A Study to Observe Treatment Patterns and Outcomes in Participants in Saudi Arabia With Human Epidermal Growth Factor Receptor 2 (HER2-Positive) Unresectable Locally Advanced or Metastatic Breast Cancer (LA/mBC)

This is a prospective, national, multicenter, non-interventional study designed to enroll participants who have an initial diagnosis of unresectable LA/mBC made up to 6 months prior to registry enrollment. These participants will be prospectively followed for at least 5 years after study enrollment to evaluate their anti-cancer treatments. Data on participants' previous anti-cancer treatments for breast cancer will be collected retrospectively at study entry.