Vaccination against cervical cancer

Why it’s important to know about it and to protect your family.

Each year almost 8 000 South African women are diagnosed with cervical cancer. In South Africa, it is the most common cancer among women aged 14-44 and the leading cause of deaths from cancer among women in general.

CERVICAL CANCER IS CAUSED BY THE HUMAN PAPILLOMAVIRUS

The cervix is the lowest part of the uterus where it opens into the vagina, forming the initial mouth of the birth canal. Because of its position, it is extremely vulnerable to infection with the human papillomavirus (HPV), a virus that can be sexually transmitted and that is responsible for a variety of cancers in men and women, and also for genital warts. In fact almost all people will be exposed to the virus at some time after they become sexually active and those at highest risk of becoming infected are young adults between the ages of 15 and 24. Although only a minority of people who are exposed to the virus will go on to develop cancer, at the present time there is no way of telling who that might be. Most people who are infected do not develop any symptoms, so they can pass the virus on to somebody else without even being aware that they have it.

Studies indicate that among young South Africans around the age of 25, more than 40% of women and approximately 20% of men are infected with HPV.

There are over 190 different strains of HPV, and about 40 of them are capable of infecting the genital area. Of those, four strains are most important; HPV types 16 and 18 are responsible for about 70% of cervical cancers, and HPV types 6 and 11 cause about 90% of genital warts.

IT TAKES MANY YEARS AFTER INFECTION WITH HPV FOR A CANCER TO DEVELOP

There are no symptoms of infection with HPV types 16 and 18 and the interval between acquiring the virus and progression to a cancer usually takes 10 years or longer. Most cases of cervical cancer are found in women younger than 50, but the disease is rare in women younger than 20. Nevertheless, cervical cancer can still be found for the first time well into older age, so it is essential for women to continue to be screened for it as they get older. In South Africa, cervical cancer is most commonly diagnosed in women between the ages of 30 and 60 years.

CERVICAL CANCER HAS NO SYMPTOMS UNTIL IT HAS ESTABLISHED ITSELF

Women with early cervical cancers have no symptoms. Symptoms only develop when the cancer becomes more advanced and invades nearby tissue. When this happens there may be abnormal bleeding or discharge from the vagina and pain during intercourse. Nevertheless, these are symptoms that are fairly nonspecific and they can occur due to other causes, like infection. So it is important for women who do experience anything out of the ordinary to see their doctor as soon as they can and to get screened regularly for cervical cancer.

HPV IS THE MOST IMPORTANT RISK FACTOR FOR CERVICAL CANCER

Although HPV is frequently sexually transmitted, it is not always so. The virus can be passed on by skin-to-skin contact and sex does not need to occur. Also, HPV can spread from one part of the body to another, so an infection could start in the cervix and then spread to the vagina, or external genital area.

Certain types of sexual behaviour, however, can increase a woman’s risk of getting HPV, such as starting sexual activity at an early age and having many sexual partners. Having said this, it is important to know that HPV infection does not mean that the person is necessarily promiscuous. A woman who has only had one sexual partner can be still become infected. There are also other factors that seem to increase the risk of developing cervical cancer. These include, but are not limited to, smoking, other illnesses or medicines that lower immunity, other sexually transmitted infections (e.g. Chlamydia, gonococcal, or herpes), a diet low in fruit and vegetables, being overweight, having a first pregnancy before the age of 17, and having a family history of cervical cancer (for example your mom, grandparent or aunt).

EARLY DIAGNOSIS IS VERY IMPORTANT

It is important to prevent cancer from occurring by going for regular pap smears and treating cells that are not yet cancerous, but if left will become a cancer. The best way to find a cervical cancer early on, is to have a regular pap smear every three years. During the pap smear, a small spatula is used to lightly scrape the cervix to collect cells and mucus, which can then be examined under a microscope to see if they are normal or not. If necessary, this may also be accompanied by a test that looks specifically for the presence of HPV in cervical cells.

TREATMENT OF CERVICAL CANCER DEPENDS ON HOW FAR IT HAS SPREAD

When cervical cancer is diagnosed, various tests will be required to determine how deep it has spread and whether or not it has spread beyond the cervix to other parts of the body (staging the cancer). Depending on that, a specific course of treatment will be considered. This might include surgery to remove the tumour, radiation therapy, chemotherapy, and/or medicines that specifically target the cancer cells. If the cancer is detected early, the chances of successfully treating it are a lot better.

VACCINATION CAN HELP PROTECT AGAINST HPV INFECTION AND CERVICAL CANCER

Vaccination against HPV is 90-100% effective in causing immunity against the most important viral strains that cause disease. In this way it helps to prevent precancerous changes in the cells of the cervix. According to the World Health Organisation (WHO), by the end of 2014, the HPV vaccine was available in 63 countries around the world. In March of that same year the South African Department of Health, supported by WHO, introduced a national plan to vaccinate girls in Grade 4 (9 years and older) in public schools.

“Vaccination programs have been remarkably successful around the world, especially in countries like Australia and Rwanda”, says Professor Hennie Botha, Head of Gynaecological Oncology at the University of Stellenbosch. In Australia, in comparison to before the vaccine was routinely available, the proportion of women between the ages of 18 and 24 infected with the virus has decreased by 77%. “In order to obtain good protection of the population as a whole, we need to vaccinate at least 70% of schoolgirls”, explains Prof Botha. “So it is essential that parents understand how important it is to allow their daughters to be vaccinated. Myths that the vaccine is unsafe, causes infertility, or leads to increased promiscuity have no basis and are simply not true. In contrast, not vaccinating your child leaves them at risk of devastating and potentially fatal disease in later life. At the moment only girls are receiving the vaccine, but there are plans to extend the vaccine to boys in the future. Although the risk of cancer from HPV is lower in boys, young men can transmit the virus to their partners, so vaccinating them not only protects their own health, but adds to protecting the health of young women and those who are not vaccinated as well.”

Dr Trudy Smith, a Johannesburg-based gynaecologist agrees. “It would be ideal to vaccinate both boys and girls, but to have a significant impact on cancer, the most important and cost-effective strategy for the government is to start with girls”, she says. “The vaccine offered in schools helps to protect against two strains of the virus most commonly responsible for cancer (the bivalent vaccine). However, there are also two other strains of HPV that cause genital warts and a different vaccine that covers all four of these strains (the quadrivalent vaccine) is available that can protect against both cancer and genital warts. Because genital warts are common, boys benefit mostly from receiving the quadrivalent vaccine and the bivalent vaccine should not be used in boys. HPV-associated cancer is relatively rare in men, however.”

The quadrivalent vaccine that protects against the four strains of HPV most commonly responsible for anogenital warts and cervical cancer is recommended for girls and women from age 9-45 years and boys and men aged between 9 and 26.

Currently, the government does not provide free vaccination to children who are at private schools. “Parents of a girl who is not at a government-run school need to be encouraged to take responsibility for their child’s health, because it is up to them whether the child gets an HPV vaccine or not”, says Dr Smith. “I strongly recommend that they speak to their local private vaccination clinic or GP about vaccinating. It can be done from 9 years of age and ideally before age 14, so that adolescents and young adults have the best possible protection long before they start any kind of sexual activity and are exposed to HPV. HPV is so common that almost everyone will be exposed at some point and most never know they are infected. So even if your daughter waits until marriage to have sex, or only has one partner in the future, she could still be exposed if her partner has been exposed to HPV. I would also advise older women to speak to their doctor about vaccination if they have not already done so.”

The quadrivalent and bivalent HPV vaccines are available from your local private vaccination clinic or general practitioner. More information can be found at www.hpv.co.za

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