Observational investigation of participants who are given neoadjuvant treatment for invasive breast cancer. The scope of the study is to collect information on standardized treatment results, to explore the causes of dose modification and its effect on efficacy, to explore potential prognostic factors, and to explore the long-term side effects of different treatment modalities.

The purpose of the study is based on the uniform application of international guidelines in Hungarian conditions. The standardized circumstances may lead to optimization of neoadjuvant therapy, it may facilitate subsequent data analysis, provide a basis for prospective clinical questions, and demonstrate improvement in pathologic complete remission (pCR) and overall survival (OS) compared to historical control. It may make possible to collect real-life data on each therapeutic option: efficacy, side effects, dose reduction, dose intensity, long-term consequences. The main scope is to collect prospective data to explore prognostic and predictive factors. The auxiliary aim is the assessment and comparison of quality of life during specific treatments and their side effects.

Inclusion Criteria:

1. Participant over 18 years of age .

2. Histologically confirmed (core biopsy) invasive breast tumor.

3. Tumor extent for the indication:

   • regression must be achieved for radical surgical removal or
   • regression is required for breast-conserving surgery or
   • if hormone receptor (HR)-positive and Her2-: stage IIB (cT2N1 or cT3NO) - IIIC,
   • if HR-negative: stage IIA (cT2N0 or cT0-1N1) - IIIC Note: In the case of a locally advanced, irresectable case, if the possibility of radical surgery later is a realistic goal, the participant may be included in the study.

4. Appropriate general condition: ECOG 0-1

5. Proper organ function

   • Neutrophil count ≥ 1.5 G / l, platelet count ≥ 100 G / l, hemoglobin ≥ 10 g / dl
   • Alanine aminotransferase (ALT) / aspartate aminotransferase (AST) is less than 1.5 times the upper limit of the normal range
   • bilirubin less than 1.5 times the upper limit of the normal range (except Gilbert's disease, where less than 3 times)
   • creatinine less than 1.5 times the upper limit of the normal range or estimated glomerular filtration rate (eGFR) higher than 60 ml / min

Exclusion Criteria:

1. Proven or suspected distant metastasis.
2. No staging studies have been performed: at least chest x-ray, abdominal ultrasound. It is preferred to perform CT from the chest, abdomen, pelvic regions and bone isotope, or PET / CT if possible in case of lymph node involvement.
3. Known significant heart disease: major arrhythmia or significant conduction defect (grade 2 or more), infarction or unstable angina within 6 months, cardiac collapse without appropriate therapy, long QT syndrome, heart failure (≥New York Heart Association/NYHA II)
4. Other severe acute or chronic conditions (organic or psychiatric illness, laboratory abnormality) that, in the opinion of the treating physician, result in an unacceptable increase in the risk of chemotherapy and are contraindicated in routine clinical practice.
5. Pregnancy or if the participant does not agree to use an appropriate non-hormonal method of contraception.

Breast cancer patients for whom neoadjuvant therapy is proposed by multidisciplinary team

The individual participant data are not planned to be shared with other researchers but will be available upon request except personal data