Who Should be Screened for Cervical Cancer?
Approximately 15,000 new cases of cervical cancer are diagnosed each year in the United States and roughly 5,000 women die annually from this disease. Screening for abnormal, precancerous or cancerous cells in the cervix is critical for prevention, early detection and diagnosis of cervical cancer.
The National Cancer Institute recommends that women over the age of 18 or those sexually active before the age of 18 should be screened for cervical cancer annually. Women at an increased risk of developing cervical cancer should be particularly diligent in their annual screening. Risk factors include early age at first intercourse (16 or younger), history of multiple sexual partners, smoking and poor nutrition. In addition, a history of sexually transmitted diseases, such as chlamydia, human immunodeficiency virus (HIV), and especially human papillomavirus (HPV) appear to increase the risk of developing cervical cancer. Thirteen different HPVs (wart-causing viruses) have been linked to almost every case of cervical cancer. However, the converse is not true, as the presence of HPV does not guarantee that cervical cancer will develop.
Annual cervical cancer screening involves a pelvic exam and Pap smear. Patients who have an abnormal Pap smear may undergo a relatively new screening test called a Hybrid Capture II to determine the nature of the abnormal cells.
A pelvic examination screens for any palpable abnormal growths or irregularities. During a pelvic exam, a health-care provider inserts a gloved and lubricated finger into the vagina to feel the vagina, cervix, uterus, ovaries, fallopian tubes, bladder and rectum. The pelvic examination is usually performed in conjunction with the Pap smear.
Routine screening with a Pap smear is used to detect cancerous cells as well as abnormal cells that may or may not be precancerous in the cervix. During a Pap smear, a sample of cells from the cervix is taken with a small wooden spatula or brush and examined under a microscope. The results of a Pap smear are classified into five categories: negative or within normal limits (normal); atypical squamous cells of undetermined significance (ASCUS); low-grade squamous intraepithelial lesions (abnormal); high-grade squamous intraepithelial lesions (abnormal); or carcinoma (cancer).
If the Pap smear results are normal, no further evaluation is necessary. Women who have normal results will simply need to continue undergoing an annual examination and Pap smear.
Abnormal results from a Pap smear do not necessarily indicate cancer. Other conditions such as inflammation and sexually transmitted diseases can cause abnormal changes in cells. Some women will exhibit mild dysplasia (abnormal cells), in which case they may need to schedule frequent Pap smears to monitor for any changes. Women with severe dysplasia may need to undergo a biopsy for closer examination of abnormal tissue. A relatively new test called the Hybrid Capture II is used to determine the presence of 13 HPV viruses specifically linked to cervical cancer. The presence of one of these key HPV viruses may further define the nature of abnormal cells identified by a Pap smear. The presence of abnormal cells and one of the 13 high risk HPV virus may indicate that the abnormal cells are precancerous in nature. Conversely, if a high-risk HPV is not present, then abnormal cells are less likely to be precancerous.
Pap smear screening techniques have facilitated the early detection of cervical cancer and have reduced the incidence of cervical cancer by 75% over the past 50 years. To determine if you are at high risk and require additional follow-up other than yearly screening, please consult your doctor.