Even as the villainous trio of AIDS, adult-onset diabetes, and lifestyle diseases continues to dominate the national mindscape, cancer has surreptitiously emerged as one of the deadliest killers in the country.

According to a study conducted by the National Cancer Registry Programme of the Indian Council of Medical Research (ICMR) in August this year, cancer kills an astounding 50 people in India every hour, while another 100 are diagnosed with the disease in the same period.

Every year, 440,000 people die of various types of cancer, while over 900,000 patients are diagnosed with it. In other words, at any given point, there are 2.5 million cancer patients in India.

Amongst urban Indian women, according to the shocking ICMR study, cancer of the cervix has been replaced by breast cancer. And though mammograms have enhanced the rate of breast cancer detection and slowed down the mortality rate, this type of cancer remains the most common affliction among women here.

Unsurprisingly, breast cancer-related deaths in India, too, have scaled up from 130,000 in 2004 to 131,900 in 2006, according to the study. Unfortunately, there are as yet no means to prevent the disease. Experts suggest that early diagnosis and treatment are the key to curb its growth.

Lung cancer is the leading killer among men, especially in metros such as Delhi, Kolkata and Mumbai. In fact, of all forms of malignancy, states ICMR's report, lung cancer is the number one killer in India - accounting for nearly 24 per cent of all cancer-related deaths. Globally, lung cancer accounts for 14 per cent of all cancers and 28 per cent of all cancer-related deaths.

In India, a higher incidence of lung cancer is being attributed to the upward spiral in tobacco consumption, even amongst women. Though official pan-India statistics are not available, random research by a global cigarette brand in 2006 reveals that the women's segment (rural and urban) accounts for about 15 per of total cigarette/cigar sales in the Indian market, up from under five per cent in 1986.

According to the World Health Organization (WHO), new lung cancer cases in India have upped from 32,000 per year in 1989 to 41,000 in 2006. "Unfortunately," states Dr Ajay Rastogi, Senior General Physician, Fortis Hospital, "treatment has very little impact on lung cancer cases at an advanced stage, as 90 per cent of such people succumb to their illness. Amongst urban Indian women, the primary reasons for an increased intake of tobacco consumption are changing lifestyles, increased workplace/relationship stress and frequent overseas travel."

According to figures released by the Minister of State for Health and Family Welfare, P. Lakshmi, (October 2007) about 50 per cent of cancer deaths in the country are caused by tobacco and are preventable. In view of this, the government has enacted a comprehensive tobacco control legislation, The Cigarettes and other Tobacco Products (Prohibition of Advertisement and Regulation of Trade And Commerce, Production, Supply and Distribution) Act, 2003.

But what is cancer? According to Dr Sanjay Mahajan, Senior Consultant and Intensivist, Kailash Hospital, NOIDA, "Cancer is an uncontrolled growth of tissue, triggered by the multiplication of abnormal cells in the human body. Instead of dying, these cells continue to multiply and outlive normal cells by forming new abnormal cells. During cancer's progress, cells can become aggressive (grow and divide without normal limits); invasive (invade and destroy adjacent tissues); and/or metastatic (spread to other locations in the body)."

Though cancer may affect people of all ages, explains Dr Mahajan, its risk enhances considerably with age.

"Nearly all cancers are caused by abnormalities in the genetic material of the transformed cells," elaborates Dr Sunil Gupta, senior oncologist, Fortis Hospital. "These abnormalities may be due to the effects of carcinogens such as tobacco smoke, radiation, chemicals, or infectious agents. Other cancer-promoting genetic abnormalities may be randomly acquired through errors in DNA replication or are inherited and, thus, present in all cells from birth."

The five most common types of cancers in India are colorectal, lung, stomach, breast and cervix. WHO figures reveal that more than 11 million people are diagnosed with cancers worldwide, every year. It is estimated that there will be 16 million new cancer cases every year by 2020, though currently cancer causes seven million deaths annually.

According to a report by the National Commission for Macroeconomics and Health (2006), while lifestyle diseases and diabetes will more than double in India over the next decade, cancers will rise by 25 per cent. Though the age factor is important, rapid urbanization and workplace stress are taking their toll on young professionals. Long and erratic hours at work, especially at BPO (Business Process Outsourcing) companies, little exercise and unhealthy eating patterns are a fertile breeding ground for cancers, warn experts. Increased alcohol consumption among youngsters too, presents a grave threat as it contributes significantly to cancers of the oesophagus (food pipe), pharynx, larynx, liver and breast.

Furthermore, skyrocketing income levels and rapidly altering lifestyles have ensured that people in rural areas and small towns, too, are not immune to cancer risk.

According to experts, apart from genetics and lifestyle factors, obesity plays a major part in the spread of cancer. According to the National Family Health Survey (NFHS-3), 2007, 13 per cent Indians are obese with a BMI or body mass index of above 25. Obesity contributes substantially to various types of cancers like breast, uterus, colon and kidneys among others, states Dr Gupta.

Small wonder then that the role of diet can hardly be overemphasized in cancer prevention. Dr Sakshi Chawla, Senior Nutritionist, Fortis Hospital, believes that food intake and vulnerability to cancer are linked. "Some types of cancers are an offshoot of a faulty diet, for instance, stomach, colon or rectoral cancer. Even the risk of breast cancer amongst women gets considerably enhanced due to the heavy intake of fatty foods as lymph nodes are formed because of a high fat intake," she says.

Dr Chawla reiterates that a fiber-rich diet, complete with vitamins, minerals, phytochemicals and antioxidants can help considerably in fobbing off the disease. "Certain foods like cabbage, broccoli, cauliflower (antioxidants), tomato (lycopene) and carrots (carotenoids) have been found to be especially helpful in inhibiting cancer growth," she says. "Also, natural products rich in vitamin C, like oranges, lemons, limes and deeply colored fruit, are beneficial."

But while diet can work its magic only at the micro level, experts feel a greater governmental emphasis on cancer prevention can help avert a public health calamity. "Mass awareness campaigns - especially about lung and breast cancer - can play a pioneering role in sensitizing the public about this disease and help whittle down cancer cases significantly in the country," sums up Dr Chawla.