To help doctors give their patients the best possible care, the American Society of Clinical Oncology (ASCO) developed evidence-based recommendations on the usefulness of laboratory tests (called assays) to find out if a cancer might be resistant or sensitive to a specific chemotherapy treatment before it is offered to a patient. In 2011, this guideline was reviewed due to new research; this research continued to support the 2004 recommendations. This guide for patients is based on ASCO's most recent recommendations.

Key Messages

• Chemotherapy sensitivity and resistance assays are laboratory tests that have been studied to help predict how well chemotherapy may work.
• However, these tests should not be used to determine treatment options for an individual patient.
• Instead, the choice of chemotherapy should be based on the research on the drugs being considered and the patient's health and treatment preferences.