What are the management options for a patient with localized, early-stage vulvar cancer?

Management of Localized, Early-Stage Vulvar Cancer

For early-stage vulvar cancer, surgery is the cornerstone of treatment, with the specific approach determined by depth of invasion and tumor location relative to the vulvar midline—microinvasive disease (≤1 mm invasion) requires only wide local excision without lymph node evaluation, while deeper invasion (>1 mm) mandates radical local excision or modified radical vulvectomy with tailored inguinofemoral lymph node assessment. 1, 2

Stage IA Disease (≤1 mm Stromal Invasion)

• Wide local excision alone is sufficient for tumors with ≤1 mm stromal invasion, as the risk of lymph node metastases is <1%. 1, 2
• No lymph node evaluation is required for these microinvasive lesions. 1, 2
• Surgical margins should be 1-2 cm of grossly normal tissue with resection to the deep fascia or minimum 1 cm tissue depth. 1
• Critical pitfall: If final pathology reveals >1 mm invasion, additional surgery for lymph node assessment becomes mandatory. 1, 2

Stage IB-II Disease (>1 mm Stromal Invasion)

Primary Tumor Resection

• Radical local excision or modified radical vulvectomy is recommended, targeting 1-2 cm margins with resection depth to the urogenital diaphragm. 1, 2
• Modern surgical technique uses separate incisions for the vulvar tumor and lymph nodes, replacing the historical en bloc approach that caused excessive morbidity without improving survival. 1, 2, 3
• Margin status is a critical prognostic factor: 4-year recurrence-free rates are 82% for negative margins, 63% for close margins, and 37% for positive margins (P=0.005). 1

Lymph Node Assessment Strategy: Location Determines Laterality

The tumor's relationship to the vulvar midline is the critical decision point for lymph node evaluation:

• Lateral lesions (≥2 cm from midline): Ipsilateral inguinofemoral lymph node evaluation only. 1, 2, 4

  • A negative unilateral lymphadenectomy carries <3% risk of contralateral metastases. 1

• Midline or near-midline lesions (<2 cm from midline): Bilateral inguinofemoral lymph node evaluation is mandatory due to risk of contralateral lymphatic spread. 1, 2, 4

Sentinel Lymph Node Biopsy vs. Complete Lymphadenectomy

Sentinel lymph node (SLN) biopsy is the preferred initial approach when specific eligibility criteria are met, as it dramatically reduces morbidity without compromising oncologic outcomes. 1, 2, 4

Eligibility criteria for SLN biopsy (all must be met):

• Unifocal tumor <4 cm in diameter 1, 2, 4
• Clinically and radiologically negative groin nodes 1, 2, 4
• No previous vulvar surgery that disrupted lymphatic drainage 1, 2, 4
• High-volume surgeon available with experience in SLN technique 1

Technical requirements:

• Dual tracer technique (technetium-99m radiocolloid plus blue dye) provides optimal detection sensitivity. 1, 2, 4
• Radiocolloid is typically injected 2-4 hours prior to surgery. 1
• If SLN is not detected intraoperatively, proceed immediately to complete inguinofemoral lymphadenectomy. 1, 4

Morbidity comparison:

• Complete inguinofemoral lymphadenectomy: 30-70% risk of lymphedema, 20-40% risk of wound complications 1, 4
• SLN biopsy: approximately 5% risk of lymphedema 4

Critical pitfall: Do not perform SLN biopsy if tumor is multifocal or >4 cm—proceed directly to complete lymphadenectomy. 1, 2, 4

Adjuvant Therapy Based on Nodal Status

Node-Negative Disease

• Observation is appropriate for patients with negative lymph nodes and adequate surgical margins. 1
• Adjuvant external beam radiation may be considered based on other primary risk factors: lymphovascular invasion, close margins (<8 mm), large tumor size, or depth of invasion. 1

Node-Positive Disease

Postoperative radiation therapy to the groins is mandatory for all node-positive patients, as this significantly decreases recurrence and improves both relapse-free and overall survival. 2, 4, 5

• Radiation dose: 50.4 Gy in 1.8 Gy fractions for adjuvant therapy. 2
• Concurrent chemotherapy should be added for high-risk features: multiple positive nodes, extranodal extension, or bulky nodal disease. 2, 4
• Chemotherapy options include cisplatin alone, 5-FU + cisplatin, or 5-FU + mitomycin C. 2
• Timing: Initiate adjuvant treatment within 6-8 weeks post-surgery once adequate healing is achieved. 2, 4

Special consideration for SLN micrometastases:

• Patients with SLN metastasis ≤2 mm can be treated with postoperative radiotherapy alone (2-year isolated groin recurrence rate of 1.6% in GROINSS-V II study), avoiding the morbidity of complete lymphadenectomy. 5
• Patients with SLN metastasis >2 mm should undergo completion inguinofemoral lymphadenectomy followed by postoperative radiotherapy, as radiotherapy alone results in unacceptably high 2-year groin recurrence rates (22%). 5

Management of Positive or Close Margins

• Positive margins for invasive disease: Re-excision is preferred if feasible; if not possible, adjuvant external beam radiation is recommended. 1
• Close margins (<8 mm): The evidence regarding re-resection versus adjuvant radiation is equivocal, but margins ≤5 mm are associated with highest recurrence risk. 1
• The risk-benefit ratio of re-excision versus radiation must be individualized based on anatomic location and potential morbidity. 1

Radiation Technique Considerations

• 3D conformal or IMRT should be used to ensure adequate coverage while minimizing toxicity. 2
• Brachytherapy boost can be utilized for anatomically amenable primary tumors. 2
• Minimize treatment breaks and aggressively manage acute toxicities to maintain treatment efficacy. 2

Imaging for Initial Staging

For early-stage disease (tumor ≤2 cm, confined to vulva/perineum, ≤1 mm invasion), imaging is usually not appropriate. 1

For tumors >2 cm but ≤4 cm with >1 mm invasion:

• MRI pelvis without and with IV contrast is usually appropriate to define extent of primary tumor and assess inguinofemoral lymph node basins. 1
• MRI has superior soft-tissue contrast and multiplanar capability for evaluating local extent. 1

Common Pitfalls to Avoid

• Never omit lymph node evaluation in stage IB-II disease—the risk of lymphatic metastases exceeds 8%. 1, 4
• Do not use primary groin radiation instead of surgical lymph node assessment in early-stage disease—this results in higher groin recurrence rates despite lower morbidity. 4
• Avoid performing SLN biopsy in patients with clinically suspicious groin nodes—proceed directly to complete lymphadenectomy. 1, 2
• Do not perform en bloc radical vulvectomy—the modern separate incision technique reduces morbidity without compromising survival. 1, 2, 3
• If any grossly enlarged or suspicious nodes are encountered during unilateral lymphadenectomy, evaluate by frozen section intraoperatively to determine need for contralateral dissection. 1