The word ‘cancer’ incites many emotions in us.
Fear, helplessness, and loss of hope are common emotions that we feel. But, not anymore!
Presently, I can talk to my patients with conviction and gauge the treatment to a fruitful outcome!
Moreover, we have VACCINES to prevent some cancers!
This has been made possible due to the vast research & development that have taken place in the world of science. Today, cancer diagnostics & treatment is not the same, as it was some 30 years ago. Today, tumour biology is deciphered by multi-omics, targeted treatment is available to prolong the life of the patient and halt cancer.
Nevertheless, as always, we know that PREVENTION is better than CURE.
Therefore, when a vaccine is available and early detection of the cancer is possible, it makes sense to go for it!
Let me take you through the journey of detection of the Human Papillomavirus, (HPV), -as a causative agent for the development of cervical cancer.
The idea that some cancers in humans are caused by microorganisms like bacteria and viruses was there since the 1970s. Research work in the labs of the world was being conducted on some viruses as cancer-causing agents. Dr Herald zur Hausen, a German Virologist was working on the papillomaviruses. In 1983, his team discovered that HPV 16 and 18 are the causative agents of 70% of cervical cancers.
Dr Herald’s team hypothesised that cervical cancer was caused by papillomaviruses. They successfully isolated and characterised the two most frequent HPV types in cervical cancer, ie HPV 16 and HPV 18.
They subsequently demonstrated the fine print of HPV-mediated cancer development in cervix cells and were involved in the development of the preventive vaccine in the late 1980s. This mammoth effort of Dr Herald zur Hausen’s team made him bag the Nobel Prize for Medicine or Physiology in 2008.
Pharma companies did not take up this idea of vaccines for cancer in the 1980s. However, in the 1990s, National Cancer Institute allowed young researchers Dr Doug Lowy and Dr John Schiller to study vaccines for HPV. Their work led to the development of multiple copies of protein covering of HPV virus, called L1, which could be assembled as virus-like particles, VLP. There is no HPV virus in this VLP, only the virus’s protein coat. The experiments then showed that injecting these VLP produced antibodies against the HPV virus. The pharma companies, Merck and GlaxoSmithKline, then brought out these CERVARIX and GARDASIL to the world. FDA had approved them in 2006. WHO introduced them to the world in 2009.
Today, 105 countries in the world use the HPV vaccine in their national immunisation program.
For India, the population of women at risk for cervical cancer is around 483.5 million.
The HPV related cancer burden in India is around 3,40,324 in 2020! This includes not only cervical cancer but also other cancers that are caused by this HPV virus. They are- in females- cancers in the cervix, vulva, vagina, anal canal, anogenital, oral cavity, oropharyngeal and larynx. In men, we get cancers in the penis, anal canal, oral cavity, larynx, and oropharynx.
More than 70% contribution of HPV in cancer development is for – cervix, vagina, anal canal, around 50% for penile cancers. India contributes to nearly 1/5th of cervical cancer cases and 1/3rd of cervical cancer deaths in the world.
Cervical cancer is a preventable cancer and treatable! In May 2018, WHO had given a call to eliminate cervical cancer from the world. The WHO Cervical Cancer Elimination strategy includes coverage targets for scale-up by 2030 of HPV vaccination to 90% of all adolescent girls, twice-lifetime cervical screening to 70%, and treatment of pre-invasive lesions and invasive cancer to 90%. HPV vaccination has resulted in a reduction of precancerous conditions and a decrease in warts by 30-50% over 8-10 years in developed countries. The HPV virus also causes warts in the genital parts. The vaccine GARDASIL covers protection for warts too. For a decrease in cancer incidence, we have to wait for another 15-20 years to see the effects. The good point in these HPV related cancers is that they grow slowly over 20-30 years.
HPV vaccines provide 90% protection against the development of cervical cancer. Vaccination at an early age of 9 to 26 years will give the children a lifetime of protection. In India, vaccination is undertaken by a few states - Punjab, Delhi, Sikkim at the school level. Cost is the major deterrent for this vaccine. Each dose of vaccine costs around Rs.3000, and 2-3 doses are needed to complete the schedule.
Apart from vaccination, other protective measures that help prevent these cancers are -
To reduce multiple sexual partners,
To treat sexually transmitted infections promptly,
To use condoms while having sex,
To get HPV test and pap smear done every 5 years.
To conclude, HPV infection is a common infection. 70-80% of sexually active partners get it. Majority of them clear this infection with their immunity. Persistent infections cause problems of cancer. There are vaccines available and ways to prevent this cancer.
Let us be wise and choose prevention to cure!
And for us Indians, there is a long way to go in preventing these cancers and saving the women and men of our country!
The article is part of Cervical Cancer Awareness Month (January).
Written by:
Dr Annapurna V
Senior Consultant & HoD - Gynaec Oncology
Sri Shankara Cancer Hospital and Research Centre, Bangalore
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