Analysis Of BRCA1/2 Mutations In Breast Cancer Of Yunnan Province

Objectives This study systematically analyzed the characteristics of BRCA1/2 gene in pan-cancer species of Yunnan Cancer Hospital and its correlation with the clinicopathological characteristics of patients,and further analyzed the BRCA1/2 gene mutations in breast cancer patients from multiple dimensions,so as to lay a theoretical foundation for the in-depth study of BRCA1/2gene mutations in breast cancer patients in Yunnan Province.Methods1.The reported results and clinical medical records of patients who underwent BRCA1/2 gene detection by next generation sequencing technology in Yunnan Cancer Hospital from August2019 to June 2022 were collected.2.The mutation frequency,mutation site,mutation type of BRCA1/2 gene in pan-cancer and the relationship between BRCA1/2 gene mutation and patients’ age,nationality,mutation source,family history and tumor metastasis were analyzed retrospectively.3.The correlation between BRCA1/2 gene mutation and ER expression,PR expression and pathological classification in breast cancer patients was analyzed retrospectively.The relationship between ER expression,PR expression and pathological classification in breast cancer patients and age of onset was described.Results1.A total of 310 patients who underwent BRCA1/2 gene detection by next generation highthroughput sequencing in Yunnan Cancer Hospital from August 2019 to June 2022 were collected,including 203 tissue samples and 107 peripheral blood samples.Among the 310 patients,222(71.61%)had breast cancer,68(21.94%)had ovarian cancer,and 20(6.45%) had other cancers.Only 46(14.84%)patients had a family history of cancer.A total of 310 cases of BRCA1/2 gene were tested by second-generation high-throughput sequencing in Yunnan Cancer Hospital from 2019 to 2022.Among them,203 cases were detected by tissue and 107 cases by peripheral blood.2.Correlation analysis between BRCA1/2 mutation and clinicopathological features of pancancer(1)The overall mutation rate of BRCA1/2 gene in 310 patients was 17.42%(54 cases),the overall mutation rate of BRCA1 was 13.55%(42 cases),and the overall mutation frequency of BRCA2 gene was 3.87%(12 cases).There was no correlation between BRCA1/2 mutation status and cancer types.Only the mutation source and family history of all patients,age and mutation source of breast cancer patients were correlated(p<0.05);(2)BRCA1 gene mutation sites were distributed in 14 exons,exon 11 mutations accounted for28.57%(12 cases)of the total BRCA1 mutations,and BRCA2 gene mutation sites were distributed in exons 3,7,11,13,and 20.Mutations in exon 11 accounted for 28.57%(12cases)of the total BRCA2 mutations.3.Correlation analysis between BRCA1/2 mutation and clinicopathological features of breast cancer(1)BRCA1/2 mutation status has no correlation with the negative and positive expression of ER and PR,but has correlation with the pathological subtype of breast cancer(p<0.001);(2)In Luminal A and triple negative breast cancer,BRCA1/2 mutation rate increased with age after 45 years old.BRCA1/2 mutation in HER2-positive and Luminal B breast cancer tends to be younger.Conclusions BRCA1/2 mutates in a variety of tumors with different mutation rates.In breast cancer,the mutation rate of BRCA1/2 is related to age and pathological typing.Young breast cancer and triple negative breast cancer patients should be more concerned about BRCA1/2 gene testing.In this study,there was no significant correlation between BRCA1/2 gene variation and the presence or lack of tumor family history,nationality,and tumor metastasis.The mutation sites of BRCA1/2 gene in breast cancer patients in Yunnan province have certain characteristics,it is necessary to further expand the sample size of the study.