In India, an overall incidence of 23.5 out of 1,00,000 cervical cancer cases has been detected by WHO. Cervical cancer is known as a preventable disease, only if screening is done at regular intervals, diagnosed at the right time and therapeutic procedures are followed as instructed by the healthcare expert. Mostly, cervical cancer is caused by Human papillomavirus (HPV) and it can be prevented with the right vaccine and right diagnosis. Pap smear has extensively reduced the incidence of cervical cancer in women by nearly 80 percent and death by 70 percent.
The cancer cells start at the ‘transformation zone’ (TZ), a susceptible area on the cervix. The prolonged effect of carcinogens (substances or infections) can produce continuous changes in the immature cells which may lead to cancer. Being sexually active at an early age and having multiple sexual partners are the prime risk factors. HPV infection is transmitted through skin to skin contact and sexual activity with the affected individual. Sexual intercourse causes viral entry to the epithelium (basal or parabasal cells) of the cervix. Women in contact with multiple partners may have high HPV DNA positivity rate (60%), compared to women with a single partner (21%).
The vital causes of cervical cancer are:
Infection with high-risk HPV
Multiple types of HPV
Compromised host immunity
CIN, also called pre-cancer of the cervix, is mainly a disease of younger women. The mean age for it is about 30 years, about 15 years less than that of cervical cancer. Hence, the scope for prevention and early detection of the pre-cancerous cells is high. Risk factors for CIN and cervical cancer include:
Early sexual intercourse (<16 years).
Sexually transmitted diseases
Early age pregnancy
Multiple sexual partners
Immunosuppressed (HIV positive) individuals
Husband whose previous wife died of cervical malignancy
Oral pill users (rarely)
Poor hygiene can be another risk factor; hence health experts ask to maintain intimate hygiene a priority. It is essential not to neglect vaginal infection and treat it immediately without a delay. Using a condom correctly can curb sexual transmission disease to an extent. Penile hygiene is vital as it may be the reservoir for high-risk HPV.
of cervical cancer
Pap smear has become the gold standard for screening. Ayre’s spatula and an endocervical brush are used for this purpose. Cells are spread on a single slide and fixed immediately.
HPV-DNA testing is useful in cervical screening. Hybrid capture method can reliably detect the high-risk HPV types within hours. However, only about 2–5 percent of women diagnosed with HPV-DNA will ever develop CIN.
Nearly, 80 percent of women who test positive will clear the infection (HPV) by their own immune defence. Positive test result in elderly women (>30 years) suggests colposcopic examination.
Visual inspection with acetic acid (VIA): The healthcare expert examines the cervix with the help of speculum and acetic acid, which temporarily shows the abnormal tissues in the cervix.
Those women with abnormal tissues are instructed to go through colposcopic examination and/or biopsy to analyse if the cells are cancerous.
How can cervical
cancer be prevented?
Pap smear test must be conducted every three years starting from the age of 21. It helps in detecting precancerous cells, which can help in early treatment. Vaccines are other preventative methods which must be taken at an early age between 12 and 18, before becoming sexually active or infected with HPV. That’s why vaccine is mostly recommended to adolescent girls by the health experts.
Vaccines are known to be effective for only 7.5 years, hence screening with pap smear test must be continued even after taking vaccines.
Also, the virus is type-specific and does not protect against the other types of HPV, so frequent pap smears must be done.
(The author is a consultant obstetrics, gynaecology & gynaec oncology.)