Study Cites Hormones as Cancer Risk
Published: July 14, 2009
CHICAGO (Reuters) ― Women who took hormone replacement therapy after menopause had a sharply increased risk of ovarian cancer, researchers in Denmark are reporting.
In a study of more than 900,000 Danish women ages 50 to 79, the scientists found 140 extra cases of ovarian cancer linked to hormone treatment over eight years. That translated to a 38 percent greater risk of contracting the disease, compared with women who did not receive the therapy.
Hormone therapy accounted for 5 percent of the cases of ovarian cancer in the study period, the researchers reported in The Journal of the American Medical Association.
“Even though this share seems low, ovarian cancer remains highly fatal, so accordingly this risk warrants consideration,” wrote the researchers, led by Lina Steinrud Morch of Copenhagen University.
The findings were similar to those in the 2002 Women’s Health Initiative study, which was stopped early because it found an increased risk of ovarian cancer, breast cancer, strokes and other health problems from hormone therapy.
Use of the treatment plunged after those findings were reported, and sales of Prempro, the combined estrogen-progestin therapy sold by Wyeth, have fallen 50 percent since 2001, to around $1 billion a year.
Wyeth’s director of global medical affairs, Dr. Corrado Altomare, who was not involved in the Danish study, said that for women considering hormone therapy, family history and personal medical history “certainly” come into play.
The risks of ovarian cancer were about the same from hormone therapy regardless of the duration of use, the formulation of the hormones, the estrogen dose or how it was administered, according to the study.
As in earlier studies, the recent one found that the cancer risk diminished about two years after therapy was stopped.
Ovarian cancer is diagnosed in roughly 18 out of 100,000 women in the United States each year, according to government statistics, and it killed 15,000 Americans in 2007.
Hormone Therapy and Ovarian Cancer
Lina Steinrud M?rch, MSc; Ellen L?kkegaard, MD, PhD; Anne Helms Andreasen, MSc; Susanne Kru"ger-Kj?r, MD, DrMSci; ?jvind Lidegaard, MD, DrMSci
Context Studies have suggested an increased risk of ovarian cancer among women taking postmenopausal hormone therapy. Data are sparse on the differential effects of formulations, regimens, and routes of administration.
Objective To assess risk of ovarian cancer in perimenopausal and postmenopausal women receiving different hormone therapies.
Design and Setting Nationwide prospective cohort study including all Danish women aged 50 through 79 years from 1995 through 2005 through individual linkage to Danish national registers. Redeemed prescription data from the National Register of Medicinal Product Statistics provided individually updated exposure information. The National Cancer Register and Pathology Register provided ovarian cancer incidence data. Information on confounding factors and effect modifiers was from other national registers. Poisson regression analyses with 5-year age bands included hormone exposures as time-dependent covariates.
Participants A total of 909 946 women without hormone-sensitive cancer or bilateral oophorectomy.
Main Outcome Measure Ovarian cancer.
Results In an average of 8.0 years of follow-up (7.3 million women-years), 3068 incident ovarian cancers, of which 2681 were epithelial cancers, were detected. Compared with women who never took hormone therapy, current users of hormones had incidence rate ratios for all ovarian cancers of 1.38 (95% confidence interval [CI], 1.26-1.51) and 1.44 (95% CI, 1.30-1.58) for epithelial ovarian cancer. The risk declined with years since last use: 0 to 2 years, 1.22 (95% CI, 1.02-1.46); more than 2 to 4 years, 0.98 (95% CI, 0.75-1.28); more than 4 to 6 years, 0.72 (95% CI, 0.50-1.05), and more than 6 years, 0.63 (95% CI, 0.41-0.96). For current users the risk of ovarian cancer did not differ significantly with different hormone therapies or duration of use. The incidence rates in current and never users of hormones were 0.52 and 0.40 per 1000 years, respectively, ie, an absolute risk increase of 0.12 (95% CI, 0.01-0.17) per 1000 years. This approximates 1 extra ovarian cancer for roughly 8300 women taking hormone therapy each year.
Conclusion Regardless of the duration of use, the formulation, estrogen dose, regimen, progestin type, and route of administration, hormone therapy was associated with an increased risk of ovarian cancer.
Author Affiliations: Gynaecological Clinic, Rigshospitalet, Copenhagen University, Copenhagen (Ms M?rch and Dr Lidegaard); Gynaecological-Obstetrical Department, Hiller?d Hospital, Copenhagen University, Copenhagen (Dr L?kkegaard); Research Center for Prevention and Health, Glostrup University Hospital, Glostrup, Denmark (Mss M?rch and Andreasen), Glostrup; and Department of Virus, Hormones and Cancer, Institute of Cancer Epidemiology, Danish Cancer Society, ?sterbro, Denmark (Dr Kru"ger-Kj?r).
|<< 前記事(2009/07/17)||ブログのトップへ||後記事(2009/07/18) >>|
|<< 前記事(2009/07/17)||ブログのトップへ||後記事(2009/07/18) >>|