Accurate tumor staging and grading are essential requisites to treatment decisions in prostate cancer, avoiding overtreatment in men with low-risk disease and drawing attention to high-risk disease requiring aggressive treatment in other cases.
The authors analyzed the impact of core biopsy fragmentation and the relation between core biopsy taken and pathological information in regard to cancer extension and aggressiveness.
The present study is, to the best of our knowledge, the first in the literature that shows the possibility of core fragmentation, explaining in part over, and under staging(1). Core fragmentation could generate confounders such as inaccuracies on cancer volume, classifying a low-risk or ”indolent” cancer as a larger volume cancer. It could impact directly the number of positive cores, the cancer percentage of core and Gleason score, which are validated aspects to predict low-risk cancer.
The authors encouraged that the fragment cores from the same site should be sent in a container and that pathologists should add the information of all fragments to give the final report as one unique core. Considering fragmented cores as one unique core could improve biopsy accuracy, mainly in the detection of patients presenting low-risk disease, avoiding overtreatment and unnecessary co-morbidities related to the treatment. This is supported by others and validates the 2005 International Society of Urological Pathology Consensus Conference on Gleason grading of prostatic carcinoma.(2) Still, submitting one core per container might reduce fragmentation and thereby improve the ability to diagnose, quantify, and grade cancer in needle core tissue.(3)
Beyond the absolute number of fragments affected, other techniques may be used to measure cancer in prostate needle biopsy cores including the total length of prostatic adenocarcinoma on a needle core, the percentage of tumor involving a prostatic needle core, the overall percentage of cancer in a specimen and the fraction of needle biopsy cores with cancer.(4, 5)
Other studies showed that is important to assign a separate Gleason score for each intact core, especially in cases with high Gleason score cancer on at least one core.(6, 7) Most of the validated and widely used nomograms (including Partin tables) use the worst Gleason in cases where multiple cores are positive with different scores. In cases where cores are fragmented, an overall global Gleason score should be reported.
UroToday