Table 2.
Incidence of End-Point Events for CYP2D6 Phenotypes Predicted by Genotype
Event | No. (% in Subgroup) | ||
---|---|---|---|
EM (n = 609)a | hetEM/IM (n = 637)a | PM (n = 79)a | |
Local recurrence including second primary breast cancer | 40 (6.6) | 66 (10.4) | 12 (15.2) |
Distant recurrence | 48 (7.9) | 57 (8.9) | 10 (12.7) |
Overall recurrences | 76 (12.5) | 113 (17.7) | 19 (24.1) |
Death from any cause | 102 (16.7) | 114 (18.0) | 18 (22.8) |
Event-free survival eventb | 135 (22.2) | 176 (27.6) | 26 (32.9) |
Abbreviations: CYP, cytochrome P450; EM, extensive metabolism; IM, intermediate metabolism; PM, poor metabolism; UM, ultrarapid metabolism.
CYP2D6 phenotypes are defined as EM with 2 functional alleles (EM/EM, including UM), hetEM/IM with intermediate or 1 poor metabolism alleles (EM/IM, EM/PM, IM/IM, or IM/PM), and PM homozygous for poor metabolism alleles (PM/PM).
Event-free survival event was defined as the first event of local, regional, or distant recurrence; a second primary breast tumor; or death from any cause.