Incidence and Mortality
Estimated new cases and deaths from thyroid cancer in the United States in 2014:
New cases: 62,980.
Carcinoma of the thyroid gland is an uncommon cancer but is the most common malignancy of the endocrine system. Differentiated tumors (papillary or follicular) are highly treatable and usually curable. Poorly differentiated tumors (medullary or anaplastic) are much less common, are aggressive, metastasize early, and have a much poorer prognosis...
Estimated new cases and deaths from vulvar cancer in the United States in 2014:
New cases: 4,850.
The vulva is the area immediately external to the vagina, including the mons pubis, labia, clitoris, Bartholin glands, and perineum. The labia majora are the most common site of vulvar carcinoma involvement and account for about 50% of cases. The labia minora account for 15% to 20% of vulvar carcinoma cases. The clitoris and Bartholin glands are less frequently involved. Lesions are multifocal in about 5% of cases. About 90% of vulvar carcinomas are squamous cell cancers. This evidence summary covers squamous cell cancers and vulvar intraepithelial neoplasias (VIN), some of which are thought to be precursors to invasive squamous cell cancers.
Survival is dependent on the pathologic status of the inguinal nodes and whether spread to adjacent structures has occurred. The size of the primary tumor is less important in defining prognosis. 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 lymph node metastasis include the following:[5,6,7,8,9]
Clinical node status.
Degree of differentiation.
Depth of stromal invasion.
Presence of capillary-lymphatic space invasion.
Overall, about 30% of patients with operable disease have lymph nodal spread.
Other risk factors
In many cases, the development of vulvar cancer is preceded by condyloma or squamous dysplasia. The prevailing evidence favors human papillomavirus (HPV) as a causative factor in many genital tract carcinomas. The HPV-related basaloid and warty types are associated with VIN. About 75% to 100% of basaloid and warty carcinomas harbor HPV infection. In addition to the much higher prevalence of HPV in these subtypes than in the keratinizing subtypes, the basaloid and warty subtypes also share many common risk factors with cervical cancers, including multiplicity of sex partners, early age at initiation of sexual intercourse, and history of abnormal Pap smears. HPV-associated VIN (termed usual-type VIN when high-grade 2 and 3) is most common in women younger than 50 years, whereas non-HPV VIN (termed differentiated-type VIN when high-grade 3) is most common in older women. The former lesion-type VIN grade 1 is no longer classified as a true VIN.[12,13]