Grading Intraductal Carcinoma of the Prostate; ISUP Versus GUPS Recommendations

Objective:  To evaluate the frequency of intraductal component (IDC-P) in prostatic adenocarcinoma and its effect on the final grade using the ISUP and GUPS grading system.

Study Design:  Descriptive study. Place and Duration of the Study: Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, between June 2021 and June 2022.

Methodology: The study included 250 cases of prostatic adenocarcinoma. The presence of the intraductal carcinoma prostate (IDC-P) was confirmed by patchy or complete staining of the basal cell layer by p63 immunohistochemical stain. Cases with IDC-P were then graded using two different methods, first using the grading criteria based on the ISUP recommendations and then by the grading criteria based on the GUPS recommendations.

Results: Two hundred and fifty cases showed invasive prostatic carcinoma ranging from Gleason grade group 2-5. IDC-P was identified in 5 of the 250 biopsies (2%). The final Gleason grade remained unchanged in these cases, when they were graded using the ISUP and GUPS recommendations.

Conclusion:  Although the present results are based on a relatively small sample size, IDC-P was not frequently present in biopsies of patients with adenocarcinoma in the studied population. Grading IDC-P in invasive prostate cancer led to only a minor change in grade group assignment of prostate cancer biopsies.

Key Words:  Prostatic adenocarcinoma, Intraductal carcinoma, IDC-P, ISUP, GUPS, Gleason Grade group.