Table 2.
Statistics of oestrogen-receptor-positive patients: association between tamoxifen therapy/no tamoxifen therapy (Tam+/Tam-) and distant recurrence rate, stratified according to genotype
Genotype | Tamoxifen therapy | Number of patientsa | Number of recurrences | Recurrence rate ratio (95% confidence interval) | P value |
SULT1A1*1/*1† | Tam- | 29 | 16 | 1.0 | |
Tam+ | 26 | 9 | 0.48 (0.21 – 1.12) | 0.074 | |
SULT1A1*2† | Tam- | 49 | 26 | 1.0 | |
Tam+ | 50 | 24 | 0.82 (0.47 – 1.43) | 0.48 | |
CYP2D6*1/*1‡ | Tam- | 55 | 27 | 1.0 | |
Tam+ | 52 | 25 | 0.91 (0.53– 1.57) | 0.75 | |
CYP2D6*4‡ | Tam- | 23 | 15 | 1.0 | |
Tam+ | 24 | 6 | 0.28 (0.11 – 0.74) | 0.0089 | |
SULT1A1*1/*1 and/or CYP2D6*4§ | Tam- | 45 | 27 | 1.0 | |
Tam+ | 43 | 15 | 0.38 (0.19– 0.74) | 0.0041 | |
SULT1A1*2 and CYP2D6*1/*1§ | Tam- | 33 | 18 | 1.0 | |
Tam+ | 33 | 15 | 1.22 (0.61– 2.40) | 0.57 |
The relative risks of distant recurrence, calculated for each combined genotype are adjusted for age, tumour size and lymph node status.
aFollow-up data of two patients were missing.
†,‡,§The risk ratio was first calculated separately for each genotype and genotype combination. Second, the test for interaction between the risk ratios was performed by Cox regression: †P = 0.27, ‡P = 0.064, and §P = 0.018. The risk ratio for patients not receiving tamoxifen (Tam-) is calculated as 1.0.