One of the most common questions I am asked by newly diagnosed lung cancer patients is “What can I, personally, do to help fight my cancer?” The two most common topics are diet and exercise. While the influence of diet on cancer outcomes is a good topic for discussion, today I wanted to focus on the question of exercise in cancer patients, and whether exercise may help people with lung cancer either live longer or at least have a better quality of life.

We have known for some time that there is a strong association between general fitness and cancer. In particular, obesity has been associated with increased risk of developing cancer of the colon, breast (in postmenopausal women), uterus, kidney, esophagus, stomach, pancreas, prostate, gallbladder, and liver. In fact, some estimates have indicated that between 14-20% of all cancer deaths can be related to obesity. In patients who already have cancer, recent studies have shown increased risk of recurrence in both colon and prostate cancer in obese patients, and weight gain is associated with increased recurrence in women with breast cancer. This may be related to increased hormone levels and levels of IGF-1 in obese patients, which can promote tumor growth. Of note, there has never been a direct association of obesity with lung cancer, probably because other risk factors are dwarfed by tobacco smoke. But obesity is an indirect measure of fitness, so what about exercise directly?

People who exercise regularly generally have a lower chance of developing cancer of any type than those who are sedentary. In patients with breast cancer, several large studies have documented up to 50% lower rates of recurrence and death with moderate levels of exercise (brisk walking up to 3 hours/week). In patients with colon cancer, observational studies have shown between 40-60% lower risk of death from colon cancer with a similar level of exercise (a few hours of exercise a week sounds better than chemo, doesn’t it?). So we have pretty good evidence now that exercise affects cancer survival, what do we know about exercise in lung cancer patients specifically?

This is a topic of particular interest to an investigator at Massachusetts General Hospital (MGH), Dr. Jennifer Temel. She is a lung cancer oncologist who runs the MGH fellowship program, and her main area of research is in studying and improving the quality of life of patients with lung cancer. The fact is, no one has any idea what the effects of exercise are on lung cancer patients since no one to date has studied it in this population. Partly because lung cancer patients tend to be older, sicker, have more medical problems outside of their cancer, and frankly, because lung cancer simply doesn’t get the research money and public attention that other cancers (yes, I’m talking about you breast cancer) get.

Dr. Temel set out to test if it was even feasible to look at exercise in advanced lung cancer patients, in a study about to be published in the Journal of Thoracic Oncology. Since 2004 she has been enrolling advanced lung cancer patients in a pilot study at MGH, testing to see if a moderate exercise program was feasible and a preliminary look into whether it improved the quality of life (QOL) of the patients. Patients underwent an initial assessment of physical fitness, and then underwent aerobic and strength training twice a week with a physical therapist for 8 weeks. The endpoint was to see how well the patients could adhere to this regimen, with secondary goals looking at strength, distance walked in 6 minutes, and QOL as assessed by well-validated surveys.

She was able to enroll 25 patients in 3 years, although as I will illustrate, she may have discovered why this hasn’t been extensively researched in the past. Take a look at the flowchart below.

Only 20 of the 25 patients who agreed to participate were even able to make it through the initial assessment, 19 started the program, and only 11 (44%) finished all 8 weeks of exercise. The patients who were unable to finish generally had declining health as a reason, which is understandable but disappointing nonetheless. Intriguingly, the 11 patients who did complete the program had improvements in their lung cancer symptoms and had no decreases in their strength or ability to walk, which would be expected perhaps to worsen with time.

One problem with drawing conclusions of benefit from this is that all the patients were getting treatment for their cancer, so we cannot rule out that the improving patients who finished their exercise program were the ones who were responding to treatment and improved for that reason rather than because of the exercise. In truth, I think we cannot draw any conclusion of benefit from exercise from this type of study without making it a randomized trial where half of the patients perform regimented exercise and half are left to do as they see fit. This trial is very important, however, because it validates what one might have thought ahead of time: advanced lung cancer patients are NOT the same as women with resected, early stage breast cancer. They are not otherwise healthy individuals by and large, but are frequently burdened by advanced age, chronic heart and lung problems, and a bad disease that quickly makes them too ill for strenuous activity. Dr. Temel discusses these issues and proposes that a less intensive exercise regimen, perhaps based at home to improve compliance, would be more tolerable. She also suggests trying this in the early stage setting where disease burden would not be such an issue, which makes a lot of sense.

Does this mean we should give up? Absolutely not! I tell all of my patients that if they are physically able, they should try and maintain some level of physical activity. I believe that if they are able to exercise, and many patients are healthy enough for this, there probably is the same or similar benefit that is seen in other cancer types, but perhaps the goal needs to be more modest and tailored to the patient.