Which procedure is typically performed to obtain a definitive cancer diagnosis?

A biopsy is the procedure typically performed to obtain a definitive cancer diagnosis because it involves taking a small sample of tissue from the suspected tumor or area of interest and examining it under a microscope for the presence of cancer cells. This process allows pathologists to provide a conclusive diagnosis by assessing the structure and cellular characteristics of the tissue, which is crucial for determining the type and grade of cancer.

Imaging techniques, while valuable for visualizing tumors and assessing their size or spread, do not allow for direct evaluation of tissue morphology. Blood tests can indicate potential issues, such as elevated tumor markers or the presence of specific proteins, but they are not definitive on their own for diagnosing cancer. A physical examination can help identify abnormalities, but it also cannot confirm cancer without further testing. Thus, the biopsy is the most definitive method for diagnosing cancer accurately.