prostate cancer is diagnosed from the results of a biopsy of the prostate gland. if the digital rectal exam of the prostate or the psa blood test is abnormal a prostate cancer is suspected. a biopsy of the prostate is usually then recommended. the biopsy is done from the rectum (trans-rectally) and is guided by ultrasound images of the area. a small piece of prostate tissue is withdrawn through a cutting needle. the trus-guided tru-cut biopsy is currently the standard method to diagnose prostate cancer. although initially a 6-core set was the standard currently most experts advocate sampling a minimum of 10 to 12 pieces of the prostate to improve the chances of detection of the cancer and also to provide a better idea regarding the extent and areas of involvement within the prostate. multiple pieces are taken by sampling the base apex and mid gland on each side of the gland. more cores may be sampled to increase the yield especially in larger glands. a pathologist a specialist physician who analyzes tissue samples under a microscope then examines the pieces under the microscope to assess the type of cancer present in the prostate and the extent of involvement of the prostate with the tumor. one also can get an idea about the areas of the prostate that are involved by the tumor by assessing which of the pieces contain the cancer and which of them do not. another very important assessment that the pathologist makes form the specimen is the grade (gleason's score) of the tumor. this indicates how different the cancer cells are from normal prostate tissue. grade gives an indication of how fast a cancer is likely to grow and has very important implications on the treatment plan and the chances of cure after treatment. a gleason score of six is supposed to indicate low-grade (less aggressive) disease while that of eight to 10 demonstrates high grade (more aggressive) cancer; seven is regarded as somewhere in between these two.
how is prostate cancer diagnosed and graded?