General Information About Cervical Cancer
Invasive Carcinomas of the Uterine Cervix
Whether adenocarcinoma of the cervix carries a significantly worse prognosis than squamous cell carcinoma of the cervix remains controversial. Reports conflict about the effect of adenosquamous cell type on outcome.[10,11] One report showed that approximately 25% of apparent squamous tumors have demonstrable mucin production and behave more aggressively than their pure squamous counterparts, suggesting that any adenomatous differentiation may confer a negative prognosis. The decreased survival is mainly the result of more advanced stage and nodal involvement rather than cell type as an independent variable. Women with human immunodeficiency virus have more aggressive and advanced disease and a poorer prognosis. A study of patients with known invasive squamous carcinoma of the cervix found that overexpression of the C-myc oncogene was associated with a poorer prognosis. The number of cells in S phase may also have prognostic significance in early cervical carcinoma. HPV type 18 DNA has been found to be an independent adverse molecular prognostic factor. Two studies have shown a worse outcome when identified in cervical cancers of patients undergoing radical hysterectomy and pelvic lymphadenectomy.[16,17]
Human Papillomavirus Infection and Cervical Cancer
Molecular techniques for the identification of HPV DNA are highly sensitive and specific. More than 6 million women in the United States are estimated to have HPV infection, and proper interpretation of these data is important. Epidemiologic studies convincingly demonstrate that the major risk factor for development of preinvasive or invasive carcinoma of the cervix is HPV infection, which far outweighs other known risk factors such as high parity, increasing number of sexual partners, young age at first intercourse, low socioeconomic status, and positive smoking history.[18,19] Some patients with HPV infection appear to be at minimal increased risk for development of cervical preinvasive and invasive malignancies, while others appear to be at significant risk and are candidates for intensive screening programs and/or early intervention.
HPV DNA tests are unlikely to separate patients with low-grade squamous intraepithelial lesions into those who do and those who do not need further evaluation. A study of 642 women found that 83% had one or more tumorigenic HPV types when cervical cytologic specimens were assayed by a sensitive (hybrid capture) technique. The authors of the study and of an accompanying editorial concluded that using HPV DNA testing in this setting does not add sufficient information to justify its cost. HPV DNA testing has proven useful in triaging patients with atypical squamous cells of undetermined significance to colposcopy and has been integrated into current screening guidelines.[20,21,22] Patients with an abnormal cytology of a high-risk type (Bethesda classification) should be thoroughly evaluated with colposcopy and biopsy.