Exercise, healthy diet extend colon cancer survival
Patients with stage III colon cancer had lower risk for death if they had a healthy weight, engaged in physical activity, and ate a well-rounded diet with little alcohol and red meat, according to study results scheduled for presentation at the ASCO Annual Meeting.
The American Cancer Society published guidelines on nutrition and physical activity for cancer survivors in 2012, but little is known about how a health lifestyle affects outcomes after a cancer diagnosis.
“American Cancer Society guidelines are based on public scientific studies, but it’s not actually known if patients who follow the guidelines after diagnosis live longer,” Erin Van Blarigan, ScD, assistant professor of epidemiology and biostatistics at University of California, San Francisco, said during a press conference. “We sought to determine whether colon cancer patients whose lifestyle was consistent with guidelines had longer [survival].”
Van Blarigan and colleagues evaluated the impact of following these guidelines — which call for a healthy body weight, physical activity, and a diet high in vegetables, fruits and whole grains and low in red and processed meats — on DFS, RFS and OS following adjuvant treatment for colon cancer.
The analysis included 992 patients with stage III colon cancer who participated in a trial of adjuvant chemotherapy conducted from 1999 to 2001.
Patients underwent lifestyle assessments twice and received a score from 0 to 6, in which a higher score indicated healthier behaviors. Because alcohol is included in the ACS guidelines for cancer prevention but not for survivors, researchers tested the score with and without an alcohol component (0 points, > 1 drink/day women and > 2 drinks/day for men; 1 point, no alcohol; 2 points, > 0-1 drink/day for women and > 0-2 drinks/day for men).
Over a median follow-up of 7 years, researchers observed 335 recurrences and 299 deaths.
Overall, the 91 patients with a score of 5 to 6 points had a 42% lower risk for death (HR = 0.58; 95% CI, 0.34-0.99) than the 262 patients with 0 to 1 points. Researchers also observed a trend toward improved DFS in the highest-scoring patients (HR = 0.69; 95% CI, 0.45-1.06).
When considering alcohol, the 162 patients who scored 6 to 8 points demonstrated significantly improved OS (HR = 0.49; 95% CI, 0.32-0.76), DFS (HR = 0.58; 95% CI, 0.4-0.84) and RFS (HR = 0.64; 95% CI, 0.44-0.94) compared with the 187 patients with scores of 0 to 2.
The effect of alcohol intake on the biologic mechanisms of colon cancer is not known, but is consistent with other diseases, such as cardiovascular disease, Van Blarigan said.
“Low-to-moderate alcohol intake was associated with improved survival compared with abstaining,” she said. “It’s important to note that heavy intake is associated with poor survival. There has been literature about alcohol’s association with cardiovascular disease, and it’s something to explore further for colon cancer.”
The researchers next plan to evaluate the feasibility and acceptability of digital health lifestyle interventions, like Fitbit, according to a press release.
“Colon cancer patients who had a healthy body weight, engaged in regular physical activity of approximately 1 hour 5 days a week, and ate a diet rich in a variety of vegetables and fruits, chose whole grains over refined, avoided red and processed meats, and drank small-to-moderate amounts of alcohol, have longer DFS and OS compared with patients who did not engage in these behaviors,” Van Blarigan said.
These results should provide optimism for those diagnosed with colon cancer, according to ASCO president Daniel F. Hayes, MD, FACP, FASCO.
“One thing we can take away from this study is the optimism we can now present to patients who have early-stage colon cancer,” Hayes said. “The odds of surviving colon cancer if it is not metastatic are quite high thanks to lots of hard work and a number of trials done over the last 30 years showing that adequate surgery and adjuvant chemotherapy improves survival.
“This study tells us that healthy people live healthier [lives],” Hayes added. “Although that might sound self-evident, one can no longer assume that because they have colon cancer it doesn’t matter anymore. You can now assume that a healthy lifestyle might even decrease the chances of colon cancer coming back, as well as having other health benefits.” – by Alexandra Todak and Chuck Gormley
Van Blarigan E, et al. Abstract 10006. Scheduled for presentation at: ASCO Annual Meeting and Exposition; June 2-6, 2017; Chicago.
Disclosure: Van Blarigan reports no relevant financial disclosures. Please see the abstract for a list of all other researchers’ relevant financial disclosures. Hayes reports stock and other ownership interests in InBiomotion and OncoImmune; honoraria from Eli Lilly; research funding from AstraZeneca, Eli Lilly, Janssen, Merrimack Pharmaceuticals/Parexel International Corporation, Pfizer, Puma Biotechnology; and travel expenses from Janssen.