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Low concordance of biomarkers in histopathological and cytological material from breast cancer
Author(s) -
Stålhammar Gustav,
Rosin Gustaf,
Fredriksson Irma,
Bergh Jonas,
Hartman Johan
Publication year - 2014
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.12344
Subject(s) - concordance , medicine , breast cancer , biomarker , immunohistochemistry , oncology , cancer , retrospective cohort study , cytology , pathology , biochemistry , chemistry
Aims The aim of this study was to investigate in primary breast cancer the congruency of routine clinical predictive biomarker evaluations, including ER , PR and K i67, obtained using immunocytochemistry ( ICC ) and immunohistochemistry ( IHC ). Methods and results Clinicopathological data were collected on all women diagnosed with primary breast cancer at Karolinska University Hospital in 2011. A total of 346 patients were included in a retrospective paired comparison of predictive biomarker evaluations on direct smear ICC and IHC . This showed a low congruency between findings with the two methods, especially evident for Ki67 (κ = 0.35–0.42). By suggested adjustments to ICC cut‐offs, we managed to improve the inter‐rater agreement of Ki67 classification slightly to κ = 0.46. Conclusions Our findings suggest that routine clinical ICC and IHC evaluations of predictive biomarkers produce discordant results. Consequently, basing therapeutic decisions on cytology with cut‐offs defined for IHC induces a risk that patients will receive suboptimal therapy. However, our analysis shows that local adjustments to biomarker cut‐off levels may improve congruency and increase the probability of correct classifications.