Nick Mulcahy

January 19, 2017

Past studies have consistently shown a link between regular exercise and improved outcomes in patients with early-stage colorectal cancer. Now, for the first time, investigators have found the same for patients with advanced disease, according to a new data highlighted at a presscast in advance of the Gastrointestinal Cancers Symposium (GICS) 2017 in San Francisco, California.

Thirty or more minutes of daily moderate activity was associated with a statistically significant 16% reduction in disease progression and a 19% reduction in mortality (P for trend = .03 for both) compared with the lowest level of activity recorded in the study, reported lead author, Brendan John Guercio, MD, from Brigham and Women’s Hospital, Boston, Massachusetts.

The findings come from a prospective cohort study of 1231 patients taking part in a randomized controlled trial for chemotherapy with metastatic disease, the CALBG 80405 trial, funded by the National Cancer Institute.

The investigators also found that walking 4 or more hours a week was associated with greater than 20% improvement in overall survival and that participating in 5 or more hours a week of nonvigorous activity, including walking or yoga, was associated with greater than 25% improvement in overall survival.

"This is definitely something we can recommend to our patients," said Nancy Baxter, MD, PhD, an American Society of Clinical Oncology (ASCO) expert from St Michael's Hospital in Toronto, Ontario, Canada, who moderated the presscast. "This study shows that even a small amount of exercise may make a big difference," she added.

This is definitely something we can recommend to our patients. Dr Nancy Baxter

A sedentary lifestyle is a risk factor for the development of colon cancer, said Dr Guercio, who added that it also poses a risk for increased recurrence and mortality in patients with earlier-stage disease.

However, it has been unknown whether an inactive lifestyle is associated with disease progression or mortality in patients with metastatic disease, he said.

Study Details

In the new cohort study, patients completed a questionnaire, at the time of initiating chemotherapy in the trial, about nine leisure time activities (including running, yoga, walking, cleaning, and gardening) and average walking pace. Total metabolic equivalent task (MET)-hours/week were determined according to responses.

The investigators adjusted for a wide range of confounders in an attempt to eliminate the possibility that sicker individuals might simply exercise less than healthier patients, explained Dr Guercio.

As noted above, compared with patients engaged in less than 3 MET-hours/week of physical activity, patients engaged in 18 or more MET-hours/week experienced an adjusted hazard ratio for overall survival (OS) of 0.81 (95% confidence interval [CI], 0.67 - 0.98; P for trend = .03) and for progression-free survival (PFS) of 0.84 (95% CI, 0.71 - 1.00; P for trend = .03).

The primary endpoint of the study was OS, with PFS as a secondary endpoint.

Greater nonvigorous physical activity and walking duration were both associated with improved OS (P for trend = .01 and .04, respectively).

"When we looked at vigorous activities alone, such as running, we actually didn't find an association with outcomes," said Dr Guercio, but he added that the data might not have had sufficient power to detect that linkage.

Randomized controlled trials and more prospective clinical studies are needed to confirm the associations between physical activity and outcomes in metastatic colorectal cancer, he commented. Notably, an ongoing randomized clinical trial is comparing patients with advanced disease who exercise during treatment and those who do not, according to ASCO press materials.

This study was supported by grants from the National Institutes of Health. Dr Guercio and Dr Baxter have disclosed no relevant financial relationships, but multiple other study investigators had ties to industry.

Gastrointestinal Cancers Symposium (GICS) 2017. Abstract 659. To be presented January 21, 2017.

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