Are we ready to include invasive cribriform and intraductal carcinoma into the prostate cancer grade grouping system?

摘要

Prostatic adenocarcinoma (PCa) is one of the most heterogeneous tumors with great morphologic and biological diversity as well as variable clinical courses. It has been more than half a century since Dr. Gleason proposed the first PCa grading system. Over the years, even with emerging prognostic molecular biomarkers, Gleason grading based on the histomorphology is still the most powerful and widely used parameter in predicting the behavior of PCa as well as in determining the treatment modalities for PCa patients. Despite a huge success, its predictability for the clinical behavior of PCa is still limited, particularly for intermediate grade (grade groups 2 and 3) PCa. With growing knowledge and better understanding of PCa biology and its pathological features, the Gleason grading of PCa has been continuously evolving. To simplify and improve the group stratification of the PCa grading, a 5 Grade Group system has been developed based on modified original Gleason grading and is now incorporated into the 2016 WHO prostate cancer grading system (1). In the past decade, invasive cribriform PCa and intraductal carcinoma (IDC) have been increasingly recognized as independent adverse histomorphologic components in predicting the poor outcome of PCa (2-8), and the International Society of Urological Pathology has recently recommended to include the cribriform PCa and IDC in the routine pathology report.