Cervical Cancer Health Article

CERVICAL CANCER

Invasive cervical cancer affects nearly 12,800 women in the United States annually, and in approximately 5,000 of these women the disease will be fatal. The incidence of cervical cancer is bimodal, with two peaks occurring between thirty-five years and sixty-four years of age. Since the advent of Pap smear screening, the incidence of cervical cancer has decreased in the United States; however it continues to be a leading cause of death for women in Third World countries.

A tremendous volume of experimental and epidemiological evidence suggests that cervical dysplasia (premalignant changes) and carcinoma (malignant changes) are caused by various subtypes of the human papillomavirus (HPV), with cocarcinogenic effects derived from tobacco abuse. HPV is sexually transmitted and is highly infectious. Women who have early coitus (prior to age eighteen) or more than two sexual partners in their lifetime have an increased risk for cervical cancer. HPV initially causes cervical dysplasia or intraepithelial neoplasm (CIN), which, if untreated, may progress to carcinoma. Although some of the smaller of these lesions may spontaneously regress, given enough time all CIN lesions carry the possibility of progression to carcinoma.

With early viral effects, often no visible features to the naked eye are observed, with the exception of occasional keratinizing lesions that appear as a whitish plaque. Therefore, most cervical dysplasia is identified by cervical cytology (e.g., the Pap smear). The Pap smear is the most important tool in the secondary prevention of cervical cancer.

The evaluation of a patient with cervical dysplasia requires a colposcopic examination. This examination uses a dilute 3 percent acetic solution to help delineate the cervical lesion under 10X to 20X magnification. The lesion should be biopsied and the determination of invasion needs to be made. If no invasion is identified, the lesion should be treated in the premalignant state; however, once the cellular basement membrane is penetrated, invasion into the deeper tissues occurs. Often a procedure known as a cervical conization is necessary to determine whether invasion has occurred and to what depth the invasion extends.

Women with cervical carcinoma often present with abnormal vaginal bleeding—postmenopausal, intermenstrual, postcoital, or increased menstrual flow. An excessive, malodouros vaginal discharge is often a presenting symptom. History of weight loss and sciatic pain are rare symptoms, but when present signify advanced stage disease.

The most common variety of invasive cervical cancer is squamous cell carcinoma, which accounts for the majority of cervical cancer. Adenocarcinoma of the cervix appears to be increasing in frequency relative to squamous cell carcinoma; recent studies suggest as many as 15 to 20 percent of cervical cancers are now adenocarcinomas. The adenocarcinomas are believed to have a poorer prognosis than squamous cell carcinomas of similar stage.

Cervical carcinomas spread by direct invasion into the cervical stroma and surrounding pelvic organs. The tumor can also spread through the lymphatic channels into regional lymph nodes. The major path of spread is lateral—through the paracervical lymphatics into the parametrium and, ultimately, into the lateral pelvic sidewall. The tumor may also spread inferiorly into the vaginal stroma, anteriorly into the bladder, or posteriorly into the rectum. These tumors are known to metastasize to the external iliac nodes, obturator nodes, internal iliac nodes, and common iliac nodes. After metastasis to the pelvic nodes, cervical cancer spreads beyond the pelvis to the paraaortic nodes, and ultimately the supraclavicular nodes. Once the diagnosis of cervical cancer is established, the stage of the disease is clinically established by an estimation of the extent of the disease. Stage I disease is localized to the cervix; stage II disease is that which has extended beyond the cervix, but not to the sidewall; stage III disease is that which extends to the pelvic sidewall; and stage IV disease extends beyond the true pelvis.

The management of stage I carcinoma can be accomplished by either surgery or radiation with chemosensitization. Both produce similar cure rates, which approach 90 percent for stage I disease. In younger patients, surgical intervention is the usual option. Surgery allows the patient to maintain ovarian function, since low doses of radiation will cause cessation of ovarian function. In elderly patients, radiation is often used instead of surgery.

Radiation may also have permanent effects on the bowel and bladder function (as may surgery), however, by tailoring the radicality of the surgery, one can often minimize bladder and bowel dysfunction. Once the tumor has extended beyond the cervix, radiation with chemosensitization is the only option for cure. As the disease advances beyond stage I, the chance for long-term survival decreases.

THOMAS J. RUTHERFORD

(SEE ALSO: Cancer; Human Papillomavirus Infection; Pap Smear; Screening)