The 51-gene signature was associated with late distant metastasis. (A) Overall survival was stratified according to events of local or distant recurrence events among 198 lymph node-negative breast tumor samples obtained from patients who did not receive systemic neoadjuvant or adjuvant treatment. Tick marks in Kaplan-Meier estimates overall survival indicate patients whose data were censored by the time of last follow-up. P values were calculated using log-rank (Mantel-Cox) test. (B) Comparing the 51-gene signature score among patients with early or late distant metastasis in the 4,767 breast tumor dataset. ‘0’ represents samples that had no distant recurrence for more than 15 years. ‘<5’ and ‘≥5’ represent samples that had early or late distant metastasis. Pair-wise comparison was assessed using the exact Mann-Whitney U test. Boxes represent the 25% to 75% quartiles, lines in the boxes represent the median level, whiskers represent the non-outlier range, and circles represent the outliers. (C) Trend increase of the 51-gene signature score according to the time of distant metastasis. Dots represent average levels. Vertical bars represent 0.95 confidence intervals. Comparison of multiple groups was conducted using analysis of variance (ANOVA). Pair-wise comparison was assessed using the exact Mann-Whitney U test.