Retrospective Study Of The Expression And Prognostic Implication Of Mammaglobin In Breast Cancer

【Purpose】To confirm whether hMAM is a mammary-specific marker and to investigate the relationship between the hMAM expression and the clinicopathologic characteristics in breast cancer by immunohistochemical analysis , and to estimate the prognostic value of hMAM.【Patient and Method】In this study,we examined hMAM expression in 245 tumors from various organs using immunohistochemical detection. A series of 142 patients who underwent modified radical mastectomy between 1996 and 2003 were selected. The clinical data including ER,PR and HER2 status were retrospectively collected.Formalin-fixed, paraffin-embeded tissues were sectioned at 5μm, mounted on charged slides, and dried. Negative controls were using PBS replaced hMAM antibody. Immunopositivity was scored as follows: hMAM negative is no staining or positive staining less than 5%, otherwise is hMAM positive reaction. Statistical analyses were carried out using SPSS 13.0 software package.Difference of hMAM expression in samples from patients categorized by clinicopathologic characteristics, used as grouping variables, were assessed with Chi-square test or nonparametric Kruskal-Wallis test where appropriated. Nonparametric correlations were established using Spearman correlation testing. Survival curves were generated using the method of Kaplan-Meier. Equality of survival distributions were tested using Log-rank testing and a COX model performed to check the independent value of survival. A P-value <0.05 was considered statistically significant. 【Result】hMAM was found in breast epithelial cells and is overexpressed in breast cancer. The positive staining was located in cytoplasm of tumor cells. Of the 96 other cancers examined, none were positive for hMAM except a proportion of sebaceous syst(1/5). The expression lever of hMAM in breast cancer tissue was significantly higher than those in benign and normal breast epithelium.(p<0.005).No hMAM-positive reaction expressed in HE negative axillary lymph nodes(0/63).Though its high expression showed in HE positive lymph nodes(37/44). Clinicopathologically, hMAM expression was associated with positive expression of ER, but not with age ,pathologic type,HER2 status ,tumor size, clinicopathologic stage and PR status.Kaplan-Meier survival analysis explored a significant difference between hMAM-positive and hMAM-negative of breast cancer. hMAM-positive patients had better outcome (Log-rank test p=0.005).COX multivariate analysis revealed that pathologic stage, ER expression, age and hMAM are significantly and independently affected overall survival.【Conclusion】In conclusion, hMAM is a highly specific marker of breast cancer, and its expression was detected in more than half of breast carcinomas examined. The expression of hMAM was significantly correlated with ER status, but unaffected by other clinicopathologic features, including pathological stage, tumor size, age, axillary lymph nodes and HER2 status.Survival curve revealed that hMAM was a independent prognostic factor of breast cancer patients'outcome.