BACKGROUND Colorectal cancer(CRC)is common in elderly patients.Mismatch repair(MMR)protein deletion is one of the causes of CRC.The RAS(KRAS/NRAS),BRAF,and PIK3CA genes are important gene targets in CRC treatment and ...BACKGROUND Colorectal cancer(CRC)is common in elderly patients.Mismatch repair(MMR)protein deletion is one of the causes of CRC.The RAS(KRAS/NRAS),BRAF,and PIK3CA genes are important gene targets in CRC treatment and are closely related to the prognosis and survival of patients.However,little is known regarding the relationship between the expression of MMR,RAS,BRAF,PIK3CA and the clinicopathological features in CRC patients.AIM To analyze the relationship between the expression of MMR,RAS,BRAF,PIK3CA and the clinicopathological features in CRC.METHODS A total of 327 elderly patients with CRC were enrolled,and immunohistochemistry was used to detect the MMR protein.Real-time quantitative polymerase chain reaction was used to detect the RAS(KRAS/NRAS),BRAF,and PIK3CA genes.The clinicopathological data of the patients were recorded and analyzed by SPSS 19.0 statistical software.RESULTS In 327 elderly patients with CRC,the rate of MMR protein loss was 9.79%(32/327),and the deletion rate of four MMR proteins(MSH2,MSH6,MLH1,PMS2)was 1.83%(6/327),3.06%(10/327),7.65%(25/327),and 7.65%(25/327),respectively.There were no significant differences between MMR protein deletion and sex,pathological type,tumor morphology,differentiation degree or lymph node metastasis(P>0.05),but there was a significant difference between MMR protein deletion and tumor diameter and tumor location(P=0.048/P=0.000).The mutation rates of the KRAS,NRAS,BRAF and PIK3CA genes in elderly CRC patients were 44.95%(147/327),2.45%(8/327),3.36%(11/327)and 2.75%(9/327),respectively;the KRAS gene mutation was closely related to tumor morphology(P=0.002)but not to other clinicopathological features(P>0.05),and there were no significant differences between NRAS gene mutation and clinicopathological features(P>0.05).The BRAF gene mutation showed a significant difference in pathological type,tumor location,differentiation degree and lymph node metastasis(P<0.05),but was not correlated with sex,tumor size and tumor morphology(P>0.05).The PIK3CA gene mutation showed no significant differences in the above clinicopathological characteristics(P>0.05).Significant differences were observed between MMR protein deletion and KRAS,BRAF,and PIK3CA gene mutations in elderly CRC patients(P=0.044,P=0.000,P=0.003,respectively),but there was no significant difference between MMR protein deletion and NRAS mutation(P>0.05).CONCLUSION In elderly CRC patients,the tumor is mainly located in the right colon,and the deletion rate of MMR protein is higher when the tumor diameter is greater than or equal to 5 cm;the deletion rate of MLH1 and PMS2 is more common;the mutation rate of KRAS gene is higher than that of the NRAS,BRAF and PIK3CA genes,the BRAF gene mutation has different degrees of correlation with clinicopathological characteristics;when the MMR protein is deleted,the BRAF and PIK3CA gene mutations are often present,and the KRAS gene mutation rate is low.展开更多
BACKGROUND Immunohistochemical(IHC)staining for mismatch repair(MMR)proteins is useful for gastric cancer treatment and prognosis.Different IHC staining patterns reflect the complex biological phenomena underlying MMR...BACKGROUND Immunohistochemical(IHC)staining for mismatch repair(MMR)proteins is useful for gastric cancer treatment and prognosis.Different IHC staining patterns reflect the complex biological phenomena underlying MMR deficiency.We herein report a rare IHC staining pattern of four MMR-related proteins in gastric cancer.CASE SUMMARY A“null”IHC staining pattern of four MMR-related proteins,including MLH1,PMS2,MSH2,and MSH6,in a 67-year-old male patient with gastric cancer pT3N3aM0 revealed promoter hypermethylation of MLH1.Next-generation sequencing showed that these four genes exhibited changes.One of these was the somatic mutation of the missing copy number in exon 14 of MSH2.Mutation analysis using peripheral blood showed no germline mutations in these four genes.The patient had no history of personal or family tumor history.We classified this case as sporadic.The patient returned to normal after operation,and there were no signs of tumor metastasis and recurrence.After six cycles of adjuvant chemotherapy,the patient was discharged in a stable condition.The patient had a mild reaction to chemotherapy and a good prognosis.At present,16 mo after the operation,the patient's condition is stable.CONCLUSION Abnormal MMR protein expression,helpful for individualized follow-up care,helped identify a sporadic case lacking familial clinical management implications.展开更多
文摘BACKGROUND Colorectal cancer(CRC)is common in elderly patients.Mismatch repair(MMR)protein deletion is one of the causes of CRC.The RAS(KRAS/NRAS),BRAF,and PIK3CA genes are important gene targets in CRC treatment and are closely related to the prognosis and survival of patients.However,little is known regarding the relationship between the expression of MMR,RAS,BRAF,PIK3CA and the clinicopathological features in CRC patients.AIM To analyze the relationship between the expression of MMR,RAS,BRAF,PIK3CA and the clinicopathological features in CRC.METHODS A total of 327 elderly patients with CRC were enrolled,and immunohistochemistry was used to detect the MMR protein.Real-time quantitative polymerase chain reaction was used to detect the RAS(KRAS/NRAS),BRAF,and PIK3CA genes.The clinicopathological data of the patients were recorded and analyzed by SPSS 19.0 statistical software.RESULTS In 327 elderly patients with CRC,the rate of MMR protein loss was 9.79%(32/327),and the deletion rate of four MMR proteins(MSH2,MSH6,MLH1,PMS2)was 1.83%(6/327),3.06%(10/327),7.65%(25/327),and 7.65%(25/327),respectively.There were no significant differences between MMR protein deletion and sex,pathological type,tumor morphology,differentiation degree or lymph node metastasis(P>0.05),but there was a significant difference between MMR protein deletion and tumor diameter and tumor location(P=0.048/P=0.000).The mutation rates of the KRAS,NRAS,BRAF and PIK3CA genes in elderly CRC patients were 44.95%(147/327),2.45%(8/327),3.36%(11/327)and 2.75%(9/327),respectively;the KRAS gene mutation was closely related to tumor morphology(P=0.002)but not to other clinicopathological features(P>0.05),and there were no significant differences between NRAS gene mutation and clinicopathological features(P>0.05).The BRAF gene mutation showed a significant difference in pathological type,tumor location,differentiation degree and lymph node metastasis(P<0.05),but was not correlated with sex,tumor size and tumor morphology(P>0.05).The PIK3CA gene mutation showed no significant differences in the above clinicopathological characteristics(P>0.05).Significant differences were observed between MMR protein deletion and KRAS,BRAF,and PIK3CA gene mutations in elderly CRC patients(P=0.044,P=0.000,P=0.003,respectively),but there was no significant difference between MMR protein deletion and NRAS mutation(P>0.05).CONCLUSION In elderly CRC patients,the tumor is mainly located in the right colon,and the deletion rate of MMR protein is higher when the tumor diameter is greater than or equal to 5 cm;the deletion rate of MLH1 and PMS2 is more common;the mutation rate of KRAS gene is higher than that of the NRAS,BRAF and PIK3CA genes,the BRAF gene mutation has different degrees of correlation with clinicopathological characteristics;when the MMR protein is deleted,the BRAF and PIK3CA gene mutations are often present,and the KRAS gene mutation rate is low.
文摘BACKGROUND Immunohistochemical(IHC)staining for mismatch repair(MMR)proteins is useful for gastric cancer treatment and prognosis.Different IHC staining patterns reflect the complex biological phenomena underlying MMR deficiency.We herein report a rare IHC staining pattern of four MMR-related proteins in gastric cancer.CASE SUMMARY A“null”IHC staining pattern of four MMR-related proteins,including MLH1,PMS2,MSH2,and MSH6,in a 67-year-old male patient with gastric cancer pT3N3aM0 revealed promoter hypermethylation of MLH1.Next-generation sequencing showed that these four genes exhibited changes.One of these was the somatic mutation of the missing copy number in exon 14 of MSH2.Mutation analysis using peripheral blood showed no germline mutations in these four genes.The patient had no history of personal or family tumor history.We classified this case as sporadic.The patient returned to normal after operation,and there were no signs of tumor metastasis and recurrence.After six cycles of adjuvant chemotherapy,the patient was discharged in a stable condition.The patient had a mild reaction to chemotherapy and a good prognosis.At present,16 mo after the operation,the patient's condition is stable.CONCLUSION Abnormal MMR protein expression,helpful for individualized follow-up care,helped identify a sporadic case lacking familial clinical management implications.
