SUMMARY OBJECTIVE: Glucose transporter-1 is a marker involved in energy transport in cancer cells. It has been shown to be a poor prognostic factor in many cancer types, including breast cancer. However, there is no satisfactory parameter predicting treatment in breast cancer patients receiving neoadjuvant therapy. This study investigated the effect of glucose transporter-1 in predicting the treatment response of patients receiving neoadjuvant therapy. METHODS: In this study, glucose transporter-1 immunohistochemistry was applied to tru-cut biopsy of patients who were diagnosed with breast cancer and received neoadjuvant therapy between 2010 and 2021. A built-in scoring system was used to evaluate both the pattern and intensity of glucose transporter-1 immunohistochemistry staining. The relationship between glucose transporter-1 immunohistochemistry staining and other clinicopathological parameters was examined. In addition, the relationship of glucose transporter-1 with response to treatment was investigated. RESULTS: A relationship was found between high glucose transporter-1 expression and other clinicopathological parameters (such as estrogen and progesterone receptor negativity, high Ki-67, triple-negative, and Her2 status). Cases with high glucose transporter-1 expression had either a complete or a partial pathologic response. The result was statistically significant. CONCLUSION: Glucose transporter-1 has the potential to be a biomarker that can be evaluated more objectively as an alternative to Ki-67 labeling index in evaluating the response to treatment in patients receiving neoadjuvant therapy.

SUMMARY OBJECTIVE: The expression of cytotoxic T lymphocyte-associated antigen 4, E-cadherin, and CD44 in the area of tumor budding was investigated in breast carcinomas in our study. METHODS: Tumor budding was counted at the invasive margins in 179 breast carcinomas. To understand the microenvironment of tumor budding, we examined the expression status of the immune checkpoint molecules such as cytotoxic T lymphocyte-associated antigen 4, E-cadherin, and CD44. RESULTS: Tumors were separated into low (≤5) and high tumor budding groups (>5) based on the median budding number. Lymphovascular, perineural invasion, and the number of metastatic lymph nodes were significantly higher in high-grade budding tumors (p=0.001, p<0.001, and p=0.019, respectively). Tumor-infiltrating lymphocytes were significantly higher in tumors without tumor buddings (p<0.001). When the number of budding increases by one unit, overall survival decreases by 1.07 times (p=0.013). Also, it increases the risk of progression by 1.06 times (p=0.048). In high tumor budding groups, the cytotoxic T lymphocyte-associated antigen 4 staining percentage of lymphocytes was significantly higher (p=0.026). With each increase in the number of buds, an increase in the percentage of cytotoxic T lymphocyte-associated antigen 4 staining was seen in lymphocytes in the microenvironment of TB (p=0.034). CONCLUSION: Tumor budding could predict poor prognosis in breast carcinomas, and anti-cytotoxic T lymphocyte-associated antigen 4 immunotherapies may be beneficial in patients with high tumor budding tumors.

SUMMARY OBJECTIVE: The stroma surrounding the tumor cells is important in tumor progression and treatment resistance, besides the properties of tumor cells. Studies on the tumor stroma characteristics will contribute to the knowledge for new treatment approaches. METHODS: A total of 363 breast cancer patients were evaluated for the tumor–stroma ratio. The percentage of stroma was visually assessed on hematoxylin–eosin stained slides. The cases of tumor–stroma ratio more than 50% were categorized as tumor–stroma ratio high, and those less than 50% and below were categorized as tumor–stroma ratio low. RESULTS: Tumor–stroma ratio-high tumors had shorter overall survival (p=0.002). Disease-free survival tended to be shorter in tumor–stroma ratio-high tumors (p=0.082) compared with tumor–stroma ratio-low tumors. Tumor–stroma ratio was an independent prognostic parameter for the total group of patients (p=0.003) and also axillary lymph node metastasis and tumor–stroma ratio was statistically associated (p=0.004). Also, tumor–stroma ratio was an independent prognostic parameter in node-positive Luminal A and B subgroups for overall survival (p<0.001). CONCLUSION: Tumor–stroma ratio is an independent prognostic parameter that can be evaluated quite easily in all molecular subtypes of all breast cancers and does not require extra cost and time to evaluate.