Vangangelt KMH, et al. - Since the presence of tumor cells in lymph nodes is important for clinical decision-making in primary breast cancer tumors, researchers assessed the impact of tumor–stroma ratio (TSR) in the primary breast tumor combined with the TSR in tumor-positive lymph nodes on prognosis in this retrospective analysis of women with invasive breast cancer. Study participants did not have distant metastasis and underwent an axillary lymph node dissection between 1985 and 1994 at the Leiden University Medical Center. Findings revealed strongly improved RFP rates among patients with primary tumor stroma-low/lymph nodes stroma-low tumors vs among those with primary tumor stroma-high/lymph node stroma-high tumors with 10-year percentages of 58% vs 8%, respectively. Incremental prognostic information could be obtained by evaluating the TSR on tumor-positive lymph nodes. The investigators also observed a significant difference with respect to stromal activation between primary tumors and lymph node metastasis.