Cervical Cancer is the second most common cancer among women worldwide. The American Cancer Society (ACS) estimated the number of new cases in the US to be 11,150 with 3670 death in 2007. The total number of new cases in the world, however, is around 500,000 with an estimated number of death rate at 190,000 per year. 

 Risk Factors:
   Cervical Cancer is mainly caused by infection with a high-risk group of human papilloma viruses (HPVs). HPV is a virus that is usually transmitted via sexual activity. Other associated risk factors that have been discussed in the medical literature include having multiple sexual partners, unprotected intercourse (which are related to the increased risk of HPV transmission), smoking, and women who are immune compromised, such as those with a history of organ transplant or HIV infection with poorly controlled T-cell counts. Furthermore, in the United States, many of the newly found cervical cancer cases are due to a lack of screening within the last 5 years. The estimated prevalence rate of HPV infection in the world could be as high as 40-50%. However, only a few women infected with the high-risk HPV develop cervical cancers where the incubation period is very, very long. This finding suggests that additional factors or molecular events are necessary for the development of cervical cancer in women infected with the HPV virus. Investigators are continuing their endeavors to identify these factors.

Screening Tests:
   Papinicolau (Pap) Smear remains the gold standard for screening of cervical cancer. The annual mortality from cervical cancer has decreased over 70% since the introduction of Pap Smear 6 decades ago. It is a fairly painless test done by a gynecologist or your family physician. The beauty of the test is that it not only can detect cancer at an early stage, it could also detect pre-cancerous lesions so that they can be treated before their progression towards cancer.

   The technology of Pap smear has evolved significantly since its initial development by Dr. George Papinicolau. The conventional Pap smear uses a spatula (Ayres) and a brush to obtain cells from the cervix and placed them on a slide. The sensitivity is reported at about 80% with a specificity of 99%. The false negative rate can be as high as 50%. The liquid-based Pap test technology is different from the conventional Pap smear in that the cells were placed into a liquid medium, spun and filtered in the laboratory before they were transferred to the slide, decreasing the contaminant such as mucus and blood, and avoided uneven distribution of the cells on the slide. It is reported to have a higher percentage of sensitivity, but at a higher cost, which can be offset if it is used at an every 3-year interval.

Screening Recommendations:  
   ACS, U.S. Preventive Services Task Force, and the American College of Obstetrics and Gynecology (ACOG) recommend that cervical cancer screening begin approximately three years after the onset of vaginal intercourse, but no later than 21 years of age. The rational is that HPV virus has a prolonged incubation period and that in general it would take the virus several years before developing any meaningful disease. Many of the precancerous cervical cells can also regress spontaneously to normal cells (thanks for our own immune system) in the first three years.

   Annual screening should continue until the age of 30. After 30 years of age.   A woman whose Pap smear was negative in three consecutive years may then have her Pap test repeated every 2-3 years, according to ACOG. Furthermore a new test combining Pap test with an FDA-approved test for high-risk type of HPV, can be used to screen women for cancer and precancerous lesion of the cervix. If a woman test negative for both tests, they may have the test repeated every 3 years. If only one of the tests is negative, the woman would still need more frequent testing.

   Women who are infected with HIV, immune compromised (organ transplant), exposed to a medication called Diethylstilbesterol when she was a fetus in utero, or diagnosed previously with cervical cancer are the exceptions to the rule. In addition, women who had a hysterectomy for precancerous disease of the cervix should have vaginal Pap smear screening annually until they have three consecutive negative tests. Women who had a hysterectomy with no history of precancerous cervical disease may discontinue Pap screening. However those who continue to have multiple sexual partners and/or unprotected intercourse, or having other risk factors described above may need further screening despite the ACOG recommendation. It is important to know that the term hysterectomy consists of removal of the uterus and the cervix. If a woman had a supercervical hysterectomy where the cervix was not removed, she must continue Pap smear screening as before.