Q&A on cancer prevention - answers by oncologist Dr. Wilson Mertens
By Dr. Wilson C. Mertens, MSBA for the Daily Hampshire Gazette
It’s a new year and many have resolved to make 2016 a healthier one. Losing weight. Eating health. Exercising more. All are popular New Year’s resolutions. But, when it comes to cancer, can it really be prevented? For 2015, the National Cancer Institute estimated that 1,658,370 new cases of cancer would be diagnosed in the United States and that 589,430 people would die from the disease. There are many factors that play a role in the likelihood of developing cancer in your lifetime. Some of these risk factors are modifiable, such as quitting smoking or not becoming a sun worshipper. Others are out of your control, such as a family history of cancer. There are, however, things that you can do to reduce your personal chance of getting cancer.
Q. What can people do to reduce their risk of cancer?
A. Many cancers are associated with obesity – breast cancer (particularly in older women), uterine, kidney, esophagus, colon and rectum. One study suggests that four percent of cancers in men and seven percent in women are attributable to obesity.
While there is a clear relationship between body weight and cancer, the lower your body weight the lower your chances of cancer. However, only a few studies have explored reducing cancer risk by losing weight, particularly for breast and colorectal cancer, and its association with improvement in cancer rates. Patients who have undergone weight loss or bariatric surgery also appear to have lower cancer rates.
Q. To what extent does eating healthy and exercising play in helping to prevent cancer?
A. Exercise has been shown to be associated with lower cancer rates for breast, uterine, colon and rectum, and even lung cancer. The amount of exercise varies, but even moderate exercise – 3-5 hours of walking at an average pace – will lead to lower rates of breast and colorectal cancer. Active people have a 20-40%, sometimes more, reduction in cancer risk compared to more sedentary individuals, regardless of their weight.
As a society, we eat too few fruits and vegetables, with most Americans falling short of the long-recommended dietary guidelines from the National Cancer Institute. Diet is far more complicated an issue to study than is exercise. Food intake is complex, and very rooted in cultural norms. Eliminating one type of food more associated with cancer often results in its replacement with other foods that may have other adverse health effects.
Q. What other lifestyle changes are recommended to help prevent cancer and can they really make a difference?
A. Of course, tobacco usage is the major avoidable cause of cancer and outweighs many other factors in our control. For example, while the recent World Health Organization (WHO) alert on consuming processed meats estimated an 18% increase in colon cancer, in comparison, cigarette use is associated with a 2,500% increase in lung cancer, as well as many other cancers and health problems. So, if you are using tobacco products, the first priority is to stop, and stop permanently. Your healthcare provider can help with aids that can assist in the quitting process. Alcohol intake is associated with a number of cancers, including breast and esophageal cancers.
Also important is the avoidance of excess sun exposure. This is particularly important for young people, as the risk of melanoma – the most deadly form of skin cancer – appears to be highly impacted by sun exposure, especially with sunburns before adolescence. But, older people continue to have increased risk for all skin cancers with ongoing exposure. So, practice sun-smart behaviors, such as avoiding peak sunlight hours, seeking shade, and using sun blocking products.
Q. Is it ever too late to benefit from lifestyle changes?
A. Any reduction in exposure to risk factors is valuable. For example, quitting smoking significantly reduces the risk of lung and other cancers over time, and even patients with advanced lung and head and neck cancer can enjoy significant survival benefits by discontinuing tobacco use. As a result, every effort should be made to quit tobacco use, to exercise more, to lose weight if overweight or obese, and to reduce your alcohol consumption. If you can only do one or two of these, then eliminating tobacco and exercising more are the most important.
Q. People with a family history and certain inherited genes are known to have a higher risk of certain cancers. What is the best way to deal with this?
A. This is a complicated area that requires a sophisticated program. Cancer is a common disease, and rare is the family without any cancers. However, research has demonstrated a number of genes associated with familial or inherited cancer syndromes. Seeking help with programs, such as Baystate Medical Center’s Family Cancer Risk Program available at the D’Amour Center for Cancer Care, allows trained genetic counselors and physicians to determine your family’s risk, your risk, the appropriate tests to perform, and the best approaches for management.
Q. What environmental factors play a role in developing cancer?
A. We are almost inundated with news reports of epidemiological studies – the study of health in populations to understand the causes and patterns of health and illness – suggesting a variety of risks associated with the development of different cancers. As a result of the nature of these studies, conflicting data can arise and often suspicious clusterings of cancer diagnoses – suggesting a common exposure, such as water contamination and industrial pollutants – cannot be attributed to a single cause. An additional reason for this frustration is that, while cancer in general is common, specific cancers, such as lung and colon cancer, may not be frequent enough to show a clear connection.
We do have clear connections to factors such as tobacco and alcohol use, obesity, dietary intake, and sedentary lifestyle that can be altered. No one will suggest that these lifestyle changes are easy – this column would not be necessary if they were – but even small changes can make a difference, which should help reinforce those New Year’s resolutions.
(Dr. Wilson Mertens is vice president and medical director, Cancer Services, for the Baystate Regional Cancer Program.)