Multimodal Prehabilitation Program That Combines Physical Exercise, Psychological Intervention and Nutritional Support to Improve the Response to Neoadjuvant Chemoterhapy in Early Breast Cancer Patients

The main variable of the trial is the RCB index score, obtained from the histological specimen of the oncological surgery performed after NAC. The four levels of response of the RCB index (RCB 0, I, II and III) will be divided into a favorable profile of response (fRCB), that will include cathegories RCB 0 and I, and an unfavorable response profile (uRCB), including RCB II and III.

It is estimated that the average rate of a favorable RCB (fRCB) score, including RCB 0 and RCB I, will be approximately 40% in the control arm. Parallelly, the expected rates of unfavorable RCB (uRCB) scores, including RCB II and RCB III, are 60%. The objective is to improve the response rates by 20% in the intervention group, with 60% of fRCB scores and 40% of uRCB scores in this group.

Formalin fixed-paraffin embedded tumor tissue blocks will be analyzed by hematoxylin and eosin staining, to check tumor surface area. Samples with ≥20% of tumor cells will be selected for RNA extraction. The High Pure FFPET RNA Isolation Kit (Roche) will purify RNA from FFPE tumor samples. A minimum of ∼100 ng of total RNA will be used to measure the expression of 185 breast cancer-related and immune-related genes including the genes of PAM50 and HER2DX and 7 housekeeping genes using the nCounter platform (Nanostring Technologies, Seattle, USA). The gene expression for each sample will be independently normalized to the geometric mean of housekeeping genes. The 14-gene immunoglobulin (IGG) signature (i.e., CD27, CD79A, HLA-C, IGJ, IGKC, IGL, IGLV3-25, IL2RG, CXCL8, LAX1, NTN3, PIM2, POU2AF1 and TNFRSF17) will be calculated.

Registered according to the TNM system by the. American Joint Committee on Cancer (AJCC) 8th edition

Reported as the percentage (%) of neoplastic cells in the surgical specimen.

The assessment will involve evaluating microvascular density through immunohistochemical staining for CD31 on tumor or tumor bed sections. This evaluation follows a two-step process:

• Hotspot Area Selection: Identification of hotspot areas under a light microscope at 4x magnification.
• Manual Counting: Manual counting of all vascular lumens in the selected field at 20x magnification.

This method ensures precise quantification of vascular density in both the peritumoral and tumor bed regions.

They will be recorded by the research team and classified according to the CTCAE (Common Terminology Criteria for Adverse Events) version 5.0. Data will be collected at the end of NAC in both groups.

The proportion of patients who received the full course of chemotherapy with the corresponding dose. This will be evaluated before surgery in both groups.

Need for hospitalization during neoadjuvant chemotherapy: the number of hospital admissions prior to surgery will be recorded as an absolute count.

Length of hospitalization after oncological surgery: Measured in days.

Pain will be assessed using the Visual Analogue Scale (VAS) during the hospital stay. The scale ranges from 0 to 10, with higher scores indicating greater pain severity.

These will be classified based on timing as immediate postoperative complications (during the procedure or within 24 hours), early complications (up to 7 days post-surgery), and late postoperative complications (from 7 to 30 days post-surgery). Severity will be recorded using the Clavien-Dindo scale.

Emergency visits and readmissions will also be reported: The absolute number, reasons, and length of hospital stay will be recorded up to 30 days post-surgery.

Weight in kilograms will be registered before and after NACT

Body mass index (BMI) will be measured before and after chemotherapy (kg/m2)

The international questionnaire of Physical Activity (IPAQ) will be used to register the level of physical activity of the subjects. Minimum score: 0 MET-min/week. Maximum score: no formal upper limit (normally 20,000 MET-min/week). According to the punctuation, the level of physical activity can be classified into low (< 600 MET-min/week), moderate (≥ 600 and < 3,000 MET-min/week) or high (≥ 3,000 MET-min/week).

Assessed through the hand grip strength test, using a hand-held dynamometer (measured in kilograms).

To evaluate the general physical status of patients (as an estimate of VO₂), the 30-Second Sit-to-Stand Test will be performed and recorded as an absolute number.

Through a Cardiopulmonary Exercise Testing (CPET), the oxygen consumption will be measured in all patients (ml/kg/min) before and after finishing neoadjuvant chemotherapy.

Measured using the EORTC QLQ-30 questionnaire (0-100 points: higher scores on functional scales and the global health status scale indicate better functioning and quality of life, while higher scores on symptom scales indicate a higher level of symptoms).

Assessed using the Hospital Anxiety and Depression Scale (HADS), which score ranges from 0 to 21 points. Higher scores indicate more severe symptoms of anxiety or depression: 0-7: Normal or no significant anxiety/depression, 8-10: Mild anxiety/depression, 11-15: Moderate anxiety/depression, 16-21: Severe anxiety/depression.

Assessed through the Five Facet Mindfulness Questionnaire (FFMQ). Score 39 - 195 points. A higher score indicates a greater level of mindfulness.

Complete blood analysis: Including liver and renal profile, blood count, ionogram, albumin, prealbumin, glucose, interleukin-6 and IGF-1.

Validated Questionnaire of Mediterranean Diet Adherence (MEDAS-14). Scoring: 0-14 points. Higher scores mean higher adherence to Mediterranean diet, being a score equal or superior to 9 considered a good adherence to such diet.

Measured by the number of sessions attended relative to the scheduled sessions.

Assessment of how patients perceive and feel about their physical appearance after the finalization of breast cancer treatments through the validated questionnaire Body Image Scale Questionnaire (BIS).