With changing lifestyle, improved longevity and better control of infectious diseases,
non-communicable diseases have emerged as major health problems worldwide, more so
in developing countries. After cardiac diseases, cancer has emerged as an important
cause of morbidity and mortality in India. According to The National Centre for Disease
Informatics and Research of the Indian Council of Medical Research (ICMR) at Bengaluru,
India, 1.45 million cases of cancer were estimated to be diagnosed in 2016. This burden
is likely to become double in the next 20 years1
2.
Magnitude & pattern of various cancers in India
The National Cancer Registry Programme was commenced by the ICMR in December 1981
and is a major source of information on cancer incidence and pattern in the country.
Currently, there are 29 population-based cancer registries (PBCRs) and 29 hospital-based
cancer registries. These cover about 10 per cent of India's population. Of these,
11 PBCRs are located in the North-East (NE) region. Age-adjusted incidence (per 100,000)
rate for males is higher in the West - 631.9 in Brazil, 493.9 in USA - Michigan, compared
to India 270.0 in Aizawl district and 149.4 in Delhi. Corresponding figures in females
are 474.6 in Brazil, 363.3 in USA, 207.7 in Aizawl and 144.8 in Delhi (India) per
100,000, respectively3. The top five cancers among men are lung, head and neck region
(mouth, tongue and larynx), prostate and oesophagus. While among women - breast, cervix,
ovary, oral cavity and uterine cancer are most common3. The incidence of cervical
cancer is declining over the past three decades in Delhi, Chennai, Bengaluru, Bhopal,
Mumbai and Barshi PBCRs. The incidence of colon/rectum, lung, breast and prostate
cancer is gradually rising in these registries3.
There is significant geographical variation in the incidence of cancer in India. For
example, in the NE region, the incidence of cancer is highest in India, for both sexes.
In males, Aizawal district (located in Mizoram) reported highest cases while Papumpare
district in Arunachal Pradesh had the highest number in females. Higher incidence
of gallbladder cancer in north India and NE region compared to other parts, higher
incidence of stomach cancer in Chennai and Bengaluru PBCRs, oesophagus cancer in Kashmir
and NE region would indicate different aetiological factors operating, for example,
environmental, diet, lifestyle and genetic factors4. Nearly 50 per cent of cancers
in males and 15 per cent in females are related to the use of tobacco in different
forms. These include cancers of aerodigestive tract (head and neck, lung and oesophagus),
pancreas and renal and urinary bladder4. It is clear that the biggest measure to reduce
the incidence of these cancers would be to reduce the consumption of tobacco. Specific
cancer research programmes to focus on biology of population present in various States
with PBCRs will help determine risk factors responsible and suggest strategies for
prevention.
Delay in diagnosis
Almost 75-80 per cent of patients have advanced disease (Stage 3-4) at the time of
diagnosis5. This has been attributed to the late presentation which in turn is due
to low level of awareness in the population and among community physicians, lack of
screening programmes, lack of diagnostic facilities locally and vast distances to
travel to reach a major tertiary cancer centre, financial constraints and stigma associated
with the diagnosis. The situation is even worse in rural areas (69% of total population)
where patients and families have to travel a long distance to reach a tertiary care
oncology centre. Lack of place to stay, long time taken for investigations, limited
finances, language and cultural differences are also some of the limitations4. As
per data from rural-based PBCRs, the incidence of cancer is low in rural India compared
to urban PBCRs2. Even the pattern of cancers in rural PBCRs is different compared
to those in urban PBCRs, suggesting a different policy/approach to adopt in rural
areas.
Infrastructure
One of the major reasons for not being able to implement screening programme in India
has been lack of workforce - physicians, health workers, technical staff and pathologist
to review pathological material. The preference of healthcare personnel to work in
urban settings has also resulted in unequal distribution of healthcare centres and
practitioners. Many tertiary care centres (not all) have a comprehensive team of professionals
comprising medical, radiation and surgical oncologists, pain and palliative care experts
and auxiliary services, for example, diagnostics and pathological tests. A complex
team like this is yet to be a reality in rural India6.
Available data from randomized trials done in south India suggest that simple innovative
methods such as visual inspection-based screening (for oral cavity)7, visual inspection
with acetic acid application for cervical cancer8 may be useful and cost-effective
methods of screening for these two common cancers. Similarly, for breast cancer self-examination
or examination by a physician may be alternative methods to screening mammography9
which are doable for early detection of breast cancer, as detection in early stages
is amenable for treatment with curative option with less morbidity. Ultimately, the
screening programmes can bring down the incidence of some of the common cancers in
India. There has been effort by the Government of India (GOI) to establish regional
cancer centres in rural areas, and upgrade medical colleges with oncology department.
Under the National Programme for Prevention and Control of Cancer, Diabetes, Cardiovascular
Disease and Stroke, the GOI has allocated ₹ 120 crores each for the establishment
of 20 State-level cancer centres10. The GOI has also allocated 20 million USD to develop
23 new tertiary care centres and to strengthen 27 regional cancer centres10. Under
the ‘Pradhan Mantri Swasthya Yojna’, eight new cancer centres would be set up in various
parts of country and 58 existing medical colleges would be upgraded in a phased manner.
This is a mammoth task and will take some years before this translates into standard
care and survival benefit. One solution to this problem might be setting up and improving
primary care services in rural areas and educating people about cancer, environmental
pollution, clean drinking water, healthy diet and avoid tobacco use11. Experienced
health practitioner, researchers and physicians should concentrate on early detection
of cancer, as cure rates are high, if cancer is detected in early stage.
Several non-government organizations are engaged in increasing public awareness, supporting
screening, early detection, patient and family support services and palliative care
by providing home care4
12. There is a need to consolidate and strengthen their role in national cancer control
programme. Further, the ICMR has taken initiative to publish consensus documents on
common cancers in India to improve quality and standardized cancer care. These are
expert and evidence-based guidelines to promote uniformity and to ensure the quality
of treatment across cancer centres in India13. In recent years, the government has
tried to address these issues by establishment of the National Health Mission and
insurance schemes such as Rashtriya Swasthya Bima Yojna (a central government initiative);
Rajiv Aarogyasri Scheme (an Andhra Pradesh government initiative); Vajpayee Arogyashree
Scheme (a Karnataka government initiative)12, and also Gujarat health scheme model13.
The emphasis is now to educate people about these programmes.
Clinical research
Although a notable progress in this field has been made in the recent years, there
is a need to develop proper clinical research environment. This includes exposing
graduate and postgraduate medical students, community physicians and medical college
teachers about translation clinical research, and developing adequate infrastructure.
Indian pharmaceutical industry has made phenomenal growth in the field of generic
molecules; they need to invest in the development of new molecules and India centric
cancer research14
15.
India has a large pool of individuals with genetic diversity (4000 anthropologically
distinct groups and 22 languages)14. This provides an opportunity to study environmental
influences on drug metabolism (such as smoking, alcohol and use of herbal medicine),
variation in drug targets (for example, higher incidence of activating mutations of
epidermal growth factor receptor in lung cancer in patients from Asia), and genetic
polymorphism in drug-related genes. Indian population is unique in terms of genetics,
culture, languages and food habits. Well-planned genome-wide association studies may
yield insights into disease aetiology and potential responses to therapy14. In the
era of precision medicine, it will be important to define risks or susceptibility
of certain population or ethnic subgroups for high incidence of cancer seen in these
areas16 and also from treatment point of view if these subgroups need dose modification
or special precaution during the treatment. Translational studies involving imaging,
pathology, gene expression profiling, sequencing, bioinformatics and detection of
circulating tumour cells can be done in few centres, and then data generated can be
evaluated for its translation at other centres14
15.
Key priority areas for research
One of the important tasks would be to develop consensus on key priorities for cancer
research in Indian context based on common cancers in males and females in a particular
region. There is a need to focus research on prevention of some cancers with high
incidence in certain areas, for example, gallbladder cancer in Gangetic belt, penile
cancer in rural population, oesophageal cancer in NE region, colon cancer in Goa,
stomach cancer in southern and northeast India4. Whether these regional differences
in epidemiology are due to a difference in genomics and biology or due to differences
in the prevalence of cancer risk factors or both are not yet known and would be an
important area of research14. These cancers are rare in West and therefore, not a
focus for large research programmes. Similarly, directing research for upcoming problems
like lifestyle and obesity-related cancers would be timely.
Since most patients have advanced disease and poor performance status at presentation,
research efforts to develop cost-effective protocols for palliative care would be
meaningful. Developing protocols to less toxic regimens (e.g. metronomic therapy with
minimal visits to a busy cancer centre)17 and minimizing need for imaging (e.g. computed
tomography scan)18 in the follow up would be simple, yet important solutions. An active
collaboration between investigators, funding agencies, industry and regulatory bodies
would be important to understand needs of each other.
Way forward
Cancer in India is emerging as a major cause of morbidity and mortality. Some of the
key features include young age (generally one decade younger compared to the western
population), advanced disease, poor performance status and possibly more aggressive
phenotype. While many tertiary cancer centres have state of the art diagnostic workup
and treatment protocols, this is yet to reach to a standard level in many other regional
cancer centres and hospital in smaller towns. Focussing on epidemiological research,
screening for certain cancers and clinical trials India-centric common cancers may
provide solutions for improvement in outcome. A planned and teamwork approach at the
institution level and collaboration with different research teams are likely the key
to success.