By: Dr Maria Alice
ACCORDING TO a report published by the World Health Organisation (WHO), cervical cancer is the second most common cause of cancer death worldwide.
The incidence of cervical cancer would be two to three per 100,000, even with optimal screening. Human papillomavirus (HPV), a sexually transmitted infection, is the most common cause of cervical cancer. Nearly 80 per cent of cases occur in low-income countries (where cervical cancer is the most common cancer in women) because of social, cultural and healthcare access barriers. Progression from HPV infection to invasive cancer takes an average of 20 years. Genital HPV transmission usually occurs within a few years after onset of vaginal or anal intercourse.
What is the significance of the cervical cancer vaccine?
When a woman is exposed to HPV, her immune system usually prevents the virus from doing any harm but, in a small number of women, the virus survives for years and eventually converts some cells on the surface of the cervix into cancer cells. These changes happen very slowly and, at first, the cells only show signs of a viral infection. Only later the cells become pre-cancerous and in time progress to invasive cervical cancer.
The cervical cancer vaccine is the first vaccine ever designed to prevent a cancer. There were 500,000 new cases of cervical cancer worldwide in 2005, according to the WHO. Thus, the impact of the cervical cancer vaccine will be tremendous.
The tragic aspect of cervical cancer is that it often strikes when a woman is still young, trying to raise a family or maybe she has not had children yet. Cervical cancer treatment may make future fertility impossible and, even with treatment, cervical cancer is a leading cause of cancer death in women.
Two HPV vaccines have been developed to decrease HPV-related cervical, penile, vulvar, vaginal and anal pre-cancerous and cancerous lesions, genital warts and laryngeal papillomatosis.
What are its targets?
Various strains of HPV, spreading through sexual contact, are responsible for most cases of cervical cancer. The vaccine targets the two most common high-risk HPVs, types 16 and 18 that cause around 70 per cent of all cervical cancers. One of the two vaccines also targets HPV types six and 11, which together cause around 90 per cent of all cases of genital warts.
The vaccine has proved to be remarkably safe, stops cervical cancer before even the first step can begin and studies have shown it to be 100 per cent effective.
Specific recommendations for HPV vaccination are as follows:
ā¢ Routine HPV vaccination for girls 11 and 12-years-old.
ā¢ Girls as young as nine can receive HPV vaccination.
ā¢ HPV vaccination for teenage girls 13 to 18-years-old to catch up on missed vaccine or to complete the vaccination series.
ā¢ The evidence is insufficient at this time to recommend for or against universal vaccination of women 19 to 26-years-old in the general population.
ā¢ HPV vaccination is not currently recommended for women older than 26 or for males.
The vaccine is most effective if given to girls before they become sexually active, as this allows a girlās immune system to be activated before she is likely to encounter HPV. Vaccination at this age also allows for the highest antibody levels and thus greater protection.
Pap tests guidelines
A catch-up immunisation is recommended for girls and women aged 13 to 26, who have not been vaccinated or who have not completed the full vaccine series. The greater the number of girls and women vaccinated, the greater the benefit from the cervical cancer vaccine.
A really important point is that women will still need to have Pap tests, as the cervical cancer vaccine is not intended to replace Pap tests. Routine screening through regular pelvic exams and Pap tests remains an essential part of a womanās preventive health care.
Although the vaccine could prevent up to 70 per cent of cervical cancer cases, it cannot prevent infection with every virus that causes cervical cancer. Routine Pap tests remain important, as they are the most effective way to detect cervical cancer in the earliest stages.
Current guidelines suggest:
ā¢ An initial Pap test within three years of when you become sexually active or at age 21, whichever comes first.
ā¢ From ages 21 to 29, every year.
ā¢ From ages 30 to 69, every two years.
ā¢ From age 70 on, you may stop having Pap tests if you have had three or more normal tests in a row and no abnormal results in the last 10 years.
Keep in mind
If you are at high risk of cervical cancer, you will need more frequent Pap tests. If you have had a hysterectomy done for a non-cancerous condition, such as fibroids, you may discontinue routine Pap tests, but not pelvic exams. If the hysterectomy was done for a pre-cancerous or cancerous condition, your vaginal canal still needs to be checked for abnormal changes.
Even with the enormous advance of this new vaccine, the best way to prevent sexually transmitted infections is to have fewer sexual partners and use condoms.
Cigarette smoking increases the risk of both pre-cancerous changes and cancer of the cervix.
Best health wishes,
Dr. Maria Alice – Consultant in General and Family Medicine, Director ā Luzdoc International Medical Service
