Table 4.

Late-distant recurrence: univariate and multivariate Cox model analysis after stepwise variable selection by AIC of likelihood of late-distant recurrence in Stockholm TAM and multi-institutional cohorts for all (ER+) and ER+/HER2 patients

All patients (ER+)ER+/HER2 Only
VariableaHR (95% CI)PHR (95% CI)P
Stockholm TAMn = 285 (20 DR)n = 266 (18 DR)
 Univariate analysis
  Age at surgery0.59 (0.26–1.34)0.210.54 (0.23–1.29)0.17
  Tumor size1.52 (0.50–4.57)0.461.43 (0.41–4.99)0.57
  Tumor grade0.69 (0.27–1.70)0.410.87 (0.32–2.35)0.78
  PR status0.45 (0.18–1.11)0.080.50 (0.18–1.34)0.17
  HER2 status1.38 (0.32–5.98)0.67NANA
  BCI4.07 (1.26–13.10)0.0194.92 (1.36–17.78)0.015
 Multivariate analysis
  PR status0.52 (0.21–1.32)0.170.54 (0.20–1.46)0.22
  BCI3.50 (1.09–11.21)0.0354.57 (1.28–16.37)0.020
Multi-Institutionaln = 312 (23 DR)n = 281 (22 DR)
 Univariate analysis
  Age at surgery1.32 (0.90–1.95)0.161.48 (1.00–2.20)0.05
  Tumor size3.37 (1.46–7.79)0.013.17 (1.35–7.41)0.01
  Tumor grade2.37 (0.88–6.38)0.092.91 (0.98–8.58)0.05
  HER2 status0.40 (0.05–2.98)0.37NANA
  Chemo0.89 (0.38–2.11)0.801.04 (0.42–2.54)0.94
  BCI8.01 (2.61–24.56)0.000311.03 (3.36–36.21)<0.0001
 Multivariate analysis
  Tumor size2.66 (1.14–6.20)0.022.53 (1.07–5.97)0.03
  HER2 status0.17 (0.02–1.32)0.09NANA
  BCI9.24 (2.85–30.00)0.00029.33 (2.83–30.76)0.0002

Abbreviations: DR, distant recurrences; NA, not applicable.

  • aAge was by 10 years increment; tumor size was greater than 2 cm versus 2 cm or less; tumor grade was poorly differentiated versus moderate/well differentiated; PR and HER2 status was positive versus negative; chemo was no versus yes; BCI was continuous variable with 5 units increment (chosen to dichotomize BCI to facilitate the comparison of HRs with clinical covariates).