Vulvar cancer is usually a squamous cell cancer, most often occurring in older women. It usually manifests as a visible or palpable lesion. Diagnosis is by biopsy. Treatment typically includes excision and lymph node dissection or sentinel lymph node mapping.
Vulvar cancer is the 4th most common gynecologic cancer in the United States; it accounts for 6% of cancers of the female genital tract. In the United States, vulvar cancer will cause an estimated 6470 new cases and 1670 deaths in 2023 (1).
Median age at diagnosis is about 70 years; incidence increases with age.
Vulvar cancer frequently occurs in the labia majora. Less often, vulvar cancer affects the labia minora, clitoris, or vaginal glands. Vulvar cancer usually develops slowly over a number of years. Precancer cellular changes can develop on the surface of the vulvar epithelium (without invasion) over a long period of time. This condition (called vulvar intraepithelial neoplasia [VIN]) can become invasive (cancerous) and so should be diagnosed and treated.
Risk factors for vulvar cancer include
Vulvar intraepithelial neoplasia (VIN)
Cigarette smoking
Immunodeficiency
Squamous hyperplasia
Squamous carcinoma or intraepithelial neoplasia of the vagina, cervix, or anus
Most vulvar cancers are caused by persistent human papillomavirus (HPV) infection. The precursor to vulvar cancer is vulvar intraepithelial neoplasia (VIN).
General reference
1. American Cancer Society: Key Statistics for Vulvar Cancer. Accessed July 14, 2023.
Pathology of Vulvar Cancer
About 90% of vulvar cancers are squamous cell carcinomas; about 5% are melanomas. Others include adenocarcinomas and transitional cell, adenoid cystic, and adenosquamous carcinomas; all may originate in Bartholin glands. Sarcomas and basal cell carcinomas with underlying adenocarcinoma also occur.
Vulvar cancer may spread as follows:
By direct extension (eg, into the urethra, bladder, vagina, perineum, anus, or rectum)
Hematogenously
To the inguinal lymph nodes
From the inguinal lymph nodes to the pelvic and para-aortic lymph nodes
Diagnosis of Vulvar Cancer
Biopsy
Vulvar cancer may mimic sexually transmitted genital ulcers (eg, chancroid), basal cell carcinoma, vulvar Paget disease (a pale eczematoid lesion), Bartholin gland cyst or abscess, or condyloma acuminatum (genital wart). Clinicians should consider vulvar cancer if a vulvar lesion develops in women at low risk of sexually transmitted infections (STIs) or if it does not respond to treatment for STIs.
A dermal punch biopsy using a local anesthetic is usually diagnostic. Occasionally, wide local excision is necessary to differentiate VIN from cancer. Subtle lesions may be delineated by staining the vulva with toluidine blue or by using colposcopy.
Pearls & Pitfalls
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Staging
Staging of vulvar cancer is based on tumor size and location and on regional lymph node spread as determined by lymph node dissection or sentinel lymph node (SLN) biopsy done as part of initial surgical treatment (see table Vulvar Cancer by Stage).
Treatment of Vulvar Cancer
Wide excision and lymph node dissection except when stromal invasion is ≤ 1 mm
Surgery, radiation therapy, and/or chemotherapy for stage III or IV cancer
(See also National Comprehensive Cancer Network (NCCN): NCCN Clinical Practice Guidelines in Oncology: Vulvar Cancer [Squamous Cell Carcinoma].)
Wide (≥ 2 cm margin) radical excision of the local tumor is indicated when the tumor confined to the vulva with no extension to adjacent perineal structures. Lymph node dissection may be done when stromal invasion is > 1 mm but is unnecessary when stromal invasion is ≤ 1 mm. Radical vulvectomy is usually reserved for Bartholin gland adenocarcinoma.
For lateralized lesions ≤ 2 cm, unilateral wide local excision and unilateral SLN dissection is recommended. Lesions near the midline and most lesions > 2 cm require bilateral SLN dissection.
For tumors with extension to adjacent perineal structures such as the urethra, vagina, or anus, a modified radical vulvectomy is indicated independent of tumor size.
Sentinel lymph node biopsy is a reasonable alternative to lymph node dissection for some women with squamous cell vulvar carcinoma. SLN mapping should not be considered if clinical findings suggest cancer has spread to lymph nodes in the groin. For SLN mapping, a tracer (blue dye, technetium-99 [99
Further evaluation of lymph nodes and treatment are based on the results of SLN biopsy or lymphadenectomy. If inguinofemoral nodes are negative, observation is reasonable. If one or more SLNs are positive, treatment depends on the size of the metastasis. For micrometastases (≤ 2 mm), inguinofemoral radiotherapy (50 Gy) is a safe alternative to inguinal lymphadenectomy. For macrometastases in an SLN (> 2 mm), inguinal lymphadenectomy is recommended to prevent isolated groin recurrence, although inguinal lymphadenectomy is associated with significant risks of morbidity, wound complications, lymphedema, and lymphoceles (1). An ongoing, single-arm, prospective phase II trial is evaluating the safety of replacing inguinofemoral lymphadenectomy with chemoradiation (56 Gy) in patients with early-stage vulvar cancer with a macrometastasis (> 2 mm) and/or extracapsular extension in the sentinel node (2).
Treatment references
1. Oonk MHM, Slomovitz B, Baldwin PJW, et al: Radiotherapy versus inguinofemoral lymphadenectomy as treatment for vulvar cancer patients with micrometastases in the sentinel node: Results of GROINSS-V II. J Clin Oncol 39 (32):3623–3632, 2021. doi: 10.1200/JCO.21.00006
2. Gien LT, Slomovitz B, Van der Zee A, Oonk M: Phase II activity trial of high-dose radiation and chemosensitization in patients with macrometastatic lymph node spread after sentinel node biopsy in vulvar cancer: GROningen INternational Study on Sentinel nodes in Vulvar cancer III (GROINSS-V III/NRG-GY024). Int J Gynecol Cancer 33(4):619-622, 2023. doi: 10.1136/ijgc-2022-004122. PMID: 36653060
Prognosis for Vulvar Cancer
Overall 5-year survival rate of vulvar cancer is approximately 70%. Risk of lymph node spread is proportional to the tumor size and invasion depth. Melanomas metastasize frequently, depending mostly on invasion depth but also on tumor size.
Key Points
Most vulvar cancers are squamous cell carcinomas; approximately 5% are melanomas.
Consider vulvar cancers if vulvar lesions, including pruritic lesions and ulcers, do not respond to treatment for STIs or the lesions occur in women at low risk of STIs.
Diagnose vulvar cancer by biopsy, and stage it surgically.
For cancers without distant metastases, use wide local excision, and unless stromal invasion is < 1 mm, do lymph node dissection or sentinel lymph node biopsy.
For cancers with lymph node or distant metastases, treat with a combination of surgery, radiation therapy, and/or chemotherapy.
More Information
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
National Cancer Institute: Vulvar Cancer: This web site provides links to information about causes, prevention, and treatment of vulvar cancer, as well as links to information about screening, statistics, and supportive and palliative care.
