Table 1.
Baseline Patient and Tumor Characteristics and Frequencies of CYP2D6 Variants
| Characteristics | Overall (N = 1325) |
CYP2D6 Extensive Metabolism (n = 609)a |
CYP2D6 Decreased Metabolism (n = 716)a |
|
|---|---|---|---|---|
| Age at diagnosis, median (range), y | 66.0 (36.5–93.1) | 66.0 (36.5–93.1) | 66.0 (40.2–91.8) | |
| Follow-up, median (range), mo | 76.1 (2.1–243.6) | 75.2 (2.1–238.3) | 76.4 (2.2–243.6) | |
| Menopausal status, No. (%) | ||||
| Premenopausal | 54 (4.1) | 24 (3.9) | 30 (4.2) | |
| Postmenopausal | 1271 (95.9) | 585 (96.1) | 686 (95.8) | |
| Tumor size, cm, No. (%) | ||||
| ≤2 | 686 (51.8) | 318 (52.2) | 368 (51.4) | |
| >2 | 624 (47.1) | 284 (46.6) | 340 (47.5) | |
| Unknown | 15 (1.1) | 7 (1.1) | 8 (1.1) | |
| Node status, No. (%) | ||||
| N0 | 850 (64.1) | 407 (66.8) | 443 (61.8) | |
| N1 | 392 (29.6) | 165 (27.1) | 227 (31.7) | |
| N2 + N3 | 57 (4.3) | 24 (3.9) | 33 (4.6) | |
| Unknown | 26 (1.9) | 13 (2.1) | 13 (1.8) | |
| Grade, No. (%) | ||||
| 1 | 161 (12.1) | 72 (11.8) | 89 (12.4) | |
| 2 | 918 (69.3) | 423 (69.4) | 495 (69.1) | |
| 3 | 201 (15.2) | 87 (14.3) | 114 (15.9) | |
| Unknown | 45 (3.4) | 27 (4.4) | 18 (2.5) | |
| Estrogen receptor status, No. (%) | ||||
| Positive | 1282 (96.7) | 592 (97.2) | 690 (96.4) | |
| Negative | 38 (2.8) | 15 (2.5) | 23 (3.2) | |
| Unknown | 5 (0.4) | 2 (0.3) | 3 (0.4) | |
| Progesterone receptor status, No. (%)b | ||||
| Positive | 984 (74.3) | 449 (73.7) | 535 (74.7) | |
| Negative | 123 (9.3) | 56 (9.2) | 67 (9.3) | |
| Unknown | 218 (16.4) | 104 (17.1) | 114 (15.9) | |
| Radiotherapy, No. (%)b | ||||
| Yes | 769 (58.0) | 354 (58.1) | 415 (57.9) | |
| No | 456 (34.4) | 206 (33.8) | 250 (34.9) | |
| Unknown | 100 (7.5) | 49 (8.0) | 51 (7.1) | |
| CYP2D6 variants by genotype (allele %)c | ||||
| 2D6*3 (PM) | 917/31/1 (1.7) | |||
| 2D6*4 (PM) | 854/400/71 (20.0) | |||
| 2D6*5 (PM) | 646/33/0 (2.4) | |||
| 2D6*10 (IM) | 1175/40/4 (2.0) | |||
| 2D6*41 (IM) | 1080/206/15 (9.0) | |||
| 2D6 duplication (UM) | (2.3) | |||
Abbreviations: CYP, cytochrome P450; EM, extensive metabolism; IM, intermediate metabolism; PM, poor metabolism; UM, ultrarapid metabolism.
a
CYP2D6 phenotypes were assigned according to genotypes with 2 functional alleles (extensive) vs genotypes with at least 1 intermediate or 1 nonfunctional allele (decreased).
b
Progesterone receptor status and radiotherapy information were not available for all patients.
c
Genotype frequencies shown in the following order: homozygous EM/heterozygous/homozygous variant. Allele frequencies in percentages are in parentheses.