The Significance of Mismatch Repair Deficiency in Young Patients With Endometrial Cancer.
The objective of this study was to identify the tumor characteristics associated with mismatch repair deficiency in young patients with endometrial carcinoma. Young patients (45 yr old or younger) with endometrial carcinoma treated by hysterectomy in our institution between July 2001 and June 2009 were identified. The clinical and pathologic data were obtained by review of clinical records. Among the 122 cases identified, paraffin sections were available in 67 cases for immunohistochemical staining and frozen tissue available in 62 cases for microsatellite instability (MSI) analysis. Both paraffin sections and frozen tissue were available in 36 cases. Among the 67 cases with immunohistochemical staining, 22 (32.8%) showed loss of expression of at least 1 mismatch repair protein. Defective MLH1 or MSH2 expression was associated with poor prognostic factors, including a higher incidence of pelvic lymph nodes metastasis (P=0.018) and higher stage (P=0.022) for MLH1, and an increased risk of lymphovascular permeation (P=0.015) for MSH2. On the contrary, defective MSH6 protein expression was associated with a lower incidence of high-grade tumors (P=0.04). Among the 62 cases with MSI analysis, 12 (19.4%) tumors were classified as microsatellite-high (MSI-H), whereas 2 (3.2%) were classified as microsatellite-low (MSI-L). There was no difference in the pathologic characteristics between MSI-stable and MSI-H tumor. We concluded that defective mismatch repair expression is important in young patients with endometrial carcinoma, with MSH6 protein being most commonly affected. The phenotype resulting from defective MSH6 expression was different from that caused by MLH1 or MSH2 loss.
Departments of Obstetrics and Gynecology (M.M.-Y.C., S.S.L., K.-F.T., H.Y.-S.N.) Pathology (P.P.-C.I., A.N.-Y.C.), The University of Hong Kong, Queen Mary Hospital, Hong Kong.
Mandy Man-Yee
MM
Chu
Stephanie Si
SS
Liu
Kar-Fai
KF
Tam
Philip Pun-Ching
PP
Ip
Annie Nga-Yin
AN
Cheung
Hextan Yuen-Sheung
HY
Ngan
D048868:Adaptor Proteins, Signal Transducing / Q000032:analysis / Q000235:genetics; D000328:Adult; D001932:Brain Neoplasms / Q000235:genetics* / Q000473:pathology; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D004268:DNA-Binding Proteins / Q000032:analysis / Q000235:genetics; D016889:Endometrial Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D005260:Female; D015870:Gene Expression; D006801:Humans; D007044:Hysterectomy; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D053842:Microsatellite Instability; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000032:analysis / Q000235:genetics; D009367:Neoplasm Staging; D009386:Neoplastic Syndromes, Hereditary / Q000235:genetics* / Q000473:pathology; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics; D010388:Pelvis; D011379:Prognosis
D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; C094443:G-T mismatch-binding protein; C501486:MLH1 protein, human; D009687:Nuclear Proteins; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein