Evolution of Pathology

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2 Traditional pathology Molecular pathology 2

3 Evolution of Pathology Gross Pathology Cellular Pathology Morphologic Pathology Molecular/Predictive Pathology Antonio Benivieni ( ): First autopsy Giovanni Morgagni ( ): Correlated patient symptoms to autopsy findings John Hunter ( ): Devised method for preserving tissue Leeuwenhuek ( ): Developed 1 st microscope Virchow ( ): Recognized that diseases arise from alterations within tissues and cells Morphologic classification of cancer Pathologists provide diagnostic and prognostic information Hematoxylin and eosin is primary stain for all cases Comprehensive molecular tumor profiling Pathologists provide personalized medicine /predictive biomarker information Proteomic and genomic data in the context of morphology Bichat ( ): Father of modern pathology 4 3

4 The pathologist as diagnostic oncologist John R. Srigley Pathology,2009;41: The role of pathologists in the era of personalized medicine Eric E. Walk Arch Pathol Lab Med, 2009;133:

5 Resection specimen: Process immediately after surgery Fix for 6-72hrs 5

6 Pre-analytic Analytic Post-analytic Time to fixation Method of tissue processing Time of fixation Method of fixation Assay validation Equipment calibration Standard Laboratory Procedure Staff training assessment Antigen retrieval Test reagents Standard controls Interpretation Image analysis Reporting QA procedures: -lab accreditation -Proficiency tests -pathologists Automation 6

7 Adenocarcinoma, well to moderately differentiated 7

8 Poorly differentiated carcinoma 8

9 We are involved in the whole continuum of cancer care: Screening Diagnosis Identification of risk factors Monitoring of cure And now: Our role in targeted therapies. (Prediction of therapeutic response). 9

10 Pharmacopathology Targeted Therapy Biological therapies that are based on specific attachment of medications to specific sites on tumor cells (receptors), or within loci in tumor cells. by targeting specific somatic alterations present in these tumors. This attachment causes specific damage to the tumor cells. Only minimal damage to non neoplastic cells. 10

11 Detection of translocations, amplifications by ISH. Sequence based detection of genes for detection of somatic mutations in tumors. Detecting mutations by RT-PCR. Circulating tumor DNA is relevant only relatively. 11

12 Targeted/ Personalized Therapy New roles for old pathologists 12

13 Paradigm shift in Pathology (Letting the gen(i)e out of the bottle) Genomics Genomic driven diagnoses Genomic driven therapies Epigenetics 13

14 Eric E Walk Arch Pathol Lab Med, 2009; 133:

15 Tamoxifen - Anti Estrogen receptor/breast Ca Herceptin - Anti HER2/neu in over-expressing tumors/breast Ca, Gastric ca. Mabthera - Anti CD20/B cell lymphomas STI571(Gleevec) - Tyrosine kinase inhibitor CML, GIST Zelboraf (Vemurafenib) BRAF inhibitor - Melanoma Avastin - Anti angiogenic factor Anti growth factor receptors Erlotinib/Tarceva (lung Ca), Cetuximab (Erbitux) (colon and head and neck Ca.) Xalkori - Anti ALK-EML (lung) 15

16 Tamoxifen Breast carcinoma (Anti Estrogen receptors) 16

17 Herceptin anti Her2/neu Protein 17

18 Immunohistochemistryt

19 FISH-HER2/amplified Non amplified 19

20 Gene Expression Profiling Measurement of expression of thousands of genes simultaneously. DNA microarray analysis. Gene chips (up to >20,000 genes), commercial, are hybridized to probes from tumor samples, labeled with fluochromes. Computerized analysis. 20

21 Microarray Analysis Pioneered by Perou/Sorlie et al, 2001, established that breast cancer can be classified into distinct molecular groups. Measurement of quantities of individual mrnas. 21

22 Unsupervised Classification cluster analysis Samples clustered by expression similarity Closer together the samples the more similar the gene expression Expression Dendrogram Sorlie T, et al. Proc Natl Acad Sci U S A Sep 11;98(19):

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24 Well diff. AC Mod. diff. AC Poorly diff. AC 24

25 TRIPLE NEGATIVE/BASAL-LIKE CARCINOMAS Low grade High grade secretory medullary metaplastic adenoid cystic no special type 25

26 Colorectal Adenocarcinoma (CRC) Anti EGFR therapy (TKIs) (Erbitux, Cetuximab) was found to be effective in CRC. However ~50% of all patients with CRC have RAS mutations and do not respond as well to anti EGFR therapy. Patients harboring RAS mutations receiving anti EGFR treatment, may do worse than those without RAS mutations. 26

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28 ASCO recommends that all patients with metastatic CRC should be tested for RAS mutational status, at least at codons 12/13. FDA - Cetuximab (Erbitux) is not recommended for CRC patients with RAS mutations. No FDA approved test yet. Tests principles: -RT-PCR -Direct sequencing 28

29 Pathologist s role The KRAS mutations are detected on DNA from tumor sections. The pathologist has to choose the right area with enough viable tumor. Perform the molecular test. Or select a reference lab. Select the technology. 29

30 Lung Cancer / New Paradigm Histology versus molecular diagnosis in lung cancer. Primary v metastatic. If primary Small Cell Lung Ca. v Non SCLC. If NSCLC Squamous Cell Ca (p40) v AdenoCa (TTF1). Clinical correlation of paramount importance. 30

31 Although there is only one sequence of morphological changes that is characterized todate for the development of invasive lung AC from AAH, there is evidence to suggest at least 2 molecular pathways: The KRAS and EGFR pathways in smoker and never-smoker AC subpopulations: 31

32 EGFR and KRAS EGFR mutations (exons 19, 21), more common in never smokers (17/30 v 1/39). KRAS mutations, more common in smokers (24/39 v 3/30). Lung adenocarcinomas in Asians had more EGFR mutations than Caucasian tumors (15/23 v 3/45). Caucasians had more KRAS mutations than Asians (25/45 v 2/23). No difference in mutation rates between women and men. Mutually exclusive. Lung adenocarcinoma of never smokers and smokers harbor differential regions of genetic alteration and exhibit different levels of genomic instability. Kelsie L. Thu et al PLoS ONE March 2012, vol 7, issue 3 32

33 Continued Smoking status most strongly associated clinical variable observed with Proportion of Genomic Alterations in a multivariate analysis, compared with other clinical variables (stage, gender ). When clinically applicable, EGFR testing is performed on lung tumor tissue (mainly on AC). ~25% of lung adenocarcinomas harbor mutations in the EGFR gene (28 mutations are investigated). If EGFR negative ALK (3-5%) mutation tested. Lung adenocarcinoma of never smokers and smokers harbor differential regions of genetic alteration and exhibit different levels of genomic instability. Kelsie L. Thu et al PLoS ONE March 2012, vol 7, issue 3 33

34 Lung Cancer Therapy Algorithm If adenocarcinoma, TTF1(+), p40 (-) and if clinically applicable EGFR testing TTF1 Positive ~25% negative p40 +ve ~3-5% Xalkori Anti EGFR therapy ALK testing -ve CT 34

35 EML4 ALK fusion gene Generally mutually exclusive with EGFR mutations and KRAS mutations; indicating that these molecular defects function as drivers of pathogenesis. Concurrent mutations have been reported 1 3 Despite correlations observed between ALK status histology/smoking history, it is possible for any patient to have ALK-positive NSCLC 35

36 EML4-ALK testing Up to recently, FISH study demonstrating the rearrangement was gold standard. Now, since ESMO 2012, Immunohistochemistry is becoming part of the algorithm validation. EML4-ALK +ve IHC and FISH EML4-ALK VE IHC and FISH 36

37 Importance of adequate tissue collection Tissue management starts with interaction 37

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42 This is just the beginning of a great friendship. Morphology Genomics Proteomics DCIS 42

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44 Thank you for your attention 44