Clinical Significance Of MGMT And ERCC1 Expression In Gastric Carcinoma And Precancerous Lesion

Objective To investigate the expression of DNA repair gene MGMT and ERCC1 in gastric mucosal carcinoma and precancerous lesions,and to explore the significance.To explore MGMT and ERCC1 could be used as a marker to predict the carcinogenesis of gastric carcinoma and to judge the biological behavior of gastric carcinoma.Methods Sixteen normal mucosa, Eighteen slight dysplasia, Twenty-four moderate and severe dysplasia, Eighteen early gastric cancer and Forty-four advanced gastric cancer were examined immunohistochemically by SP method.Results 1. MGMT protein mainly expressed in cellular nuclei. MGMT in normal mucosa,slight dysplasia, moderate and severe dysplasia,early gastric cancer,advanced gastric cancer, the positive expression rates were 93.8%(15/16),94.4%(17/18),91.7%(22/24),66.7%(12/18),68.2%(30/44), respectively. In the early of gastric MGMT protein expression rate 66.7% (12/18) and adanced gastric cancer expression rate 68.2%(30/44)obviously lower than slight dysplasia expression rate 94.4%(17/18), there was significant difference among the three groups(P<0.05). In carcinoma, the positive rate of MGMT expressions in well-moderate differentiation and poor differentiation were 81.1%(30/37)and 48.0%(12/25), there was significant difference between the two groups(P<0.05). The positive ratio was 59.5%(25/42)and 85.0%(17/20)respectively in group with and without lymph node metastasis, there was significant difference between the two groups(P<0.05). The expressions of MGMT had no relationship with age,sex,size and infiltrate depth (P >0.05). 2. ERCC1 in normal mucosa,slight dysplasia,moderate and severe dysplasia,early gastric cancer,advanced gastric cancer , the positive expression rates were 93.8%(15/16),72.2%(13/18),75.0%(18/24),55.6%(10/18),45.5%(20/44), respectively. The positive rate of ERCC1 in normal mucosa 93.8%(15/16)was higher than that in early 55.6%(10/18)and advanced gastric carcinoma 45.5%(20/44), there was significant difference among the three groups (P<0.05). In carcinoma, the positive rate of ERCC1 expressions in well-moderate differentiation and poor differentiation were 59.5%(22/37)and 32.0%(8/25), there was significant difference between the two groups(P<0.05). In the depth of myometrial invasion of the tumor and reached the serosal layer of the tumor were 69.2% (18/26) and 33.3% (12/36), there was significant difference between the two groups(P<0.05). The positive ratio was 38.1%(16/42)and 70.0%(14/20)respectively in group with and without lymph node metastasis, there was significant difference between the two groups(P<0.05). The expressions of ERCC1 had no relationship with age,sex and size (P>0.05).3. Besides, 62 cases of gastric cancer, MGMT and ERCC1 common positive in 26 cases, 16 cases of the common negative, expressing the same in 42 cases, 20 cases are inconsistent, MGMT-positive ERCC1-negative in 16 patients, MGMT-negative ERCC1-positive 26 cases. The expression of MGMT was positively correlated with ERCC1 in gastric carcinoma tissue ( vs=0.392, P<0.05).Conclusions 1. The positive rate of MGMT in early and advanced gastric carcinoma was lower than that in slight dysplasia(P<0.05). The positive rate of ERCC1 in normal mucosa was higher than that in early and advanced gastric carcinoma (P<0.05). Clew MGMT and ERCC1 express discretion may represent stomach organization DNA damage, may become malignant behavior prediction of gastric cancer.2. MGMT and ERCC1, in the stomach cancer splits up in the degree different patient's masculine expression rate to have statistics significance(The high split up group is higher than the low split up group, P<0.05), The group of lymph node metastasis rate below lymph node metastasis of positive group without (P<0.05), Therefore two targets have certain prompt function regarding stomach cancer's split up degree and the lymph node shift situation's judgment.3. With the progress of gastric mucosal lesion, MGMT and ERCC1 in gastric precancerous lesions gradually decreasing rate, The expression of MGMT was positively correlated with ERCC1 in gastric carcinoma tissue (P<0.05). Prompts both, in the gastric mucosa becomes malignant in the process to play the important role, may take the monitor gastric mucosa pathological change progress and the judgment biology behavior useful target, applies in the gastric mucosa high-risk group's revisit examination, raises the early stomach cancer formation rate by the time.4. Expressing checking MGMT protein white and ERCC1 protein white at the same time, is helpful to the cancer of the stomach early warning.