Minichromosome Maintenance Protein 7 and SMAD 4 Expressions in Squamous Cell Carcinoma of the Esophagus
JH Ahn, HK Chang. Kosin University College of Medicine, Gospel Hospital, Busan, Korea
Background: Minichromosome maintenance protein-7 (MCM7) plays a critical regulator of DNA replication as a component of the DNA replication licensing complex. Recently it has been shown that MCM 7 protein could be correlated with the clinicopathological profiles of some human tumors. In the present study, we evaluated the expression of MCM7 in squamous cell carcinoma of esophagus to clarify the pathobiological significance including prognostic relevance, correlation with clinicopathological characteristics and with that of one of tumor suppressor gene, SMAD4.
Design: We examined the immunohistochemical expression of MCM7 and SMAD4 in 67 surgically resected esophageal specimens, which consisted of 16 early cancer and 47 late-stage(II-IV) cases. Twenty-seven cases(40.3%) showed lymph node metastasis. The overall 5-year survival rate was 56.7%. Distinct nuclear staining of MCM7 and cytoplasmic staining of SMAD4 was considered as positive. The percentage of tumour cells positive for MCM7 was classified into four groups: 1 (< 5-25%), 2 (2550%), 3 (5175%) and 4 (> 75%). For statistical analysis, those with negative and positive cases were compared first. The labeling indices of each four group were also compared.
Results: The positivity of MCM7 was 79.1% and significantly correlated with the T status (P=0.008), N status(P=0.032), UICC stage (P=0.03), survival period(p=0.036)and survival(P=0.047). The positivity of SMAD4 was 26.9%, and was not significantly associated with clinicopathological characteristics. Kaplan-Meier survival curves showed that the patients with positive- MCM2 had a poorer prognosis (P < 0.05), however those with positive-SMAD4 had no prognostic significance.
Conclusions: These results indicate the expression of MCM7 may be a useful poor prognostic marker in squamous cell carcinoma of esophagus. However, the clinical implication of SMAD 4 expression could not be demonstrated here.
Wednesday, March 11, 2009 1:00 PM
Poster Session VI # 101, Wednesday Afternoon