Randomized trial of exercise on cancer-related blood biomarkers and survival in women with ovarian cancer

Background: In randomized trials in women with breast cancer, exercise has been shown to have beneficial effects on cancer-related circulating biomarkers that may impact survival. Such studies are lacking for ovarian cancer. Methods: This secondary analysis of a published randomized controlled trial examined the impact of a 6-month exercise intervention versus attention-control on change in prespecified circulating biomarkers (cancer antigen 125 (CA-125), C-reactive protein (CRP), insulin-like growth factor-1(IGF-1), insulin and leptin) in a subset of participants who provided a fasting blood draw (N = 104/144) at enrollment and at 6 months. Change in biomarkers between study arms was compared using a linear mixed effects model analysis. An exploratory analysis of the exercise intervention versus attention-control on all-cause mortality included all (N = 144) participants. All statistical tests were two-sided. Results: Participants included in the biomarker analysis were 57.0 +/- 8.8 (mean +/- SD) years old and 1.6 +/- 0.9 years post-diagnosis. Adherence to the exercise intervention was 176.4 +/- 63.5 min/week. Post intervention IGF-1 (group difference in change: -14.2 (-26.1 to -2.3) ng/mL (least squared means (95% CI))) and leptin (-8.9 (-16.5 to -1.4) ng/mL) were significantly reduced in the exercise group (N = 53) compared to those in attention-control (N = 51). No group difference in change was seen for CA-125 (p = 0.54), CRP (p = 0.95), or insulin (p = 0.37). With median follow-up of 70 months [range 6.6-105.4 months], 50/144 (34.7%) (exercise group; 24/74 (32.4%) versus attention-control group; 26/70 (37.1%)) participants died with no between group difference in overall survival (p = 0.99). Conclusions: Further studies are needed to determine the clinical significance of exercise-induced changes in cancer-related circulating biomarkers in women with ovarian cancer.