highly significantp = 0.0002
For risk groups, a highly significant (likelihood ratio test p = 0.0002) Cox proportional-hazards model included statistically significant covariates age (HR 1.1 (1.0 − 1.2) p = 0.004), stage IV (HR 173.8 (9.1 − 3325.5) p = 0.0006), and invasive ductal (ICD-0-3 code 8500/3) histologic type (HR 0.06 (0.006 − 0.68) p = 0.023).