Developed By: iNFOTYKE
By Preeet Dhillon
Recently, ICMR’s National Center for Disease and Informatics Research released the most recent cancer rates for India, based on data from 27 population-based cancer registries located across the country including all northeast states. The latest estimates predict 15 lakh new cases of cancer each year in India with breast, lung and cervical cancers topping the list. There are regional variations across the country that reflect the diversity of our customs, lifestyle habits and health care services; for example, stomach and liver cancer are more commonly occurring in Meghalaya and Tamilnadu, gall bladder in Lucknow, lung in Gujarat, prostate in Delhi and Kerala, and leukemia in Jammu and Kashmir. Some sites in India are amongst the highest in the world, such as oral and cervical cancers, due to the high prevalence of underlying risk factors such as tobacco and pan chewing, beedi smoking and the human papilloma virus. On the other hand, rates in India for some commonly occurring cancers such as breast and colo-rectal are much lower than the West, but they are approaching the global average, and that is without any large-scale screening programmes. This means that what we are observing in India, is an under-estimate of the true burden of these cancers in our population. In other words, the actual burden of cancer is much larger.
For many years, there were no registries in many parts of the country, such as the Northeast. In response to this lack of data, registries have now been established in all north eastern states – Assam (Guwahati, Cachar and Dibrugarh Districts), Manipur, Mizoram, Meghalaya, Tripura, Nagaland and Arunachal Pradesh (Naharlagun and Pasighat), as well as Sikkim. This is an important and welcome step. Unfortunately, the latest data show the highest age-adjusted cancer rates in India are in the Northeast, with Aizawl district in Mizoram for males (271 per 100,000) and Papumpare district in Arunachal Pradesh for females (249 per 100,000). In fact, the top 4-5 registries for men and women are in the northeast (East Khasi Hills ranks third at 211.5 per 100,000 for men). For certain cancer sites, the highest rates occur in Meghalaya, such as oesophageal cancer in East Khasi Hills for both men (71.2 per 100,00) and women (33.2 per 100,000) as well as hypopharynx (22.2 per 100,00) and larynx (10.8 per 100,000) in men. In the Northeast, tobacco-related cancers have the highest rates in the country (eg, tongue in males; lung, mouth, nasopharynx and oesophagus in both men and women). Other types of cancers with known infectious causes are also highest in the Northeast, for examples, cancers of the liver in men and cervix in females.
While the registries represent less than 5% of India’s population, they do represent major urban metros as well as rural populations. Most cancer registries in countries around the world, such as India and the US, cover only a small proportion of a population, with the intent that the sample will provide representative data for the country overall. For India, accurate sampling remains a challenge due to the incredible diversity of our country. To address this challenge, the ICMR and the Public Health Foundation of India have initiated efforts to better understand the distribution of cancer (and all diseases) across all states, to better inform state-level decision-making and initiatives in health in the country.
Overall, the increasing cancer rates in India are due to reasons such as increasing life expectancy, infections such as HPV (cervical), Hepatitis C (liver) and gastric H pylori (stomach), lifestyle risk factors such as tobacco, alcohol, diet (low fiber), higher body weight and lower physical activity, and reproductive risk factors related to age at first pregnancy, number of children and breastfeeding. However, there may be other important environmental, lifestyle (eg, diet), occupational and genetic factors unique to our settings, which require further investigation. Moreover, in different parts of India, such as the Northeast, genetic and environmental influences may combine together to yield even greater risks. More well-designed epidemiological and genetic studies building on the registries in India, are required to increase our understanding of the causes and patterns of these cancers in various parts of the country.
Meanwhile, one world-wide initiative to quantify cancer – the Global Burden of Disease -suggests that for some countries such as the US and the UK, some cancer rates (eg, breast) are beginning to plateau or decline. Unfortunately, India’s trends show no sign of abetting. In cancer prevention there are two strategies that are generally employed, primary prevention wherein we address the underlying causes to prevent the onset of cancer in the first place, and secondary prevention where we attempt screening for early detection in order to treat early and improve survival after diagnosis. India’s 5-year survival rates are increasing for some cancer sites due to improved treatments and access, while China, on the other hand, showed improved cancer survival from 1995-2009 for nearly all cancer sites. In India, the majority of patients present with late stage of diagnosis, which limits treatment options for better survival, and patients who present at earlier stages, are not always informed about the risks, benefits and side effects of various treatment options.
The latest ICMR estimates are a reminder of the rising cancer burden in this country, which will continue to rise until we start controlling the underlying risk factors. If we eliminate tobacco use for example, we could reduce the cancer burden by at least 30% in this country. It is also a reminder of the need for effective early detection to improve cancer outcomes and survival in India, we are moving ahead but not fast enough or consistently enough across all sites. We individuals have the power of information, it’s what we choose to do with that information that will make all the difference.
As communities, our health systems are only partially geared for addressing the many challenges that an increasing cancer burden among our population will unleash. We need to improve and strengthen our health teams at community levels and in institutions while concurrently addressing preventive measures.
For more information on risk factors for each cancer, one can visit websites at various governmental such as the National Cancer Institute, US (http://www.cancer.gov/about-cancer/causes-prevention/risk), the World Cancer Research Fund (http://www.wcrf-hk.org/hk-en/preventing-cancer/ways-reduce-cancer-risk) and for information that is relevant to Indians, one can also visit ICMR’s National Institute of Cancer Prevention and Research which provides information on cancer treatment, symptoms, risk factors and financial aid (http://cancerindia.org.in/cp/). For cancer patients and their families, there are numerous organizations that are dedicated to improving awareness and the livelihood of cancer patients and their families (Indian Cancer Society, CanKids, Can Support, St. Jude Hospital are a few based in Delhi).
(The writer is Epidemiologist Public Health Foundation of India)