S. Woo Jennifer, A. Moatamed Neda, S. Sullivan Peggy, Y. Lu David, Callahan Rena, Apple Sophia, Comparison of Phosphohistone H3 Immunohistochemical Staining, Ki-67, and H&E Mitotic Count in Invasive Breast Carcinoma, Journal of Breast Cancer Survival, Volume 1, Issue 1, 2015, Pages 1-11, ISSN 0000-0000, https://doi.org/.
(https://oap-researcharticles.org/jbcs/article/195)
Abstract: The mitotic count is the most frequent reason for discordance between pathologists in modified Bloom and Richardson (mBR) scoring. Recently, the phosphohistone H3 (PHH3) immunohistochemical stain has been proposed as a potential surrogate marker for mitotic figures. This study examines the differences between H&E mitotic count, PHH3 mitotic count, and Ki-67 index in invasive breast carcinoma. A retrospective review of invasive breast carcinoma cases from 2013- 2014 was performed. H&E and PHH3 mitotic counts were assigned a mitotic score of 1 to 3 using mBR criteria. Ki-67 index was categorized into a three-grade system: <10% (low), 10 - <20% (intermediate), and >20% (high). A total of 451 cases were evaluated. PHH3 versus H&E mitotic count changed mBR scores in 24% of cases, upgrading in 23% and downgrading in 1%. A total of 431 cases had both Ki-67 and PHH3 available for comparison. Both H&E and PHH3 mitotic scores correlated with Ki-67 in 51% of cases; however, PHH3 had better correlation. We conclude that PHH3 in breast carcinoma allows for a more sensitive and practical approach in the identification of mitotic figures. PHH3 IHC is useful as a confirmatory tool in assessing the final mitotic score for more accurate mBR scoring and grading. In this study, 48 out of 451 (10.6%) of patients had a significant upgrade that may change the patient's treatment plans, including the addition of chemotherapy
Keywords: phosphohistone-H3 (PHH3); mitotic count; Ki-67; invasive breast carcinoma; modified Bloom and Richardson score