Table 3.

Summary of trials examining impact of extended tamoxifen therapy

Trial name	Median follow-up, y	Sample size	Length of treatment in control arm, y	Length of treatment in experimental arm, y	OR for recurrence	95% CI	P
ATLAS	7.6*	6846	5	10	0.84	0.74 to 0.94	.003
aTTom	9†	6953‡	5	10	0.84	0.74 to 0.95	.006
ECOG E4181/E5181	9.6	140‖	5	Indefinite	0.33	0.15 to 0.70	.004
NSABP B-14	7	1172	5	10	1.18	0.80 to 1.72	.41
Scottish	10	132§	5	Indefinite	0.93	0.46 to 1.92	.85

^*Results for estrogen receptor (ER)-positive patients. Mean listed. ATLAS = Adjuvant Tamoxifen Longer Against Shorter; aTTom = Adjuvant Tamoxifen–To Offer More?; CI = confidence interval; ECOG E4141/E5181 = Eastern Cooperative Oncology Group; NSABP B-14 = National Surgical Adjuvant Breast and Bowel Project; OR = odds ratio; Scottish = Scottish adjuvant tamoxifen trial a randomized study updated to 15 years.

^†Estimated follow-up.

^‡Whole cohort analyzed (40% ER positive, 60% ER untested).

^§ER level less than 20 fmol/mg on ligand-binding assay deemed ER negative and excluded.

^‖Follow-up for ER-positive group is shorter than for the whole study population.

Modified from (34).