THYROID TUMOR DIAGNOSIS: MARKER OF THE MONTH CLUB

Transcription

1 THYROID TUMOR DIAGNOSIS: MARKER OF THE MONTH CLUB

2 CHARACTERISTIC OF THE IDEAL TUMOR MARKER Specific Sensitive Easy to perform Easy to interpret Adaptable to FNA Reasonable cost (CHEAP)

3 THYROID TUMOR MARKERS Thyroglobulin Calcitonin Chromogranin CEA Thyroid peroxidase Cytokeratin 19 Galectin 3 HBME 1 S100 Dipeptidyl ase Cytokeratins Cited Ret/PTC PPAR gamma Braf K ras N ras H rasytokeratin 7 Cytokeratin 20 Cytokeratin 14 TTF 1 TTF 2 CD44 Metallothiones Met Trk Ki67 Factor VIII CD34 CD31 CD68 PGP5.5NSE Chromogranin Metalloproteinases Synaptophysin CGRP CK5/6 CD56 34Beta E 12 APC gene Beta Catenin Neuramidase Immunoglobulins LCA

4 THYROID TUMOR MARKERS L26 UCHL1 CD3 CD15 CD79AFactor VIII CD34 CD31 CD68 PGP5.5NSE Chromogranin Synaptophysin CGRP CK5/6 CD56 34Beta E 12 APC gene Menin CD21 CD35A PCNA P53 P63 Cyclin D1 CEA monoclonal CEA polyclonal Neuraminidase NSE BCL2 ACTH CRF N ras H ras Cytokeratin 7 Cytokeratin 20 Cytokeratin 14 TTF 1 TTF 2

5 THYROID TUMOR MARKERS We will now proceed at warp speed to go through all these markers and their utility and problems.

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7 JUST KIDDING!!

8 THE TUMORS IN QUESTION Papillary Follicular Hurthle cell Medullary Anaplastic

9 LECTURE WILL FOCUS ON Papillary patterned lesions Follicular patterned lesions

10 PAPILLARY PATTERN LESIONS Papillary carcinoma Papillary hyperplastic nodule

11 PAPILLARY LESIONS THE BEST MARKER: NUCLEAR MORPHOLOGY

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14 PAPILLARY LESIONS Distinction between papillary thyroid hyperplasia and papillary thyroid carcinoma by immunohistochemical staining for cytokeratin 19, galectin-3, and HBME-1. Casey MB, Lohse CM, Lloyd RV. Endo Path 2003.

15 PAPILLARY LESIONS Papillary hyperplasia v. Papillary carcinoma 30 cases of each. Overlap of staining of Galectin 3 and CK19 in benign and malignant lesions HBME 1 negative in 29 benign lesions and focally positive in one.

16 FOLLICULAR PATTERN LESIONS Follicular carcinoma v. adenoma Follicular variant papillary carcinoma v. Follicular adenoma

17 THE MARKERS : MOST EXPERIENCE Galectin 3 CK 19 HBME 1 TPO

18 THE MARKERS GALECTIN 3 Much debate in literature as to utility. Some feel it is very helpful even in FNAs

19 THE MARKERS GALECTIN 3 Others feel it is not sensitive enough nor specific enough.

20 THE MARKERS GALECTIN 3 All cases of classic variant of papillary thyroid carcinoma were consistently positive for gal- 3; The invasive type of FVPTC with or without metastasis was strongly positive for gal-3 (78.2% and 96% respectively) whereas only 46.8% of encapsulated FVPTC without metastasis showed immunostaining for this marker. Torregrossa L et al Human Pathol 2007.

21 THE MARKERS GALECTIN 3 Originally positive only in thyroid cancers (PTC, FTC) BUT Occasionally positive in benign (11% adenomas)

22 THE MARKERS GALECTIN 3 CAVEATS. Galectin is present in endothelial cells and histiocytes which can cause confusion especially in FNA. Galectin can be positive in thyroiditis and other inflammed epithelium.

23 THE MARKERS CYTOKERATIN 19 Stains classic papillary carcinoma % Stains follicular variant about 70% BUT Stains inflammed epithelium-thyroiditis, FNA sites.

24 THE MARKERS HBME-1 Found in malignant follicular derived thyroid tumors, not only papillary carcinoma Early studies: positive in 54-70% of malignant lesions; 0% benign.

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27 THE MARKERS HBME-1 As more cases studied, it was noted that epithelium that is inflamed (thyroiditis, FNA sites) can be positive. Occasionally positive in papillary hyperplasia (Casey 2003)

28 THE MARKERS THYROID PEROXIDASE (TPO) Initially claimed to differentiated benign from malignant follicular lesions In larger studies, TPO does not give a sufficient degree of diagnostic certainty that a lesion is benign. Savin et al Endo Pathol 2006

29 THE USE OF MULTIPLE MARKERS Panels of markers including CK 19, HBME 1, and Gal 3 may give better diagnostic yields as some tumors can express some but not all markers. Nakamura et al Endo Pathol 2006 Baroetta et al Endo Pathol 2006

30 THE USE OF MULTIPLE MARKERS However, even here authors disagree and get varied results. Some claim HBME-1 is best marker combined with p16 and ERK, WHEREAS, Others find HBME-1, CK 19 and Gal 3 best.

31 CAVEAT: THE MIMICS Chronic Lymphocytic Thyroiditis Post FNA WHAFFT Decalcification

32 CONCLUSION THE MARKERS DISCUSSED: 1. Are excellent for classic papillary carcinoma. 2. Are not terribly good for follicular patterned lesions. 3. May give slightly better assistance when used in combination. 4. Inflamed epithelium a problem.

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34 THYROID MOLECULAR MARKERS Ret/PTC Ras Pax8-PPAR gamma Braf

35 MOLECULAR MARKERS Ret/PTC Translocation in ret protooncogene originally discovered in 1987 in human papillary carcinoma.

36 THYROID MOLECULAR Ret/PTC MARKERS For many years felt to be specific for papillary type cancer. Numerous translocations known two most common: Ret/PTC 1 and ret/ptc 3

37 THYROID MOLECULAR Ret/PTC MARKERS Marked variation in frequency related to ethnicity of population studied. Variation whether radiation associated tumor or not. Concern regarding translocation and virulence of the cancer.

38 MOLECULAR MARKERS Ret/PTC THE ISSUE OF THYROIDITIS

39 THYROID MOLECULAR MARKERS Ret/PTC and thyroiditis Does translocation occur in thyroiditis or only if gland harbored a papillary cancer. Different methods used in studies, different definitions of thyroiditis clouded the issue. One recent study seems to document that translocation found in 68% of cases (FISH); (PCR 17%) (Rhoden JCEM 2006; Nikiforov JCEM 2006)

40 MOLECULAR MARKERS Ras MUTATIONS N-ras, K-ras, H-ras

41 THYROID MOLECULAR Ras mutations MARKERS Found in follicular and Hurthle cell tumors Also found in some follicular variants of papillary carcinoma -(? Interrelattionships here) However, Ras mutations present in adenomas and carcinomas so not diagnostically helpful.

42 MOLECULAR MARKERS Pax8-PPAR gamma Initially described in follicular carcinomas (Kroll et al Science 2000). Eight cases studied; 5 were positive Appeared to correlate with vascular invasion.

43 THYROID MOLECULAR MARKERS Pax8-PPAR gamma Found also in adenomas (about 30%), follicular variants of papillary carcinoma (about 40%) as well as follicular carcinoma (45-50%) Gustafson et al AJCP (2003); Rebocho et al JCEM 2006)

44 THYROID MOLECULAR MARKERS Braf Mutation at hot spot found in melanoma, ovarian cancer, colon cancer and thyroid carcinoma. Papillary (45%) and anaplastic (30%)

45 Structure explains function V600 F467 T599 Hydrophobic interactions hold P-loop and Activation segment together in a conformation incompatible with catalysis. Phosphorylation at T599 and S602 disrupts this. Wan et al. Cell :

46 MOLECULAR MARKERS Braf Some reports of Braf in thyroiditis. Is this ret/ptc redux?

47 MOLECULAR MARKERS Braf Studied cases of thyroiditis with and without papillary carcinoma Braf mutation in 14% of the cancers No mutations in the thyroiditic epithelium (Sargent et al Endo Pathol 2006)

48 MOLECULAR MARKERS Braf Since Braf seems mutated in papillary cancer, 45% and less in FVPTC (10%) will it be useful in those pesky follicular lesion follicular neoplasm diagnoses that are used for FNA?

49 Braf THYROID MOLECULAR MARKERS Is there enough experience to use it routinely on thyroid FNA? Not recommended routinely except in FNA with atypical or suspicious findings. (Sapio et al Clin Endocrinol 2007; Kumagai et al Endocr J 2007 )

50 CONCLUSIONS 1. Molecular studies are essential for our understanding of thyroid carcinogenesis and neoplasia. 2. Practically they are too costly and not specific enough for routine use. 3. Braf may be the exception and shows promise since it does not appear to be present in benign lesions (SO FAR!)

51 MOLECULAR MARKERS IS THERE ANYTHING NEW?

52 MOLECULAR MARKERS ONE POSSIBILITY: Micro RNAs

53 MOLECULAR MARKERS Micro RNAs LITERATURE EXPERIENCE

54 mirnas and cancer Greater than 50% of known mirnas reside in cancer associated genomic regions (CAGRs). mirnas function as tumor suppressors (let 7). mirnas function as oncogenes (mir-21). Calin GA and Croce CM. Nature Reviews Cancer :

55 mirna expression profiles can be interrogated in archival tissues mirnas can be profiled from archival tissues. Microarrays In situ hybridization Nelson PT et al. Nature Methods : Nelson PT et al. RNA :

56 Papillary thyroid carcinoma in mirna expression profiling Ample archival tissue available. Two previous fresh tissue studies available for comparison. He H et al. Proc Natl Acad Sci USA (52): Pallante P et al. Endocr Relat Cancer (2): Potential to develop a useful molecular assay for mirnas dysregulated in thyroid cancer.

57 MOLECULAR MARKERS Micro RNAs OUR EXPERIENCE

58 13 13 mirnas significantly significantly up-regulated upregulated 26 mirnas significantly down-regulated downregulated Tetzlaff et al Endo Pathol 2007

59 Our Conclusions Up-regulation of mirna-21, mirna-221, mi-rna-222 and mirna-31 validated in PTC. Archival tissue is a suitable resource for mirna studies and mirna expression profiles very similar to those from fresh tissue. A molecular assay for mirnas dysregulated in thyroid cancer can potentially be devised.

60 MOLECULAR MARKERS Micro RNAs PROBLEMS: 1. Difficult to do 2. Cost WHAT CAN WE DO TO MAKE IT SIMPLER? IN SITU TECHNIQUE. Tetzlaff, Montone et al Mod Path 2008 (abst)

61 MOLECULAR MARKERS Micro RNAs THIS IS EARLY DATA BUT MAY, WITH MORE STUDIES, HAVE DEFINITE POTENTIAL. WE ARE LOOKING AT IT USE IN FNA SAMPLES NEED TO ADAPT TO REGULAR FNA, LIQUID BASED TECHNIQUES, CELL BLOCKS, CORE BIOPSIES.

62 WHAT DO WE DO TODAY? OLD FASHIONED MORPHOLOGY IS WHAT WE NEED TO USE. NEED TO BE PRACTICAL.

63 HOPE FOR THE FUTURE IN THE NEXT FEW YEARS OF USCAP MEETINGS THERE WILL BE RESULTS OF MANY STUDIES OF ADAPTING MOLECULAR TECHNIQUES TO DAY TO DAY CYTOLOGY AND HISTOLOGY DIAGNOSES COME BACK IN 2009, 2010,

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