new insights in the diagnosis of...

New insights in the diagnosis of mesothelioma

Pr. Francoise Galateau SalléMESOPATH-MESOBANK.fr

Department of BiopathologyCancer Center Leon Berard

28 Rue de Laennec, Lyon, France

31 st European Congress of PathologyNice 7 – 11 September 2019

Pathology in Nice

Disclosure

Diagnostic and research supports from French National Institute of Health (SpF) and from French National Institute of Cancer (INCA)

http://whobluebooks.iarc.fr/WHO Booth #403– Exhibition Hall

WHO Classification 2015, European and International multidisciplinaryworkshop

New advancesin the diagnosis, prognosis, treatment

Nicholson A et al , Accepted JTO

http://whobluebooks.iarc.fr/

EURACAN/IASLC proposals for updating the histologic classification of pleural mesothelioma towards a more multidisciplinary approach, Nicholson et al, JTO in press

1) Classification should include: Architectural patterns, Stromal response, Cytologic characteristics for prognostication2) Malignant mesothelioma in situ could be an additional category3) Favorable/unfavorable category should be routinely recognized and reported4) Clinically relevant molecular abnormalities BAP1, CDKN2A (p16) HD, PDL-1 should also be incorporated in the reports5) Other molecular data should be accrued as part of future clinical trials (MET etc..)6) Resection specimens ( Pleurectomy/decortication and EPP ) should be pathologically staged while small biopsies should be

clinically staged7) 3 different areas should be samples if possible8) Correlation with image –acquisition protocol/imaging terminology are needing standardization for clinical staging and

research practice9) Multidisciplinary board should include pathologists to ensure appropriate treatment10) All histologic subtypes should be considered for chemotherapy11) Patients with Biphasic and sarcomatoid mesothelioma should not be excluded from first line clinical trials12) Tumor subtyping should be assessed in relation to response to immunotherapy13) Systematic screening of all patients for germline mutation is not recommended in the absence of family history of BAP1

syndrom

WHO 2015 CLASSIFICATION-Classic subtypes

Epithelioid (81%) Biphasic (10%) Sarcomatoid (6%)

ArchitecturePapillaryAcinousTrabecularSolidMicropapillary

Cell characteristicsDeciduoidClear cellMicrocystic/adenomatoid-likeSignet ring cellSmall cell (<1%)Rhabdoid

Stromal characteristicsLymphohistiocytoid (10%)Myxoid stroma (45%)

So called ‘’in situ’’ MM (1%)

Any combination of pattern of epithelioid and sarcomatoid with at least 10% of one component

Undetermined class

Morphological characteristicsTranstional 7%Pleomorphic? (20%)

Stromal characteristicsDesmoplastic (2%)

Morphological characteristicsWith heterologous elements:2%)1° rhabdomyosarcomatous, (2%) 2°osteosarcomatous, 3°chondrosarcomatous

Rare variants MESOPATH cohort selection 10669 cases Pleura 9% Peritoneum 10%

Early lesions

MESOPATH COHORT 1998-2018 selection of 13.246 definitively certified cases of MM

But huge variety of features !!!!

Micropapillary: tufts of papillary

structure without central

fibrovascular core

Papillary: papillary structure

with central vascular core

Acinar: combination of simple

or more complex tubules

Trabecular: cord arrangement

of uniform epithelioid cells

Solid/diffuse: nests or sheets

or of epithelioid cells

Epithelioid Mesothelioma: Some features have prognostic significance

MESOPATH data & IMP 2011 USCAP 2011

More precise diagnostic criteria is mandatory +++++ cut off of %

Kadota et al, 2011

Rhabdoid:strong eosinophiliccytoplasm

Lessaggressive

More aggressive

Various morphological charcateristics mimickers of metastasis

Lung BreastRenal/

urothelial

Ovarian

Mullerian

EMM: Some featureshave pr

EMM: Some features are important to recognize to avoid misdiagnosis

Le Stang N et al, Systematic review Archiv Pathol Lab in press

TTF1 8G7G3/1 pos

Calretinin neg

Lung meso

Carcinoma metastasis 2 pos & 2 neg IHC markers specific of organs

CalretininER alpha

Other misleading features: Phenotype should be mesothelialImpact on survival we don’t know !!!!

VHL gene alteration involving exon 2

Smith-Hannah et al, Hum Pathol (2019) 83, 199–203

Differential D# Other clear cell tumors:Renal cell carcinoma PAX8 >90% nuclear (+)Pecoma HMB45 (+) and others……

Ordonnez et al, Mod Pathol 2013

Clear cell mesothelioma (Glycogen rich mesothelioma)

8 cases 7 M 1 F all PleuraTTF-1, chromogranin A, synaptophysin, CD99, and desmin were all negativeMean Survival was 8.2 months.

Small cell variant of MMDeciduoid mesothelioma: Ordóñez NG. 21 cases Mod Pathol. 2012 Nov;25(11):1481-95Aggressive variants are characterized by nuclear atypia, and high mitotic activity (>5 per 10 HPF. Mean Survival 7 mo compared to 29 mo

Nascimento AG, Deciduoid peritoneal MM . An unusual phenotype affecting young females. Am J Surg Pathol. 1994May;18(5):439-45

Ordonnez Mod Pathol 2012, 25, 689–698 Ordonnez , 2012, Nascimento 1994

Pathologists have to complete a score sheet

1° A biphasic is any combination of EMM or SMM component of at least 10%

Biphasic mesotheliomaDiagnosis were based on the criteria for each types defined in the last 2015 WHO.

BMM epithelioid predominant BMM BMM sarcomatoid predominant

Galateau Salle et al, JTO 2018

AE1AE3

Calretinin

Biphasic mesothelioma: utility of ancillary technicsA biphasic is any combination of EM or SM component of at least 10%With the appropriate phenotypeAE1/AE3 or any PANCKs expressed on both component, may be beneficial in the identification of Sarcomatoid component

Reactive

Malignant

Reproducibility of BMM: % of sarcomatoid component

Thirteen members of the International Mesothelioma Panel reviewed 54 cases of biphasic mesothelioma, completed the survey of 25 questions and rendered 607 interpretations.

A stricter definition of sarcomatoid component and prognostic value of % of sarcomatoidcomponent is under evaluation

Dacic Mod Pathol, 2019

BAP1 loss was observed in 50% (n=21/42) of the total cases in both components for 27% of the cases (n=11/41)

BAP1 loss on the sarcomatoid component alone was not observed.

Molecular assessment can help in the identification of malignant sarcomatoid component

p16 homozygous deletion by FISH was present in 74 % of the series (n=28/38)

p16 homozygous deletion by FISH was observed on the EM alone in 18% (n=5/28) in both components in 82% (n=23/28)

HD p16 EM HD p16 SM

BAP1 loss on EM alone

Biphasic mesothelioma: utility of ancillary technics

Molecular assessment of exuberant stromal component should be evaluated by p 16 HD

Sarcomatoid mesothelioma: the historic definition remains

The current definition: Elongated and tapered mesothelial cells with various degree of atypia and mitosis

The definition of the difficult area of desmoplastic variant of sarcomatoidmesothelioma initially defined by Mangano Am J Pathol 1998 should be improved

Conventional SM 145 (44%

SM with desmoplastic area 70 (21%)

Desmoplastic 110 (34%)

With heterologous elements 8 (1%)

LHMM 2 (<1%)

Klebe et al, Mod Pathol 2010; 23:470-479,

Pathologists have to complete a score sheet

° The Diag of TM was based on experts consensus when TM features were recognized by at least 7 out of 14 pathologists of the IMP The criteria for TM was on the basis of sheets of plump cells starting to lose their epithelioid morphology but not overtly spindle shaped and lacking frank sarcomatous features

Epithelioid predominant[EM Transitional??????[TM] pattern Sarcomatoid predominant[SM]

Demographic, clinical, histopathological treatment and follow up data were retrieved from the MESOBANK.

Mesothelioma with transitional pattern: Study conducted with the IMP

Galateau Salle et al, submitted for publication to JTO

Definition of transitional variant of mesothelioma: Galateau Salle et al, JTOThe criteria for TM was on the basis of sheets of large ovoid cells starting to lose their epithelioid morphology but no overtly spindle shaped and lacking frank sarcomatous features

Reticulin to identify TM patternseries of n=25

TransitionalEpithelioid

Results

BAP1 loss was observed in 50% (n=21/42) of the total cases in both components for 27% of the cases (n=11/41)

.

BAP1 loss in the TM group (50%), (n=8) and non-TM group (50%) (n=13) (p=1.00).

p16 homozygous deletion by FISH was present in 74 % of the series (n=28/38) and in 80% (n=15) of the TM group (p=NS). .

HD p16 EM HD p16 SM

BAP1 loss on EM alone

Molecular assessment

Galateau Salle et al, JTO 2018

WHO 2015 9051/3 ICD-O code WHO 2015 8022/3 ICD-O code

Rare usually<10%Dyspnoea, chest pain, weight loss and loss of performance status, Asbestos exposureMen 96%>women 4%Older pts>74 yrsPleural plaques 79%Histological asbestosis 27%Elevated asbestos content in lung tissue 93%

Rare o,3 to 3% of all NSCLCHeavy smokers 82%, asbestos exposure, chemicals exposure and immunosupressionMen in 61%68 years (range, 32-89 years

WHO 2015, & Klebe S, Roggli V series of 326 casesMod Pathol, 2010; 23:470-479,

WHO 2015 & Franks Arch Pathol Lab Med 2010 134:49-54, Maneenil, Clin Lung Cancer, May 2018

Marked pleural thickening and encasement of the lungparenchyma or pleural based mass

Solitary peripheral mass with a predilection for the upper lobes invading the pleura

Tumor are large 2 to 18 cm large mean 7cm

Sarcomatoid mesothelioma versus sarcomatoid carcinoma

Sarcomatoid mesothelioma versus Sarcomatoid Carcinoma

WHO 2015 9051/3 ICD-O code

Proliferation of spindle cells arranged in fascicles or with haphazard pattern involving the adipose tissue or lungparenchyma and may present heterologous elements. Wide range of morphologies but in conventional SMNuclear atypia varies from minimal to moderate

WHO 2015 8022/3 ICD-O code

Malignant spindle cell proliferation arranged in fascicular or storiformpatterns. Differentiated elements are absent Nuclei are often hyperchromatic , irregular with nucleoli and granularchromatinInflammation is common


Table 1

Populations

SC

(n=46)

SMM

(n=892)Comparison

test

Gender

Male

Female

36 (78%)

10 (22%)

748 (84%)

144 (13%)

p†=0.43

Age

Median

Range

69 yrs

33-88

75 yrs

40-96

p‡=0.0003

p† : Chi2 test p-value

p‡ : Mann-Whitney test p-value

The study was designed to review the experience at MESOPATH and query the English literaturefor best available evidence for the immunophenotype of SMM and SPC

The differential diagnosis between SM and SC

Loss of BAP1 nuclear staining is rare in SMM and more prevalent in EMM Righi et al, JTO 2016

Can we use BAP1 immunostaining for the separation between SMM vs SC.NoNO!!!

Carbone et al Oncotarget 2017

BAP1 staining is low in NSCLC

Owen et al, Human Pathology (2017) 60, 82–85 TMA 133 confirmed cases

BAP1 loss (nuclear) 1%

SM

SC


Can we use GATA3 for the separation between SM and SC: Yes

GATA3

<10%

≥10%

n=20

16 (80%)

4 (20%)

n=136

40 (29%)

96 (71%)

p†<0.0001

Table 2

Immunohistochemical markers

SC

(n=64)

SMM

(n=892)Comparison test

• GATA binding protein 3 (GATA3) is a transcription factor, • GATA3 function is important in the regulation of genes such as MUC1/EMA involved in the luminal differentiation of breast epithelium

and genes related to T-cell development

• GATA3 cl.L50-823 has been evaluated in surgical pathology as a marker for breast metastatic carcinoma in 80-90% and 67% of triple neg tumors

Berg & Churg(Am J Surg Pathol 2017;41:1221–1225)

SM

SCMarchevsky et al, Hum Pathol, 2017 67, 160-168 updated


Can we use P16/CDKN2A HD for the separation of SMM versus SC=No

P16/CDKN2A promoter hypermethylation was significantly lower in AE pts than in Non AE pts

while P16/CDKN2A HD was higher in AE pts than in non AE pts p= 0.0062 after adjustment for age and cumulative tobacco consumption


MTAP by immunohistochemistry

The MTAP gene is located adjacent to CDKN2A on chromosome 9p21. Its protein product, methylthioadenosine phosphorylase (MTAP) Potential for therapies exploiting synthetic lethality in MTAP deficient tumors.

FISH analysis showed MTAP co-deletion in up to 90% of pleural and peritonealmesotheliomas with CDKN2A homozygous deletion.

Conclusion; Immunohistochemical staining is a surrogate for FISH p16 HDExcellent interobserver agreementLoss of MTAP showed 80% sensitivity and ~ 100% specificity

Other causes of misdiagnosis

Myxoid variant of EMM

H=F

63.7 yrs

Median survival 24 mo

55% at 2 yrs

Pr dependant of Solid component

High BAP1 loss

HD p16 low

D# Oedema

Myxoid tumor

Myxoid sarcoma

Synovial sarcoma

H=F

Any age

Young adult

5 to 10yrs survival 62 and 52 %

Biphasic or monophasic

Myxoid changes and calcifications

rearrangement SS18 SYT

D# SM, Ewing etc…

Lymphohistiocytoidmesothelioma

M:F 3:1

Median age 70 yrs old

Median survival 8 mos

Histiocytoid cells in background of CD8

# Hodgkin and non hodgkin lymphoma and

lymphoepithelial carcinoma

Pleomorphic mesothelioma

M>F

Median age

67yrs

Median survival 7mos

Bizarre and giant cells with neutrophils

D# Pleomorphiccarcinoma,UPST,

MPNST,Pleomorphicrhadomyosarcoma

Alchami et al, J Clin Pathol, 2017Perret et al, Am J SurgPathol?2018

SMARCA4- DTS-Rhabdoid tumor

M:F ratio 9:1Median age 48 yrsMedian survival 6 mos

Current or ex smokersRhabdoid featuresCo-loss of SMARCA4 and SMARCA2Overexpression of SOX2Metastatic disease frqt

D# Rhabdoid MM, Lung ADC

Klebe et al , Pathology,,2018

Galateau Salle et al Am J Surg Pathol, 2004 Kadota et al 2011Galateau Salle 2008

Unusual morphological characteristics shoudl be identified to avoid misdiagnosis

New insights in grading 2

Nuclear grade I without necrosis 29 monthsNuclear grade I with necrosis & grade II without necrosis 16 months Nuclear grade II with necrosis 10 monthsNuclear grade III 8 months

Rosen LE, Karrison T, Ananthanarayanan V, et al. Nuclear grade and necrosis predict prognosis in malignant epithelioid pleural mesothelioma: a multi-institutional study. Mod Pathol. 2018.


Pelosi G, Papotti M, Righi L, Rossi G, Ferrero S, Bosari S, Calabrese F, Kern I, Maisonneuve P, Sonzogni A, Albini A, Harari S, F, Capelletto E,Catino AM, Cavone D, De Palma A, Fusco N, Lunardi F, Maiorano E, Marzullo A,Novello S, Papanikolaou N, Pasello G, Pennella A, Pezzuto F, Punzi A,Prisciandaro E, Rea F, Rosso L, Scattone A, Serio G. Pathologic Grading of Malignant Pleural Mesothelioma: An Evidence-Based Proposal. J Thorac Oncol. 2018 Nov;13(11):1750-1761.


Rosen LE, Karrison T, Ananthanarayanan V, et al. Nuclear grade and necrosis predict prognosis in malignant epithelioid pleural mesothelioma: a multi-institutional study. Mod Pathol. 2018.

1°All specialty recommended that grading od epithelioid mesothelioma shoud be routinely part of reporting for all types of samples favoring a two-tier system and high grade based on nuclear atypia, mitotic activity and the presenceof necrosis

2° it was recommended that favorable and unfavorable histologic characteristics should also be reported

Mesothelioma ‘’in situ’’

‘’The most striking finding to emerge from this study is that BAP1 loss in flat surface mesothelium confers a very high risk of subsequent appearance of invasive tumor’’. In this series 70% of such patients developed an invasive mesothelioma

1°Whitaker D, Henderson DW, Shilkin KB. The concept of mesothelioma in situ: implications for diagnosis and histogenesis. Semin Diagn Pathol.

1992;9(2):151-161.

2°Churg A, Hwang H, Tan L, et al. Malignant mesothelioma in situ.Histopathology. 2018. 72(6):1033-1038

3°Churg A, Galateau-Salle F, Roden AC, Attanoos R, von der Thusen JH, Tsao MS, Chang N, De Perrot M, Dacic S. Malignant mesothelioma in situ: morphologic features and clinical outcome. Mod Pathol. 2019 Aug 2

10 cases with repeated pleural effusion

BAP1 clone C4 Santa Cruz

The recommendation of the MDgroup is that MMIS could potentially be added as a category in future classification

F>MMedian age : 60 years old Code ICD0-9052/1 Male 69 yrs old

Asbestos exposedUnilateral pleural effusionDisseminatedmicronodules

BAP1 lossSurvival 17 months

Median survival 2-year survival

WDPM 26 months 61% CI 95% = [30% ; 92%]

Epithelioid 12 months 18% CI 95% = [14% ; 21%]

WDPM EMM mimicking WDPM

BAP1 100% retainedHD p16 0% homozygous deletionStevers et al, genetically defined by mutually exclusive mutations in TRAF7 and CDC42. Mod Pathol. 2019 Jan;32(1):88-99

The separartion between WDPM from EMM mimicking WDPM

New mutations in Malignant Mesothelioma

Desmeules P, Joubert P, Zhang L, Al-Ahmadie HA, Fletcher CD, Vakiani E, Delair DF, Rekhtman N, Ladanyi M, Travis WD, Antonescu CR. A Subset of MalignantMesotheliomas in Young Adults Are Associated With Recurrent EWSR1/FUS-ATF1Fusions. Am J Surg Pathol. 2017 Jul;41(7):980-988.

Panagopoulos I, Thorsen J, Gorunova L, Micci F, Haugom L, Davidson B, Heim S. RNA sequencing identifies fusion of the EWSR1 and YY1 genes in mesothelioma with t(14;22)(q32;q12). Genes Chromosomes Cancer. 2013 Aug;52(8):733-40.

Take home messageWhat will change our practice is the therapeutic options

1° The way to evaluate morphologyHistologic type: Epithelioid, biphasic or sarcomatoid/desmoplastic; if biphasic, include percentages of epithelioid and sarcomatoid components

GradingGrade: High/low grade (use only for epithelioid)

Report favorable and unfavorable variantsAll elements should be added to the histopathological report as following ‘’List all architectural patterns present (give predominant pattern and percentages for each pattern listed) and any cytologic and/or stromal features present .

2° The use of diagnostic and predictive immunohistochemical and molecular markerBAP1 should be part of a diagnostic work up of mesothelial proliferationsMolecular characteristics that might be useful for clinical managementCDKN2A/p16 HD, MTAP? MesothelinMET and others if necessary for targeted therapiesPDL-1 if requested pathologists should score PDL-1 in mesothelioma in similar fashion to lung cancer in providing a % of positivity of staining cellsRNA-sequencing will help you to untangle mesothelioma classification !

3° Given the rarity of BAP1 germline mutation it is recommended to perform systematic staining only in case of family history suspicious for BAP1 syndrome and in this case oncogenetic counselling

N. Le StangStatistician

Elise & Cyril

Daniel PissalouxSandrine Paindavoine

Sylvie Lantuejoul

Annabelle BojElodie FerreyRuth Sequeiros

Francesca DamiolaClara Farge

Franck Tirode

Leader molecular group

JP Michot &The lab

Thanks

EURACAN/IASLC proposals for updating the histologicclassification of pleural Mesothelioma towards a more multidisciplinary approach

Nicholson A et al, JTO in press

Access to the following books:

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WHO Classification of TumoursONLINE

Now available at: tumourclassification.iarc.who.int

Special launch rate of 100 Euros

More details from the IARC team – Booth A14, 2nd level, Agora 2 Hall

9am to 5.15pm, from Sunday 8 to Tuesday 10 September

https://tumourclassification.iarc.who.int/

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