologic Oncology Group Study
Is it safe to do sentinel lymph node biopsy as a replacement for inguinal femoral lymphadenectomy in selected women with vulvar cancer.
Type of study
prospective multi-institution validation trial
Sentinel lymph node biopsy vs inguinal femoral
Experimental arm (Intervention)
Sentinel Lymph Node Biopsy (SLN)
Negative predictive value of a sentinel groin lymph node
- Tumour at least 2 cm and no more than 6 cm. Depth at least 1 mm.
- Tumour confined to vulva.
- Good performance status and able to undergo surgery.
Women who had:
- Prior groin irradiation
- Prior groin dissection
- Multifocal disease
- Recurrent vulvar cancer
- Grossly inflamed tumor were excluded.
With lymph node metastasis
Identified by immunohistochemistry
23% of TP cases
- 515 patients accrued. 452 had SLN mapping.
- 320 had bilateral SLN and 132 had unilateral SLN.
- Analysis available for 418 patients.
- Metastasis detected in 132/418 = 31.6%.
- Of the 132 node-positive women, 11 had false-negative findings on SLN (8.3%; 90% CI, 4.7% – 13.4%).
- The sensitivity was 91.7%, and the false negative predictive value was 3.7%.
- For women with tumors smaller than 4 cm, the false-negative predictive value was 2.0%, and for women with tumors 4 to 6 cm, the false-negative predictive value was 7.4%.
- Sentinel lymph node biopsy is a reasonable alternative to inguinal femoral lymphadenectomy in selected women with squamous cell carcinoma of the vulva.
- Women with primary tumours smaller than 4 cm who can be counselled preoperatively that if the SLN is negative, they have a less than 3% risk of a groin relapse due to a false-negative SLN.
- The study took longer to complete than anticipated (1999-2009).
- The false-negative rate might have been lower if surgeon skill verification had been required
- The rate of performance of immunohistochemical analysis was much lower than required by the protocol.
- Preoperative imaging was not required.
- The management of women with positive findings on SLN was not addressed in this study.