Vulvar Cancer: A Plain-Language Overview

The vulva is the outer genital skin. Cancer that starts there behaves more like a skin cancer than like cancer of the uterus or ovary. More than 90 percent of invasive cases are squamous cell carcinoma. The rest is a short list: melanoma, Paget disease of the vulva, basal cell carcinoma, sarcoma, and verrucous carcinoma.

It is uncommon. The figures on SEER's Stat Facts page for 2026 — 7,130 new cases and 1,750 deaths in the United States — are projections the American Cancer Society makes and SEER publishes. That is 0.3 percent of all new cancer diagnoses. NCI puts it at about 6 percent of cancers of the female genital system. Median age at diagnosis is 70.

This is the fact that reframes everything else, and most overviews skip it. Vulvar squamous cell carcinoma arrives by two separate routes.

The HPV route. It grows out of usual-type vulvar intraepithelial neoplasia, or VIN. VIN means abnormal cells confined to the surface layer. NCI reports that 75 to 100 percent of the basaloid and warty subtypes carry human papillomavirus. This pathway is most common in women younger than 50. Risk climbs with a high number of sexual partners, early first intercourse, and a history of abnormal Pap smears.

The chronic inflammation route. It grows out of differentiated-type VIN, is not driven by HPV, and shows up in older women. The usual background is lichen sclerosus. That is a long-running inflammatory skin condition. It thins and whitens vulvar skin. Years of itching that got treated as a yeast infection is a common history.

Age itself is the single most important risk factor. HPV infection, lichen sclerosus, and prior vulvar dysplasia follow.

Precancer is not harmless. NCI cites a 9 percent progression rate from untreated VIN 3 to invasive cancer. Follow-up in those reports ran 12 to 96 months. Some studies report about 16 percent over 3.9 years.

Invasive squamous cell carcinoma shows up as a vulvar lesion, itching, bleeding, or pain. VIN often causes no symptoms at all and gets found on exam.

The delay problem is real. Itching, a sore that does not heal, and a color change on genital skin all look like things that are not cancer. If a topical treatment has not fixed a vulvar symptom after a reasonable trial, the next step is a biopsy, not a third cream.

Biopsy is the gold standard. Everything else supports it. That means physical and pelvic examination, Pap smear, and HPV testing. It also means colposcopy, which uses a lighted magnifier to inspect the tissue. MRI, CT, and PET-CT come in for staging when the tumor is larger or nodes are a question.

Vulvar cancer is staged with a combined AJCC and FIGO system, and the early stages hinge on measurements you can read off your own pathology report.

• Stage IA requires both a tumor 2 cm or smaller and stromal invasion of 1 mm or less.
• Stage IB is a tumor larger than 2 cm, or invasion deeper than 1 mm.
• Stage II means extension into the lower third of the urethra, vagina, or anus, with negative nodes.
• Stage III is node-positive disease, split by node size. IIIA is for node deposits 5 mm or smaller. IIIB is for larger than 5 mm. IIIC is for extracapsular spread, meaning cancer has broken through the node's outer capsule.
• Stage IVA means fixed to bone, or fixed or ulcerated regional nodes. Stage IVB means distant metastases.

That 1 mm cutoff is measured a specific way. NCI measures from the basement membrane of the deepest adjacent dysplastic rete ridge. The endpoint is the deepest point of invasion. Ask whether your report states this measurement, because it decides whether groin nodes need to be addressed at all.

Tumor size matters less here than most people assume. NCI says prognosis depends on the pathological status of the inguinal lymph nodes. Tumor size, it adds, is less important in defining prognosis.

The stakes are clear in the numbers. Without nodal involvement, overall survival is about 90 percent. With nodal involvement, five-year overall survival falls to roughly 50 to 60 percent. Between 20 and 35 percent of tumors that look confined to the vulva turn out to have node metastases. About 30 percent of operable disease overall does.

This is why sentinel lymph node biopsy matters. Instead of removing the whole groin node bed, a surgeon maps and removes only the first node the tumor drains into. NCI's criteria are specific. The primary must be squamous cell cancer smaller than 4 cm. Groin nodes must be clinically negative. The tumor must be unifocal, meaning one site rather than several. In unifocal tumors the actuarial groin recurrence rate was 2 percent at 2 years. The payoff is less lymphedema and less wound breakdown. Full inguinofemoral lymphadenectomy causes far more of both.

For stages I and II, surgery leads. Wide local excision aims for a 1 cm margin, paired with lymph node assessment. The more extensive option is radical local excision with inguinal and femoral lymphadenectomy. Radiation therapy, alone or combined with surgery, is used in selected cases.

For stage III and IVA, one option is modified radical or radical vulvectomy with lymphadenectomy. Another is neoadjuvant chemoradiation followed by surgery. NCI lists three findings that may call for adjuvant local radiation after surgery: a surgical margin smaller than 8 mm, capillary-lymphatic space invasion, and tumour thickness greater than 5 mm. Where groin nodes are positive, pelvic radiation is an alternative to pelvic node resection; the trial NCI cites used 45 to 50 Gy.

For stage IVB, treatment is chemotherapy, with combinations built from fluorouracil, cisplatin, and mitomycin.

Two other tools appear in NCI's patient version. Imiquimod cream, an immune-stimulating topical, is used for some lesions. Pelvic exenteration, the most extensive surgery, is reserved for advanced local disease.

SEER puts overall 5-year relative survival at 69.7 percent, counting women diagnosed from 2016 through 2022. Break that out by how far the cancer had spread at diagnosis. Localized disease is 58 percent of cases, with 85.5 percent survival. Regional disease is 27 percent of cases, at 51.4 percent. Distant disease is 8 percent of cases, at 20.8 percent.

• Is my cancer HPV-associated or the lichen sclerosus type, and does the pathology say?
• What is the depth of stromal invasion in millimeters?
• Is my tumor unifocal and under 4 cm, which would make sentinel node biopsy an option?
• Were the groin nodes positive, and was there extracapsular spread?
• What margin was achieved, and was capillary-lymphatic space invasion present?
• Is a gynecologic oncologist leading this, and does this center do sentinel node mapping regularly?

See Cancer Staging, Pathology Reports, and Getting a Second Opinion.

• https://www.cancer.gov/types/vulvar/hp/vulvar-treatment-pdq
• https://www.cancer.gov/types/vulvar/patient/vulvar-treatment-pdq
• https://seer.cancer.gov/statfacts/html/vulva.html
• https://www.cancer.org/research/cancer-facts-statistics.html