Advances in cancer treatment have increased dramatically in recent years. In cancer treatment, it is emphasized that the tumor microenvironment is important, as well as the cellular properties of the tumor [1]. The tumor microenvironment comprises components such as fibroblasts/myofibroblasts, glial, epithelial, fat, immune, vascular, smooth muscle, and immune cells in the extracellular matrix [2]. Although these cells themselves are not malignant, their interactions with each other and with cancer cells play a role in carcinogenesis [2].

Components of the microenvironment were first evaluated in colorectal carcinomas using the most well-known parameters. Using the parameters such as the tumor stroma percentage and local inflammatory response, the Glasgow microenvironment score (GMS) was determined and its prognostic significance was demonstrated [3]. Also, it has been reported that the Glasgow microenvironment score is a prognostic parameter in other localizations of the gastrointestinal tract, such as the stomach and bile duct [4], [5], [6], [7]. The tumor microenvironment facilitates local and metastatic spread by aggravating the epithelial-mesenchymal transition as well as cellular interactions [8], [9]. Tumor budding, which occurs as a result of epithelial-mesenchymal transition, was added as an additional parameter to the Glasgow microenvironment score, and its prognostic significance was investigated in colorectal carcinomas [10], [11].

There are many studies investigating the tumor microenvironment in breast cancers [12]. In our study, we determined the combined microenvironment score (CMS) by evaluating the well-known parameters, such as tumor budding (TB), tumor stroma ratio (TSR), and tumor-infiltrating lymphocytes (TILs). We investigated the relationship between CMS and prognostic parameters and survival and aimed to present all parameters of the microenvironment in a practical and reproducible way.