Although the number of people who die from cancer has decreased in the past decade, advances in cancer treatment have not been as effective as those for other chronic diseases (e.g., cardiovascular disease). Given this slow progress, primary prevention strategies, such as smoking cessation programs, must continue to play a central part in the fight against this disease. Researchers have extensively studied cancer risk factors, but most studies have been restricted to one risk factor, one site of cancer, or one population.

In a new study in the November 19, 2005 issue of the Lancet , researchers examined data on cancer risk factors from around the world. They attributed nine potentially modifiable risk factors to one-third of cancer deaths worldwide; smoking, excessive alcohol use, and diets low in fruits and vegetables led the pack.

About the Study

Researchers reviewed published studies, government reports, and other data to determine worldwide exposure to the following modifiable risk factors: overweight and obesity, low fruit and vegetable intake, physical inactivity, smoking, alcohol use, unsafe sex, urban air pollution, indoor smoke from household use of solid fuels (e.g., coal), and contaminated injections in health care settings. They developed an equation to estimate the reduction in cancer deaths that would result if each risk factor was altered to reflect the lowest possible risk (e.g., the whole population became lifelong non-smokers, everyone had an optimal intake of fruits and vegetables).

Of the seven million deaths from cancer worldwide in 2001, an estimated 2.4 million were attributed to the nine risk factors examined in this study. Smoking, excessive alcohol use, and low fruit and vegetable intake were the leading risk factors for cancer deaths worldwide and in low- and middle-income countries. In high-income countries, the leading risk factors were smoking, excessive alcohol use, and overweight and obesity.

This study is limited because in some regions of the world, less precise measures were used to estimate the incidence of cancer deaths.

How Does This Affect You?

These findings suggest that over one-third of cancer deaths worldwide are potentially preventable through lifestyle modification and environmental interventions. In the US, reductions in smoking and increases in cancer screening have been associated with significant decreases in deaths from certain cancers (e.g., lung , breast , and cervix ). According to these results, other successful policies and programs to encourage lifestyle and environmental modifications could have a substantial impact on the incidence of cancer deaths throughout the world.

These findings are encouraging because they indicate that your lifestyle can have a real impact on your health. To reduce your risk of developing cancer, aim to achieve and maintain a healthy weight, increase your fruit and vegetable intake, exercise regularly, stop smoking, avoid or limit alcohol use, and practice safe sex.

Lifestyle changes, however, are only one part of cancer prevention puzzle. Talk to your doctor about the types of cancer screening tests you should undergo. In many cases, the earlier cancer is detected, the better the chances of successful treatment.