Background: Tools to support clinical decision making regarding breast cancer (BC) are becoming more available to clinicians. NHS PREDICT is a freely available webbased tool for prognostication and assistance in BC management. Recent research shows doubt in using the tool for BC subtypes. There is fear over the possibility of overor undertreatment of patients. Methods: Ninety-four patients regardless of their ER (estrogen receptor), PR (progesterone receptor) and HER2 (human epidermal growth factor receptor 2) status were included in this study. Through using the platform NHS PREDICT 2.0 we evaluated through the pilot study the prediction of patients with newly diagnosed breast cancer. We evaluated the prediction of 10-year survival, benefit of surgical treatment, treatment with hormonal therapy, transtuzumab treatment and benefit of chemotherapy. Results: The median age at diagnosis was 60.10 years (SD 14.4). Patients were classified according to hormonal status: i) ERþ BC (n ¼ 69), ii) ERþ and HER2þ BC (n ¼ 8), iii) ER-, but HER2þ BC (n ¼ 7) and iv) triple negative BC (n ¼ 10). Overall 10-year survival for ERþ, HER2-was 86.1 % (benefit of adjuvant chemotherapy adding 2.8 %), for ER-and HER2þ 83.7% (benefit of adjuvant chemotherapy adding 7.0 %) and for TNBC 77.4% (benefit of adjuvant chemotherapy 5.5 %). Overall data is represented in Table . Conclusions: This pilot analysis estimates that overall survival was in accordance to available treatment data. TNBC 10-year survival was appropriate (decreased), but the tool estimated very low chemotherapy benefits for TNBC patients in comparison to other patient groups thus posing the risk of patient undertreatment.