The prognostic value of tumour–stroma ratio in primary breast cancer with special attention to triple-negative tumours: a review

PURPOSE: There is a strong need to improve the prognostication of breast cancer patients in order to prevent over- and undertreatment, especially when considering adjuvant chemotherapy. Tumour stroma characteristics might be valuable in predicting disease progression. METHODS: Studies regarding the prognostic value of tumour–stroma ratio (TSR) in breast cancer are evaluated. RESULTS: A high stromal content is related to a relatively poor prognosis. The most pronounced prognostic effect of this parameter seems to be observed in the triple-negative breast cancer (TNBC) subtype. CONCLUSIONS: TSR assessment might represent a simple, fast and reproducible prognostic factor at no extra costs, and could possibly be incorporated into routine pathological diagnostics. Despite these advantages, a robust clinical validation of this parameter has yet to be established in prospective studies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10549-018-4987-4) contains supplementary material, which is available to authorized users.