NEW YORK (Reuters Health) – The tumor volume threshold of 0.5 mL for clinically insignificant prostate cancer, established in the early 1990s, remains valid, according to researchers who revisited this cut point in a contemporary group of prostate cancer patients.
But the study also suggests that clinically insignificant prostate cancer may include an index Gleason score of 6 and pT2 tumors with volumes up to at least 1.3 mL.
Therefore, it may be time to reconsider current methods and nomograms used for pretreatment risk assessment prostate cancer, conclude Dr. Tineke Wolters from Erasmus Medical Center in Rotterdam, the Netherlands, and colleagues in the November 12 online issue of The Journal of Urology.
Using the European Randomized Study of Screening for Prostate Cancer (ERSPC), the investigators mathematically modeled the predicted lifetime risk of prostate cancer diagnosis in their screened population as 64 of 1,000 (6.4%) men and a predicted lifetime risk of 130 of 1,000 (13.0%) men for clinically detecting prostate cancer in their nonscreened population.
Therefore, of all screen detected cancers, only 49.2% (64 of 130) would have been clinically detected (clinically significant), they point out. The investigators used the 49.2% largest tumor volume of 325 prostatectomy specimens to determine the threshold tumor volume for insignificant prostate cancer.