Dear OncoLink "Ask The Experts,"
After receiving a TURP procedure, I was told that a T1B, 3+3 tumor was found in 19 out of the 99 slices of prostate tissue removed. The tumor's presence was not reflected in an elevated PSA score or a digital exam. What does the (B)3+3 rating mean?
Richard Whittington, MD, Associate Professor of Radiation Oncology at the University of Pennsylvania School of Medicine, responds:
"(B) 3+3" are actually the two critical parameters in staging and prognosis. This is a T1b, Gleason 6 (3+3) prostate cancer.
T1 means no palpable disease (unable to feel it on digital exam). T1a is incidental cancer with Gleason score <8 and fewer than 5% of the chips in a TURP specimen containing tumor. Stage T1B is defined as a Gleason 8-10 or >5% of the TURP chips containing tumor. Stage T1c is no palpable tumor but a positive biopsy (done because of an elevated PSA). T2 disease means a palpable nodule within the gland on digital rectal exam: T2a if the nodule is less than 1/2 of one lobe, T2b if more than 1/2 of one lobe, and T2c if both lobes.
The Gleason 6 score (see Gleason description below) is a combination of two sub-scores that tells you how big the tumor is and how aggressively it may behave.
The important thing to keep in mind is that the hierarchy of good vs. bad tumors does not directly correlate to the staging system. T1a has the best prognosis, followed by T1c/T2a. T2b is next, followed by T1b, followed by T2c.
Gleason score: The pathologist characterizes how much the cancer looks like normal prostate tissue, and this is known as the grade of the tumor. Pathologists often use a scale when they grade prostate tumors known as the Gleason score. The Gleason score runs from 2 to 10, with 2 being a very normal looking tumor and 10 being a very abnormal looking tumor. Generally, the more abnormal the tumor looks, the more aggressively it acts. We characterize grades on a scale because, together with staging, it gives us a way to offer a prognosis and it often guides our choice of therapy.