[263] Triple Negative Breast Carcinoma in African American vs. Caucasian Populations: Clinicopathologic Parameters, Marker Expression, and Outcome.

Harold C Sullivan, Amy Adams, Gabriela M Oprea, Andrew J Page, Cynthia Cohen. Emory University, Atlanta, GA

Background: Breast cancers are classified based on the presence or absence of hormone receptors and growth factor oncogenes including estrogen receptor, progesterone receptor, and HER2. Those cancers that do not stain positively for any of these markers are Triple negative breast carcinomas (TNBrCa) and do not benefit from specific targeted therapy. 15% of breast carcinomas are of the TNBrCa type. Epidemiologically, African American (AA) women are more likely to have TNBrCa with younger age of onset and poorer survival than Caucasians (CS). We compared clinicopathologic parameters and immunohistochemical markers of prognostic and/or predictive significance, and outcome (overall and recurrence free survival, recurrence, dead of disease) for both groups.
Design: Invasive TNBrCa from AA (n =94) and CS (n =68) patients were studied. Clinicopathologic criteria (age, tumor size, grade, lymph node status, angiolymphatic invasion) and survival were compared. Marker expression (CK5/6, CK7, CK8, CK14, CK18, CK19, p53, p63, topoisomerase, androgen receptor, Ki-67, c-kit, EGFR, p-cadherin, vimentin, CD44), assessed in tissue microarrays with 2 1mm cores from each carcinoma, was scored based on intensity (0-3) and percent of tumor cells stained.
Results:

Clinicopathologic characteristics, marker expression, and outcome of TNBrCa in AA and CS women

Characteristic/marker	African American no. (%)	Caucasian no. (%)	P-value
Mean age (y)	52.28	59.06	0.002
Tumor size (cm)	3.2	2.0	<0.01
> 1 + lymph node	37/90 (41)	16/61 (26)	0.06
CK5/6	8/88 (9)	50/63 (79)	<0.001
CK8	63/82 (77)	57/63 (91)	0.031
CK19	65/89 (73)	51/58 (88)	0.030
c-Kit (CD117)	49/85 (58)	19/62 (31)	0.001
Androgen receptor	6/86 (7)	11/59 (19)	0.032
Ki-67	73/83 (88)	33/61 (54)	<0.001
CD44	47/85 (55.3)	44/59 (74.6)	0.018
Dead of disease	33/94 (35)	3/68 (4)	<0.001
Overall survival (y)	5.8	6.3	<0.01

All other clinicopathologic parameters, markers, and outcomes were present at similar frequencies in both populations.
Conclusions: AA TNBrCa were more aggressive occurring at a younger age, being larger, with higher proliferation, patients more frequently dying of disease, with a shorter overall survival, and with a trend towards positive lymph node status. The heterogeneity of marker expression suggests variation in the genetics of breast carcinomas in different races.
Category: Breast

Monday, February 28, 2011 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 34, Monday Morning