Table 2.

Risk groups as defined by CYP2D6 metabolism and HOXB13/IL17BR gene ratio

Risk groupHOXB13/IL17BR gene ratioCYP2D6 metabolism phenotype (CYP2D6*4 genotype: CYP2D6 inhibitor use)n = 110Estimated 5-y DFS rate (95% CI)
1<−1.339Extensive4693.5% (86.6-99.9%)
    (Wt/Wt: no)(46)
2<−1.339Decreased1883.8% (67.8-99.9%)
    (Unknown: yes)(2)
    (Wt/Wt: yes)(5)
    (Wt/*4: yes)(1)
    (Wt/*4: no)(9)
    (*4/*4: no)(1)
3≥−1.339Extensive3275.0% (61.4-91.6%)
    (Wt/Wt: no)(32)
4≥−1.339Decreased1457.1% (36.3-89.9%)
    (Wt/Wt: yes)(1)
    (Wt/*4: no)(11)
    (*4/*4: no)(2)
  • NOTE: The Kaplan-Meier estimates of 5-y DFS rates and corresponding CIs for each group are given. CYP2D6 inhibitors coadministered during tamoxifen in nine patients were as follows: cimetidine (n = 4), fluoxetine (n = 2), paroxetine (n = 2), sertraline (n = 1), and haloperidol (n = 1); one patient was coprescribed two CYP2D6-inhibiting drugs.