title: "Score the Core" Web-based pathologist training tool improves the accuracy of breast cancer IHC4 scoring.
abstract: Hormone receptor status is an integral component of decision-making in breast cancer management. IHC4 score is an algorithm that combines hormone receptor, HER2, and Ki-67 status to provide a semiquantitative prognostic score for breast cancer. High accuracy and low interobserver variance are important to ensure the score is accurately calculated; however, few previous efforts have been made to measure or decrease interobserver variance. We developed a Web-based training tool, called "Score the Core" (STC) using tissue microarrays to train pathologists to visually score estrogen receptor (using the 300-point H score), progesterone receptor (percent positive), and Ki-67 (percent positive). STC used a reference score calculated from a reproducible manual counting method. Pathologists in the Athena Breast Health Network and pathology residents at associated institutions completed the exercise. By using STC, pathologists improved their estrogen receptor H score and progesterone receptor and Ki-67 proportion assessment and demonstrated a good correlation between pathologist and reference scores. In addition, we collected information about pathologist performance that allowed us to compare individual pathologists and measures of agreement. Pathologists' assessment of the proportion of positive cells was closer to the reference than their assessment of the relative intensity of positive cells. Careful training and assessment should be used to ensure the accuracy of breast biomarkers. This is particularly important as breast cancer diagnostics become increasingly quantitative and reproducible. Our training tool is a novel approach for pathologist training that can serve as an important component of ongoing quality assessment and can improve the accuracy of breast cancer prognostic biomarkers.
authors.affiliation: Center for Comparative Medicine, University of California Davis, Davis, CA 95616. Electronic address: jesse.engelberg@gmail.com.
authors.forename: Jesse A
authors.initials: JA
authors.lastname: Engelberg
authors.affiliation: School of Medicine, University of California San Francisco, San Francisco, CA 94143.
authors.forename: Hanna
authors.initials: H
authors.lastname: Retallack
authors.affiliation: Department of Pathology, University of California San Francisco, San Francisco, CA 94143.
authors.forename: Ronald
authors.initials: R
authors.lastname: Balassanian
authors.affiliation: Centre for Molecular Pathology, Royal Marsden Hospital, London, SW3 6JJ United Kingdom.
authors.forename: Mitchell
authors.initials: M
authors.lastname: Dowsett
authors.affiliation: Institute of Cancer Research, London, SM2 5NG United Kingdom.
authors.forename: Lila
authors.initials: L
authors.lastname: Zabaglo
authors.affiliation: Center for Comparative Medicine, University of California Davis, Davis, CA 95616.
authors.forename: Arishneel A
authors.initials: AA
authors.lastname: Ram
authors.affiliation: Department of Pathology, University of California Los Angeles, Los Angeles, CA 90404.
authors.forename: Sophia K
authors.initials: SK
authors.lastname: Apple
authors.affiliation: Department of Pathology, University of California Davis, Davis, CA 95616.
authors.forename: John W
authors.initials: JW
authors.lastname: Bishop
authors.affiliation: Department of Pathology, University of California Davis, Davis, CA 95616.
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Borowsky
authors.affiliation: Department of Pathology, University of California Irvine, Orange, CA 92697.
authors.forename: Philip M
authors.initials: PM
authors.lastname: Carpenter
authors.affiliation: Department of Pathology, University of California San Francisco, San Francisco, CA 94143.
authors.forename: Yunn-Yi
authors.initials: YY
authors.lastname: Chen
authors.affiliation: Department of Pathology, University of California San Diego, San Diego, CA 92093.
authors.forename: Brian
authors.initials: B
authors.lastname: Datnow
authors.affiliation: Center for Comparative Medicine, University of California Davis, Davis, CA 95616.
authors.forename: Sarah
authors.initials: S
authors.lastname: Elson
authors.affiliation: Department of Pathology, University of California San Diego, San Diego, CA 92093.
authors.forename: Farnaz
authors.initials: F
authors.lastname: Hasteh
authors.affiliation: Department of Pathology, University of California Irvine, Orange, CA 92697.
authors.forename: Fritz
authors.initials: F
authors.lastname: Lin
authors.affiliation: Department of Pathology, University of California Los Angeles, Los Angeles, CA 90404.
authors.forename: Neda A
authors.initials: NA
authors.lastname: Moatamed
authors.affiliation: Department of Pathology, University of California Davis, Davis, CA 95616.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Pathology, University of California Davis, Davis, CA 95616.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Cardiff
mesh_terms: D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D020407:Internet; D060787:Neoplasm Grading; D010336:Pathology / Q000193:education*; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone
keywords: Breast cancer; Digital microscopy; IHC4; Immunohistochemistry; Pathology education; Training; Whole-slide imaging