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

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

This is a cross-sectional, single-center study. It aims to compare women with breast cancer at the end of chemotherapy (Group 1 - patient group) with healthy women (with no history of cancer) matched for age, weight, and physical activity level (Group 2 - control group).

Both groups will undergo a single evaluation session lasting two hours and 25 minutes, during which cardiovascular responses and levels of neuromuscular fatigue will be assessed and compared. For the patient group, this evaluation will take place within the first three weeks following the end of chemotherapy treatment. The details and sequence of the assessments are provided in the section dedicated to the trial description.

Inclusion Criteria:

Patient group :

• Stage I to III breast cancer
• Having completed (neo)adjuvant chemotherapy treatment less than three weeks ago

Control group :

- healthy women (no history of cancer) of similar age, weight, and physical activity level

Exclusion Criteria:

• History of cancer
• Any known chronic pathology
• Protected minor or adult
• Psychiatric, musculoskeletal or neurological problems
• Implantation of a pacemaker
• Pregnant woman
• Presenting at least one contraindication to the use of transient blood flow occlusion