Cancer mortality is on the rise in India, as in many parts of the world. Prognosis of cancer is still bleak as treatment faces new challenges and long term survival rates do not show very encouraging results. Multifaceted approach to battle cancer is being devised in many countries and prevention is at the centre of all these efforts. Prevention is better than cure. Never has this English proverb been so relevant than in today’s cancer burdened environment, especially for cervical cancer as its etiology is known. “Cervical cancer is the only cancer where we know what is causing the cells to change. We know for certain that human papillomavirus (HPV) causes cervical cancer,” informs Dr Partha Basu, Head, Department of Gynecologic Oncology/Officer in Charge, Preventive Oncology Division, Chittaranjan National Cancer Institute.
HPV connection
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“HPV types 16 and 18 cause 70 per cent of cervical cancers worldwide.”HPV is a common form of sexually transmitted virus infection and a large chunk of population gets infected with HPV in their lifetime. Most infections are asymptomatic and so women do not know that they are infected. Some times infections manifest in the form of warts in the genital area. In fact the signs of infection can appear weeks, months, or even years after infection with the virus.
What is interesting is that these infections are tackled by individual’s immune system much like common cold and get cleared on their own, yet a few persist and lead to cervical cancer. “Many HPV infections go away on their own. In fact, about 70 per cent to 90 per cent of cases of HPV infection are cleared from the body by the immune system,” says Dr Basu.
Types of HPV
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“13 types of HPV are considered ‘high-risk’ and can lead to cervical cancer.”HPV infection thus can cause a range of symptoms from warts to cancer. So why do some HPV cause cancer? Dr Mauricio Maza, Medical Director, Basic Health International, an organisation dedicated to reducing the burden of cervical cancer in Latin America and the Caribbean explains, “HPV is a group of viruses that includes more than 150 different strains or types. 13 of these types of HPV are considered ‘high-risk’ types and can ultimately lead to cancer of the cervix. In the majority of cases, the immune system overcomes the infection. However, those that are unable to clear the virus and have persistent infection are at the highest risk of developing cervical cancer.”
Elaborating further, Dr Basu says, “HPV types 16 and 18 cause 70 per cent of cervical cancers worldwide, while types 6 and 11 are responsible for the majority of genital warts.” These HPV strains can be identified using a DNA test and can be treated accordingly.
HPV also infects men though in general, HPV infection does not place a man at a significantly higher risk for health problems. However, HPV prevention is still important for men, as the virus has been linked to uncommon cancers such as penile, anal, and head and neck.
Primary prevention
Two vaccines — the bivalent vaccine (Cervarix) and quadrivalent vaccine (GARDASIL) — are mostly used for prevention of HPV infections. These are also available in India, but cervical cancer vaccination has been highly controversial in the country. “The issue related to cervical cancer vaccination are centred around partial efficacy of the vaccine, vaccine safety and of course cost,” says Dr Basu. “A lot of research and fine- tuning is required to make cervical cancer vaccination effective for the Indian population. In the mean time we need to have other prevention strategies in place to prevent women from developing the disease,” he adds.
As the duration of protection of these vaccines is uncertain, even the women who gets vaccinated need screening to monitor the cervix and thus secondary prevention becomes equally important in cervical cancer.
Secondary prevention
Screening for cervical cancer is a very important prevention tool. While many researchers are trying to evaluate the accuracy and effectiveness of cervical cancer screening techniques, Pap test and visual inspection of the cervix with acetic acid [VIA] or with Lugol’s iodine [VILI]) are most commonly used in India. These are cost-effective, low in technology and can be performed by trained healthcare workers. Besides these cytology-based tests and DNA testing for HPV is also used, these are more advanced and accurate but expensive techniques.
Growing burden in India
In 2008, a quarter of the global incidence and mortality caused by cervical cancer was in India alone. “Cervical cancer is the most common cancer among Indian women above 15 years of age: 38 per cent of cases occur among women age 15 to 49,” explains Dr Basu. The majority of cases are diagnosed at advanced stages of the disease. Consequently, it is not surprising that cervical cancer is also the leading cause of cancer mortality among women in India, accounting for 17 per cent of all cancer deaths among women age 30 to 69. In 2011, India’s national government launched a programme to address chronic and non-communicable diseases, including screening and treatment of cervical cancer. In parallel, several state governments are pilot-testing alternative non-communicable disease prevention strategies. However, the effect of these well founded programmes is not yet visible. “Much more efforts need to be mobilised for tackling a disease burden of such proportions as cervical cancer. The current efforts are not very focussed,” says Dr Basu.
CPCI project
Cervical Cancer Prevention & Control Initiative (CPCI) is a joint collaboration between Chittaranjan National Cancer Institute (CNCI), the Ministry of Health, Government of West Bengal and Qiagen. The objective was to reduce cervical cancer incidence and mortality in rural West Bengal. This was a large-scale community-based pilot cervical cancer screening programme using HPV testing for primary screening of women aged 30 or above.
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“HPV testing is most effective when used as a screening test on non-symptomatic women.”Talking about the project Dr Basu informs that 10,000 women were screened from February 2010-March 2011 and 50 cases of high-grade CIN 2/3 pre-cancers were detected of which 45 were treated. In addition, 10 cases of cancer were detected of which eight were treated. Talking about the effectiveness of HPV testing, Dr Geraldine Roeder, Associate Director, Women’s Health Market Development, Qiagen says, “HPV testing can be used in a number of different ways – e.g. for diagnosis of symptomatic women or as a ‘test of cure’ following treatment for cervical pre-cancer. However, it is most effective when used as a screening test on non-symptomatic women.” But DNA testing is expensive and many people can’t afford it. Nevertheless, Dr Roeder says that when looking at the larger picture this cost is small as compared to the cost of treatment if cervical cancer is not detected early. “If all women are given an HPV test, we can identify women with pre-cancer before their disease progresses too far to treat. This saves lives and also money because the treatment for pre-cancer is highly effective as well as simple and very cheap compared to the cost of hysterectomy, radical surgeries, chemotherapy and radiotherapy required for advanced cancers,” she explains. “HPV tests like careHPV have been specifically designed and proven in large clinical trials to identify the relevant HPV infections – the ones that could lead to cancer,” she adds.
Conclusion
Cervical cancer is preventable. If detected early it can be cured. However, screening and awareness education is the need of the hour to keep mortality rates in check.
Research and programmes in India have demonstrated that cervical cancer prevention initiatives have the potential to significantly reduce morbidity and mortality. To date, both research and programme efforts have faced challenges to achieving high levels of screening coverage and adherence to diagnostic and treatment recommendations. Further work is needed to better understand the kinds of messages and communication methods that will promote utilisation of prevention services and the kinds of strategies that may be needed to strengthen referral mechanisms.
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