Table 1

Frequency of contralateral breast cancer in patients taking adjuvant tamoxifen therapy compared with controls^1-a

Clinical trial	Menopausal status	Tamoxifen-treated patients		Controls
Clinical trial	Menopausal status	Number of patients	Number of cancers	Number of patients	Number of cancers
NATO, 1985^1-b	Pre and post	564	15	567	17
Stewart et al., 1992	Pre and post	661	9	651	12
Rutqvist et al., 1987	Post	931	18	915	32
Pritchard et al., 1987	Post	198	3	202	3
Cummings et al., 1986	Post	91	1	90	3
Fisher et al., 1989	Pre and post	1419	23	1428	32
CRC, 1988	Pre and post	947	7	965	18
Andersson et al., 1992	Post	864	10	846	8
Ryden et al., 1992	Post	239	11	236	15
Mason et al., 1993	Not stated	367	4	1980	57
Total		6281	101	7880	197
			1.6%		2.5%

↵1-a The incidence of contralateral breast cancer in 15,000 women receiving adjuvant tamoxifen therapy was determined by the analysis of 11 separate clinical trials (adapted from Nayfield et al., 1991).
↵1-b NATO = Nolvadex Adjuvant Trial Organization; CRC = Cancer Research Campaign.