HR+/ HER2- Advanced/ Metastatic Breast Cancer Real World Treatment Patterns and Outcomes

Study Overview
=================
Brief Summary
-----------------
This is a retrospective, observational study that will document the treatment patterns and clinical outcomes of patients diagnosed with HR+/HER2- A/MBC who received CDK4/6i combination therapy with aromatase inhibitors (AI) as the initial endocrine-based therapy in the A/MBC setting.

Official Title
-----------------
Patient Characteristics, Treatment Patterns, and Clinical Outcomes in Patients Diagnosed With HR+/HER2- Advanced/Metastatic Breast Cancer Receiving CDK4/6i + Aromatase Inhibitor (AI) Combination Therapy as Initial Endocrine-based Treatment

Conditions
-----------------
Breast Cancer

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Female or male sex. Diagnosis (confirmed by clinical review) of A/MBC, defined as breast cancer at stage IIIB, stage IIIC, stage IV or identified as having distant metastasis. Age ≥18 years at A/MBC diagnosis. Initiated a CDK4/6i in combination with an AI as initial endocrine-based therapy after A/MBC diagnosis on or after 2/3/2015 and before 4/1/2019. •Note that the date of the start of the inclusion period reflects the month that the first CDK4/6i (ie, Palbociclib) received U.S. FDA approval. Evidence of ER or PR positive disease, or absence of any indication of ER and PR negative disease closest to A/MBC diagnosis (ie, patients are eligible without affirmative indication of ER/PR+ status as long as ER/PR- indication is not present). Evidence of HER2 negative disease, or absence of any indication of HER2 positive disease closest to A/MBC diagnosis (ie, patients are eligible without affirmative indication of HER2- status as long as HER2+ indication is not present). Exclusion Criteria: 1. Enrollment in an interventional clinical trial for A/MBC during the study observation period.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Breast Cancer Patients<br>HR + /HER2- Advanced/Metastatic Breast Cancer patients in U.S.A | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Different Type of Treatment Regimens | Treatment regimen was defined as one or more anti-cancer agents given in combination, over a period of time. | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Number of Participants Who Received Different Treatment Sequence Across Lines | Lines of therapy was defined as the following progression-based lines, in which a disease progression must occur for a new regimen to be interpreted as a new line of therapy. Disease progression was taken to have occurred when a pathology report or radiological scan indicated disease progression and/or there was a physician progress note consistent with that determination. | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Number of Participants With Start and End Dose of CDK4/6 Inhibitors |  | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Duration of Treatment of CDK4/6 Inhibitors |  | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Number of Participants With Reason for Treatment Discontinuation of CDK4/6 Inhibitors |  | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Time to Dose Discontinuation of CDK4/6 Inhibitors |  | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Number of Participants With Type of Dose Adjustments of CDK4/6 Inhibitors |  | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Time to First Dose Adjustment of CDK4/6 Inhibitors |  | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Real Progression Free Survival (rwPFS) | rwPFS was defined as the time from the index date to disease progression, death, or end of record or end of data availability, whichever comes first. Index date was defined as the date of A/MBC diagnosis. Disease progression was taken to have occurred when a pathology report or radiological scan indicated disease progression and/or there was a physician progress note consistent with that determination. | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Overall Survival (OS) | OS was defined as the time between the index date to disease progression, death due to any cause or end of data availability, whichever comes first. Index date was defined as the date of A/MBC diagnosis. Disease progression was taken to have occurred when a pathology report or radiological scan indicated disease progression and/or there was a physician progress note consistent with that determination | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Real-World Tumor Response (rwTR) | rwTR was defined as the best overall response for each regimen. Responses were classified as complete response (CR), partial response (PR), stable disease (SD), progressive disease (PD), not evaluable (NE), or undocumented. The date of the first positive response (CR or PR) and of the best overall response for each regimen was collected. CR: Complete resolution of all visible disease. PR: Partial reduction in size of visible disease in some or all areas without any areas of increase in visible disease. SD: no change in size of visible disease. PD: Disease progression was taken to have occurred when a pathology report or radiological scan indicated disease progression and/or there was a physician progress note consistent with that determination. | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Percentage of Participants With Complete Response (CR) or Partial Response (PR) | CR: Complete resolution of all visible disease. PR: Partial reduction in size of visible disease in some or all areas without any areas of increase in visible disease. | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Time to First Positive Response |  | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Duration of Response (DOR) | DOR: time from first documented occurrence of response (CR or PR) until date of first documented PD or death due to underlying cancer. Participants without a PD assessment or death were censored at the data cutoff date. CR: Complete resolution of all visible disease. PR: Partial reduction in size of visible disease in some or all areas without any areas of increase in visible disease. PD: Disease progression was taken to have occurred when a pathology report or radiological scan indicated disease progression and/or there was a physician progress note consistent with that determination. | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) | 
| Duration of Initial Endocrine-based Treatment |  | From the start date of the initial endocrine-based therapy to the end date of the initial endocrine-based therapy (during 15 months of retrospective observation period) | 
| Duration of Treatment |  | From the start date of the initial endocrine-based therapy to the end date of the initial endocrine-based therapy (during 15 months of retrospective observation period) | 
| Duration of Follow-up |  | From start to end of treatment, for a maximum of 33 months (during 15 months of retrospective observation period) |