The effect of Ki67 visual scale to improve accuracy of Ki67 index estimation in breast cancer
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Abstract
Background: The Ki67 index is an important prognostic marker in breast cancer. The current Ki67 index estimation by unaided optical microscope is widely criticized on the grounds of high inter-observer and intra-observer variability. For more accurate assessment, we create the Ki67 visual scale by using the figure from digital image analysis. The aims of this study were to validate the effect of Ki67 visual scale to improve accuracy of Ki67 index estimation in breast cancer.
Methods: This is an experimental study including 30 cases diagnosed with invasive breast carcinoma. The Ki67 index was determined using DIA. Manual Ki67 scoring by VE was performed with and without the aid of Ki67 visual scale sheet. Inter-observer agreements between Ki67 index by VE (with and without Ki67 visual scale) and by DIA were assessed using Kendall’s correlation coefficients and scatterplots.
Results: Correlation for inter-observer agreement between VE without scale sheet and DIA reveals an almost perfect agreement with a Kendall’s correlation coefficient of 0.826 (p < 0.01) whereas the correlation between VE with scale sheet and DIA also reveals an almost perfect agreement but with a Kendall’s correlation coefficient of 0.950 (p < 0.01). Although the correlation coefficients of both comparisons similarly reveal an almost perfect agreement, the correlation for inter-observer agreement between VE with scale sheet and DIA was even higher.
Conclusions: Ki67 visual scale would appear to improve accuracy and reproducibility of Ki67 index estimation using optical microscope in breast cancer patients. Such study would help define a practical tool for more standardized Ki67 index estimation by optical microscope.
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References
2. Gerdes J, Lemke H, Baisch H, Wacker HH, Schwab U, Stein H. Cell cycle analysis of a cell proliferation-associated human nuclear antigen defined by the monoclonal antibody Ki-67. J Immunol. 1984;133(4):1710-1715.
3. Denkert C, Budczies J, von Minckwitz G, Wienert S, Loibl S, Klauschen F. Strategies for developing Ki67 as a useful biomarker in breast cancer. Breast. 2015;24(Suppl 2):S67-S72. doi: 10.1016/j.breast.2015.07.017.
4. Dowsett M, Nielsen TO, A'Hern R, Bartlett J, Coombes RC, Cuzick J, et al; International Ki-67 in Breast Cancer Working Group. Assessment of Ki67 in breast cancer: recommendations from the International Ki67 in Breast Cancer working group. J Natl Cancer Inst. 2011;103(22):1656-1664. doi: 10.1093/jnci/djr393.
5. Polley MY, Leung SC, McShane LM, Gao D, Hugh JC, Mastropasqua MG, et al; International Ki67 in Breast Cancer Working Group of the Breast International Group and North American Breast Cancer Group. An international Ki67 reproducibility study. J Natl Cancer Inst. 2013;105(24):1897-1906. doi: 10.1093/jnci/djt306.
6. Polley MY, Leung SC, Gao D, Mastropasqua MG, Zabaglo LA, Bartlett JM, et al. An international study to increase concordance in Ki67 scoring. Mod Pathol. 2015;28(6):778-786. doi: 10.1038/modpathol.2015.38.
7. Leung SCY, Nielsen TO, Zabaglo L, Arun I, Badve SS, Bane AL, et al; International Ki67 in Breast Cancer Working Group of the Breast International Group and North American Breast Cancer Group. Analytical validation of a standardized scoring protocol for Ki67: phase 3 of an international multicenter collaboration. npj Breast Cancer. 2016;2:16014. doi: 10.1038/npjbcancer.2016.14.
8. Laurinavicius A, Plancoulaine B, Laurinaviciene A, Herlin P, Meskauskas R, Baltrusaityte I, et al. A methodology to ensure and improve accuracy of Ki67 labelling index estimation by automated digital image analysis in breast cancer tissue. Breast Cancer Res. 2014;16(2):R35. doi: 10.1186/bcr3639.
9. Soenksen D. Digital pathology at the crossroads of major health care trends: corporate innovation as an engine for change. Arch Pathol Lab Med. 2009 Apr;133(4):555-9. doi: 10.5858/133.4.555.
10. Kayser K, Borkenfeld S, Kayser G. How to introduce virtual microscopy (VM) in routine diagnostic pathology: constraints, ideas, and solutions. Anal Cell Pathol. 2012;35(1):3-10. doi: 10.3233/ACP-2011-0044.
11. Purdie CA, Quinlan P, Jordan LB, Ashfield A, Ogston S, Dewar JA, et al. Progesterone receptor expression is an independent prognostic variable in early breast cancer: a population-based study. Br J Cancer. 2014;110(3):565–572. doi: 10.1038/bjc.2013.756.
12. Abubakar M, Orr N, Daley F, Coulson P, Ali HR, Blows F, et al. Prognostic value of automated KI67 scoring in breast cancer: a centralised evaluation of 8088 patients from 10 study groups. Breast Cancer Res. 2016;18(1):104. doi:10.1186/s13058-016-0765-6
13. Goldhirsch A, Wood WC, Coates AS, Gelber RD, Thürlimann B, Senn HJ, et al. Strategies for subtypes—dealing with the diversity of breast cancer: highlights of the St. Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2011. Ann Oncol. 2011;22(8):1736-1747. doi:10.1093/annonc/mdr304
14. Dowsett M, Smith IE, Ebbs SR, Dixon JM, Skene A, Griffith C, et al; IMPACT Trialists. Short-term changes in Ki-67 during neoadjuvant treatment of primary breast cancer with anastrozole or tamoxifen alone or combined correlate with recurrence-free survival. Clin Cancer Res. 2005;11(2 Pt 2):951s-958s.
15. Penault-Llorca F, André F, Sagan C, Lacroix-Triki M, Denoux Y, Verriele V, et al. Ki67 expression and docetaxel efficacy in patients with estrogen receptor-positive breast cancer. J Clin Oncol. 2009;27(17):2809-2815. doi: 10.1200/JCO.2008.18.2808.
16. Hugh J, Hanson J, Cheang MC, Nielsen TO, Perou CM, Dumontet C, et al. Breast cancer subtypes and response to docetaxel in node-positive breast cancer: use of an immunohistochemical definition in the BCIRG 001 trial. J Clin Oncol. 2009;27(8):1168-1176. doi: 10.1200/JCO.2008.18.1024.
17. Kwon AY, Park HY, Hyeon J, Nam SJ, Kim SW, Lee JE, et al. Practical approaches to automated digital image analysis of Ki-67 labeling index in 997 breast carcinomas and causes of discordance with visual assessment. PLoS One. 2019;14(2):e0212309. doi: 10.1371/journal.pone.0212309.
18. Ayad E, Soliman A, Anis SE, Salem AB, Hu P, Dong Y. Ki 67 assessment in breast cancer in an Egyptian population: a comparative study between manual assessment on optical microscopy and digital quantitative assessment. Diagn Pathol. 2018;13(1):63. doi:10.1186/s13000-018-0735-7
19. Gudlaugsson E, Skaland I, Janssen EA, Smaaland R, Shao Z, Malpica A, et al. Comparison of the effect of different techniques for measurement of Ki67 proliferation on reproducibility and prognosis prediction accuracy in breast cancer. Histopathology. 2012;61(6):1134-1144. doi: 10.1111/j.1365-2559.2012.04329.x.
20. Koopman T, Buikema HJ, Hollema H, de Bock GH, van der Vegt B. Digital image analysis of Ki67 proliferation index in breast cancer using virtual dual staining on whole tissue sections: clinical validation and inter-platform agreement. Breast Cancer Res Treat. 2018;169(1):33-42. doi: 10.1007/s10549-018-4669-2.