As a gynecological cancer, cervical cancer is unique to women. In 2007 approximately 11,150 new cases of cervical cancer will be diagnosed. Cervical cancer will cause approximately 3,670 deaths.
Someone with cervical cancer will not experience symptoms until the cancer advances enough to invade other tissues. Once cervical cancer spreads, the most common symptom is abnormal vaginal bleeding, caused by the encroaching cancer.
Infection with Human Papilloma virus (HPvV) causes the majority of cervical cancers. HPV is a sexually-transmitted virus that often causes no symptoms, except for genital warts. While there are over 100 types of HPV, most cervical cancer is associated with HPV types 16 and 18. Genital warts usually occur after infection with HPV types 6 and 8. For more information about sexually transmitted diseases, please our topic center.
A women's risk of cervical cancer increases with multiple sexual partners. Because HPV infects approximately 50% of sexually-active people, even a small number of sexual partners increase a women's chance of exposure to HPV. Furthermore, sexual partners are often unaware of HPV infection since commonly there are no symptoms.
Recently, Gardasil (a vaccine against HPV) was approved for use with women ages 9 to 26. Gardasil causes the immune system to produce antibodies against HPV types 6, 8, 16, and 18. This vaccine also prevents precancerous changes that occur in the cervix (the portion of the uterus where it joins with the vagina) caused by HPV type 16 and 18.
To be effective, the vaccine must be given before a woman is exposed to HPV, and therefore ideally before she is sexually active. However, Gardasil only protects against the most common HPV types that cause cancer. Since it is possible to get cervical cancer from other types of HPV, it is still important to have regular pap smears (see description below). Other HPV vaccines are under study and pending approval of the FDA.
The first goal of screening for cervical cancer is early identification of precancerous abnormal cells by pap smear. A pap smear or test is a quick procedure where a physician uses a special stick or brush to collect a few cells from inside and around the cervix for laboratory examination. Through pap screening, precancerous cells can be identified and destroyed, thereby preventing progression to cancer. Because HPV is sexually transmitted, routine pap smears (one time per year) are recommended once a female becomes sexually active or reaches the age of 18 years. The timing for discontinuing pap screening is less certain. A women older than 65 years with multiple normal pap smears is considered low risk and no longer requires routine pap screening
Depending on the results of an abnormal pap test, a woman may be followed with frequent, repeat pap tests or evaluated by colposcopy. Colposcopy allows a magnified examination of the cervix and any areas of concern are then biopsied (a procedure where a small amount of tissue is collected for study under a microscope). The tissue obtained during a pap smear or colposcopy can be used to detect the presence of HPV 16 and 18. This testing helps determine the likelihood of the abnormal cervical cells progressing to cancer.
Some mild cervical changes not associated with HPV 16 or 18 may resolve on their own. To make certain, women may also be monitored with more frequent pap smears. During these evaluations, if the types of changes noticed are thought to be precancerous or cancerous, then treatment aims at either destruction or removal of the abnormal cells. Treatments include cryotherapy (destruction of the cancer cells by freezing), LEEP (surgical removal of the abnormal cells), or destruction of the cells by laser (laser ablation).
For a small proportion of women, the diagnosis of cervical cancer occurs once the cancer spreads into other nearby areas or into other parts of the body. Typically, treatment then involves surgery, radiation (using beams of energy to destroy cancerous cells and shrink tumors) and sometimes chemotherapy (using medicines to destroy cancerous cells or shrink tumors).
A women's prognosis is excellent when abnormal cervical changes are identified early with pap testing. The 1-year survival rate (i.e, the percentage of women with cervical cancer who live at least 1 year after diagnosis) for all cervical cancers is 88% and the 5-year survival rate is 73%.