Tumor-stroma type and tumor-stroma ratio predict neoadjuvant chemotherapy response in breast cancer

OBJECTIVE: Breast cancer is the most common cancer type among women. One of the most important parameters in the prognosis of patients is the response to neoadjuvant chemotherapy. The most important parameter for neoadjuvant chemotherapy success is appropriate patient selection. We investigated the effect of tumor-stroma type and tumor-stroma ratio on neoadjuvant chemotherapy response, using the Residual Cancer Burden scoring systems. METHODS: Patients diagnosed with breast carcinoma in core needle biopsy materials between 2010 and 2023 and whose neoadjuvant treatments and surgeries were performed in our institution were scanned from the database. A total of 158 patients who met the study criteria were included in the study. RESULTS: Tumor-stroma ratio and collagen-dominant tumor-stroma type were associated with neoadjuvant chemotherapy resistance, and tumorstroma ratio was found to be an independent risk factor in treatment response. The probability of response to neoadjuvant chemotherapy treatment was higher in luminal molecular subtype breast cancer patients with low tumor stroma. CONCLUSION: An effective risk analysis for neoadjuvant chemotherapy treatment is not always possible with current clinicopathological parameters. Tumor-stroma ratio and tumor-stroma type seem useful in predicting neoadjuvant chemotherapy response as a reproducible practical marker and do not require additional cost and time.