Table 3

Relative risks associated with recurrence score among ER-positive patients, stratified by treatment with tamoxifen
Score
 Cases
 Controls
 RR1
 (95% CI)
 P value
Tamoxifen treated (55 cases and 150 controls)
Recurrence Score






     Continuous2
 55
 (100%)
 150
 (100%)
 7.6
 (2.6–21.9)
 <0.0001
     Pre-specified categories






          Low risk (<18)
 16
 (29%)
 95
 (63%)
 1.0
 reference
          Intermediate risk (18–30)
 22
 (40%)
 35
 (23%)
 4.0
 (1.8–8.8)
          High risk (≥31)
 17
 (31%)
 20
 (13%)
 6.2
 (2.4–15.8)
     Quartiles3





0.0004
          1st (0–8.25)
 5
 (9%)
 38
 (25%)
 1.0
 reference
          2nd (8.26–14.43)
 6
 (11%)
 37
 (25%)
 1.0
 (0.3–3.7)
          3rd (14.44–20.95)
 15
 (27%)
 38
 (25%)
 2.9
 (1.0–8.9)
          4th (20.96–78.78)
 53
 (53%)
 37
 (25%)
 5.8
 (2.0–16.6)
Tamoxifen untreated (110 cases and 251 controls)
Recurrence Score






     Continuous2
 110
 (100%)
 251
 (100%)
 4.1
 (2.1–8.1)
 <0.0001
     Pre-specified categories





<0.0001
          Low risk (<18)
 40
 (36%)
 160
 (64%)
 1.0
 reference
          Intermediate risk (18–30)
 32
 (29%)
 47
 (19%)
 2.7
 (1.5–5.0)
          High risk (≥31)
 38
 (35%)
 44
 (18%)
 3.3
 (1.8–5.9)
     Quartiles4





<0.0001
          1st (0–7.53)
 11
 (10%)
 63
 (25%)
 1.0
 reference
          2nd (7.54–14.25)
 19
 (17%)
 64
 (25%)
 1.5
 (0.7–3.4)
          3rd (14.26–21.86)
 23
 (28%)
 62
 (25%)
 2.1
 (0.9–4.9)
          4th (21.87–85.82)
 57
 (52%)
 62
 (25%)
 5.3
 (2.5-1.3)

1Conditional logistic regression models include Recurrence Score variables only. 2Relative risks for Recurrence Score calculated with regard to an increment of 50 units (chosen to be consistent with and comparable with previous studies). 3Quartiles based on distribution among controls treated with tamoxifen. 4Quartiles based on distribution among controls not treated with tamoxifen. CI, confidence interval; ER, estrogen receptor; RR, relative risk.

Habel et al. Breast Cancer Research 2006 8:R25   doi:10.1186/bcr1412

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