Correlation analysis and exploration of potential biomarkers in patients with breast cancer combined with thyroid cancer

Objective(s): 1. The common differential genes of breast cancer and thyroid cancer were identified by Gene Express Omnibus database (GEO). The Cancer Genome Atlas (TCGA) database was used to determine the relationship between the screened differential genes and the clinicopathologic features. Gene set enrichment analysis (GSEA) was used to identify the enrichment pathways of the differential genes in breast and thyroid cancers.2. Retrospective studies were conducted to analyze the relationship between the general characteristics, clinicopathological features, and hormone expression levels in patients with dual cancers of breast cancer combined with thyroid cancer and patients with breast cancer and thyroid cancer alone, and to further analyze the KRT19 expression levels in their tissues. analyze the expression of KRT19 protein in their tissues. Method(s): 1. Download the datasets GSE70947 and GSE3467 from the GEO database, analyze the differential genes of breast cancer, thyroid cancer and normal tissues respectively by using R, and take the intersection of the differential genes of the two tissues to continue the next step of the study. 2. Download the mRNA-seq data of the above differential genes of BRCA and THCA from the TCGA database, and identify the differences in expression of differential genes between normal tissues and tumor tissues by using the above differential gene substitution in R. Gene set enrichment analysis (GSEA) identifies the differences in expression of differential genes enriched in breast and thyroid cancer. Differential gene substitution analysis, and identify the differences in differential gene expression between normal and tumor tissues, Gene set enrichment analysis (GSEA) to identify the pathways of enrichment in breast and thyroid cancers, and then screened out the representative differential gene KRT19 (human cytokeratin 19).3. Collect the mRNA-seq data of BRCA and THCA in the database of TCGA, and use the R language in the substitution analysis of the above differential genes, and identify the differences in differential gene expression between normal and tumor tissues. 3. July 2023 in Zhongshan People's Hospital and puncture or surgical treatment of breast cancer combined with thyroid cancer patient data, a total of 92 cases (experimental group), another randomly collected in the past two years in Zhongshan People's Hospital in the simple breast cancer patients 100 cases (control group 1), thyroid cancer patients, 100 cases (control group 2). 4. the experimental group and the control group 1, 2 of the patient pathology data for Pathological data of patients in experimental and control groups 1 and 2 were retrospectively analyzed, and additional surgical bulk or puncture specimens were subjected to immunohistochemical staining (IHC) to examine the expression of KRT19 protein in the tissues, and to explore whether there was a difference in its expression between experimental and control groups. Result(s): 1. KRT19 mRNA levels were significantly overexpressed in breast and thyroid cancer tissues as analyzed by the GEO database, and KRT19 was associated with clinicopathological features of breast and thyroid cancers as analyzed by the TCGA database, and the GSEA showed that both the breast and thyroid cancer-KRT19 overexpression groups were significantly enriched in the estrogen-responsive pathway.2. In the dual-primary cancer group, of which breast cancer preceded In the dual-primary cancer group, breast cancer preceded thyroid cancer in 86 cases and thyroid cancer preceded in 6 cases, i.e., breast cancer preceded thyroid cancer in the vast majority of patients (> 90%). Compared with the breast cancer group, the dual-primary cancer group was younger at the time of diagnosis, more often in the premenopausal state, with a larger tumor size, and more often positively expressed estrogen receptors (ER) and progesterone receptors (PR), with a statistically significant difference (all P  < 0.050). Compared with the thyroid cancer group, the odds of tumors occurring bilaterally were increased in the double primary cancer group, and the levels of triiodothyronine (T3) and thyroxine (T4) (both P  < 0.050) were significantly higher. KRT19 was more frequently positively expressed in breast cancer than in breast cancer alone in dual primary cancers ( P  = 0.069), and in thyroid cancer than in thyroid cancer alone in dual primary cancers ( P  < 0.050). Conclusion(s): Pathogenesis correlates between breast and thyroid cancers, estrogen receptor expression is associated with dual carcinogenesis, and KRT19 influences dual carcinogenesis through the estrogen response pathway.