CDK4/6 Inhibitors in Metastatic HR-Positive Breast Cancer

RETROSPECTIVE STUDY OF OUTCOME OF CDK4/6 INHIBITORS IN METASTATIC LUMINAL A AND LUMINAL B BREAST CANCER

This study is a retrospective review aimed at evaluating the real-world outcomes and clinical efficacy of CDK4/6 inhibitors (such as Palbociclib, Ribociclib, or Abemaciclib) in patients diagnosed with metastatic luminal A and luminal B breast cancer. The study will assess how patients responded to these treatments based on their specific breast cancer subtype (Luminal A vs. Luminal B) by reviewing their medical records.

This is a retrospective, observational cohort study conducted at Sohag University Hospital].

The study will include medical records of female patients diagnosed with metastatic Luminal A and Luminal B breast cancer who received CDK4/6 inhibitors as part of their treatment regimen between 2021 and 2026 Data will be collected regarding Patient demographics and baseline clinical characteristics. Pathological features (Hormone receptor status and Ki-67 levels to differentiate Luminal A and B).

Treatment duration and response rates. Outcomes such as Progression-Free Survival (PFS) and Overall Survival (OS), as well as documented adverse effects.

The primary objective is to compare the clinical outcomes and effectiveness of CDK4/6 inhibitors between the Luminal A and Luminal B metastatic breast cancer subgroups in a real-world setting.

Inclusion Criteria:

• patients who are more than 18 years old at time of diagnosis and less than 80 years
• metastatic breast cancer luminal A and luminal B of either sex

Exclusion Criteria:

• patients diagnosed with double malignancy

  • patients with incomplete medical records
  • patients with organ failure