Preventable and cancer are words rarely used in the same sentence. So when the World Health Organization (WHO) launched its global strategy to accelerate the elimination of cervical cancer by 2030, the world took note of this particular variant of the disease.
Cervical cancer arises in the cells of the cervix. It is caused by the human papillomavirus (HPV) strain, a sexually transmitted infection. Usually countered by the body’s immune system, the virus sometimes manages to survive, making it cancerous on these occasions. Currently the fourth most common cancer in the world, the burden of cervical cancer is greatest in low- and middle-income countries, where vaccination, screening and care take a back seat.
While over the past 26 years, the burden of cervical cancer has decreased significantly (DALY -20.2%)(1) With the implementation of the Smear Pap test, the question remains, is it still the most effective test available in the Indian/Global market?
Cervical Cancer Diagnosis and WHO Guidelines
While screening for various diseases has certainly taken a back seat due to the COVID-19 pandemic, a shift in mindset among consumers about the importance of diagnosis is what has offset the negative imbalance. HPV DNA, Pap smear, Acetic acid visual inspection (VIA), VIA with magnification and Lugol’s iodine visual inspection are the various diagnostic tests currently available in the market, HPV DNA and Pap smear being the best known/used. .
In 2021, the WHO published its second edition of guidelines for the screening and treatment of precancerous lesions in relation to cervical cancer. This recommendation operated on the fundamental principle that a screening test should have high sensitivity (the ability of a test to correctly identify women at risk) and high negative predictive value (whether women are truly diagnosed as negative, c that is to say that they are not affected by the disease). Currently on the market there are a variety of tests that help in the detection of the HPV virus, but only one meets the WHO global standard – the HPV DNA test. WHO has recommended HPV DNA testing as the primary screening test in 5 out of 7 algorithms. It is also suggested for the screening and treatment approach.
HPV DNA VS PAP smear test
Recommended by WHO, American Society of Clinical Oncology guidelines for secondary prevention of cervical cancer (ASCO), Federation of Obstetrics and Gynecology Societies of India (FOGSI) and International Federation of Cervical Pathology and Colposcopy (IFCPC) – HPV DNA testing is by far considered the most effective screening option for cancer of the cervix.
Lower sensitivity (50% to 60%) which may miss precancerous lesions and a recommendation of testing frequency every 3 years due to the potential for detection failures are some of the major causes for the decline in demand Pap Smear World for Public Health Programs. Documented in various publications, the limitations of cytology/pap testing are well known, with 32% of cervical cancer cases attributed to Pap test detection failures.(2)
In comparison, the HPV DNA test has greater sensitivity (>90%) and negative predictive value (>98%), an automated process that eliminates human error, increased reproducibility through objective positive test results or negatives and processing steps to protect against false negative results (Cell Control for human ß-globin) and false positive results (no carry-over contamination, no cross-reactivity) and a prescribed screening interval of 5 at age 10, making it the main choice for current and future screening. The WHO has recommended that 70% of women be screened using a high performance test twice in their lifetime – at 35 and 45.
Cervical Cancer and HPV DNA Tests in India
At present, India currently faces an amalgamation of factors that contribute to its cervical cancer burden. Research suggests that countries with a low socio-demographic index (SDI*) generally have a higher number of women who succumb to cervical cancer, as factors such as early care, lack of resources and stigma contribute all to the problem.
In India, ~ 160 million women aged 30-59 are most at risk of developing cervical cancer(3) . Contribute to 20.51% of new cases and 22.62% of deaths worldwide(4)India’s cervical cancer burden is increasing at an alarming rate, >123,000 new cases diagnosed each year(5) (Globocan).
As the transition to HPV DNA testing continues, India must follow suit if we are to meet the WHO deadlines. While countries like Norway, UK, Netherlands, Germany, Australia, Argentina, Chile, Malaysia, Thailand, Vietnam, Belgium, France, Denmark , Malta and Turkey to adopt HPV test as primary screening test, India to begin transition to instead of global 2030 deadline. A government push in close collaboration with private and public stakeholders will go a long way towards help reach people in the last mile and save lives from this preventable and curable cancer.
The opinions expressed above are those of the author.
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