Tumor markers are special substances made by tumors or by our bodies when there are tumors. They help doctors understand what kind of tumors are present.

1. Finding and Tracking Tumors:

• About 75% of tumors have unique markers.
• For instance, the prostate-specific antigen (PSA) level goes up in 80% of prostate cancer cases.

2. Distinguishing Between Types of Tumors:

• Some markers can show whether a tumor is harmful or not.
• For example, carcinoembryonic antigen (CEA) is a marker related to colorectal cancer and can suggest that the tumor is serious.
• Harmful tumors usually produce more markers than non-harmful ones, with detection rates between 90-95%.

3. Understanding the Outlook:

• Higher levels of tumor markers can mean a worse situation for patients.
• Research shows that patients with higher markers have a 50% greater chance of having serious problems.