A assessment of the efficacy of first-/second-line endocrine therapies ± target therapies and chemotherapy in real-life of in patients with hormone receptor-positive (HR+)/HER2-negative metastatic breast cancer has not yet been conducted in Moscow.

Methods: Observational, retrospective study carried out in oncology hospitals in Moscow, in patients with hormone receptor-positive (HR+)/HER2-negative metastatic breast cancer. The descriptive analysis will be conducted for patient characteristics, responses to treatment and treatment outcomes.

This study will provide retrospective chart review of evidence on the use of therapy in routine clinical practice, with a focus in population of Moscow

The combination CDK4/6 inhibitors (CDK4/6i) (Palbociclib, Ribociclib and Abemaciclib) with endocrine therapy (ET, i.e. aro- matase inhibitors (AI) or Fulvestrant) has significantly increased objective response rate (ORR) and progression-free survival (PFS) of first- and second-line treatments in patients with hormone receptor positive, HER2 negative (luminal) mBC. Now this combination is the standard treatment for luminal mBC. Recommendation for endocrine therapy versus chemotherapy as first-line treatment of luminal mBC is endorsed by the main international guidelines such as ASCO and ESO-ESMO guidelines. Endocrine therapy should be used as initial treatment except in cases of immediately life-threatening disease, tumors refractory to endocrine therapy, visceral crisis, or rapid progressive disease that mandate a high response rate treatment. The aim of this study is to provide real-life treatment patterns data for luminal MBC with a focus in population of Moscow

Inclusion Criteria:

• Patient has a histologically and/or cytologically confirmed diagnosis of estrogen-receptor positive and/or progesterone receptor positive breast cancer based on the most recently analyzed tissue sample and all tested by local laboratory. ER should be more than 10% ER positive or Allred ≥5 by local laboratory testing.
• Patient has HER2-negative breast cancer defined as a negative in situ hybridization test or an IHC status of 0, 1+ or 2+. If IHC is 2+, a negative in situ hybridization (FISH, CISH, or SISH) test is required by local laboratory testing and based on the most recently analyzed tissue sample.
• Patient has inoperable locally advanced or metastatic breast cancer
• Patient has adequate bone marrow and organ function
• Patient must be physically well enough that they are capable of treatment

Exclusion Criteria:

• Patient has severe acute or chronic medical or psychiatric condition, including recent or active suicidal ideation or behavior, or laboratory abnormality that may interfere with the interpretation of study results
• no clinical and anamnestic information or information about safety or information about effectiveness treatment

patients with histologically or cytologically confirmed luminal (HR positive/HER2 negative) inoperable locally advanced or metastatic breast cancer