Study to Compare Overall Survival in Medicare Patients With Metastatic Breast Cancer Treated With a Medicine Called Palbociclib in Combination With Aromatase Inhibitor and Aromatase Inhibitor by Itself.

Pfizer779 enrolled

Overview

A retrospective study of de-identified (to preserve patient privacy) patient information from the SEER-Medicare Database to compare overall survival of first line palbociclib + aromatase inhibitor (AI) therapy versus AI therapy alone treatment in women or men aged 65 and older with newly diagnosed hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) metastatic breast cancer (MBC) in the United States

Study Type

OBSERVATIONAL

Enrollment

779

Conditions

Breast Cancer

Interventions

PalbociclibDRUG

Palbociclib with an aromatase inhibitor therapy

Eligibility

Sex: ALLMin age: 65 Years

Medical Language ↔ Plain English

Inclusion Criteria: * De novo metastatic (stage IV) disease at initial breast cancer diagnosis during 2015-2019 * HR+/HER2- molecular subtype at diagnosis * Initiated 1L systemic therapy with palbociclib + AI or AI alone Exclusion Criteria: * Patients will be excluded if their metastatic breast cancer diagnosis was first recorded in a death certificate or at the time of autopsy.

Outcomes

Primary Outcomes

Overall Survival According to Unadjusted Analysis

Overall survival was defined as time in months from the study index date to all cause death. Study index date in this outcome measure was the date of first line of treatment initiation with palbociclib + AI or AI alone after the de novo mBC diagnosis. De novo mBC referred to breast cancer that physician diagnosed for the first time after it had already spread outside of the breast to distant parts of the body. Unadjusted analysis: analysis not considering any covariates, specifically potential differences in baseline characteristics that could confound the association between treatment and survival. Overall survival was assessed using Kaplan-Meier analysis.

Time frame: From index date to death (approximately 69.9 months); retrospective data evaluated in 4 months (approximately) of this study

Overall Survival According to Stabilized Inverse Probability of Treatment Weighted (sIPTW) Analysis

Overall survival was defined as time in months from the study index date to all cause death. Study index date in this outcome measure was the date of first line of treatment initiation with palbociclib + AI or AI alone after the de novo mBC diagnosis. De novo mBC referred to breast cancer that physician diagnosed for the first time after it had already spread outside of the breast to distant parts of the body. sIPTW analysis: stabilized inverse probability treatment weighting. This is a statistical method that reweights participants to create groups with similar baseline characteristics. The analysis therefore adjusts for differences in baseline characteristics that could confound the association between treatment and survival. Overall survival was assessed using Kaplan-Meier analysis.