Gleason Scoring System 2017 JASREMAN DHILLON, MD

ASSOCIATE PROFESSOR,

DEPARTMENT OF ANATOMIC PATHOLOGY,

MOFFITT CANCER CENTER,

TAMPA, FLORIDA

Learners Objectives

u  Latest changes per ISUP 2014 that impact Gleason patterns

u  Changes in the reporting of PA with inclusion of Grade Groups and % of Grade 4 component in GS 7

u  When to report and when not to report GS in post therapy biopsies

u  Concepts about IDC-P

Gleason Score

1977 2005 2014

Gleason Score

1977 2005

Gleason Score 2-4 is Not Made on Needle Biopsies and Prostatectomies

u 1) Poor reproducibility among experts for lower grade tumors.

u 2) Correlation with the prostatectomy score for Gleason 2-4 tumors is poor and up to 50% of the corresponding prostatectomies may have extraprostatic extension.

American Journal of Surgical Pathology 2012

u  Totally embedded RPs from 1975-2010 reported as GS <6 were identified from the combined RP databases of four large academic centers. Participating institutions were The Johns Hopkins Hospital, Henry Ford Hospital, University of California San Francisco (UCSF), and Baylor College of Medicine.

u  19 cases, mostly from the 1990s, diagnosed as GS<6 with a positive LN

Conclusions From Study

u  Of over 14,000 totally embedded radical prostatectomies from multiple institutions, there was not a single case of a GS ≤6 tumor with LN metastases.

u  GS ≤6 tumors do not appear to metastasize to LNs.

u  Gleason patterns 4 or 5, as defined by the current ISUP system, is required for metastatic disease.

u  Cannot rely on grading prior to 2005 as accurate.

Gleason Score

1977 2005

Smoothly circumscribed small cribriform nodules of tumor

Gleason Pattern 3

After ISUP 2005 there were multiple studies showing small foci of smoothly circumscribed cribriform prostate cancers are associated with an adverse prognosis

Epstein et al

The American Journal of Surgical Pathology: Volume 40. February 2016, p 244-52

Gleason Score

1977 2005 2014

Gleason Pattern 3

u  Individual well-formed discrete glands

Gleason Score

1977 2005 2014

Epstein et al

All Cribriform Cancer Glands are Graded as Gleason Pattern 4

Gleason Grading System

u  Gleason’s original data u GS 2-5 comprised 28% u GP 4 (GS 7, 8, 9) comprised 12%

u  Danneman et al u GS 2-5 comprised 27% in 1998 u GS 2-5 comprised 1% in 2011 u GS 7 comprised 38% in 2011

u  Grade scores 2-5 have disappeared from clinical practice

Foamy Gland Cancer

Pseudohyperplastic Cancer

Colloid Carcinoma

Signet Ring Cell-Like Adenocarcinoma

Ductal Adenocarcinoma

Are graded by same rules as the usual prostate cancer

Variants of Prostate Cancer

Ductal Adenocarcinoma

u  Ductal adenocarcinomas

is graded as Gleason score 4+4=8

u  Ductal adenocarcinoma

with necrosis grades as Gleason pattern 5.

u  PIN-Like ductal

adenocarcinoma is graded as 3+3=6 as it has excellent prognosis

Small Cell Carcinoma

Small cell carcinoma of the prostate is not assigned a Gleason score since it is unique histological, immunohistochemical, and clinical features.

Post-Therapy Prostate Cancer

If histologically, usual prostate cancer is seen following hormone therapy, radiation therapy, cryotherapy or HIFU and it resembles non-treated cancer – “Cancer without significant treatment affect” and a Gleason score is assigned.

Histologically cancer is seen,

and it shows treatment effect – no Gleason score is assigned.

Reporting Percent Pattern 4 u  1.Ac&vesurveillanceinpa&entswith7(3+4)

u Age

u co-morbidity

u extentofcancer

u MRIfindings

u pa&entdesire

u CanbecandidatesforASifthe%ofpaJern4islimited

u  2.Borderlinecasesof7(3+4)or7(4+3)

u Benefitthetrea&ngphysicianindecidingtheappropriatetherapyforthepa&entincombina&onwithotherclinicalparameterssuchasPSAlevels,%oftumorpresent,numberofcoreposi&ve,MRIfindings

GradingGroups

•  Fiveprognos&callydis&nctGradeGroupsbasedonthemodifiedGleasonscoregroups

– GradeGroup1=Gleasonscore≤6– GradeGroup2=Gleasonscore3+4=7– GradeGroup3=Gleasonscore4+3=7– GradeGroup4=Gleasonscore8– GradeGroup5=Gleasonscores9and10

Intraductal Carcinoma of the Prostate (IDC-P)

u  IDC-Pisamalignantlesionu Expansileprolifera&onofmalignantprosta&cepithelialcellswithinprosta&cductsandacini

u  significantarchitecturalandcytologicalatypiau  IDC-Passociatedwith

u  largetumorvolumeu advanceddiseasestage-extraprosta&cextension,seminalvesicleinvasion,andpelviclymphnodemetastases

u highGleasonscoreu  increasedriskofrecurrence

IDC-PisnotassignedaGleasonscore

IDC-P in Prostate Biopsies

u  IDC-P,whenpresentinacoreneedlebiopsy,requiresaprompt

re-biopsyordefini&vetreatment

u  IDC-Phasbeenreportedinabout2.8%ofbiopsies

u  ThepresenceofisolatedIDC-Pwithoutaccompanyinginvasiveadenocarcinomaisextremelyrare,occurringin<0.3%ofcoreneedlebiopsies

u  IDC-Pinprostatebiopsies

u Earlybiochemicalfailure

u metasta&cdiseasefollowingradia&ontreatmentinpa&entswithintermediateorhigh-riskprostatecancer.

IDC-P in Radical Prostatectomies

u  IDC-Pinradicalprostatectomyspecimensu increaseintheincidenceofbiochemicalrecurrence

u  61-84%ofIDC-PcasesshowlossofPTEN

u  TMPRSS2:ERGgenefusion>2/3rdofcasesofIDC-P

ERG IHC

References

u  Hillary M. Ross, Oleksandr N. Kryvenko, Janet E. Cowan, Jeffry P. Simko, Thomas M. Wheeler and Jonathan I. Epstein. Do adenocarcinomas of the prostate with gleason score (gs) ≤6 have the potential to metastasize to lymph nodes? Am J Surg Pathol. 2012 Sep; 36(9): 1346–1352.

u  Epstein JI, Egevad L, Amin MB, Delahunt B, Srigley JR, Humphrey PA; Grading Committee. The 2014 International Society of Urological Pathology (ISUP) Consensus Conference on Gleason Grading of Prostatic Carcinoma: Definition of Grading Patterns and Proposal for a New Grading System. Am J Surg Pathol. 2016 Feb;40(2):244-52.

u  Mukul K. Divatia and Jae Y. Ro. Intraductal Carcinoma of the Prostate Gland: Recent Advances. Yonsei Med J. 2016 Sep 1; 57(5): 1054–1062.

u  Thomas M Schneider and Adeboye O Osunkoya. ERG expression in intraductal carcinoma of the prostate: comparison with adjacent invasive prostatic adenocarcinoma. Modern Pathology (2014) 27, 1174–1178.

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