A Healthy Lifestyle Increases Longevity in Patients With Colorectal Cancer, Study Finds

Patients with stage 3 colorectal cancer who maintained a healthy body weight, engaged in regular physical activity and adopted healthy eating strategies experienced a 42 percent lower chance of death and a trend toward reduced cancer recurrence than those who engaged in less healthy lifestyles, a study shows.

Results from the study of 992 patients were presented in a presscast in advance of the 2017 Annual Meeting of the American Society of Clinical Oncology, set for June 2-7 in Chicago. The findings showed that patients with colorectal cancer who followed lifestyle recommendations made by the American Cancer Society experienced longer disease-free survival and overall survival.

“There are over 1.3 million colorectal cancer survivors in the United States. These patients need survivorship care, including guidance on what they can do to lower their risk of recurrence,” said the study’s lead author, Erin Van Barigan, Sc.D., assistant professor of epidemiology and biostatistics at the University of California San Francisco. “In response to patient interest and need, the American Cancer Society (ACS) published ‘Nutrition and Physical Activity Guidelines for Cancer Survivors’ in 2012, but it is not known if following the guidelines after cancer diagnosis is associated with improved outcomes.”

Investigators enrolled the patients from 1999 through 2001, adding them to the study within eight weeks of surgery and immediately starting them on six months of chemotherapy. The primary purpose of the study was to consider the effects of two types of post-surgical chemotherapy on cancer recurrence and death. But also during the study, lifestyle was assessed twice using validated surveys — at enrollment and six months after each patient finished chemotherapy.

Patients were assigned a score from zero to six that reflected how closely their lifestyles synced with the ACS recommendations. The guidelines suggest maintaining a normal body weight (with a body mass index of 18.5 to 25 considered healthiest), engaging in regular physical activity (one hour or more of brisk walking each day was considered ideal) and eating a diet rich in whole grains, vegetables and fruits, and low in red meat and processed meat. A score of zero indicated that a patient was engaging in none of those healthy behaviors, while a score of six indicated that patients were adhering to all of them. Patients’ level of alcohol use was also assessed, with no drinking to moderate consumption considered healthiest (up to one drink a day for women and up to two per day for men).

Investigators sought to determine whether healthy behaviors would affect disease-free survival, recurrence-free survival or overall survival. They followed study participants through 2009 for a median seven years, during which they recorded 335 cancer recurrences. Of the patients who experienced recurrences, 256 died, and another 43 patients died without any cancer recurrence.

The 91 survivors who logged the highest healthy lifestyle scores (five to six points) experienced a 42 percent lower risk of death, as well as a 31 percent trend toward reduced chance of recurrence, compared with the 262 survivors who logged the lowest lifestyle scores (zero to one points). When alcohol consumption was included in the score, the 162 survivors with the highest scores for a healthy lifestyle (six to eight points) had a 51 percent lower chance of death and a 36 percent lower chance of cancer recurrence than did the 187 survivors with the lowest healthy lifestyle scores (zero to two points). It wasn’t one healthy lifestyle factor that drove these associations; rather, body weight, regular physical activity and a healthy diet were all found to be important.

The researchers noted that maintaining a healthy lifestyle can do more than improve colon cancer-specific outcomes; it can also help patients to improve their overall health, which is important because some have other ongoing health problems, such as diabetes or heart disease.

One caution was mentioned about the findings.

“It should be emphasized that the authors are not suggesting that a healthy lifestyle alone should be considered a substitute for standard chemotherapy and other treatments for colon cancer, which have dramatically improved survival. Rather, patients with colon cancer should be optimistic, and they should eat a healthy diet and exercise regularly, which may not only keep them healthier, but may also further decrease the chances of the cancer coming back,” said ASCO President Daniel F. Hayes, M.D., FACP, FASCO.

Next steps for the research team will involve testing digital interventions aimed at promoting a healthy lifestyle, such as Fitbits, in patients with colorectal cancer, Van Blarigan said.

“If our interventions are acceptable and useful to patients, we will test their impact on risk of cancer recurrence and mortality in future studies,” she said.

This study received funding from the National Cancer Institute, part of the National Institutes of Health.