Research Article A Multicenter Randomized Trial of the Effects of Exercise Dose and Type on Psychosocial Distress in Breast Cancer Patients Undergoing Chemotherapy

Background:Exercisemay improvepsychosocial distress inpatientswith cancer; however, fewstudies have examined the effects of different types or doses of exercise, or whether exercise effects are related to baseline depression levels. Methods: In a multicenter trial in Canada, we randomized 301 patients with breast cancer initiating chemotherapy to thrice weekly, supervised exercise consisting of either a standard dose of 25 to 30 minutes of aerobic exercise (STAN; n 96), a higher dose of 50 to 60 minutes of aerobic exercise (HIGH; n 101), or a combined dose of 50 to 60 minutes of aerobic and resistance exercise (COMB; n 104). The primary endpoint was depression assessed by the Center for Epidemiological Studies-Depression scale at baseline, twice during chemotherapy, and postchemotherapy. Secondary endpoints were anxiety, perceived stress, and self-esteem. Results:RepeatedmeasuresANOVA indicated that neitherHIGH [mean difference0.9; 95 % confidence interval (CI), þ0.0 to 1.8; P 0.061] nor COMB (mean difference 0.4; 95 % CI,þ0.5 to 1.3; P 0.36) was superior to STAN for managing depressive symptoms. In a planned subgroup analysis, there was a significant interaction with baseline depression levels (Pinteraction 0.027) indicating that COMB and HIGH were effective for managing depressive symptoms in patients with clinical levels of depressive symptoms at baseline. Conclusions:Comparedwith a standard volumeof aerobic exercise, higher volumes of exercise did not help managedepressive symptoms inunselectedpatientswithbreast cancer receiving chemotherapy, but theywere effective in patients with clinical levels of depressive symptoms at baseline. Impact: A phase III exercise trial targeting depressed patients with breast cancer is warranted. Cancer Epidemiol Biomarkers Prev; 1–8. 2014 AACR