Projection of Cancer Incident Cases for India-Till 2026

Projection of cancer incidence is essential for planning cancer control actions, health care and allocation of resources. Here we project the cancer burden at the National and State level to understand the magnitude of cancer problem for the various calendar years from 2011 to 2026 at 5-yearly intervals. The age, sex and site-wise cancer incidence data along with populations covered by the registries were obtained from the report of National Cancer Registry Programme published by Indian Council of Medical Research for the period 2001-2004. Pooled age sex specific cancer incidence rates were obtained by taking weighted averages of these seventeen registries with respective registry populations as weights. The pooled incidence rates were assumed to represent the country's incidence rates. Populations of the country according to age and sex exposed to the risk of development of cancer in different calendar years were obtained from the report of Registrar General of India providing population projections for the country for the years from 2001 to 2026. Population forecasts were combined with the pooled incidence rates to estimate the projected number of cancer cases by age, sex and site of cancer at various 5-yearly periods Viz. 2011, 2016, 2021 and 2026. The projections were carried out for the various leading sites as well as for 'all sites' of cancer. In India, in 2011, nearly 1,193,000 new cancer cases were estimated; a higher load among females (603,500) than males (589,800) was noted. It is estimated that the total number of new cases in males will increased from 0.589 million in 2011 to 0.934 million by the year 2026. In females the new cases of cancer increased from 0.603 to 0.935 million. Three top most occurring cancers namely those of tobacco related cancers in both sexes, breast and cervical cancers in women account for over 50 to 60 percent of all cancers. When adjustments for increasing tobacco habits and increasing trends in many cancers are made, the estimates may further increase. The leading sites of cancers in males are lung, oesophagus, larynx, mouth, tongue and in females breast and cervix uteri. The main factors contributing to high burden of cancer over the years are increase in the population size as well as increase in proportion of elderly population, urbanization, and globalization. The cancer incidence results show an urgent need for strengthening and augmenting the existing diagnostic/treatment facilities, which are inadequate even to tackle the present load.


Introduction
Nearly 12.7 million new cancer cases (12,661 thousand cases-Males 6,617 and Females 6,044) and 7.6 million cancer deaths (7,564 thousand cases-Males 4,219 and Females 3,345) occurred in 2008 worldwide.In India, 0.95 million new cancer cases (948 thousand cases, Males -430 thousand cases, Females -518 thousand cases) and 0.63 million cancer deaths (633 thousand cases, Males-321 thousand, Females-312 thousand) occurred (Globocan, 2008;IARC, 2010).Cancer incidence will continue to grow in the country in the future as a result of increase in life expectancy , increase in the proportion of elderly population, size of population and due to absence of any mass screening programmes in the country.Rising longevity, alterations in lifestyles, urbanization, globalization and progressive control of communicable diseases has led to emergence of cancer and other non-

Projection of Cancer Incident Cases for India -Till 2026
Neevan DR Dsouza 1 , NS Murthy 2 *, RY Aras 1 communicable diseases as an important health problem.In India, the life expectancy at birth has steadily risen from 45years in 1971 to 63.4 years in 2002, indicating a shift in demographic profile (SRS, 2002(SRS, -2006)).It is estimated that life expectancy of Indian population will increase from 68years to 71years by 2011-2015to 2021-2025(MOH and FW, 2011).The population of India on 1st March 2011 was 1,210.2 million as per the provisional population totals of (Census of India, 2011) compared to a total of 1028.7 million in 2001.
Due to such changes in age structure, population would face an increase in incidence of cancers and some other non-communicable diseases, which have a higher chance of occurrence among elderly.The major environmental risk factors for cancer are carcinogen and co-carcinogen exposure in tobacco, insufficient exercise and above all an unhealthy diet.What we eat or do not eat is exceedingly important in determining what cancers or other chronic disease we may suffer from (Moore, 2009).At present, for India as a whole the magnitude of the cancer incidence projections by site and sex based on scientific methods was available till the year 2016 (Murthy et al., 2008) and 2020 (Takiar et al., 2010).However, no such projections are available for future based on data from several Indian registries.A precise knowledge about the magnitude of the cancer problem, present as well as for future would help health policy planners to evolve and implement cancer facilities in the country.The present study estimates load of Cancer incidence at the country as well as state levels for quin-quennial (every five years) years from 2011 to 2026 for all sites of cancer as well as for some of the leading cancer sites reported by the population based cancer registries.

Materials and Methods
The data on the occurrence of cancer in India is available from the population-based cancer registries established in various parts of the country.Although the area and population covered by these registries is small, it gives a fair idea of the extent of the cancer problem in the country.A network of 26 Population Based Cancer Registries (PBCR) is functioning under the National Cancer Registry Programme (NCRP) of the Indian Council of Medical Research (ICMR) based on 3 year report of PBCR 2006-2008(NCRP, 2010).They are located at Bangalore, Bhopal, Chennai (earlier known as Madras), Delhi, Mumbai (earlier known as Bombay), Kolkata (earlier known as Calcutta) and a rural registry at Barshi (Maharashtra), Ahmedabad rural registry, Ahmedabad Urban registry (Gujarat), Pune, Aurangabad, Nagpur , Wardha , Thiruvananthapuram, Kollam (Kerala) and eleven in the northeastern region.
The age, sex and site-wise cancer incidence data along with populations covered by the registries were obtained from the report of National Cancer Registry Programme published by Indian Council of Medical Research for the period 2001-2004(NCRP, 2006)).In this study, the data on Cancer Incidence of 17 Population based registries viz.Bangalore, Chennai, Delhi, Mumbai(Bombay), Bhopal, Barshi from period 2001-2003, six North Eastern Registries i.e Dibrugarh, Kamrup, Silchar, Imphal, Mizoram, Sikkim (2003-2004), Nagpur, Pune, Aurangabad (2001), Ahmedabad rural (2004) and Thiruvananthapuram for the period 2001-2002 were obtained.The number of cancer cases by site, sex and five-year age group for each of the registries were obtained by multiplying the age-specificincidence rates with the respective populations.In order to obtain number of cases per year, the number of cases thus obtained was divided by the time period for particular registries.The respective number of cases thus obtained through above step, were summed-up for all the registries to get the total number of cases in each five-year age group by site and sex.The number of cancer incident cases per year by age, sex and site were estimated and combined with the data of 17 registries.Thus, it represented the data for 17 registries located in different parts of the country.The populations by sex in the respective five-year age groups of all the above registries were added-up to obtain the total population covered by all the 17 registries.The pooled age and sex wise specific incidence rates based on the 17 registries were obtained by dividing the respective number of cases with the corresponding pooled population in each of the five-year age group by sex.

Population exposed to risk
Population of the country as well as various 15 major states of the country, according to age and sex exposed to the risk at different quin-quennial years from 2011 to 2026 were obtained from the report of population projections carried out for the country for the years 2001 to 2026 based on Census of India 2001 by the Registrar General of India.(Registrar General of India, 2006).

Estimation of load of cancer
The respective age and sex-specific pooled incidence rates by site of 17 registries were multiplied with the corresponding projected age and sex specific population figures to estimate the projected number of cases by age, sex and site of cancer at various 5 year intervals Viz. 2011Viz. , 2016Viz. , 2021Viz. and 2026.The number of new cases of cancer for site "s" (N s ) in a particular year was estimated using the relationship N=∑ n P x * n I x , where n P x represents the projected population in the x to x+n age group for a particular year and n I x being the pooled incidence rate of cancer by site in the same age group for a particular site.The projections have been carried out for the various selected sites of cancer and tobacco related sites taken together.Estimation of incidence has been done both at the national level as well as for 15 major states of India which covers 95% of the countries population.
Assumptions: The projection of number of persons developing cancer have been done with the following assumption: i) rates obtained from these 17 Population Based Cancer registries represent country's incidence rate as well as for the various states of the country and; ii) age-specific cancer incidence rates for the latest available year will remain unchanged over next 15 years.

Results
According to the projections based on total fertility rates, the total estimated population of India for the years 2011, 2016, 2021 and 2026 (as 4).
Table 5 shows the projected number of Tobacco Related Cancers (TRC) cancer incidence in males and females.The sites of cancers included amongst TRC's were lip, tongue, mouth, pharynx, oesophagus, larynx, lung and urinary bladder.Selection of these sites as TRC is based on the NCRP report (NCRP, 2005).The estimated number of new TRC cases in males would rise from 276,316 cases (0.276 million) in 2011 to 448,276 cases (0.448 million) in 2026.TRC accounted for nearly, 46-48% of all cancers seen amongst men.However, in females TRC account for 16-18 percent of cancers.When both sexes are considered, the incidence due to TRC's would rise from 383,407 cases (0.383 million) to 622,502 (0.623 million) cases.
Table 6 shows projected number of cancer incident cases in India by broader age group.The estimated cancer cases are increasing from younger age group to an older age group from 2011 to 2026.

Discussion
It is well known that life styles, age composition of the population and total population size are determinants of cancer magnitude.These factors gradually changed in the developed world; as a result cancer has become one of the greater killer diseases.Several models have been attempted in the developed countries to predict the cancer situation in the years to come by using registry data.The precision of the estimates is made more accurate by taking into account the ecological data.
As per the indices of burden of cancer in 2004 the number of cases of cancer in males are 0.390 million and in females 0.428 million in India (ICMR, 2006).The new cancer cases in India were estimated to be 0.95 million in 2008 out of which 0.430 million cases were in Males and 0.518 million in Females (Globocan 2008, IARC 2010).
The new cancer cases estimated for the year 2001 was 0.92 million based on the data of 3 population based registries for the period 1982-84 (Murthy et al., 1990).Considering the data of ten Population based cancer Registries of India the estimated new cancer cases in 2001 were 566 thousand (Yeole,1997).Based on the data published in Volume VIII of cancer incidence in 5 continents for the period 1993-97 of 9 population based registries and 3 other population based registries for the period 1997-1998 ,the annual new cancer cases estimated DOI:http://dx.doi.org/10.7314/APJCP.2013.14.7.4379 Projection of Cancer Incident Cases for India -Till 2026 were 797,657;919,417;1,058,980 and 1,219,649 for the year 20011,058,980 and 1,219,649 for the year , 20061,058,980 and 1,219,649 for the year , 20111,058,980 and 1,219,649 for the year and 20161,058,980 and 1,219,649 for the year respectively (Murthy et al., 2008)).According to another study based on 2001-2006 data of Population Based Registry (Takiar et al.,2010), the estimates of new cancer cases for all sites in 2010, 2015 and 2020 are 979,787; 1,060,889 and 1,148,758 respectively.Out of the total estimates, new cancer cases for Indian Males are 462,408; 497,081 and 534,353 for the years 2010, 2015 and 2020.Estimates of new cancer cases for Indian Females are 517,378; 563,808 and 614,404.The results of our study showed a progressive increase in incidence of cancer cases.In 2011In , 2016In , 2021In and 2026 there were 1,193,426; there were 1,193,426;1,387,068;1,611,645 and 1,869,983 respectively.Our findings are slightly on the higher than those reported by other authors (Murthy et al., 2008;Takiar et al., 2010).Assuming the average duration of survival of a cancer patient to be 3 years, it can be said that at any point of time during 2016 there would be nearly 4 million cancer cases in the country (Dhar et al., 2006).The incidence of cancer is increasing every year and this is attributed to changes in lifestyle, improper dietary habits and increase in Life expectancy.Our projection has shown increase in incidence of cancer for all sites as a result of change in size and composition of population.In India the first three leading cancer sites are breast, cervix and lung (Satyanarayana and Asthana, 2008).The results obtained are similar in our study where cancer of breast and cervix are leading sites among females and lung cancer among males.Also the incidence of leading cancer cases in women such as breast, cervical, ovary etc., is increasing from 2011 to 2026.Our study shows 50% of cancers in women are of breast, cervical, ovary and corpus uteri.About 50-60% of all cancers among women in India are related to four organs Cervix, Breast, Corpus Uteri and Ovaries (Uma Devi, 2009).Another study stated amongst females, cancers of breast, cervix and ovary contribute about 50% of total incidence (Kurkure and Yeole, 2006).Breast cancer is the most common cancer diagnosed in women.Over the years the incidence of breast cancer in India has steadily increased and as many as 100,000 new patients are detected every year (Thun and Jemal, 2003;Yip et al., 2006).India does not have mass screening programs for any of the cancers such as breast, cervical and oral cancers in India.
The rising trends in breast cancer might be associated with a shift towards more westernized life style among the urban population (Notani, 2001).The possible reasons for high breast cancer incidence in women could be early age at menarche, late age at first birth, nulliparity, late age at menopause, dietary factors (Reddy, 2004).In another study, nulliparous women had a 2.2 fold higher risk than parous women for breast cancer (Rao et al., 1994).Young women who smoke or who have regular long term exposure to second hand smokers have an increased risk of developing premenopausal breast cancer (Battorff et al., 2010).The evidence that lactation protects against breast cancer and alcoholic drinks are a cause of breast cancer at all ages is convincing (American Institute for Cancer Research, 2007).Intake of high protein foods, particularly red meat and fried meat has been associated with increase in breast cancer incidence.Fruits and vegetable consumption are probably associated with reduced breast cancer (Lima et al., 2008).Alcohol consumption increases the risk of breast cancer (Anstey and Cheurbin, 2010;Tamimi et al., 2005).A cohort study in Finland (Gastrin et al.,1994) and a case control study in Canada (Harvey et al.,1997) suggested Breast self Examination to be beneficial (reduction in breast cancer mortality) at all ages.Regarding secondary prevention, Breast Self Examination may be the most effective approach in much of Asia, if only to improve awareness and early presentation at hospital when symptoms are detected (Moore and Sobue, 2010).
Improvement in the living standard of women has resulted in a reduction in the incidence of cervical cancer.Early age at first intercourse, multiple sexual partners,  poor sexual hygiene, repeated child birth etc. are some of the reproductive risk factors for cervical cancer.Regular cervical cytology examination (Pap smear) by all women who have initiated sexual activity can prevent the occurrence of cervical cancer (Takiar et al., 2010).Unlike most other types of cancer, cervical cancer is preventable when precursor lesions are detected and treated.In India, to date, there is no organized cervical cancer screening program.Hence, a large proportion of these cancer cases present in advance stages at the time of diagnosis, when cure is not possible (Mishra et al., 2011).Launching community based low intensity cervical screening in combination with awareness campaign and monitoring system should be the priority of the cervical cancer control program (Basu and Chowdhury, 2009).
In order to plan and develop control measures for non-communicable diseases an accurate estimation of disease load is essential.Studies on health projections provide an indication of the strong interest shown by scientific and public-health communities in the definition and quantification of scenarios of future health (Murray and Lopez, 1997).
In the developing countries when society is undergoing a rapid change in life styles the problems are more complex due to population growth.The consumption of cigarettes/ tobacco is increasing rapidly in both sexes worldwide.This would lead to large increases in the incidence of lung cancer.Lung cancer incidence was strongly related to the amount of bidis smoked a day, duration of smoking and age at starting smoking (Jayalekshmy et al., 2008).One third of male cancers are attributable to Tobacco smoking (WHO 2010).As per our study, TRC accounted to 46.8% of all cancers in males in 2011.Compared to other developed countries, smoking rate is still high in many Asian countries.The prevalence is over 50% in Korea, China and India and around 40% in Malaysia, Indonesia, Japan, Philippines, Bangladesh etc.The lowest level is shown in Singapore (Yoo et al., 2006).
In order to plan and develop cancer control actions, an accurate estimation of cancer incidence load is essential.Unlike in developed countries we are handicapped because of paucity of essential data to be utilized for making projections with a better degree of precision.Authentic data on cancer incidence for different regions is available only from 1982 when the Indian Council of Medical Research initiated National Cancer Registry Programme.In addition to this, a few of the cancer centers started their own population based registries.These registries routinely undertake various exercises to ensure that the data they collect and process is of high quality.A thorough check of data is also done before tabulation.It has been reported that the data collected by the Indian population-based registries are both complete and reliable (NCRP, 2001;Parkin et al., 2002).
The present estimates have been based on the data of 2001-2004 from 17 population based registries only (out of 21 registries functioning at the time of study in 2009).Detailed published data needed for the present exercise were not available from the four registries Viz: Ambilikai, Karunagapally, Ahmedabad urban and Kolkatta.The present projections carried out have not made any adjustments for possible increase in the tobacco habit.The percentage of men and women aged 15-19 using any kind of Tobacco in India are 57% and 10.8% respectively (NHFS-3, 2005-06).Increasing tobacco smoking might lead to increase in incidence of lung cancer.Tobacco is the most widely used harmful product and the main avoidable cause of cancer (Shin et al., 2012).However, the present estimates (without consideration of possible increase in risk factors) do indicate that existing treatment facilities need to be substantially increased to combat this deadly disease.
Even, if the age specific cancer incidence rates remain unchanged, large increase in absolute number of cancer cases in the next one and half decade of the present century is already programmed due to aging of population in the developing countries.With the increasing longevity, the proportion of Indian population in the cancer age will increase substantially.It is envisaged that in years to come cancer morbidity and cancer mortality would rise disproportionately to population increase and therefore strengthening/augmenting the existing diagnostic/ management facilities, palliative care made available to cancer patients along with primary prevention of tobacco related cancers should be initiated as early as possible.This approach would help in early detection and linked reduction of mortality, but is not likely to reduce the incidence.
Prevention of cancers through reduction of tobacco use should be an important strategy of National cancer Control Programme of India.Organized Cancer screening facilities should also be initiated so that leading cancer sites like breast, Cervix and oral can be detected at early stages or at pre-cancerous stage.High numbers of cancers of lung, prostate, ovary, esophagus, stomach, gallbladder (in certain areas) indicate need for augmented research efforts to identify effective screening tools.Incorporating screening activities into peripheral health infrastructure would effectively change the shift of clinical staging to left when less extensive surgical procedures could be attempted.Establishment of cancer diagnostic facilities, adequate treatment guidelines, pain relief and palliative care that can effectively be carried out at different levels (district hospitals, specialized hospitals, medical colleges etc.) would also help in reduction of mortality due to cancer.Increasing trends in cancer incidence have also been noted for several cancers such as Colon and Rectum, Gallbladder, Lung, Ovary, Prostate, Brain, Leukemia's (Murthy, 2006) etc.This has an important implication for public health.However, in the present exercise, no efforts have been made to incorporate the effects of changing trends or dietary practices.Over the next two decades it is expected that there will be a substantial increase in the incidence of cancers because of increasing longevity, migration from rural to urban, inadequate physical activity, greater exposure to environmental carcinogens due to industrialization, pollution, use of fossil fuels, wide variety of chemical agents in the industry, agriculture and continued use of tobacco.
With an estimated 1.19 million cases in 2011 and 1.86 million cases in 2026, Cancer appears to be a significant public health problem in India.The present estimates DOI:http://dx.doi.org/10.7314/APJCP.2013.14.7.4379 Projection of Cancer Incident Cases for India -Till 2026 may indicate that the people are not yet fully aware of the risk factors/their associated life style or behavior related factors leading to probable increasing figures for this disease.In short, reduction of cancer morbidity by 2026 would be an unrealistic goal, unless drastic measures are taken for its holistic control.Reduction of mortality through early detection/down staging could be still beexpected to a limited extent.For prevention of Cancer, Cancer Education is an important strategy for people to understand the risk factor associated with cancer and further to recognize early signs of cancer by screening and seek prompt medical attention for symptoms.

Table 2 .
It can be observed that the age-specific rates of cancers increase substantially after the age group of 40 years.It can also be noted the life expectancy at birth for the Indian population crossed 40 DOI:http://dx.doi.org/10.7314/APJCP.2013.14.7.4379  Projection of Cancer Incident Cases for India -Till 2026

Table 3 . Projected Annual Number of New Cancer Cases in Males and Females During Quinquennial Years, 2011-2026
Thus, it can be said that cancer started appearing as a health problem in the country after 1961.The estimated number of new cancer cases for "all sites" by sex is presented in Table3.The results reveal that an estimated1,193,426 (1.19 million)persons developed cancer during the year 2011.The estimates of cancer incidence would increase to 1,869,983 (1.87 million) by the year 2026.New cancer cases in female are higher as compared to males at all time periods.Further estimation of new cancer cases, by major states of India, reveals that burden is very high, in those states which are highly populous.Among males, Lung cancer is the leading cancer site in India with the estimated 62,650 (0.063 million) new cases in 2011.The next leading cancer site is Oesophagus,

Table 2 . Pooled Age-Specific, Crude and Age Standardized Cancer Incidence Rates per 100,000
*A crude rate (CR) is calculated by dividing the number of new cancers or cancer deaths observed during a given time period by the corresponding number of person years in the population at risk.For cancer, the result is usually expressed as an annual rate per 100,000 persons at risk.(http://globocan.iarc.fr/glossary.htm).An age-standardised rate (ASR) is a summary measure of the rate that a population would have if it had a standard age structure.The ASR is a weighted mean of the age-specific rates; the weights are taken from population distribution of the standard population (http://globocan.iarc.fr/glossary.htm)