Home-Based Exercise Program During Neoadjuvant Treatment to Improve Fatigue and Quality of Life in Early HER2-Positive and Triple-Negative Breast Cancer Patients

• Home-based exercise program (Behavioral), also known as HoPEx-Breast intervention, Exercise: The home-based program follows the National recommendations on Physical Exercise for Cancer Patients \[Bruno RC, 2023\]. It is logbook-guided and technology-enabled. It consists of: * Two initial supervised explanatory sessions, in the Physic and Rehabilitation Medicine Gym of our institution. * Followed by 2 muscular training sessions + 3 additional periods of aerobic exercise per week in their home environment until the end of neoadjuvant treatment. Patients are given a logbook with instructions and a sports bracelet for heart rate monitoring. The training sessions will be monitored by smartwatch heart rate measurements and self-notion of effort according to Borg Categorization \[Borg GA, 1982\] and recorded by the participants in the Mi Fitness application or an Exercise Diary.\[Nilsen TS, 2018\]
• Promotion of Healthy Physical Activity (Behavioral), also known as Short counseling, Control: The short counseling consists of at least one opportunistic talk for promotion of physical activity, taking up to 5 minutes, during the Medical Oncology appointment or during Physical Assessments at T0. It should follow the instructions of the Portuguese Directorate-General of Health, "Short Counselling for the Promotion of Physical Activity", including the delivery of a Physical Activity Guide plus a Auxiliar of Decision or a Plan of Action or Maintenance.\[Mendes R, 2020\] All patients will receive a Guide about Nutrition for Cancer Patients \[Capela AM, 2023\] and may be offered Nutritional, Psychological or other additional consultations according to clinical judgement of the Medical Oncologist.

Primary outcomes

• Health-related quality of life [From enrolement to up to 2 months after the end of intervention period, i.e. after breast surgery]: Changes in health-related quality of life, measured by EORTC QLQ-30, from baseline (T0) to 12 weeks of systemic therapy (T1) and to 1 month after surgery (T2)
• Fatigue [From enrolement to up to 2 months after the end of intervention period, i.e. after breast surgery]: Changes in patient-reported fatigue, measured by FACIT-Fatigue, from baseline (T0) to 12 weeks of systemic therapy (T1) and to 1 month after surgery (T2)

Secondary outcomes

• Exercise capacity [From enrolement to up to 2 months after the end of intervention period, i.e. after breast surgery]: Change on exercise capacity, measured as 6MWT distance, from T0 to T1 and from T0 to T2.
• Physical activity levels [From enrolement to up to 2 months after the end of intervention period, i.e. after breast surgery]: Change on physical activity levels, measured by IPAQ-SF questionnaire (or by accelerometer), from T0 to T1 and from T0 to T2.
• Hand grip strength [From enrolement to up to 2 months after the end of intervention period, i.e. after breast surgery]: Change on hand grip strength, from T0 to T1 and from T0 to T2.
• Timed Up and Go [From enrolement to up to 2 months after the end of intervention period, i.e. after breast surgery]: Change on "Timed Up and Go", from T0 to T1 and from T0 to T2.
• Complete pathologic response rate [From 1 month up to 2 months after breast surgery. Data can be restropectively collected from the pathologic report after this period.]: Percentage of participants of each arm that achieved complete pathological response, as assessed by a dedicated pathologist from our institution, blinded for the intervention.
• Compliance to intervention [From enrolement to up to 2 months after the end of intervention period, i.e. after breast surgery]: Rate of participants that accepted to participate, that completed intervention, and the percentage of programed exercise sessions that were completed ", at T0, T1 and T2.
• Safety [From enrolement to up to 2 months after the end of intervention period, i.e. after breast surgery]: Reported adverse events potentially related to exercise.
• Compliance to questionnaires [From enrolement to up to 2 months after the end of intervention period, i.e. after breast surgery]: Rate of participants who replied to the quality of life and fatigue questionnaires, at T0, T1 and T2.

Other outcomes

• Lymphedema [From enrolement to up to 12 months after the end of intervention period.]: Changes in arms circumferences from T0 to T2, and from T0 to 6-12m after the surgery.
• Disease free survival [From date of randomization until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 120 months]: Time from the beginning of neoadjuvant treatment until death or recurrence of breast cancer disease.
• Overall survival [From date of randomization until the date of death from any cause, assessed up to 120 months]: Time from the beginning of neoadjuvant treatment until death.
• Health costs [From enrolement up to 6 months after surgery.]: Health costs estimation based on number of emergency episodes, in-hospital days, delayed day hospital sessions, off-labor days.

Sex: All, ages: 18 Years to any

Inclusion Criteria (must meet all):

* Adult patients,
* Any gender,
* Diagnosed with breast cancer, of HER2-positive or triple-negative subtypes,
* Proposed to neoadjuvant systemic cancer therapy. May be included: Patients non-eligible for anthracyclines or anti-HER2 therapies; patients with oligometastatic disease proposed for primary/neoadjuvant systemic cancer therapy with intent of radical treatment.

Exclusion Criteria:

* Patients that do not perform any neoadjuvant antineoplastic therapy, for example because of refusal, impeditive comorbidities, re-staging or other reasons.
* Contraindications for exercise or impediments to perform the intervention program, because of previous comorbidities or according to medical assessment (e.g. blindness).
* Patients who are unable to take questionnaires because of language or cognitive barriers (even with small help from a relative or investigator, still cannot answer properly).
* Luminal-like subtype, with hormonal receptor expression and HER2-negative.

Individual participants will be discontinued from the trial, in agreement with their physician where appropriate, if any health problem arises that will significantly affect their safety to participate in exercise for more than one month or if the participant decides to withdraw their consent.

• António Araújo, MD PhD, Study director, Centro Hospitalar Universitário de Santo António, Unidade Local de Saúde de Santo António, Serviço de Oncologia Médica, Porto, Portugal. Oncology Research, UMIB, ICBAS-School of Medicine and Biomedical Sciences, University of Porto, Porto, Portugal.