Stages of Cancer
The American Cancer Society says many forms of cancer are treated most successfully when caught early. This is why regular screenings, such as Pap tests, mammograms, PSA tests, etc., are so important. (Read about Prevention & Detection)
If a screening produces a suspicious result, or if a doctor suspects cancer for some other reason, additional tests can be done, for example, blood or urine tests or imaging scans.
However, for cancers, the way to make a definitive diagnosis is a tissue diagnosis with a biopsy. Biopsy is the removal of cells or tissues for examination by a specialist physician called a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue. Examination of suspicious cells through a biopsy helps the doctor determine if the cells are malignant (cancerous) or benign.
If cancer is present, a doctor must determine what type of cancer it is, how fast it is growing, and whether or not it has invaded nearby healthy tissue or spread to other parts of the body. This helps the doctor determine at what stage the cancer is, and how best to treat it.
Staging is the term used to describe the extent or severity of an individual's cancer. A cancer's stage depends on different factors, including its location, its size, whether lymph nodes have been affected and whether or not the cancer has spread.
NCI says different tests can be used to help determine a cancer's stage. These include blood and urine tests; imaging tests such as x-rays, CT scans, MRI, PET and ultrasound; pathology reports from the biopsy; and surgical reports. Knowing a cancer's stage helps to determine the best way to treat it. (Read about Medical Oncology and Radiation Oncology)