Breast cancer (BC) is considered the second commonest human carcinoma and the most incident and mortal in the female population. Despite promising treatments for breast cancer, mortality rates of metastatic disease remain high. Gasdermin C (GSDMC) is an affiliate of the gasdermin (GSDM) family, which is involved in the process of pyroptosis. Pyroptosis is implicated in tumorigenesis, but the role of GSDMC in cancer cells is yet to be fully elucidated. In this study, we investigated the role and mechanism of GSDMC in breast cancer. We conducted a pan-cancer analysis of the expression and prognosis of GSDMC utilizing multidimensional data from The Cancer Genome Atlas (TCGA). We investigated GSDMC expression levels in 15 BC tissues and matched adjacent normal tissues by immunohistochemistry (IHC). Further verification was performed in the Gene Expression Omnibus (GEO) database. We discovered that elevated GSDMC expression was considerably linked to a worse prognosis in breast invasive carcinoma (BRCA). Next, we identified noncoding RNAs (ncRNAs) which contributing to higher expression of GSDMC by a series of expression, survival, and correlation analysis. We finally identified LINC00511/hsa-miR-573 axis to be the most promising ncRNA-associated pathways that account for GSDMC in BRCA. Furthermore, we demonstrated the significant correlations between GSDMC expression and immune infiltrates, immune checkpoints, and immune markers in BRCA. This study illustrated that ncRNAs-mediated upregulation of GSDMC linked to dismal prognosis and also exhibited a correlation with tumor immune cell infiltration in BRCA. It is anticipated to offer novel ideas for the link between pyroptosis and tumor immunotherapy.