What is the management of inguinal (groin) lymph nodes in early-stage vulvar cancer?

From the Guidelines

The management of groin lymph nodes in early stage vulvar cancer should prioritize inguinofemoral lymph node evaluation, with sentinel lymph node biopsy being the preferred approach for patients with stage I vulvar cancer and unifocal tumors not involving the midline, as it results in decreased postoperative morbidity without compromising detection of lymph node metastases, as supported by the most recent guidelines from the National Comprehensive Cancer Network 1.

Key Considerations

• The standard primary treatment of early-stage vulvar cancer involves conservative, individualized tumor excision with inguinofemoral lymph node evaluation, aiming for oncologically appropriate margins of 1 to 2 cm if feasible 1.
• Surgical dissection and radiation therapy have been evaluated for treating the groin in early-stage disease, with limited data suggesting primary groin radiation results in less morbidity than surgical dissection, but surgical treatment of the groin has been associated with lower groin recurrence rates and remains the preferred approach 1.
• Sentinel lymph node biopsy is recommended for patients with negative clinical groin examination and imaging, a primary unifocal vulvar tumor size of <4 centimeters, and no previous vulvar surgery that may have impacted lymphatic flow to the inguinal region, as it reduces postoperative morbidity and accurately assesses lymph node status 1.

Surgical Approach

• For larger tumors (>2 cm), tumors with >1 mm invasion, or midline tumors, bilateral inguinofemoral lymphadenectomy is generally recommended, involving the removal of superficial and deep inguinal lymph nodes through an incision parallel to the inguinal ligament.
• The use of a gamma probe to detect the injected radiocolloid within the inguinofemoral region is recommended prior to making the groin incision, to tailor the location and size of the incision 1.

Postoperative Care

• Postoperatively, patients should be monitored for complications such as lymphedema, wound infection, and wound breakdown, with prophylactic antibiotics given perioperatively, and early ambulation and compression stockings recommended to reduce the risk of deep vein thrombosis.
• The rationale for lymph node management is that lymphatic spread is the primary route of metastasis in vulvar cancer, and nodal status is the most important prognostic factor, guiding decisions about adjuvant therapy while minimizing morbidity associated with unnecessary radical surgery 1.

From the Research

Management of Groin Lymph Nodes in Early Stage Vulvar Cancer

• The management of groin lymph nodes in early stage vulvar cancer has evolved with the use of sentinel lymph node (SLN) biopsy, which has been shown to be a safe and effective alternative to full inguinofemoral lymphadenectomy (IFL) in select patients 2, 3, 4, 5, 6.
• SLN biopsy has been associated with better quality of life, lower morbidity, and improved pathologic evaluation compared to full lymphadenectomy 3, 6.
• The detection rate for SLNB using radiocolloid tracer and blue dye is high, with a per groin detection rate of 87% 5.
• The false negative rate with SLNB is relatively low, at 6.4% 5.
• Recurrence rates with SLNB and IFLD are similar, with rates of 2.8% and 1.4%, respectively 5.

Patient Selection for SLN Biopsy

• SLN biopsy is recommended for women with unifocal tumors <4 cm and clinically non-suspicious nodes in the groin, provided that specific infrastructure and human resource needs are met 5.
• Patients with larger tumors or midline lesions may require caution when undergoing SLN dissection 4.
• The utilization of SLN biopsy is increasing in the management of vulvar cancer, and is associated with superior perioperative outcomes without impacting overall survival 6.

Management of Positive SLN

• For patients with positive SLN, the management approach may vary depending on the size of the metastasis and the presence of other high-risk features 2.
• Micrometastatic disease in the SLN may be managed with radiotherapy, with no recurrences reported in irradiated groins 2.
• Unilateral SLN metastasis may be managed with unilateral groin dissection, with low rates of contralateral groin recurrence 2.