Table 1

Frequency of contralateral breast cancer in patients taking adjuvant tamoxifen therapy compared with controls1-a

Clinical trialMenopausal statusTamoxifen-treated patientsControls
Number of patientsNumber of cancersNumber of patientsNumber of cancers
NATO, 19851-b Pre and post5641556717
Stewart et al., 1992 Pre and post661965112
Rutqvist et al., 1987 Post9311891532
Pritchard et al., 1987 Post19832023
Cummings et al., 1986 Post911903
Fisher et al., 1989 Pre and post141923142832
CRC, 1988Pre and post947796518
Andersson et al., 1992 Post864108468
Ryden et al., 1992 Post2391123615
Mason et al., 1993 Not stated3674198057
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.