There are many types of cancer, and the type and location of cancer plays a role in how large tumors are. Tumors found in breast cancer, the most common type of cancer, are typically 1.5 to 2 centimeters, but some expand up to 5 centimeters or larger, says Mayo Clinic.
Prostate cancer, the second most common type of cancer, has tumors that are normally evaluated based on their size relative to the lobe of the prostate, says Cancer.net. Cancerous tumors are found in many other parts of the body have a wide range of sizes. The size and spread of a tumor plays a key factor in evaluating the severity and stage of a cancer, explains National Cancer Institute.