Effects of Chemotherapy Treatment on Metaboreflex, Mechanoreflex, and Baroreflex Function: PROTECT-08B Study

Conditions studied

Breast Adenocarcinoma

About this study

Breast cancer is the most common cancer worldwide, with over 2.2 million new cases diagnosed in 2020. Treatments such as chemotherapy often lead to a reduced exercise capacity, mainly due to cardiovascular and neuromuscular dysfunctions. This decline appears to be primarily caused by increased central fatigue, while peripheral fatigue remains unchanged. This imbalance suggests a hyperactivation of type III-IV afferent nerve fibers, which are involved in the metaboreflex-a mechanism that significantly influences cardiovascular responses during exercise. Two non-invasive methods, post-exercise circulatory occlusion (PECO) and passive leg movement (PLM), will be used to assess this hyperactivity in patients. Additionally, baroreflex function-crucial for regulating blood pressure-will be evaluated using a direct method to determine its sensitivity and reactivity. By comparing patients with healthy controls under submaximal stimuli, this study aims to better understand chemotherapy-induced cardiovascular dysfunctions. Ultimately, the goal is to design personalized exercise programs to restore cardiovascular function and reduce treatment-related side effects.

Interventions

• Other: Test of neuromuscular fatigue and associated hemodynamic responses — Baseline measurements of neuromuscular function and hemodynamic responses will be performed. Baroreflex sensitivity will be assessed using a neck collar applying positive and negative pressures to stimulate the carotid baroreceptors, thereby modulating baroreflex activity in a dose-dependent manner. Mechanoreflex activation will then be evaluated using the passive leg movement (PLM) technique. After the PLM, participants will perform four fatigue tasks, each followed by 2 minutes of post-exercise circulatory occlusion (PECO). Tasks involve isometric quadriceps contractions at 20% of maximal voluntary contraction (MVC) during 1 min (block 1), 2 min (blocks 2 and 3) and until failure (block4). Neuromuscular function will be assessed through MVC changes and quadriceps twitch responses. Mean arterial pressure (MAP) will be recorded continuously. Metaboreflex activity will be determined by plotting post-PECO changes in peripheral fatigue against the change in MAP during PECO phases.

Primary outcomes

• Characterize the metaboreflex in breast cancer patients at the end of chemotherapy treatment (3 weeks after end of chemotherapy)

Eligibility information

Study locations

• Institut de cancérologie Strasbourg Europe, Strasbourg, 67100 France