With rising incidence of cancer, focus turns to prevention
By: Dr Lata Kini, Lead Clinical Pathologist, CORE Diagnostics
One of the most widespread killers of our times, cancer was responsible for a whopping 8.2 million deaths worldwide in 2012. According to World Health Organization, the annual cancer cases are expected to rise from 14 million in 2012 to 22 million within the next 2 decades, accounting for a massive 70 per cent increase. A number of factors are believed to be responsible for the rising incidence of most types of cancers.
These include an increasing ageing population, rapid urbanization, drastic lifestyle changes, industrial and environmental pollution and the inadvertent entry of chemicals in the human food chain. Contrary to perceptions, cancer is not a disease more prevalent in the developed world. Over 60% of the total new cases occur in Africa, Asia and Central and South America, which are largely developing regions. In fact, these regions account for 70% of the world’s cancer deaths.
While genetic predisposition plays a major role as a risk factor for cancer, a series of behavioral and dietary habits (which are modifiable) are believed to be the triggers for almost one-third of all cancers. These behavioral factors include high body mass index, low fruit and vegetable intake, lack of physical activity, tobacco and alcohol use. It is estimated that over 30% of cancer related deaths can be prevented by modifying key risk factors, particularly tobacco use.
In India, lack of a cancer registry limits the availability of data concerning the disease. However, clinical evidence cited by doctors and diagnostic experts suggest that the incidence of cancers is rising significantly. While it is rising faster in urban areas and cities, the increase is also apparent in rural areas. Another worrying concern is increasing incidence in younger patients, even in those in their 20s and 30s, something that was considered a rarity two decades back.
Focus on prevention
Urbanization and its accompanying attributes such as obesity, lack of physical activity, lifestyle changes and intake of alcohol tend to increase the risk of cancer. Apart from it, packaged and processed foods, whose consumption has increased radically today also contain additives and chemicals that may cause damage to the body.
With an alarming rise in incidence of cancer, there is growing consensus among medical community that focusing only on treatment is not enough to deal with this epidemic. Focus on multiple prevention strategies including modifying risk factors, changing behavior factors, ensuring early diagnosis and taking recourse to genetic testing, are equally important. However, while there is a lot of talk about the need for establishing cancer screening programs and improved treatment modalities, there is not enough discussion about the need to push large scale prevention programs.
Addressing Modifiable Risk Factors
It is estimated that nearly one third of all cancers can be prevented if adequate steps are taken by all individuals to avoid or modify risk factors. This makes for a massive figure. More importantly, prevention is always better than treatment, when it comes to a disease as maleficent as cancer.
Here is a look at the major risk factors associated with cancer:
Ø No prizes for guessing that tobacco consumption takes the top most spot here. Tobacco is the single biggest preventable risk factor for cancer associated with not just the lungs but also with carcinomas of the oesophagus, larynx, mouth, kidney, stomach and cervix, among others. When it comes to lung cancer, almost 70% of the disease burden can be attributed to tobacco smoking. Eliminating or minimizing use of tobacco smoke – both direct and second hand, can go a long way in reducing the disease burden. Governments here have to play a lead role, not just in raising awareness but also in imposing higher taxes on tobacco products to discourage their use.
Ø A large number of studies conducted worldwide have consistently found a proportional relationship between the levels of physical activity and risk of several types of cancer. While researchers are still trying to comprehensively explain the mechanism through which physical activity helps lower the risk, there is wide consensus that people who increase their physical activity reduce the risk of cancers of the colon, breast, lung, as well as endometrium.
Ø Obesity is another growing problem that is directly responsible for a series of health disorders. It is linked to as an increased risk for as many as 13 types of cancers.
Ø Diet plays a role in reducing cancer risk in two ways. While on the one hand the right diet helps in keeping body weight under check; on the other hand a diet rich in fruits and vegetables may have a protective effect against many cancers by infusing a rich dose of anti-oxidants in the body. At the same time, excess consumption of red meat as well as preserved or canned meat is associated with an increased risk of GI cancers.
Early diagnosis as a preventive tool
In a number of developed countries, large scale cancer screening programs have been instituted to identify the disease early, a strategy that has helped significantly cut cancer related mortality rates. Cancer screening is aimed at identifying the disease in an asymptomatic person. It helps spot the disease in its earliest stages when it is the easiest and most likely to treat. Cancer screening for some forms of the disease, especially breast cancer and cervical screening, has been particularly found to be beneficial. However, not all cancer screening programs have found to be useful since they also pose the risk of false positive or false negative results; or the chances of unnecessary overtreatment in cases where treatment may not prolong the life of an individual. Cancer screening must therefore be conducted by individuals in close consultation with their physicians.
Genetic testing as a preventive tool
Genetic testing is a relatively new diagnostic tool that allows experts to look into the genetic predispositions of individuals and predict (to some degree) the likelihood of a cancer. Genetic testing looks for inherited mutations in a person’s genes and chromosomes. Inherited genetic mutations are believed to be linked with around 5 to 10 percent of cancers. Mutations in tumor suppressing genes (genes that control cell growth) are especially associated with increased cancer risk. For example, inherited mutation in the BRCA 1/BRCA 2 genes, significantly increase an individual’s risk of breast and ovarian cancers.
Knowledge of your inherited risk can allow you to make informed decisions about possible measures such as preventive mastectomy. Similarly, genetic testing to check for EGFR (Epidermal growth factor receptor) mutations is emerging as an important intervention in the diagnosis and treatment of lung cancer.
At CORE Diagnostics, we provide a comprehensive range of genetic tests to evaluate an individual’s risk of developing several types of cancer. We also offer diagnostic tools to help early stage cancer patients determine their risk of cancer relapse, thereby allowing clinicians to tailor treatment modalities accordingly.