Cervix is the narrow lower end of the uterus which opens in the vagina. When cancer occurs in the cervix it is called cervical cancer.
Cervical cancer is the second most common cancer in women, after breast, colon and lung. The major burden of the disease occurs in the less developed countries. There were 528,000 new cases of cervical cancer in the world in 2012 and 266,000 deaths worldwide from cervical cancer in 2012.
There are usually no symptoms in early stages and that is why it is very important to screen for cervical cancer.
In advanced stages, there may be irregular bleeding, postcoital bleeding, pain and foul smelling vaginal discharge. In case of any of these symptoms patients must consult the general physician or gynaecologist. Cervical cancer must be ruled out.
Cause of cervical cancer:
The cause of cervical cancer is Human Papilloma Virus (HPV). HPV is a common virus that is transmitted through sexual contact. At least half of sexually active women will have HPV infection at some point in their lives, but not all will have cervical cancer. HPV infection normally clears on its own. At times, the HPV infection of the cervix persists to cause cervical cancer.
There are 2 types of HPV: high-risk type and low-risk type.
The high-risk type is responsible for causing cervical cancer. Type 16 and 18 cause 70% of all cervical cancers. However, before cervical cancer actually occurs, there are some changes in the cells lining the surface of the cervix. These pre-cancerous changes (Cervical Intra-epithelial Neoplasm or CIN) can be detected by screening through a PAP test. Treatment of these lesions is highly successful in preventing cervical cancer.
Risk factors for cervical cancer:
- HIV infection or any condition that lowers immunity
- Multiple births
- Multiple sexual partners
- Oral contraceptive pills if taken for longer than 5 years
Risk goes back to normal when the pills are stopped
- Lower age at the time of first delivery
- Low socio-economic status as they do not have access to healthcare
Prevention of cervical cancer:
As there are changes in the cells lining the cervix i.e. precancerous changes before cancer actually develops, it is possible to prevent cervical cancer by screening for these precancerous cells on the cervix and treating them.
Cervical Pap smear is a test where the cells from the cervix is scraped and stained and examined under the microscope to detect any pre-cancerous changes. This is the procedure for screening for cervical cancer. The American Cancer Society recommends that all women should get Pap smears done at interval of 3 to 5 years from age 22 to age 65. After the age of 65, Pap tests are not required if all previous tests have been normal. Regular screening of women by Pap smears have significantly reduced the incidence of cervical cancer in UK and USA. Along with Pap test, HPV typing is also done to check for high risk or low risk type. The progression from pre-cancerous changes to cancer is very slow and treating these lesions prevent the progression of these lesions to cervical cancer.
Once abnormal cells are detected by the PAP test or if HPV typing shows the high-risk type, then the patient is advised to have colposcopy done. During the procedure of colposcopy, the cervix is examined with an instrument, the colposcope, which is like a microscope. If any abnormal areas are seen on the cervix, biopsies are taken. Once biopsy confirms pre-cancerous lesions, treatment is by minor procedures such as cautery or excision of lesions.
Vaccines are available against HPV infections. Garadsil vaccine which is used in UK provides protection against HPV type 16, 18, 6 and 11. HPV types 6 and 11 cause genital warts. Young girls of the age of 12 to 13 are injected with this vaccine. Vaccine can be given to women up to the age of 26. The other vaccine is the Cervarix which protects against HPV type 16 and 18. The idea is to vaccinate young girls and protect them from HPV infection before they become sexually active. The vaccine has been used in UK and USA since 2008.
Management for cervical cancer:
Cervical cancer is usually managed by a gynaecologist, oncologist or gynae-oncologist. Firstly, staging is done to find out the extent of spread of disease and then depending on stage and patient’s personal and family history, treatment is given. The treatment options are surgery, radiotherapy, chemotherapy or a combination of these treatment modalities.