Dr. Sunil Gandhi, Cancer & Blood Disease, 03/19/13

Patients ask me this question all the time. It is a very important and pertinent question. Sometimes the answer is a simple one, e.g. lung cancer or bladder cancer in a smoker or ex-smoker. Sometimes the answer is not so easy, for example in colon or rectal cancer.

We know that in some cases it can be due to obesity or lack of exercise or both. The study, published online Feb. 26 in Cancer Research, found that increased body weight and decreased levels of physical activity are only associated with an increased risk for colorectal cancer that tests negative for the biomarker CTNNB1. This subtype accounted for 54 percent of the cases tested. CTNNB1 is a gene mutation on chromosome No. 3.

For CTNNB1-positive colorectal cancer, which accounted for the remaining 46 percent of cases tested, no such association was found. It appears that these cancers are independent of those lifestyle factors.

This is very early research and a lot more research in this field is needed and being done. This clearly helps in answering the question, “What caused my cancer?” in more than half of the patients with colorectal cancer.

At the same time, this research has a lot more implications. Can we prevent these colon cancers by preventing obesity and exercising regularly? The answer to this is not clear yet. Another question is for the patients who already have colon cancer: Does exercise and maintaining healthy weight help? In my opinion, the answer is yes.

I strongly believe in doing regular exercise and maintaining healthy weight. Moderate and/or vigorous exercise is associated with several beneficial health outcomes, including a decreased risk of obesity, heart disease, stroke, certain types of cancer, and all-cause mortality.

There are three main types of exercise. They are:

+ Aerobic exercise — Aerobic exercise raises a person’s heart rate. Examples of  aerobic exercise are walking, running, or swimming.

+ Resistance training — Resistance training helps make your muscles stronger. People can do this type of exercise using weights, exercise bands or weight machines.

+ Stretching — Stretching exercises help your muscles and joints move more easily.

It’s important to have all three types of exercise in your exercise program. That way, your body, muscles and joints can be as healthy as possible. If you have not exercised before or have not exercised in a long time, talk with your doctor before you start a very active exercise program.

In short, lack of exercise and obesity are responsible for many cancers, and are easily correctible causes in most people.

Dr. Sunil Gandhi is a hematologist and oncologist. He is the volunteer medical adviser of the Citrus Unit of American Cancer Society. Write to 521 N. Lecanto Highway, Lecanto, FL 34461, email sgandhi@tampabay.rr.com or call 352-746-0707.