[1152] Claudin-18, MUC1, MUC2, and MUC5AC Are Differentially-Expressed in Ovarian Intestinal- and Endocervical-Type Mucinous Borderline Tumors

Sultan Ahmed Halimi, Daichi Maeda, Masashi Fukayama. Graduate School of Medicine, the University of Tokyo, Tokyo, Japan

Background: Ovarian mucinous borderline tumors (MBTs) are currently classified into two types: intestinal (IMBT) and endocervical (EMBT). Distinguishing between the two types is important, because their histogenesis and clinicopathological features differ significantly. The aim of this study was to analyze the expression of Claudins (CLDNs), which are tight junction proteins known to be differentially expressed in various tumors, in ovarian IMBTs and EMBTs. Mucin (MUC) expression was also examined to reveal the mucin profiles of these two lesions.
Design: A total of 62 cases of ovarian MBTs (40 IMBTs and 22 EMBTs) were retrieved from the archives of the Department of Pathology of the University of Tokyo Hospital. MBTs were classified into IMBTs and EMBTs, based on the review of hematoxylin and eosin stained slides of all the cases. The MBT tissues were arranged in tissue microarrays (TMAs) with duplicate 2 mm tissue cores obtained from the tumor area in each MBT. Immunohistochemistry for Claudins (CLDN1, 3, 4, 7 and 18), MUCs (MUC1, 2, 5AC and 6), CK7, CK20, CA125, ER, PgR and vimentin were performed on the TMAs.
Results: CLDN18 expression was observed in all IMBTs, whereas only one EMBT was CLDN18-positive. There was no significant difference in the expression of CLDNs 1, 3, 4, and 7 between IMBTs and EMBTs. With regards to MUCs, MUC1 was more frequently expressed in EMBTs than in IMBTs. Positive immunoreactivity for MUC2 and MUC5AC were observed more often in the IMBTs. ER, PgR, and vimentin expression were seen almost exclusively in the EMBTs.

CLDN132/40 (80%)20/22 (91%)0.2638
CLDN340/40 (100%)22/22 (100%)-
CLDN438/40 (95%)22/22 (100%)0.2864
CLDN740/40 (100%)22/22 (100%)-
CLDN1840/40 (100%)1/22 (5%)<0.0001
MUC117/40 (43%)22/22 (100%)<0.0001
MUC219/40 (48%)3/22 (14%)0.0077
MUC5AC37/40 (93%)14/22 (64%)0.0044
MUC610/40 (25%)4/22 (18%)0.5390
CK740/40 (100%)22/22 (100%)-
CK2029/40 (73%)1/22 (5%)<0.0001
CA1259/40 (23%)22/22 (100%)<0.0001
ER1/40 (3%)22/22 (100%)<0.0001
PgR1/40 (3%)16/22 (73%)<0.0001
Vimentin0/40 (0%)22/22 (100%)<0.0001

Conclusions: Frequent expression of CLDN18, MUC2, and MUC5AC by IMBTs supports a “gastrointestinal” phenotype of the IMBT tumor cells, since CLDN18 and MUC5AC are known gastric epithelial markers and MUC2 is a colonic marker. Furthermore, our study indicates that ER, PgR, vimentin, and CA125 can be used as endocervical-type markers, and CLDN18 and CK20 can be used as intestinal-type markers, for classifying ovarian mucinous tumors into two subsets.
Category: Gynecologic & Obstetrics

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 191, Tuesday Morning


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