Anne-Vibeke Laenkholm1, Dorthe Grabau2, Maj-Lis Møller Talman3, Eva Balslev4, Anne Marie Bak Jylling5, Tomasz Piotr Tabor6, Morten Johansen7, Anja Brügmann8, Giedrius Lelkaitis3, Tina Di Caterino9, Henrik Mygind1, Thomas Poulsen10, Henrik Mertz11, Gorm Søndergaard12, Birgitte Bruun Rasmussen4. 1. a Department of Surgical Pathology , Zealand University Hospital , Slagelse , Denmark. 2. b Department of Pathology , Skåne University Hospital , Lund , Sweden. 3. c Department of Pathology , Rigshospitalet , Copenhagen , Denmark. 4. d Department of Pathology , Herlev Hospital , Herlev , Denmark. 5. e Department of Pathology , Odense University Hospital , Odense , Denmark. 6. f Department of Pathology , Lillebaelt Hospital , Vejle , Denmark. 7. g Department of Pathology , North Denmark Regional Hospital , Hjørring , Denmark. 8. h Department of Pathology , Aalborg University Hospital , Aalborg , Denmark. 9. i Department of Pathology , Hospital of South West Jutland , Esbjerg , Denmark. 10. j Department of Pathology , Sygehus Soenderjylland , Sønderborg , Denmark. 11. k Department of Pathology , Regional Hospital of Randers , Randers , Denmark. 12. l Department of Pathology , Region Hospital of Viborg , Viborg , Denmark.
Abstract
INTRODUCTION: In 2011, the St. Gallen Consensus Conference introduced the use of pathology to define the intrinsic breast cancer subtypes by application of immunohistochemical (IHC) surrogate markers ER, PR, HER2 and Ki67 with a specified Ki67 cutoff (>14%) for luminal B-like definition. Reports concerning impaired reproducibility of Ki67 estimation and threshold inconsistency led to the initiation of this quality assurance study (2013-2015). The aim of the study was to investigate inter-observer variation for Ki67 estimation in malignant breast tumors by two different quantification methods (assessment method and count method) including measure of agreement between methods. MATERIAL AND METHODS: Fourteen experienced breast pathologists from 12 pathology departments evaluated 118 slides from a consecutive series of malignant breast tumors. The staining interpretation was performed according to both the Danish and Swedish guidelines. Reproducibility was quantified by intra-class correlation coefficient (ICC) and Lights Kappa with dichotomization of observations at the larger than (>) 20% threshold. The agreement between observations by the two quantification methods was evaluated by Bland-Altman plot. RESULTS: For the fourteen raters the median ranged from 20% to 40% by the assessment method and from 22.5% to 36.5% by the count method. Light's Kappa was 0.664 for observation by the assessment method and 0.649 by the count method. The ICC was 0.82 (95% CI: 0.77-0.86) by the assessment method vs. 0.84 (95% CI: 0.80-0.87) by the count method. CONCLUSION: Although the study in general showed a moderate to good inter-observer agreement according to both ICC and Lights Kappa, still major discrepancies were identified in especially the mid-range of observations. Consequently, for now Ki67 estimation is not implemented in the DBCG treatment algorithm.
INTRODUCTION: In 2011, the St. Gallen Consensus Conference introduced the use of pathology to define the intrinsic breast cancer subtypes by application of immunohistochemical (IHC) surrogate markers ER, PR, HER2 and Ki67 with a specified Ki67 cutoff (>14%) for luminal B-like definition. Reports concerning impaired reproducibility of Ki67 estimation and threshold inconsistency led to the initiation of this quality assurance study (2013-2015). The aim of the study was to investigate inter-observer variation for Ki67 estimation in malignant breast tumors by two different quantification methods (assessment method and count method) including measure of agreement between methods. MATERIAL AND METHODS: Fourteen experienced breast pathologists from 12 pathology departments evaluated 118 slides from a consecutive series of malignant breast tumors. The staining interpretation was performed according to both the Danish and Swedish guidelines. Reproducibility was quantified by intra-class correlation coefficient (ICC) and Lights Kappa with dichotomization of observations at the larger than (>) 20% threshold. The agreement between observations by the two quantification methods was evaluated by Bland-Altman plot. RESULTS: For the fourteen raters the median ranged from 20% to 40% by the assessment method and from 22.5% to 36.5% by the count method. Light's Kappa was 0.664 for observation by the assessment method and 0.649 by the count method. The ICC was 0.82 (95% CI: 0.77-0.86) by the assessment method vs. 0.84 (95% CI: 0.80-0.87) by the count method. CONCLUSION: Although the study in general showed a moderate to good inter-observer agreement according to both ICC and Lights Kappa, still major discrepancies were identified in especially the mid-range of observations. Consequently, for now Ki67 estimation is not implemented in the DBCG treatment algorithm.
Authors: Garazi Serna; Sara Simonetti; Roberta Fasani; Francesca Pagliuca; Xavier Guardia; Paqui Gallego; Jose Jimenez; Vicente Peg; Cristina Saura; Serenella Eppenberger-Castori; Santiago Ramon Y Cajal; Luigi Terracciano; Paolo Nuciforo Journal: Breast Date: 2020-07-13 Impact factor: 4.380
Authors: Gisela L G Menezes; Ritse M Mann; Carla Meeuwis; Bob Bisschops; Jeroen Veltman; Philip T Lavin; Marc J van de Vijver; Ruud M Pijnappel Journal: Eur Radiol Date: 2019-05-27 Impact factor: 5.315
Authors: Nikolaos A Trikalinos; Deyali Chatterjee; Jane Lee; Jingxia Liu; Greg Williams; William Hawkins; Chet Hammill Journal: Ann Surg Oncol Date: 2020-03-23 Impact factor: 4.339
Authors: Torsten O Nielsen; Samuel C Y Leung; David L Rimm; Andrew Dodson; Balazs Acs; Sunil Badve; Carsten Denkert; Matthew J Ellis; Susan Fineberg; Margaret Flowers; Hans H Kreipe; Anne-Vibeke Laenkholm; Hongchao Pan; Frédérique M Penault-Llorca; Mei-Yin Polley; Roberto Salgado; Ian E Smith; Tomoharu Sugie; John M S Bartlett; Lisa M McShane; Mitch Dowsett; Daniel F Hayes Journal: J Natl Cancer Inst Date: 2021-07-01 Impact factor: 13.506