The effects of exercise training on the health-related fitness of colorectal cancer survivors (ABC)

Background

In Canada, colorectal cancer is the third most common cancer for both men and women. Due to this high incidence, there are approximately 90,000 colorectal cancer survivors currently living in Canada.

Unfortunately, it is estimated that two thirds of individuals who undergo surgery with curative intent will have a colorectal cancer recurrence or their cancer will metastasize. An estimated 9,100 Canadians will die from colorectal cancer in 2010 making it the 2nd leading cause of cancer death.

This highlights the need for interventions aimed at improving survival outcomes in individuals diagnosed with colorectal cancer. Recent research has emerged suggesting that physical inactivity and poor body composition (i.e. obesity) may be associated with an increased risk for disease recurrence and mortality following a colorectal cancer diagnosis.

Exercise interventions have been shown to improve a number of outcomes in other cancer survivor groups, including fitness levels and body composition, and could provide a means for individuals diagnosed with colorectal cancer to improve outcomes that may be related to their survival. However, to the best of our knowledge, there have been no supervised exercise training programs completed with colorectal cancer survivors. Therefore we are conducting a pilot time-series trial to examine the effects of a 12-week exercise program for colorectal cancer survivors.
 
Objectives

The primary aim of this trial is to determine the safety, feasibility, and preliminary efficacy of a 12-week supervised, combined aerobic and resistance training program in colorectal cancer survivors. We hypothesize that exercise training will be well tolerated, safe, and favourably change aerobic capacity and body composition (i.e. increased lean mass and decreased fat mass) in colorectal cancer survivors. Secondary aims of this trial are to determine the effects of the exercise training program on the muscular strength, flexibility, anthropometric variables (skinfold and circumference measurements, body mass index), oxygen uptake kinetics, self-reported and objectively measured physical functioning, quality of life (QoL), fatigue, determinants of exercise behaviour, sleep quality, depression, self-esteem, and dietary intake in colorectal cancer survivors. We hypothesize that exercise training will improve the above outcomes compared to study baseline values.
 
Study Design

The aims of this trial will be accomplished by assessing colorectal cancer survivors for all outcomes described above at baseline ( 6 months after the completion of adjuvant treatment), following a 4-week a usual care ‘control’ period, and following the 12-week study intervention period. A study questionnaire will also be administered 6-months following completion of the 12-week intervention period to assess patient reported outcomes to determine any lasting effects from the intervention and exercise behaviour at that time.

The 12-week exercise intervention will consist of 3 training sessions per week, with 2 sessions including both aerobic and resistance training components and 1 session of aerobic training only. The aerobic training sessions will be completed on cycle ergometres, and will progress in duration and/or intensity over the study period. The resistance training will be completed on machines with 9 exercises selected to target the major muscle groups in the upper and lower body. Both the resistance training loads and the number of sets will be increased over the 12-week study period.