[1542] Expression of IMP3, an Oncofetal Protein, in Various Malignant Primary and Metastatic Neoplasms, a Study of 1099 Cases

D Lu, Y Zhou, M Kamionek, M Lyle, BA Woda, SY Hao, KL Rock, Z Jiang. UMass Memorial Healthcare, Worcester, MA

Background: IMP3, an oncofetal protein, plays an important role in tumor proliferation and invasion. Recently, we have demonstrated that IMP3 is a new prognostic biomarker for cancer progression and metastasis of renal cell carcinoma and urothelial carcinoma. However, little is known about expression of IMP3 in other malignancies. In this study, we investigated expression of IMP3 in 1099 cases of various primary and metastatic carcinomas.
Design: 907 primary (P) malignant tumors and 192 metastatic (M) carcinomas selected from the surgical pathology files of the Departments of Pathology of the University of Massachusetts Medical Center were examined by immunohistochemical analysis. These cases included urothelial carcinoma (UC, P=238; M=28); skin melanoma (SM, P=78; M=11) endometrioid carcinomas of uterus (EMU, P=70; M=6); papillary thyroid carcinoma (PTC, P=21; M=10); squamous cell carcinoma of the skin (SCC, P=10; M=5); renal cell carcinoma (RCC, P=159; M=36); ductal carcinoma of the breast (DCB, P=24; M=27); colonic adenocarcinoma (CA, P=86; M=30); non-small cell carcinoma of the lung (NSCCL, P=26; M=10); prostatic adenocarcinoma (PA, P=35; M=8); ovarian serous and mucinous carcinoma (OC, P=97; M=5); pancreatic adenocarcinoma (PA, P=38; M=5) and gastric adenocarcinoma (GA, P=25; M=6).
Results: We identified IMP3 protein in the cytoplasm of tumor cells. A high percent of metastatic carcinomas compared to their primary tumors expressed IMP3 (P<0.05), including P: 21% (51/238) vs. M: 93% (26/28) of UC; P: 7% (5/70) vs. M: 83% (5/6) of EMU; P: 19% (4/21) vs. M: 80% (8/10) of PTC; P: 50% (5/10) vs. M: 80% (4/5) of SCC; P: 16% (25/159) vs. M: 78% (28/36) of RCC; P: 8% (2/24) vs. M: 48% (13/27) of DCB and P: 69% (54/78) vs. 91% (10/11) of SK. Other tumors including colonic, lung, prostatic, pancreatic, ovarian and gastric carcinomas showed no significant difference of IMP3 expression between primary and metastatic carcinomas. IMP3 expression was not found in any of benign tissue adjacent to the malignancies.
Conclusions: Our data provide important baseline information for IMP3 expression in different malignancies. As there is significant higher expression of IMP3 in metastatic cancers compared to their primary counterparts, IMP3 may have a potential prognostic value for thyroid, breast, uterus and skin cancers.
Category: Pathobiology

Tuesday, March 10, 2009 1:00 PM

Poster Session IV # 207, Tuesday Afternoon