[1948] Nottingham-Defined Mitotic Score: Comparison to Visual and Image Cytometric Phosphohistone H3 Labeling Indices and Correlation with Oncotype DX Recurrence Score.

Blazej Zbytek, Cynthia Cohen, Andrew J Page, Amy L Adams. Emory University, Atlanta, GA

Background: Prognosis of breast cancer patients has been determined traditionally by lymph node status, tumor size, and histologic grade. In recent years the Oncotype DX Recurrence Score (RS) assay has emerged as a costly adjunct prognostic tool. Markers of proliferation play a large role in determination of RS, and we have shown previously that immunohistochemical expression of proliferation markers Ki-67 and phosphohistone H3 (PPH3) correlates with RS. Our current goal is comparison of the hematoxylin-and-eosin (H&E) mitotic score, defined by the Nottingham grading system, to anti-PPH3 mitotic figure labeling assessed by both visual and automated image analysis and correlation of mitotic score results with RS.
Design: Estrogen receptor-positive breast carcinomas from 138 patients with Oncotype DX testing were selected. A representative H&E-stained tumor section was evaluated. Mitoses were counted per 10 HPF and tumors graded using the Nottingham criteria by one pathologist in accordance with CAP-recommended mitotic count cutoffs for a field diameter of 0.55 mm. An additional section was immunostained with PPH3 antibody (Dako). PPH3 mitotic scores were determined visually per 10 HPF and by the Automated Cellular Imaging System III (Dako) in 10 “hotspots”. Statistical analysis was performed using univariate tests and Pearson's correlation coefficient.
Results: There was a significant association between H&E mitosis score and RS (p<0.001, R=0.34).

Mitotic score	Oncotype DX Recurrence Score
	Low	Intermediate	High
1	65 (56%)	43 (37%)	9 (7%)
2	6 (32%)	4 (21%)	9 (47%)
3	0 (0)	1 (50%)	1 (50%)

RS associations with visual and automated PPH3 mitotic scores were also significant (visual: p<0.001, R=0.32; automated: p<0.005, R=0.25). The three methods of mitotic score assessment were strongly associated with each other.

Method	Pearson's R	p
Mitotic Score: H&E vs. PPH3 Visual	.41	<0.001
Mitotic Score: PPH3 Visual vs. Automated PPH3	.71	<0.001
Tumor Grade Using H&E Mitotic Score vs. PPH3 Visual	.81	<0.001

Conclusions: The Nottingham-derived H&E mitotic score is significantly associated with RS. There is significant correlation between mitotic scores determined by H&E and by PPH3 labeling assessed visually and by imaging. There is significant correlation between grades determined by H&E and PPH3 labeling. Mitotic score by any of the three methods studied may be useful in assessing tumor grade, proliferation,and prognosis.
Category: Techniques

Monday, February 28, 2011 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 249, Monday Morning