Cancer is a major public health concern in India. According to estimates from National Cancer Registry Program of ICMR, there are approximately 28 lakh cases of cancer in India at any given point of time and about 11 lakh new cases occur every year. Nearly 5 lakh patients die due to the disease each year. The trend is gradually rising.
According to WHO, Cancer is a leading cause of death worldwide, accounting for 7.6 million deaths (around 13% of all deaths) in 2008. About 70% of all cancer deaths in 2008 occurred in low- and middle-income countries. Deaths from cancer worldwide are projected to continue rising, with an estimated 13.1 million deaths in 2030.
The cancer of uterine (Uterus) cervix & breast are most common cancers in women while in men, cancer of oral cavity, pharynx & gastro-intestinal tract (Stomach, etc.) are common. Breast cancer cases are on the rise. In Delhi & Mumbai, breast cancer is the most common cancer in women.
How Cancer Occurs
Inside the country itself, there is geographical variation in the pattern of occurrence of various cancers. For example; in the North Eastern States, the incidence of lung and stomach cancers are much higher than the other parts of the country. The incidence of gall bladder cancer is high in northern and some northeastern registries. Breast is most common cancer in the metropolitan areas, whereas, cervix cancer is the most common among females in the rural registries. Another important information which has been provided by the NCRP is that except for cervical cancer, which is showing a downward trend over the years, many other cancers including prostate, breast, ovary and corpus uteri are increasing in incidence.
The transformation from a normal cell into a tumour cell is a multistage process, typically a progression from a pre-cancerous lesion to malignant tumours. These changes are the result of the interaction between a person's genetic factors and three categories of external agents, including (i) physical carcinogens, such as ultraviolet and ionizing radiation (ii) chemical carcinogens, such as asbestos, components of tobacco smoke, aflatoxin (a food contaminant) and arsenic (a drinking water contaminant) and (iii) biological carcinogens, such as infections from certain viruses, bacteria or parasites. All these factors, some of which are specific to our country, need in-depth research.
More than 30% of cancer could be prevented by modifying or avoiding key risk factors, including:
- tobacco use
- being overweight or obese
- low fruit and vegetable intake
- lack of physical activity
- alcohol use
- sexually transmitted HPV-infection
- urban air pollution
- indoor smoke from household use of solid fuels.
The Need for More Cancer Research
We urgently need to understand the various causes specific to our country, and to study our lifestyle particularly in different regions. The improvements in treatment in various cancers like those of the cervix and head and neck would have to be developed within India, since these diseases are no longer of major public health problem for the developed western world. Some cancers e.g. cervix, head and neck, mouth, gall bladder, liver, etc. are more prevalent and specific to our country. Hence, we require a more understanding and in depth research for their causation and treatment.
The management of cancer in general has been undergoing rapid changes, due to improvements in our understanding of the cause, prevention and development of newer approaches of early detection and management. However, many unanswered questions still remain in the quest to conquer this deadly disease. The results of treatment in advanced stages of most malignancies continue to be dismal, and there is an ever-increasing need to improve upon these. All cancer patients require a lifelong follow up, in order to take care of the treatment, and later, its after effects and watch for recurrences.
Recent technological advances in genomics and the molecular sciences have opened new vistas to accelerate knowledge about the genetic and environmental components of cancer initiation promotion and progression through studies in molecular epidemiology. A more complete understanding of the causes and mechanisms of cancer will enable us to provide more effective ways to prevent the disease. Worldwide, too, there is an increased focus on research on the causes of human cancer and the mechanisms of carcinogenesis in addition to developing scientific strategies for cancer control.
Research over the years has shown that many cancers are caused primarily by mutations in specific genes and much of the deranged behaviour of cancer cells stemmed from damage to their genes and alterations in their functioning. It is time that comprehensive and coordinated efforts are made to understand the molecular basis of cancer through the application of genome analysis technologies, including genome sequencing, genome characterization etc. Similarly, scientific advances are providing new evidence for the potential use of drugs, vaccines and other substances to reverse precancerous conditions and prevent cancer in people at risk.
New models of therapy such as gene therapy, etc are being tried for different cancers. In our country too, we need to develop committed research institutions to explore the new areas of cancer research such as genomics, proteomics, molecular biology, pharmaco-genomics, stem cell research, vaccine development etc. and evolve innovative, models of therapy such as gene therapy, etc.