Note: Estimated new cases and deaths from vulvar cancer in the United States in 2009:
- New cases: 3,580.
- Deaths: 900.
Vulvar cancer is primarily a disease of elderly women but has been observed in premenopausal women as well. It is most commonly squamous cell carcinoma in type, though other histologic types do occur. Vulvar cancer is highly curable when diagnosed in an early stage.
Survival is most dependent on the pathologic status of the inguinal nodes. In patients with operable disease without nodal involvement, the overall survival (OS) rate is 90%; however, in patients with nodal involvement, the 5-year OS rate is approximately 50% to 60%. Risk factors for node metastasis are clinical node status, age, degree of differentiation, tumor stage, tumor thickness, depth of stromal invasion, and presence of capillary-lymphatic space invasion.[2,3,4,5,6] Overall, about 30% of patients with operable disease have nodal spread. A multifactorial analysis of risk factors in squamous vulvar cancer demonstrated that nodal status and primary lesion diameter, when considered together, were the only variables associated with prognosis. Patients with negative inguinal nodes and lesions no more than 2 cm had a 98% 5-year survival rate, while those with any size lesion with three or more unilateral nodes or two or more bilateral nodes had a 29% 5-year survival rate. Intermediate groups with intermediate survival were also identified. These discriminants were most useful as assessment criteria for stage III disease in the Federation Internationale de Gynecologie et Obstetrique staging system.
In many cases, the development of vulvar cancer is preceded by condyloma or squamous dysplasias. The prevailing evidence favors human papillomavirus (HPV) as a causative factor in genital tract carcinomas. The labia majora is the most common site of involvement and accounts for about 50% of cases. The labia minora accounts for 15% to 20% of cases. The clitoris and Bartholin glands are less frequently involved.
The pattern of spread is influenced by the histology. Well-differentiated lesions tend to spread along the surface with minimal invasion, while anaplastic lesions are more likely to be deeply invasive. Spread beyond the vulva is either to adjacent organs such as the vagina, urethra, and anus, or via the lymphatics to the inguinal and femoral lymph nodes, followed by the deep pelvic nodes. Hematogenous spread appears to be uncommon.
American Cancer Society.: Cancer Facts and Figures 2009. Atlanta, Ga: American Cancer Society, 2009. Also available online. Last accessed January 6, 2010.
Homesley HD, Bundy BN, Sedlis A, et al.: Assessment of current International Federation of Gynecology and Obstetrics staging of vulvar carcinoma relative to prognostic factors for survival (a Gynecologic Oncology Group study). Am J Obstet Gynecol 164 (4): 997-1003; discussion 1003-4, 1991.
Boyce J, Fruchter RG, Kasambilides E, et al.: Prognostic factors in carcinoma of the vulva. Gynecol Oncol 20 (3): 364-77, 1985.
Sedlis A, Homesley H, Bundy BN, et al.: Positive groin lymph nodes in superficial squamous cell vulvar cancer. A Gynecologic Oncology Group Study. Am J Obstet Gynecol 156 (5): 1159-64, 1987.
Binder SW, Huang I, Fu YS, et al.: Risk factors for the development of lymph node metastasis in vulvar squamous cell carcinoma. Gynecol Oncol 37 (1): 9-16, 1990.
Homesley HD, Bundy BN, Sedlis A, et al.: Prognostic factors for groin node metastasis in squamous cell carcinoma of the vulva (a Gynecologic Oncology Group study) Gynecol Oncol 49 (3): 279-83, 1993.
Macnab JC, Walkinshaw SA, Cordiner JW, et al.: Human papillomavirus in clinically and histologically normal tissue of patients with genital cancer. N Engl J Med 315 (17): 1052-8, 1986.