Patients with stage III colon cancer who maintained a healthy lifestyle during and after treatment had a 42% reduced risk for death and a trend for a lower chance of recurrence compared with patients with less healthy lifestyles, according to the results of a study (abstract 10006) presented during a press conference ahead of the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting.
The definition of healthy lifestyle was based on guidelines called “Nutrition and Physical Activity Guidelines for Cancer Survivors” released by the American Cancer Society; the guidelines include recommendations for maintaining a healthy body weight; engaging in physical activity; and eating a diet high in whole grains, vegetables, and fruits, and low in red or processed meats, with only moderate alcohol intake.
“Individuals often seek information on what they can do to lower risk of cancer recurrence, including changes to lifestyle,” said Erin Van Blarigan, ScD, assistant professor of epidemiology and biostatistics at the University of California, San Francisco, during the press conference. “The American Cancer Society released guidelines based on scientific studies but it is not known if patients who followed these guidelines actually lived longer.”
The prospective study included 992 patients with stage III colon cancer enrolled in an adjuvant chemotherapy trial from 1999 to 2001. Patients were enrolled within 8 weeks of surgery and received 6 months of adjuvant chemotherapy. The trial assessed lifestyle twice using validated surveys. Patients were assigned a score from 0 to 6 (0 = no healthy behaviors) that measured the degree to which their lifestyle matched the American Cancer Society guidelines.
With a median follow-up of 7 years, there were 335 cancer recurrences and 299 deaths. Compared with 26% of patients with the least healthy lifestyle (score 0–1), the 9% of patients with the healthiest lifestyle (score 5–6) had a 42% lower risk for death (hazard ratio [HR], 0.58; 95% CI, 0.34–0.99; P = .01 for trend). They also had a trend toward improved disease-free survival (HR, 0.69; 95% CI, 0.45–1.06; P = .03 for trend).
Alcohol consumption is included in the guidelines for cancer prevention, but not cancer survivors. When alcohol was included in the lifestyle score, the adjusted HRs for patients with 6–8 points compared with 0–2 points were 0.49 for overall survival (P = .002 for trend), 0.58 for disease-free survival (P = .01 for trend), and 0.64 for recurrence-free survival (P = .05 for trend).
Commenting on the results of the study, ASCO President Daniel F. Hayes, MD, said, “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.”