Improving Response to Chemotherapy by Adding Physical Exercise in the Neoadjuvant Setting of Breast Cancer Patients

Pathological response as the primary outcome will be assessed by a blinded pathologist from the tumour surgical specimens after the breast surgery (post-intervention) and will be defined as complete, partial or no response. Besides pathological complete response (defined as ypT0/ypN0), groups will be compared as those with response (complete or partial) versus those with no response. The residual cancer burden which quantifies residual disease after NAC (post-intervention) will also be assessed.

Number of participants with clinically assessed treatment-related adverse events. Will be assessed according to the Common Terminology Criteria for Adverse Events v5.0. The scale uses a minimal value of 1 and a maximal value of 5 to grade each adverse event, with higher scores representing worse outcomes.

Number of participants with patient-reported adverse events. Will be assessed using the Patient reported outcomes version of the Common Terminology Criteria for Adverse Events v1.0 questionnaire. The scale uses a minimal rating 0 and a maximal rating of 4 to grade each adverse event, with higher scores representing worse outcomes.

Chemotherapy relative dose intensity will be calculated by the following formula: (Delivered dose intensity / Standard dose intensity) x 100%, where Delivered dose intensity = (Delivered total dose, in mg/m2)/(actual time to complete chemotherapy with imputation for missed cycles, in days) and Standard Dose Intensity = (Standard total dose, in mg/m2)/(standard time to complete chemotherapy, in days).

Number of patients that had to reduce the dose of chemotherapy from the dose of chemotherapy initially prescribed (standard dose intensity).

Number of patients that had to delay a cycle of chemotherapy, in comparison to what had initially been prescribed (standard dose intensity).

Number of patients that had to interrupt chemotherapy before the standard dose had been administrated.

Assessed at Histology Slides. Intratumoral and stromal infiltrating lymphocyte (TIL) population will be assessed in tumour biopsies (at baseline) and surgical resection specimens collected from the post-neoadjuvant chemotherapy surgery (post-intervention). This will be used to compute intratumoral and stromal TIL's score, recorded as the percentage of TIL's on the analysed area. Only stromal TIL ́s will be quantified in patients with complete pathological response.

Assessed at Histology Slides. Ki67 will be assessed in tumour biopsies (at baseline) and surgical resection specimens collected from the post-neoadjuvant chemotherapy surgery (post-intervention).

Flow cytometry will be the method used to assess the number of CD3+CD8+ (cytotoxic T cells) on peripheral blood lymphocytes.

Flow cytometry will be the method used to assess the number of CD3+CD56+ (natural killer T cells) on peripheral blood lymphocytes.

Flow cytometry will be the method used to assess the number of CD3+CD4+ (T helper cells) on peripheral blood lymphocytes.

The enzyme-linked immunosorbent assay method will be used to identify the concentration of the cytokine IFN-gamma on plasma.

The enzyme-linked immunosorbent assay method will be used to identify the concentration of the cytokine TNF-alpha on plasma.

The enzyme-linked immunosorbent assay method will be used to identify the concentration of the hormone Irisin on plasma.

The enzyme-linked immunosorbent assay method will be used to identify the concentration of the protein SPARC on plasma.

The enzyme-linked immunosorbent assay method will be used to identify the concentration of the protein Decorin on plasma.

The enzyme-linked immunosorbent assay method will be used to identify the concentration of the cytokine Oncostatin-M on plasma.

As an indicator of cardiorespiratory fitness, the number of meters that the participant is able to walk/run in the 10 meter-incremental shuttle walk test will be assessed.

The participant will be subjected to a maximal incremental conventional cardiopulmonary exercise test on a treadmill. The maximal intensity the participant is able to attain in this assessment will be recorded in METS.

The 30 second sit-to-stand test will be used to assess lower limb dynamic muscular strength. The maximal number of repetitions the participant is able to perform in the 30 second sit-to-stand test will be recorded.

The maximal force (in kilograms) the participant is able to produce in an isometric handgrip test will be recorded, using a hand dynamometer.

The maximal force (in kilograms) the participant is able to produce in an isometric strength test for the quadriceps muscle will be recorded using a load cell. Additionally, the time to maximal strength (in seconds) will also be recorded.

Assessed by accelerometry over a period of seven days, the time (in minutes) that the participants spend in light, moderate and vigorous physical activity will be recorded. Additionally, the time (in minutes) spent in sedentary behaviours will also be recorded.

The questionnaires European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire (version 1.0) and the Breast 23 Questionnaire (version 1.0) will be implemented to assess cancer-related quality of life. The final scores will range from 0 to 100, with higher scores on the functional scales representing a high level of functioning and higher scores on the symptom scales implying a stronger symptom burden.

Using bioimpedance, the participants' total body weight, in kilograms, will be assessed with the lightest clothes possible.

Using bioimpedance, the participants' total body skeletal muscle mass, in kilograms, will be assessed.

Using bioimpedance, the participants' total body fat, in kilograms, will be assessed.

Using weight and height, these parameters will be combined to report BMI in kg/m^2.