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.
|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|