Factors underlying disparities in cervical cancer incidence, screening, and treatment in the United States.

W orldwide, an estimated 493,243, cases of invasive cervical cancer (ICC) occur each year and 273,505 women die of the disease. There is a global disparity in the incidence of cervical cancer, with the burden of cases occurring in less developed countries (83%), where effective cervical cancer screening and treatment services have often been difficult to implement (Fig 1). In more developed countries, such as the United States, the incidence of cervical cancer has decreased dramatically ( 75%) since the 1940s, largely as a result of the introduction of cervical cancer screening programs. An estimated 20,000 new cases of cervical cancer are diagnosed in the United States each year, and approximately 5000 women die from this preventable disease. However, the incidence of cervical cancer and treatment of the disease show marked disparities based on socio-demographic and health care access characteristics. Papanicolaou (Pap) smears were designed to detect cervical changes which may represent premalignant forms of squamous cell cervical cancer, the most common type of cervical cancer. Squamous cell cervical cancer, hereafter called cervical cancer, results from infection with oncogenic human papillomavirus (HPV) types which are acquired through sexual intercourse. Major risk factors for acquiring HPV include an early age at the onset of sexual activity, having multiple sexual partners, and having promiscuous male partners. Several cofactors may act in conjunction with HPV to increase the risk of cervical cancer, including cc-interferon with other sexually transmitted infections, smoking, multiparity, oral contraceptive use, immunodeficiency, and dietary factors, such as low 18-20 carotene, low vitamin C intake, or folate deficiency.