Immunohistochemical Profile of Gastric Type Endocervical Adenocarcinoma, Including HER2/Neu Status
Yevgeniy Karamurzin, Vinita Parkash, Takako Kiyokawa, Robert A Soslow, Kay J Park. Memorial Sloan-Kettering Cancer Center, New York, NY; Yale University School of Medicine, New Haven, CT; Chiba University School of Medicine, Chiba, Japan
Background: Gastric type (GA) and minimal deviation adenocarcinoma (MDA) are subtypes of endocervical adenocarcinoma not related to infection by human papillomavirus (HPV) and are characterized by expression of gastric pyloric gland type mucin as evinced by HIK1083 immunoreactivity. The extent to which these tumors express other Mullerian or gastrointestinal (GI) immunophenotype has not been previously studied. We evaluated a series of GA/MDA for expression of such markers. Since gastric and ovarian mucinous carcinomas have been shown to overexpress HER2/neu with concurrent amplification (and are therefore amenable to targeted therapy with traztuzumab), we also included this stain in our panel.
Design: A retrospective review of GA or MDA from the pathology databases of two institutions was performed. Using standard protocols, immunohistochemical (IHC) studies were performed on formalin-fixed, paraffin embedded tissue for CK7, p16, CK20, CDX2, p53, PAX8 and Her2/neu. Her2/neu expression was scored according to the ASCO/CAP guidelines (0 to 3+). All others were scored semiquantitatively as POS (>50%), NEG (0), FOC (any to 50%).
Results: 16 cases with blocks available for staining were identified. Results are summarized in Tables 1 and 2. Four cases also had tissue from metastatic sites available for staining.
|POS (%)||FOC (%)||NEG (%)|
|CK20||3 (19)||2 (13)||11(69)|
|p16||0||1 (6)||15 (94)|
|CDX2||0||4 (19)||12 (81)|
|p53||3 (19)||13 (81)||0|
|PAX8||7 (47)||3 (20)||5 (33)|
|3+ (%)||2+ (%)||0/1+ (%)|
|Her2/neu||1 (6)||1 (6)||14 (82)|