Table 1.

Multivariate predictive models for bRFR after prostate cancer radiotherapy

VariableHR (95% CI)P
Metformin (Y vs. N)a0.228 (0.073–0.709)0.0106
Metformin with timeb1.018 (1.004–1.033)0.0138
Systemic Treatment
 ADT (Y vs. N)0.729 (0.516–1.030)0.0734
Clinical Prognostic Factors
 Gleason (7 vs. 6c)1.044 (0.705–1.547)0.8296
 Gleason (8-9 vs. 6c)2.234 (1.159–4.306)0.0163
 PSA (Continuous)1.027 (1.013–1.033)0.0002
 T-stage (T2+ vs T1c)1.390 (0.992–1.948)0.0555

Abbreviations: ADT, androgen deprivation therapy; bRFR, biochemical relapse-free rate.

  • aEffect of metformin on bRFR.

  • bTime-dependent effect of metformin.

  • cUsed as reference variable.