Patients who have vulvar lesions that are greater than 2cm away from the midline can have a unilateral lymph node assessment, while those with lesions within 2cm from the midline, or lesions that involve the anterior labia minora need a bilateral lymph node assessment.
If a patient has a negative SLN, they do not require any further nodal treatment. The isolated groin recurrence risk is 2.5%3.
Management of a positive SLN will depend on the size of the lymph node metastasis. For patients with one micrometastasis (≤2mm) they have the option of either having a full inguinofemoral lymph node dissection in the groin with the positive sentinel node or adjuvant radiation. Both options have a low risk of groin recurrence (around 2%) but the toxicity is higher with a full inguinofemoral lymph node dissection compared to adjuvant radiation4. Patients with one macrometastasis (>2mm) must undergo a full inguinofemoral lymph node dissection in the groin with the positive sentinel node. Radiation is not a safe alternative to full inguinofemoral dissection in patients with a macrometastasis4.
The current consensus is that for midline lesions (<2cm from the midline), it is reasonable to omit a full inguinofemoral lymph node dissection in the
contralateral side to a positive sentinel node when that sentinel node was
negative in that contralateral groin. Lateral lesions (>2cm from the midline)
only need assessment of the ipsilateral groin5.
If a patient is found to have more than one metastasis of any size or there is extracapsular spread6, they should receive adjuvant radiation to both the groins and the pelvic nodes. The risk of pelvic nodal metastasis if there is a positive groin node is 20%.
A recurrence in a previously un-dissected groin is almost universally fatal.
1. The primary vulvar lesion
Locally advanced vulvar cancer refers to FIGO stage III or IV carcinoma of the vulva, with local extension that infiltrates the urinary and or digestive tract or when the tumor is fixed to bone. If primary surgery would result in the need for a bowel or urinary stoma, it is preferable to have these women treated with primary radiation with chemosensitization (chemoradiation) followed by a more limited resection of the residual tumor bed if it is still persistent.
2. The inguinofemoral lymph nodes
a. Clinically normal nodes:
Patients with locally advanced vulvar cancer should have a Pelvic CT or PET/CT to evaluate for any suspicious nodes on imaging. If there are no suspicious nodes on the scan, bilateral full inguinofemoral lymphadenectomy can be performed. If final pathology reveals positive nodes, adjuvant radiation should be given to the groins and pelvis, as per early stage disease.
Alternatively, women with locally advanced disease can be treated with primary chemoradiation to the groins and pelvis.
The decision on whether or not women should have surgical nodal evaluation as compared primary nodal and pelvic radiation should be individualized. On one hand, having a full groin dissection followed by adjuvant radiation places the women at an extremely high risk of chronic lymphedema, however on the other hand, performing a full groin dissection may spare node-negative women (40%) the toxicities of radiation.
b. Bulky, but mobile groin nodes:
Bulky nodes should be biopsied in order to confirm the diagnosis. If there is no ability to biopsy the node preoperatively, an intraoperative frozen section should be performed. If the bulky node is metastatic, surgery should solely entail removal of the bulky nodes as all of these women will require adjuvant groin and pelvic radiation. If the bulky node is inflammatory, a full inguinofemoral lymph node dissection should be performed.
c. Fixed or ulcerated groin nodes:
After having a biopsy to confirm the diagnosis, patients with fixed or ulcerated groin nodes should receive primary chemoradiotherapy to the groins and the pelvis.