Role of IHC in Breast Pathology

ESPC Breast Workshop 2017 14 December

Outline

◼Diagnostic

▪ Benign vs malignant ductal lesions

▪ Ductal vs lobular lesions

▪ Papillary lesions

◼Prognostic

Young F, Mass Core Biopsy

VOTE: Diagnosis

1. Benign2. Atypical3. In situ4. Malignant

◼Mastectomy done

VOTE: What stain would you order

1. none2. basal myoepithelial, i.e. p633. ER/PR4. CerbB2

DCIS in Adenosis

◼DCIS◼ Involving adenosis

ME MarkersLiu. Immunohistochemistry in breast pathology. Arch Pathol Lab Med. 2014;138:1629

S100 vs p63

Her2 in DCIS vs ADH

◼15-20% of invasive ca◼Up to 60% in DCIS

DCIS

Margin

CerbB2

Lobular Lesions

◼Vs ductal◼Vs myoepithelial

Papillary Lesions

50 F Subareolar

VOTE

1. Benign2. Atypical3. In situ4. Invasive

Solid PapillaryZhao et al. Diagnostic Role of Immunohistochemistry in the Evaluation of Breast Pathology Specimens. Arch Pathol Lab Med. 2014;138:16

Papillary LesionsPeng et al. Update on Immunohistochemical Analysisin Breast LesionsArch Pathol Lab Med. 2017;141:1033

Prognostic Markers

Ki67

2nd tumor; multifocal

Well Differentiated

IHC Surrogates for MolecularTang and Tse. Immunohistochemical Surrogates for Molecular Classification of Breast Carcinoma: A 2015 Update. Arch Pathol Lab Med. 2016;140:806

IHC Surrogates

Molecular IHC: Basal Like Breast CALeidy et al. Basal-Like Breast Cancer: Update on Clinicopathologic, Immunohistochemical, and Molecular FeaturesArch Pathol Lab Med. 2014;138:37

Novel MarkerJensen et al. Diagnosis of Basal-Like Breast Cancer Using aFOXC1-Based Assay. JNCI J Natl Cancer Inst (2015) 107: djv148

Allred vs FOXC1

DSS Curves: PAM50 vs FOXC1

H&E is King (Queen Sheikha)!

References

◼Peng et al, Arch Pathol lab Med 2017. 141:1033

◼Ray et al. Cancer Res 70:10, 2010◼Liu. Arch Pathol Lab Med 2014:138:1629◼Zhao et al. Arch Pathol Lab Med 2014:138:16◼Tang and Tse. Arch Pathol Lab Med 2016:

140:806