Reactions 890 - 23 Feb 2002

HRT increases the risk of breastcancer

Recent, long term use of hormone replacementtherapy (HRT) is associated with an increased risk ofbreast cancer, according to researchers from the US.

Using data from the Group Health Cooperative (GHC)of Puget Sound, the researchers conducted a nestedcase-control study of 705 postmenopausal women(aged 50–74 years) who had been diagnosed withprimary invasive breast cancer between 1 July 1990 and31 December 1995, and 692 matched controls, toexamine the association between HRT and breastcancer.

Analysis of HRT use during the 5 years ending 1 yearprior to diagnosis revealed that recent long-term use (≥57 months) of oral HRT* was associated with anincreased risk of breast cancer compared with no HRTuse during the 5-year period [odds ratio (OR)1.7; 95%CI 1.15–2.5]. The results were similar (60-85%increased risk) whether the women used estrogen aloneor in combination with progestogen, and for bothsequential and continuous therapy.

Recent long-term use (≥ 57 months) of HRT wasassociated with a 3-fold increase in the risk of lobularcancer (OR 3.07; 95% CI 1.55–6.06) and a 50% increasein nonlobular (primarily ductal) cancer (OR 1.52; 95% CI1.01–2.29). Current use of combination therapy wasassociated with a 4-fold increase in the risk of lobularbreast cancer (3.91; 2.05–7.44).* measured as months of estrogen pill use with or withoutprogestogen

Chen C-L, et al. Hormone replacement therapy in relation to breast cancer. JAMA:the Journal of the American Medical Association 287: 734-741, 13 Feb2002 800896446

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Reactions 23 Feb 2002 No. 8900114-9954/10/0890-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved