Tamoxifen for women at high risk of breast cancer

Figures & data

Figure 1 Overview of tamoxifen metabolism pathway and the main enzymes involved. Thickness of the arrow demonstrates the relative contribution of each pathway.

Note: Adapted from Springer and Current Oncology Reports, 12,2010,7–15, CYP2D6 polymorphisms and tamoxifen metabolism: clinical relevance, Higgins MJ, Stearns V, figure number 1, with kind permission from Springer Science and Business Media.
Abbreviations: CYP, cytochrome P450; OH, hydroxide.

Table 1 Summary of major randomized trials of tamoxifen prevention

Study (reference)	Study subjects (n)	Subject age, years	Events (n)		RR (95% CI)
			Placebo	Tamoxifen
NSABP^Citation6	13,388	35–80
All invasive			250	145	0.57 (0.46–0.70)
ER-positive			182	70	0.38 (0.28–0.50)
ER-negative			42	56	1.31 (0.86–2.01)
Royal Marsden Trial^Citation8	2,494	30–70
All invasive			104	82	0.78 (0.58–1.04)
ER-positive			86	53	0.61 (0.43–0.86)
ER-negative			17	24	1.4 (0.7–2.6)
International Breast	7,145	35–70	195	142	0.73 (0.58–0.91)
Cancer Intervention
Study^Citation9
ER-positive			132	35	0.66 (0.50–0.87)
ER-negative			35		1.00 (0.53–1.87)
Milan study^Citation10	5,408	35–70	74	62	0.84 (0.60–1.17)
ER-positive			52	40	0.77 (0.51–1.16)
ER-negative			19	21	1.10 (0.59–2.05)

Abbreviations: CI, confidence interval; ER, estrogen receptor; RR, relative risk; NSABP, National Surgical Adjuvant Breast and Bowel Project.

FisherBCostantinoJPWickerhamDLTamoxifen for prevention of breast cancer: current status of the National Surgical Adjuvant Breast and Bowel Project P-1 StudyJ Natl Cancer Inst2005971652166216288118

 PubMed Web of Science ®Google Scholar

PowlesTJAshleySTidyATwenty-year follow-up of the Royal Marsden randomized, double-blinded tamoxifen breast cancer prevention trialJ Natl Cancer Inst20079928329017312305

 PubMed Web of Science ®Google Scholar

CuzickJForbesJFSestakILong-term results of tamoxifen prophylaxis for breast cancer – 96-month follow-up of the randomized IBIS-I trialJ Natl Cancer Inst20079927228217312304

 PubMed Web of Science ®Google Scholar

VeronesiUMaisonneuvePRotmenszNTamoxifen for the prevention of breast cancer: late results of the Italian Randomized Tamoxifen Prevention Trial Among Women With HysterectomyJ Natl Cancer Inst20079972773717470740

 PubMed Web of Science ®Google Scholar