Cervical cancer is the most common cancer in Indian women. According to World Health Organization (WHO), every year 132,082 women are diagnosed with cervical cancer and 74,118 women die from this disease. Currently there are about 365.71 million women aged over 15 years who are at risk of developing it. Globally it affects 500,000 women. The majority of these women live in developing countries, including over 100,000 in India alone.
What is cervical cancer?
Cervical cancer, a malignancy of the cervix, is the second most common cancer in the world affecting women. It may present with vaginal bleeding but symptoms may be absent until the cancer is in advanced stages, which has made cervical cancer the focus of intense screening efforts using the Pap smear. The most important risk factor for cervical cancer is being infected with the human papillomavirus (HPV). Most women diagnosed with cervical cancer have this virus. HPV is passed on through skin or sexual contact with an infected part of the body, usually on or near the sexual organs.
The high-risk group in India
There are varied socio-economic risk factors for cervical cancer in India including education, income, lifestyle, multiple partners, sexual exposure before the age of 17years (and higher risk for exposure prior to 15 years), and early age (less than 18yrs) at first delivery (higher risk if delivery before 16yrs). In particular, married women over the age of 35 years, in the low socio-economic strata, with little or no education are most vulnerable to cervical cancer. Since over 80% of the population of India is rural, the focus for preventing and treating cervical cancer has to be on rural women.
How to reduce the risk of cervical cancer?
The following points help reducing the risk of contracting cervical cancer:
1. Regular Pap smear: The Pap smear can be the greatest defence against cervical cancer. The test can detect cervical changes early (10-15 years) before they turn into cancer. During a Pap smear, the doctor takes a sample of cells from the cervix (opening of the uterus or womb) to be tested and examined. To take the sample, the doctor puts a special instrument called a speculum into the vagina. This helps open the vagina so the sample can be taken. The doctor then collects a sample of cells with a small brush and a tiny spatula. This sample is put on a glass slide and sent to a lab to be checked under a microscope. The first Pap smear is recommended 3 years after becoming sexually active and definitely by 25years of age (if sexually active).
2. Avoid sex with multiple partners: Studies have shown women who have many sexual partners increase their risk for cervical cancer. They also are increasing their risk of developing HPV. The risk of getting this virus increases if you have sex at an early age, if you have more than one sexual partner during your lifetime, if your partner has had multiple sex partners, or if you have sex with uncircumcised males.
3. Quit smoking: Smoking cigarettes increases the risk of developing many cancers, including cervical cancer. Smoking combinedwith an HPV infection can actually accelerate cervical dysplasia.
4. Avoid unprotected sex: Having unprotected sex without a condom puts one at a high risk for HIV and other sexually transmitted diseases and infections including cervical cancer.
5. Get vaccinated against HPV: The following two recombinant HPV vaccines are readily available in India:
a. Gardasil, which is a vaccine against HPV types 16 and 18 (oncogenic) and types 6 and 11 (these HPV types account for 90% of genital warts in the western countries - exact data for India is not available). Approximate cost per injection is Rs 2,800, which is given intramuscularly. Side effects are almost negligible - commonest is soreness at injection site. Other mild side effects are headache, mild fever, itching at injection site and, sometimes, fainting (common after any injection especially in teenage girls). Therefore the women/girls are advised to lie down or sit for 15 minutes after reciving the injection. Rare case reports of muscle weakness in girls have been reported (Guillain-Barré Syndrome,GBS). Analysis of this rare adverse event has shown that this was not related to the vaccine, and the US FDA continues to recommend Gardasil for vaccination. It is manufactured by Merck and is recommended for girls between 9 and 13 years of age (before sexual exposure). If not given at this time, it can be given till 26 years of age. Doses are given at day 0, and then 2 months and 6 months after the 1st injection.
b. Cervarix is a vaccine against HPV types 16 and 18 (oncogenic), which currently cause 70% of cervical cancer cases worldwide and 90% of cancers in India. Approximate cost is Rs 3200 per injection. Recommendations for vaccination are same as for Gardasil. The recommended dosage schedule is the same. In India, Cervarix is being administered to women up to 45 years of age. It is manufactured by GlaxoSmithKline (GSK).
Both companies do not recommend testing for HPV prior to giving vaccine (not cost effective, according to them). However, in women who are already sexually active a baseline Pap smear is a must, prior to giving vaccine, and colposcopy (if indicated).
Also, though almost 90% of cervical cancers in India are caused by HPV types 16 and 18, it must be brought to the knowledge of the woman / parent of girl receiving the vaccine that she needs to be continuously screened for cervical cancer by Pap smear (for the girl child, after she becomes sexually active). This is because the vaccine will not protect against the 11 other oncogenic HPVs. Counselling of the woman or the parents of the minor girl prior to vaccination is essential.
Research is on for evaluating the benefits of the vaccine in boys / men, as HPV causes genital warts and penile cancer in men. The issue about a booster dose is not yet resolved (research is on going). However, both companies say that it is definitely effective for five years.
The vaccine is contraindicated in girls and women with a known allergy to yeast and any component of the vaccine, or moderate or severe illness at time vaccine is scheduled. If the woman notes she has conceived after receiving the vaccine, she need not undergo a termination of the pregnancy. The vaccine has not shown to harm the pregnant woman or unborn baby, but as such vaccination is not recommended during pregnancy. A woman can receive the vaccine during lactation.
Additional advantages of HPV vaccine
These oncogenic HPV types cause majority of vulval and vaginal cancer; therefore, the vaccine protects against these cancers as well (though vulvar and vaginal cancer are very rare). Recent studies have shown that some oral cancers are caused by these same oncogenic HPVs (transmiited through oral sex); vaccination can possibly protect against these cancers as well.
Challenges ahead
Although there are many options for preventing HPV infection and cervical cancer, all have limitations. Preventing HPV infection is challenging because the virus is easily transmitted and generally does not produce any symptoms. Genital warts caused by some types of HPV can be treated, but no treatment can eliminate the underlying infection and the virus can remain infectious for years. Condom use has been shown to have a limited preventive effect because HPV can reside throughout the anogenital region. Nonetheless, women can protect themselves from HPV infection to some degree by ensuring regular condom use and limiting the number of sexual partners. While it is clear that vaccines will not eliminate the need for effective cervical screening and treatment for many years to come, they can substantially reduce the burden that cervical cancer imposes on women and health services.
In developing countries like India, lack of effective screening programmes for cervical cancer further adds to the menace. As a result, no clinically significant reduction in the incidence of cervical cancer has occurred during the past three decades in India. In developed countries, by contrast, there has been a major decline in cervical-cancer mortality after the introduction of large-scale screening by Pap smear cytology. The limited success of such screening in developing countries has stimulated evaluation of testing for human papillomavirus (HPV) and visual inspection of the cervix with acetic acid (VIA).
Things all women should know about cervical cancer
Cervical cancer is preventable – screening and vaccination are key interventions.
Most women will have HPV, but only few will develop cervical cancer.
Only HPV infections that persist can lead to cancer.
Using an HPV test with a Pap test in women over 35 years can better identify women at risk for cancer.
An HPV vaccine that prevents 70-90% of cervical cancers is now available.
Women should talk to their healthcare providers about screening for cervical cancer and immunization.