252 Table 2 Summary of clinical- pathological characteristics of the 4,444 breast cancer patients Breast Cancer Res Treat (2008) 107:249–257 % within group % within known values % within group % within known values Test set n Total 2,222 Age at diagnosis (years) Median 60 (25–95) (range) <40 170 40–54 457 55–69 702 ‡70 893 Gender Female 2,211 Male 11 Nodal status Negative 1,272 Positive 943 Unknown 7 Number of positive nodes Median 2 (1–24) (range) 1–3 586 4–9 243 ‡10 82 Unknown 32 ER Status at diagnosis Negative 472 Positive 1,689 Unknown 61 Tumor size (cm) Median 2.0 (0.1–9.9) (range) 0.1–1.0 265 1.1–2.0 864 2.1–5.0 949 >5.0 117 Unknown 27 Tumor grade 1 125 2 876 3 1,083 Unknown 138 7.7 20.6 31.6 40.2 99.5 0.5 57.2 42.4 0.3 62.1 25.8 8.7 3.4 21.2 76.0 2.7 11.9 38.9 42.7 5.3 1.2 5.6 39.4 48.7 6.2 7.7 20.6 31.6 40.2 99.5 0.5 57.4 42.6 64.3 26.7 9.0 21.8 78.2 12.1 39.4 43.2 5.3 6.0 42.0 52.0 Validation set n 60 (23–91) 2 (1–28) 2,222 157 468 809 788 2,210 10 1,256 957 9 614 229 84 30 472 1,687 63 285 864 915 126 32 103 844 1,153 122 2.0 (0.1–9.9) 7.1 21.1 36.4 35.5 99.5 0.5 56.5 43.1 0.4 64.2 23.9 8.8 3.1 21.2 75.9 2.8 12.8 38.9 41.2 5.7 1.4 4.6 38.0 51.9 5.5 7.1 21.1 36.4 35.5 99.5 0.5 56.8 43.2 66.2 24.7 9.1 21.9 78.1 13.0 39.5 41.8 5.8 4.9 40.2 54.9 Training set results Survival analysis 123 A total of 2,222 patients were included in the training set analysis. After excluding cases which had insufﬁcient invasive tumor, missing core or un-interpretable staining pattern, 1,801 cases were carried forward for the analysis. Out of these, MCs were present in 508 (28.2%) cases. The mean survival time of patients with presence of stromal MCs was 15.0 years (95% CI, 14.5–15.5) compared to 13.9 years (95% CI, 13.5–14.2) for those who did not have positively stained MCs in their tumor stroma. KM survival analysis (Fig. 2a) showed that the presence of stromal MCs