Strength Training During Chemotherapy Elevates IL-6, IL-17 in Breast Cancer, No Autophagy Changes

Chemotherapy for breast cancer often leads to debilitating side effects like fatigue, muscle weakness, and inflammation, contributing to treatment non-completion and reduced quality of life. These toxicities are partly mediated by systemic inflammation and altered muscle metabolism, including processes like autophagy, which are crucial for cellular maintenance and adaptation to stress. Understanding how interventions like exercise impact these pathways could offer strategies to mitigate adverse effects. This study investigates if strength training can modulate inflammatory cytokines and muscle autophagy during chemotherapy, addressing a critical gap in supportive care.

Researchers randomized women with breast cancer to either a strength training group (n = 23) or a usual care group (n = 17) during chemotherapy. The training group completed supervised strength training twice weekly throughout their chemotherapy regimen, while the usual care group maintained habitual physical activity. Assessments were conducted pre-chemotherapy (T0) and post-chemotherapy/intervention (T1). Primary endpoints included quantifying serum cytokines (IFN-γ, IL-1RA, IL-6, IL-8, IL-10, IL-17, MCP-1, TNF-α) and analyzing muscle biopsies for autophagy- and heat-shock-related proteins using unspecified biochemical assays. Exploratory analyses also assessed associations between changes in physiological outcomes (strength, fitness, capillary density) and biomarker responses.

In the strength training group, mean serum IL-6 significantly increased from 1.21 ± 0.47 to 1.69 ± 0.71 pg/mL, and IL-17 rose from 1.24 ± 0.25 to 2.18 ± 0.87 pg/mL. While IFN-γ also increased in the training group (from 14.4 ± 8.6 to 28.8 ± 17.3 pg/mL), the group×time interaction for IFN-γ was not statistically significant. Conversely, IL-6 and IL-17 decreased in the usual care group over the same period. No significant changes were observed in other measured cytokines, nor in any of the targeted skeletal muscle autophagy- or heat-shock-related proteins across either group. Exploratory analyses revealed no associations between changes in muscle strength and autophagy proteins, cardiorespiratory fitness and cytokines, or capillary density and cytokines. This suggests a dissociation between the systemic inflammatory response and local muscle protein regulation in this context.

Despite significant group differences in IL-6 and IL-17 over time, strength training during chemotherapy did not alter selected skeletal muscle autophagy- or heat-shock-related proteins.