Cancer of the cervix is the second most common gynecological
cancer worldwide and is a leading cause of cancer-related death in
women in underdeveloped countries. Simple screening programs can reduce
its prevalence and severity.
Cervical cancer develops in the lining of the cervix, the lower part of the uterus (womb) that enters the vagina (birth canal).
This condition usually develops over time. Normal cervical cells may gradually undergo changes to become precancerous and then cancerous.
Cervical intraepithelial neoplasia (CIN) is the term used to describe these abnormal changes.
CIN is classified according to the degree of cell abnormality. Low-grade CIN indicates a minimal change in the cells and high-grade CIN indicates a greater degree of abnormality.
CIN may progress to squamous intraepithelial lesion (SIL; condition that precedes cervical cancer) or to carcinoma in situ (cancer that does not extend beyond the epithelial membrane). SIL is also classified as low-grade or high-grade.
High-grade SIL and carcinoma in situ may progress to invasive carcinoma (cancer that has spread to healthy tissue). Most (80-90%) invasive cervical cancer develops in flat, scaly surface cells that line the cervix (called squamous cell carcinomas).
Approximately 10-15% of cases develop in glandular surface cells (called adenocarcinomas).
Incidence and Prevalence
Cancer of the cervix is the second most common gynecological cancer worldwide and is a leading cause of cancer-related death in women in underdeveloped countries.
Worldwide, approximately 500,000 cases of cervical cancer are diagnosed each year.
Routine screening has decreased the incidence of invasive cervical cancer in the United States, where approximately 13,000 cases of invasive cervical cancer and 50,000 cases of cervical carcinoma in situ (i.e., localized cancer) are diagnosed yearly.
Invasive cervical cancer is more common in women middle aged and older and in women of poor socioeconomic status, who are less likely to receive regular screening and early treatment.
There is also a higher rate of incidence among African American, Hispanic, and Native American women.
Causes and Risk Factors
The cause of cervical cancer is unknown.
Infection with two types of human papilloma virus (HPV), which is transmitted sexually, is strongly associated with cervical and vulvar cancer and is the primary risk factor. Evidence of HPV is found in nearly 80% of cervical carcinomas.
Human immunodeficiency virus (HIV) infection reduces the immune system’s ability to fight infection (including HPV infection) and increases the likelihood that precancerous cells will progress to cancer.
Sexual activity that increases the risk for infection with HPV and HIV and for cervical cancer includes the following:
• Having multiple sexual partners or having sex with a promiscuous partner
• History of sexually transmitted disease (STD)
• Sexual intercourse at a young age
Women who smoke cigarettes are twice as likely to develop cervical cancer. Chemicals in cigarette smoke may increase the risk by damaging cervical cells.
Other risk factors include age (the condition is rare in women younger than age 15) and race (invasive cancer rates are higher in African Americans, Hispanics, and Native Americans).
Regular screening with a Pap smear effectively lowers the risk for developing invasive cervical cancer by detecting precancerous changes in cervical cells.
Women who do not receive regular Pap smears have a higher risk for the condition.
Signs and Symptoms
Early cervical cancer is often asymptomatic (does not produce symptoms).
In women who receive regular screening, the first sign of the disease is usually an abnormal Pap test result.
Symptoms that may occur include the following:
• Abnormal vaginal bleeding (e.g., spotting after sexual intercourse, bleeding between menstrual periods, increased menstrual bleeding)
• Abnormal (yellow, odorous) vaginal discharge
• Low back pain
• Painful sexual intercourse (dyspareunia)
• Painful urination (dysuria)
Cervical cancer that has spread (metastasized) to other organs may cause constipation, blood in the urine (hematuria), abnormal opening in the cervix (fistula), and ureteral obstruction (blockage in the tube that carries urine from the kidney to the bladder).
Cancer Diagnosis and Screening
Currently, cervical cancer is screened via Pap smear as a screening test.
The introduction of Pap smear reduced the incidence of invasive disease by diagnosing the pre-malignant stages.
Nevertheless, this screening test lacks in sensitivity with results of about 50% detection rate. Therefore repeated Pap smears are required to reassure that no pre-malignant cells are present – a disadvantage for both patient and healthcare providers.
Women currently diagnosed having suspicious or pre-malignant cells, usually undergo a colposcopy procedure. The colposcope magnifies, or enlarges, the image of the outer portion of the cervix allowing manipulation and biopsies for better diagnosis. It also provides a platform for minor treatments and activities. Colposcopy is performed in the traditional lithotomy position making it unpleasant to the patient and physician.
Treatment options
Pre-malignant stages (CIN) are usually treated with follow-up visits, minor or major excisions or surgery according to the stage and severity.
Invasive(malignant) disease are usually treated with radical surgery, chemo and radiotherapy.
