Description

Breast cancer (BC) is the most common and incident neoplasia in women in Spain and is the third cause of cancer death after lung and colorectal cancer. In turn, BC with hormone receptor expression is the most common and corresponds to approximately 75% of BC cases.

Suppression of ovarian function combined with endocrine treatment (gonadotropin-releasing hormone analog (LHRH) associated with tamoxifen (TAM) or aromatase inhibitors (AI)) has demonstrated a benefit in terms of relapse-free survival (PFS) and overall survival (OS) in premenopausal women diagnosed with localized BC with estrogen receptor (ER) and progesterone (PR) expression. This benefit is mainly focused on patients diagnosed at younger ages (under 45 years) and those with other clinical-pathological factors that imply an exceptionally high risk of relapse.

Despite their benefits, the adverse effects of these treatments are not trivial and include significant toxicities in the cardiorespiratory, metabolic, sexual, and emotional spheres. Metabolic alterations include unfavorable changes in body composition with increases in the percentage of fat and weight that can be observed already in the first months of treatment, which in turn is directly related to an increased risk of BC relapse in these patients.

Changes in body composition with increased fat and decreased muscle mass lead to a pro-inflammatory and dysfunctional state of the immune system, which in turn has been linked to the development of cardiovascular diseases and a worse oncological prognosis.

Scientific evidence suggests that nutritional interventions combined with physical exercise and adapted to physiological needs, the baseline physical level, and the adverse effects derived from the treatments can be safe and effective in achieving adequate weight control and body composition. All of this would favor restoring the immune system's functionality and increasing patients' cardiorespiratory capacity (CRF), which could ultimately translate into a better quality of life.

However, adherence to these programs is low for many reasons, and psycho-oncological support with behavioral interventions could favor adherence to them and stimulate changes in patients' lifestyles.

Despite the evidence, there is no scientific consensus regarding the dosage of exercise and the type of nutritional intervention that should be applied to patients with BC whose treatment includes suppression of ovarian function. In this sense, these interventions should be individualized and adapted to the characteristics of each patient, taking into account all the factors that could affect adherence to these programs.

This project has been designed as a pilot study to evaluate the impact of an intervention program incorporating physical exercise and nutritional control strategies adapted to the baseline situation and level of physical fitness of each premenopausal patient with localized BC on adjuvant treatment with ovarian function suppression.

HYPOTHESIS AND OBJECTIVES: combined intervention based on physical exercise, nutritional control, and individualized psycho-oncological support can achieve weight control and maintain adequate body composition in premenopausal women with localized BC with ER and PR expression who receive aLHRH in combination with TAM or AI as part of their adjuvant treatment.

The study's primary objectives are to evaluate the impact of the combined intervention on weight reduction and favorable modification of body composition in terms of reduction of body fat and increase of lean mass.

The secondary objectives aim to evaluate the impact of the combined intervention program on CRF, heart rate (HR), capillary lactate levels, upper and lower body strength, physical functionality, patient-reported outcomes (PROs) (exercise level, asthenia, self-perception, anxiety, and depression), blood count and biochemistry values that could be modified, nutritional status and side effects of the treatments.

The exploratory objectives, on the other hand, consist of evaluating the impact of the combined intervention on the levels of pro-inflammatory substances (C-reactive protein (CRP) and TNF-alpha) and anti-inflammatory substances (adiponectin) as well as on the levels of oncostatin M, a myokine whose release increases with exercise and seems to stimulate apoptosis and interfere with exercise.