Role of physical exercise in modulating the insulin-like growth factor system for improving breast cancer outcomes: A meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 34098007 · doi:10.1016/j.exger.2021.111435
What was done
A systematic review and meta-analysis was conducted across PubMed, Embase, CENTRAL, and SPORTDiscus through October 2020. The authors evaluated randomized controlled trials assessing the impact of physical exercise interventions on insulin-like growth factor (IGF) markers and glycemic indices in women with breast cancer.
What was found
Twelve randomized controlled trials comprising 736 participants were included. Exercise resulted in significant reductions in: - Serum insulin: MD -1.24 μIU/mL (95% CI -2.12 to -0.36, p = 0.006) - IGF-II: MD -54.21 ng/mL (95% CI -61.41 to -47.00, p < 0.00001) - IGFBP-1: MD -2.90 ng/mL (95% CI -3.91 to -1.90, p < 0.00001) - HOMA score: MD -0.47 (95% CI -0.87 to -0.06, p = 0.02) Changes were not statistically significant for: - Serum glucose: MD -0.71 mg/dL (95% CI -2.57 to 1.15, p = 0.45) - IGF-I: MD -5.23 ng/mL (95% CI -13.00 to 2.53, p = 0.19)
Why it matters
Physical exercise can modulate hyperinsulinemia and select IGF pathway components in breast cancer patients, though effects on circulating IGF-I and glucose were not statistically significant.
Limits
The total sample size across 12 trials is relatively modest (736 participants, mean ~61 per trial). The abstract omits details regarding exercise modality, duration, intensity, adherence, cancer stage, concurrent oncology treatments, and long-term clinical or oncologic endpoints.
Cited by
- supports Exercise reduces levels of insulin and insulin-like growth factor (IGF), which promote cancer cell growth and division.