Clinical And Pathological Characteristics Of Triple-negative Breast Cancer And A Relative Mouse Model Research

Purposes:1.Clinical and pathological information and outcomes of 61 triple-negative(TN)breast cancers were compared with those of 323 non-triple-negative (NTN)breast cancers to investigate the characteristics of human TN breast cancer and thefactors influencing its prognosis.2.To investigate biological behavior and immune features of TA2 spontaneousbreast cancer.TA2 breast cancer metastasis model was established to separate andincrease metastatic breast cancer cells,and TA2 breast cancer invasion andmetastasis-associated proteins were identified to find metastasis marker and treatmenttargets of human TN breast cancer.3.The expressions of TA2 breast cancer invasion and metastasis-associatedproteins were detected in human TN breast cancer.According to the results,prediction formulas were set up to identify metastasis marker of human TN breastcancer.Methods:1.384 breast cancer patients undergoing surgery and chemotherapy at TianjinCancer hospital from 1993 to 1994 were collected,and there were 61 TN and 323NTN cases.The clinical and pathological factors including age,tumor size,lymphaticnode metastasis,treatment,relapse and distant metastasis of TN and NTN cases werecompared with Person chi-square test.Kaplan-Meier survival analysis was performedto see if there is significant difference in the prognosis between TN and NTN breastcancer.2.Biological behavior,morphological and immune features of 84 TA2spontaneous breast cancers were observed.Immunohistochemical staining was usedto detect ER,PR,HER2,p53,cyclinD and PCNA expression,and real time PCR wasperformed to detect ERαand PR mRNA expression.Peripheral blood of TA2 micewith spontaneous breast cancers was injected into the peritoneum of normal TA2 topurify breast cancer cells with high metastastic potential.2-DE and MS wereperformed to isolate and identify the differentially expressed proteins betweenprimary and metastasis breast cancers.3.In the first set of 61 human TN breast cancer cases,the expressions of TA2breast cancer invasion and metastasis-associated proteins were compared betweennode-positive group and node-negative group.According to the results,prediction formulas were set up to identify metastasis marker of human TN breast cancer.Anindependent second set of 66 human TN breast cancers were used to validate thevalues of prediction formulas.Results:1.In this study,13.8% breast cancer cases were TN.Middle age of TN and NTNbreast cancer are 50 years (34～78)and 48 years (27～75),respectively.Tumordiameter of TN breast cancer was more than 2cm,while 5.1% of non-triple-negativebreast cancer has a small tumor.The axillary node-positive percentage in two groupswas close to 40%.There were 8 TN breast cancer cases in stageⅠ,while all TNbreast cancer patients were in stageⅡorⅢ.About 67.6% TN breast cancer patientsunderwent pre-chemotherapy which was significantly more than 40.0% in the NTNgroup (x~2=8.779,P=0.003).Five cases in 61 TN cases reoccurred,and it is 4.6% in NTN breast cancer.Themetastastic rate in 2 groups was 29.5% and 19.4%,respectively (x~2=4.009,P=0.045).TN breast cancer was likely to metastasize to lung and liver.13.5% TN casesdeveloped lung metastasis,and 16.2% suffered from liver metastasis.However,theywere 5.1% and 3.6% in non-triple-negative breast cancer (x~2=5.002,7.691,P=0.024,0.005).The metastastic rate of TN breast cancer within 2,5 and 10 years was 13.5%,24.3% and 29.4% respectively,whereas it was 8.2%,12.8%and18.9%.In TN breast cancer,90.2% in pre-chemotherapy group survived that issignificantly more than non-pre-chemotherapy TN patients.Kaplan-Meier survivalanalysis showed that the overall survival and disease-free survival of TN breastcancer undergoing pre-chemotherapy was better than non-treated patients (P＜0.050).2.The structure of TA2 spontaneous breast cancer was similar to human invasivebreast cancer that is mostly composed of poorly differentiated and small round cellwith few cytoplasms and well-developed stroma.Great deals of cells are undergoingmitosis.Necrosis occurred in the centre of the tumor nest.TA2 breast cancer isnegative for ER,PR and HER2.Some of them expressed p53,cyclinD and PCNA.After about 90 days of the injection of peripheral blood of 10 TA2 mice withbreast cancer,two receptors developed ascites and tumor in their peritoneum.Theceliac cancer was injected into the groin of normal TA2,and it metastasized into lung,liver and spleen in 10 days.It showed a more invasive morphological feature.22differentially expressed proteins between celiac cancer and spontaneous breast cancer were separated with 2-DE and identified with MS.Eight proteins relating to humanbreast cancer metastases were validated.The results indicated that Actin,14-3-3,Vimentin,HSP70,Moesin and CK18 expression were higher in lung metastases ofspontaneous breast cancer mice than thoese in primary tumors.Primary tumorsexpressed more HSP90 and Tubulin-βthan metastatic sites.3.In the first set of 61 human TN breast cancer cases,14-3-3 and HSP70 wereexpressed in a significant high level in the breast cancer cells that developedmetastasis (U=134.500,83.500,P=0.006,0.004).According to the independentsecond set of 66 TN breast cance,14-3-3 and HSP70 expression were valuable and topredict the metastatic potential of TN breast cancer.Conclusions:1.TN breast cancers have a bigger tumor and a late clinical stage than NTNbreast cancers.TN breast cancer tends to metastasize to lung and liver in 2 to 5 yearsafter surgery.The prognosis and life quality of TN breast cancer are poor,butpre-chemotherapy can improve their survival.2.TA2 spontaneous breast cancer in the biological behavior,morphologicalfeature and immune characteristic was similar to human TN breast cancer.TA2mouse isa good animal model for human TN breast cancer research hence.3.The celiac cancer developing from the tumor embolus in the peripheral bloodof TA2 mice with spontaneous breast cancers are greatly different from spontaneousbreast cancer in the morphological feature.It is more invasive and metastatic.4.Many proteins involved in the metastasis of TA2spontaneous breast cancer.TA2 breast cancer metastasis-associated proteins include cytoskeleton,mobilityregulation proteins,and proliferation and apoptosis regulation proteins.Theirexpression change enables tumor cells to be more active,proliferous and resistant toapoptosis.They can migrate into a new site and survive and develop a new lesion.5.The increase of 14-3-3 and HSP70 expression are associated with TN breastcancer metastasis,and they can be the prediction markers for TN breast cancer.