Doctors are appreciating more and more that treating cancer effectively means treating the whole patient, not just the cancer cells. Clinical evidence is showing just how important metabolic health is to successful outcomes for cancer patients undergoing treatment.
The issue is not to gain more than five percent of your body weight during treatment for cancer. However, most people do exceed this limit.
You only have to do two things — measure blood pressure and measure abdominal circumference — to get the triage to identify the roughly 10% of people who are really at colossal risk. Those measurements were taken at baseline in the Women’s Health Initiative, and those women were at three-fold risk of dying from breast cancer compared to women who had no metabolic syndrome component.
I always counsel the patient not to gain weight. I’ll tell her that weight gain will definitely shorten her duration of benefit from the Xeloda or endocrine therapies. My scribe will often capture that in the notes, which will be sent back to the referring doctor. If they can avoid weight gain, they should do well for years on Xeloda.
While the tumor-centric approach — where cancer prevention and cancer treatments are directed at the biology of the tumor itself — has been successful, we’re learning we can enhance this success by also focusing on the person as a whole and on what’s going on around the tumor. This is where metabo-oncology really becomes important, because the metabolic state of a person as a whole contributes quite a bit to how tumors develop and behave.
You need either a lifestyle intervention or a pharmacologic approach to attempt to attenuate weight gain during the treatment course.
In the WINS Study, we were able to show a statistically significant 24-percent reduction in breast-cancer recurrence risk through weight loss. The women went down to about 20 percent of calories from fat, but they were anxious to increase fat intake as soon as the intervention ended. In the primary prevention study, the women went from about 34 percent calories from fat to a little under 25 percent. This appeared to be a sustainable solution because it looks like people could do that through simple substitution.
As you gain weight, adipocytes become hypertrophic and sometimes die. Adipocyte death triggers phagocytes, like macrophages, to be recruited to clean up the cellular debris. This stimulates damage recognition pathways that are integral to basic immunology, by upregulating cytokines that are needed to mount an immune response. Cytokines can communicate systemically to other immune cells, to activate T cells and trigger adaptive immune responses. They’re highly conserved defense mechanisms. They’ve evolved to protect our bodies, but unfortunately these same mechanisms are now chronically hijacked during obesity and instead have detrimental effects.
Pronounced reductions in fat intake were difficult to maintain, but you really have to watch everything. Making such a big change is almost like taking a cancer therapy. And in the Women’s Health Initiative, when women made these moderate changes, they were able to sustain them.
We know that among those who have completed cancer treatment, those who are more physically active, eat a healthier diet and maintain a healthy weight have a number of improvements in their symptoms and patient-reported outcomes, such as with fatigue, pain and lymphedema.
The idea of focusing on host metabolism and its consequences on tumor biology makes good sense.
In the context of a patient dealing with morbid obesity, I’ll tell the referring oncologist to recommend weight loss through caloric reduction and increased physical activity. But that’s difficult to do it in the setting of an oncology clinic unless the doctor has the ancillary staff to help them do that.
Doctors know that obese patients do worse with therapy for every kind of malignancy. Obese patients are going to have the worst outcomes. Doctors understand that whether it’s a woman or a man, a patient who is on a steady trajectory of gaining weight is compromising their outcome.
There’s no one nutritional component that has been shown to be important in a consistent fashion in multiple large studies. But overall, having a lower-calorie diet and maintaining a healthy body weight are absolutely associated with primary and secondary prevention of cancer.
The only things you can do that would actually make a difference are to maintain a healthy body weight and eat fewer calories, period. That’s it.
When I get a call from a referring doctor, at least 60 percent of the time, they ask about what they should be telling a patient about their diet or their exercise levels and their metabolic health. In my opinion, every treating oncologist should be thinking about these things.
I did a study called Women In Steady Exercise Research (WISER) Sister. It was a dose-response exercise-intervention trial, aerobic activity, for women at very high risk for breast cancer. A good portion of them were BRCA carriers, while others had a really strong family history but no mutation. Three groups: no exercise, 150 minutes a week, 300 minutes a week.
We showed that we had a dose-response effect on reducing circulating estrogen. In addition, we did MRIs and showed that in the breast tissue, the background parenchymal enhancement, which is an estimate of the hormonally sensitive tissue in the breast, was reduced in a dose response — a very strong response, in keeping with what we saw in the circulating estrogens.
Women who are on Xeloda for a longer period of time really have to fight the battle of the bulge. It’s chemotherapy, so it’s probably foiling metabolism. Many women who are doing well on Xeloda will start gaining a significant amount of weight. It’s really an adverse issue.
The recommendations right now are not personalized. They’re not tailored to the individual. So for me, it comes down to two things: infrastructure and what we’re actually telling individuals.
Right now, what we’re left with is oncologists making a 30-second recommendation to a patient about what they should eat or whether they should lose weight or exercise. Of course, the impact of that is going to be minimal, to be honest.