[125] Metadherin (MTDH/AEG1): A Novel Marker for Metastasis and Chemoresistance Expression in Lymphnode Negative(LN -), Estrogen Receptor Positive (ER+) Breast Cancer Women.

Mamatha Chivukula, Adam Brufsky, Rachel Jankowitz, Kim Mcmanus, Gloria Carter. Magee Women's Hospital of UPMC, Pittsburgh, PA

Background: Gene expression profiling of breast cancer has identified two biologically distinct estrogen receptor positive (ER+) subtypes of breast cancer namely luminal A and luminal B. Luminal B tumors tend to have higher proliferation and poorer prognosis than luminal A tumors based on the molecular profiling. Studies to distinguish luminal B from luminal A tumors by immunohistochemistry are evolving. We undertook the study to perform immunohistochemistry in a large cohort of luminal A tumors and to further define this group in terms of non –recurrence and recurrence.
Design: 262 patients with ER (+), lymph node negative (LN -) from 1990-2003 were selected. Hematoxylin and eosin (H&E) slides were reviewed and representative tumor blocks were retrieved from our pathology files. Immunohistochemistry staining were performed on formalin fixed, paraffin-embedded tissue blocks using ER, Ki-67 and HER 2.
Results: Of the 262 patients, 212 were Non –recurrence group, 56 patients presented with recurrence {distant recurrence (DR) (44/56); loco regional recurrence (LRR) (12/56)} with a median follow-up of 10.1 years. Initial results in the non –recurrence group (145 cases) and all cases of recurrence to date are shown in Table 1.

Metadherin (MTDH) expression in LN (-), ER+ patients in Non recurrence, locoregional and distant recurrence groups

	nuclear membrane staining			cytoplasmic staining
	3+	2+	1+ - 0	3+	2+	1+ - 0
non-recurrence(NR) (n-28)	32% (9/28)	54% (15/28)	18% (5/28)	7% (2/28)	54% (15/28)	39% (11/28)
		recurrence group
locoregional recurrence (LRR) (n-12)	100% ( 12/12)	0 (0/12)	0 (0/12)	8% ( 1/12)	33% (4/12)	58% (7/12)
Distant recurrence (DR) (n-43)	0% (0/43)	49% (21/43)	51% (22/43)	0 % (0/43)	14% (6/43)	88% ( 38 /43)

Conclusions: The non –recurrence (ER +) tumors show low-moderate nuclear grade in contrast to recurrence (ER+) group which showed moderate –high nuclear grade.
When HER 2 and Ki-67 were used to distinguish these groups. We found that the non-recurrence group showed lower proliferation index in comparison to recurrence group ( p= 0.0168)
HER 2 tends to be strongly expressed in the recurrence group (both DR, LRR) compared to the non recurrence group (p=1.000).
Expression of ER, HER2 and the Ki67 index appears to distinguish the luminal A breast cancers which can present with recurrence versus the non-recurrence.
Category: Breast

Wednesday, March 2, 2011 1:00 PM

Poster Session VI # 18, Wednesday Afternoon