Background
GROINSS-V I (Groningen International Study on Sentinel Nodes in Vulvar Cancer). Prospective multicenter observational study. N=403, T1–T2N0 squamous cell carcinoma of the vulva (≤4 cm unifocal primary, clinically negative nodes). Sentinel node (SN) biopsy with 99mTc-nanocolloid + blue dye, reserving inguinofemoral lymphadenectomy (IFL) for SN-positive patients.
Interventions and follow up
Treatment: Sentinel node biopsy (99mTc-nanocolloid + blue dye); IFL only if SN-positive
Primary endpoint: Groin recurrence rate in SN-negative patients (safety)
mFollow up: Median 35 month
Primary endpoint: Groin recurrence rate in SN-negative patients (safety)
mFollow up: Median 35 month
Results
SN detection rate: 100% (403/403)
SN-negative groin recurrence: 2.3% (8/345) at median 35 month
Short-term morbidity (wound breakdown + lymphedema): 11.7% SN biopsy vs 40.2% IFL, P<.0001
3-year OS (SN-negative): 97%
SN-negative groin recurrence: 2.3% (8/345) at median 35 month
Short-term morbidity (wound breakdown + lymphedema): 11.7% SN biopsy vs 40.2% IFL, P<.0001
3-year OS (SN-negative): 97%
Adverse events
SN biopsy: Minor wound complications ~7%; no lymphedema in SN-negative patients
IFL (SN-positive, subsequent): Wound breakdown 34%, lymphedema 25%
Blue dye: Allergic reaction 1.4%
IFL (SN-positive, subsequent): Wound breakdown 34%, lymphedema 25%
Blue dye: Allergic reaction 1.4%
Conclusions
Sentinel node biopsy is safe and accurate in T1–T2N0 vulvar cancer — groin recurrence only 2.3% in SN-negative patients with dramatically less morbidity than full IFL. Established SN biopsy as standard of care at experienced centers, replacing mandatory bilateral IFL.
Key Limitations
Non-randomized observational design (IFL comparison vs historical controls). Requires experienced centers (≥10 cases/year). Unifocal lesions ≤4 cm only — not applicable to multifocal or larger tumors. 8/345 groin failures remain a concern for individuals; long-term update (Te Grootenhuis, Gynecol Oncol 2016) confirmed 3-year groin recurrence 2.5%, mostly salvageable.
Clinical Context
Fundamentally changed surgical management of early vulvar cancer; prior bilateral IFL caused severe morbidity in 20–40%. Shift to SN biopsy improved quality of life. GROINSS-V II addressed SN-positive management (inguinofemoral RT vs IFL). ASCO/ESMO/ESGO/SGO guidance endorses SN biopsy for T1–T2N0 unifocal vulvar cancer with negative groins at centers performing ≥10 cases/year.