What to Know: ASCO's Guideline on HER2 Testing for Breast Cancer

Key Points:

• HER2 is a specialized protein found on breast cancer cells that controls cancer growth and spread.
• All patients with invasive breast cancer should have their tumors tested for HER2 with one of the two approved testing methods.
• This testing should be performed by an accredited laboratory that follows specific testing procedures and handles the samples in a consistent way

To help doctors give their patients the best possible care, the American Society of Clinical Oncology (ASCO) asks its medical experts to develop recommendations for specific areas of cancer care. ASCO and the College of American Pathologists (CAP) issued a joint clinical practice guideline about human epidermal growth receptor 2 (HER2) testing for breast cancer. This guide for patients is based on ASCO and CAP's recommendations.

As you read this guide, please keep in mind that every person treated for cancer is different. These recommendations are not meant to replace your judgment or that of your doctor. The final decisions you and your doctors make will be based on your individual circumstances.