Table 1.

Patient characteristics and ctDNA detection at baseline.a

CharacteristicsPatients, nPatients with detectable ctDNA at baseline, n (%)Correlation with ctDNA positivity (Fisher exact test)Correlation with ctDNA concentration (Pearson correlation test)
Age, years≤501913 (68)NSbNS
>501714 (82)
cT1–22820 (71)NSNS
3–487 (87)
cNcN02214 (64)0.06NS
cN1–31413 (93)
StageI20 (0)0.060.03
II3124 (77)
III33 (100)
Tumor grade110 (0)0.0050.003
241 (25)
33126 (84)
HistologyIC-NST3324 (73)NSNS
Other33 (100)
Ki67%≤2011 (100)NScNS
20 < Ki67 <5044 (100)
≥ 502114 (67)
Mitotic indexLow31 (33)0.030.003
Intermediate52 (40)
High2723 (85)
pCRRCB 01612 (75)NSNS
RCB ≥12015 (75)
  • a Baseline plasma sample was available for 36 patients.

  • b NS, not significant; cT, clinical tumor size [tumor, node, metastasis (TNM) classification]; cN, clinical nodal involvement (TNM classification); IC-NST, invasive breast carcinoma of no specific type.

  • c Student t-test.