Table 1.
Baseline Characteristics (n = 89), Grouped by CYP2D6 Metabolism Phenotype, and No. of Patients With Each CYP2D6 Combination Grouped by CYP2D6 Metabolism Phenotype (n = 89)
| Characteristic | EM (n = 29) | IM (n = 51) | PM (n = 9) | P |
|---|---|---|---|---|
| Median age, years | 49 | 49 | 47 | .587* |
| Range | 35-77 | 35-72 | 36-56 | |
| Race/ethnicity | .738 | |||
| White | 22 | 40 | 6 | |
| African American | 4 | 9 | 3 | |
| Asian | 1 | 2 | — | |
| Hispanic | 2 | — | — | |
| Median tamoxifen duration, years | 0.7 | 1.3 | 1.0 | .055* |
| Range | 0.3-4.4 | 0.3-5.0 | 0.5-3.0 | |
| Menopause | .892 | |||
| Pre/peri | 16 | 30 | 4 | |
| Post | 13 | 21 | 5 | |
| SSRI/SNRI use | .489 | |||
| Total | 5 | 16 | 1 | |
| Citalopram | 3 | 4 | — | |
| Venlafaxine | 1 | 9 | 1 | |
| Escitalopram | 1 | 3 | — | |
| Reason on tamoxifen | .07 | |||
| Invasive carcinoma | 28 | 41 | 9 | |
| DCIS | 1 | 10 | — | |
| Prior chemotherapy | .041 | |||
| Yes | 22 | 27 | 8 | |
| No | 7 | 24 | 1 | |
| EM | EM/UM = 1; 1.1% | |||
| EM/EM = 28; 31.5% | ||||
| IM | EM/IM = 20; 22.5% | |||
| EM/PM = 19; 21.3% | ||||
| IM/IM = 4; 4.5% | ||||
| IM/PM = 8; 9.0% | ||||
| PM | PM/PM = 9; 10.1% |
Abbreviations: DCIS, ductal carcinoma in situ; EM, extensive metabolizer; IM, intermediate metabolizer; PM, poor metabolizer; SNRI, serotonin-norepinephrine reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor.
*
The Kruskal-Wallis test was used to test the shift of location from the median value.