Vulvar Cancer Demographics
Vulvar cancer is a rare gynecologic malignancy with an age-adjusted incidence rate of 2.2 per 100,000 women in the United States, occurring predominantly in older women with a median age at diagnosis of 64-67 years, though HPV-associated cases tend to affect younger women. 1, 2
Incidence and Epidemiology
The overall incidence of vulvar cancer has been increasing over the past two decades:
- From 2000-2019, the incidence increased with an average annual percent change (AAPC) of 0.80% 3
- In 2003, there were 3,507 cases (age-adjusted incidence rate: 2.2 per 100,000) and 775 deaths (death rate: 0.4 per 100,000 females) 4
- During 1973-2000, in situ vulvar cancer increased by 400%, while invasive vulvar cancer increased by 20% 4
- More recent data (2000-2019) shows the incidence rose from 18.3 to 19.6 per 1,000 woman-years 5
The incidence increases dramatically with age, peaking in the 85+ age group. The proportion of cases in women >65 years increased from 36.62% (1992-1996) to 49.82% (2012-2015), while cases in women <50 years decreased from 42.05% to 19.75% over the same period 6.
Racial and Ethnic Disparities
Significant demographic variations exist:
- Non-Hispanic White women show the most pronounced increasing trend (AAPC: 1.30 from 2000-2019) 3
- Black women are diagnosed at younger ages compared to White and other races 2
- Black patients demonstrate better survival outcomes compared to other racial groups, which is an unusual finding requiring further investigation 2
- Treatment approaches vary considerably by race/ethnicity, age, and insurance status, particularly for advanced disease 1
Histology and Pathways
Ninety percent of vulvar cancers are squamous cell carcinoma (SCC) 1. The disease arises through two distinct pathways:
HPV-Dependent Pathway
- HPV is associated with approximately half of vulvar squamous cell cancers 4
- HPV types 16 or 18 detected in 76% of VIN 2/3 and 42% of vulvar carcinoma samples 4
- HPV-associated vulvar cancer tends to occur in younger women and may be preceded by vulvar intraepithelial neoplasia (VIN) 4
- HPV-positive tumors can occur into the 70s and 80s 6
HPV-Independent Pathway
Risk Factors
The NCCN guidelines identify key risk factors 1:
- Increasing age (most significant demographic factor)
- HPV infection (particularly types 16 and 18)
- Cigarette smoking
- Inflammatory conditions affecting the vulva
- Immunodeficiency (including solid organ transplant recipients with SIR of 7.3-22.8) 7
Additional considerations:
- 15% of women with vulvar cancer had a prior high-grade cervical lesion or cervical cancer 7
- Immunosuppressed populations (transplant recipients, HIV-positive patients) show dramatically elevated risk 7
Socioeconomic Factors
Prognostic factors associated with better survival include 2:
- Private insurance (versus public/uninsured)
- Median income >$63,000
- Receiving care from Academic/Research Programs
- Lower Charlson-Deyo comorbidity scores
Stage at Diagnosis
Most vulvar neoplasias are diagnosed at early stages 1, with 5-year survival rates of:
- 86% for localized disease (stages I-II)
- 57% for regional/locally advanced disease (stages III-IVA)
- 17% for distant metastasis (stage IVB) 1
COVID-19 Impact
There was a significant decrease in age-standardized incidence rates across all races/ethnicities and age groups (AAPC: -10.15) over 2019-2020, likely reflecting diagnostic delays during the pandemic 3.
Clinical Implications
The increasing incidence in older women, combined with recommendations against routine pelvic examinations in asymptomatic women >65 years, represents a missed opportunity for early detection 6. The bimodal age distribution—with HPV-associated cases in younger women and HPV-independent cases in older women—requires age-appropriate screening and prevention strategies, including HPV vaccination programs and smoking cessation 8.