Breast Cancer
Conditions
Keywords
Breast neoplasm, Hormone receptor-positive Human epidermal growth factor receptor 2 negative (HR+,HER2-), palbociclib, Metastatic, Medicare, SEER-Medicare
Brief summary
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
Interventions
DRUGPalbociclib
Palbociclib with an aromatase inhibitor therapy
DRUGAromatase Inhibitor
Aromatase Inhibitor Therapy
Sponsors
Pfizer
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
65 Years to No maximum
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Overall Survival According to Unadjusted Analysis | From index date to death (approximately 69.9 months); retrospective data evaluated in 4 months (approximately) of this study | 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. |
| Overall Survival According to Stabilized Inverse Probability of Treatment Weighted (sIPTW) Analysis | From index date to death (approximately 69.9 months); retrospective data evaluated in 4 months (approximately) of this study | 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. |
Countries
United States
Participant flow
Recruitment details
Data of eligible participants diagnosed with hormone receptor (HR+)/ human epidermal growth factor receptor 2-negative (HER2) metastatic breast cancer (mBC) treated with palbociclib in combination with aromatase inhibitor (AI) was extracted from clinical and administrative claims data from the linked surveillance, epidemiology, and end results (SEER)-Medicare database from 1-August-2014 until 31-December-2020 were observed retrospectively.
Pre-assignment details
Available data from eligible participants was evaluated in approximately 4 months of this retrospective observational study.
Participants by arm
| Arm | Count |
|---|---|
| AI Alone Participants who received an AI (alone) as first line therapy under standard real world routine clinical practice for HR+/HER2- mBC during the period 1-February-2015 to 30-June-2020 were included in this retrospective observational study. | 483 |
| Palbociclib + AI Participants who received Palbociclib in combination with an AI under standard real world routine clinical practice for HR+/HER2- mBC during the period 1-February-2015 to 30-June-2020 were included in this retrospective observational study. | 296 |
| Total | 779 |
Baseline characteristics
| Characteristic | AI Alone | Palbociclib + AI | Total |
|---|---|---|---|
| Age, Customized 65-69 years | 86 Participants | 86 Participants | 172 Participants |
| Age, Customized 70-74 years | 91 Participants | 84 Participants | 175 Participants |
| Age, Customized 75-79 years | 101 Participants | 67 Participants | 168 Participants |
| Age, Customized Greater than or equal to (>=) 80 years | 205 Participants | 59 Participants | 264 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 23 Participants | 14 Participants | 37 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 460 Participants | 282 Participants | 742 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized Race American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized Race Asian or Pacific Islander | 14 Participants | 13 Participants | 27 Participants |
| Race/Ethnicity, Customized Race Black | 45 Participants | 23 Participants | 68 Participants |
| Race/Ethnicity, Customized Race Other or unknown | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized Race White | 417 Participants | 256 Participants | 673 Participants |
| Sex: Female, Male Female | 480 Participants | 294 Participants | 774 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 279 / 483 | 113 / 296 |
| other Total, other adverse events | 0 / 0 | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 | 0 / 0 |
Outcome results
Primary
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.
Time frame: From index date to death (approximately 69.9 months); retrospective data evaluated in 4 months (approximately) of this study
Population: Analysis population included all eligible participants whose data was extracted and evaluated for the retrospective analysis.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| AI Alone | Overall Survival According to Stabilized Inverse Probability of Treatment Weighted (sIPTW) Analysis | 25.5 Months |
| Palbociclib + AI | Overall Survival According to Stabilized Inverse Probability of Treatment Weighted (sIPTW) Analysis | 37.6 Months |
Primary
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
Population: Analysis population included all eligible participants whose data was extracted and evaluated for the retrospective analysis.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| AI Alone | Overall Survival According to Unadjusted Analysis | 24.2 Months |
| Palbociclib + AI | Overall Survival According to Unadjusted Analysis | 44.0 Months |