Diagnosis & Biopsy
Abnormal screening results may indicate that further testing is needed. A diagnosis of prostate cancer is achieved through an ultrasound-guided biopsy of the prostate gland. A prostate biopsy is conducted with a transrectal ultrasound and biopsy needle to collect small slivers of prostate tissue that are analyzed for cancer. This tissue is then examined under a microscope for cancer cells. A biopsy of the prostate can be performed in the physician’s office and patients usually return home the same day. Keep in mind that it is still possible to have cancer, even if the biopsy is negative, because the cancer cells may not have progressed enough to be detected by a microscope or the biopsy may miss the areas of cancer within the prostate.
Gleason Score: If prostate cancer is seen in the biopsied tissue the pathologist will assign it a Gleason Score. A Gleason Score is the total of two numbers (3+3=Gleason Score 6) that range from 2-10 and describes the appearance of the cancerous tissue. If cancerous cells appear to resemble the normal prostate tissue very closely they would receive a Gleason score of 1. If the cancerous cells are irregular and very different from normal prostate cells, they would receive a Gleason score 5. Gleason Scores are assigned to the largest area of cancer and the two most commonly occurring patters of cells. Low-risk Gleason scores are 2 through 4, conversely Gleason scores on the higher end of the scoring system 7 through 10; usually indicate a more serious prognosis.
TNM Staging: The stage of cancer is an important factor in choosing treatment. The stage tells how much the cancer may have grown within the prostate and whether it has spread to other tissues or organs. Doctors use a standard rating system to describe the stage of prostate cancer called the T- (size of the main tumor) N- (if lymph nodes are involved) M- (cancer has metastasized) System.
There are new prognostic tools available at the time of diagnosis that provide additional information to help patients and their physicians make the best decisions for treatment options.
In recent years a new prostate biopsy method has emerged called a Staging or Mapping Biopsy. This method of biopsy is similar to the standard transrectal ultrasound needle biopsy is an outpatient surgical procedure in which a transrectal ultrasound biopsy where 12 biopsy samples are taken. However, this procedure is performed as an outpatient procedure under general anesthesia. A physician places a grid below the patient’s scrotum and takes between 35- 80 biopsies of the prostate. This procedure allows the entire prostate to be biopsied and allows the physician to create a three-dimensional image of the prostate, including the location of the cancers within the gland. This biopsy may better determine the size and locations of the cancer, and allow patients and their physicians to more appropriately select a treatment option, including ongoing evaluation. This method of biopsy may help to eliminate the under- and over- grading of prostate cancer leading to patients undergoing treatments that are unnecessarily invasive or being subjected to the risk of associated morbidities from other treatment methods.