Hormone Therapy and Mammography Use Influence Breast Cancer Rates
A rise in breast cancer incidence from the 1980s through 2001 paralleled trends in mammography screening and hormone therapy use, while a recent decline in incidence was consistent with a drop in hormone therapy use, according to a study of a large group of women enrolled in a single health plan,.
Breast cancer incidence has been on the rise since the late 1930s, but a recent report showed the first statistically significant decline in breast cancer incidence in 2003. Over this period, rates of hormone therapy use and mammography screening have changed too, but their individual influence on breast cancer rates was unclear.
Andrew Glass, M.D., of Kaiser Permanente's Center for Health Research in Portland, Ore., and colleagues compared breast cancer incidence rates with mammography use and menopausal hormone therapy prescriptions among patients in the health plan between 1980 and 2006.
Among women 45 years and older, breast cancer incidence rose 25% from the early 1980s to the early 1990s and continued to rise but at a lower rate--15%--through 2001. The rates dropped by 18% from 2003 to 2004, and then edged up slightly in 2005 and 2006. This pattern was seen predominantly in estrogen receptor-positive breast cancers. Meanwhile, mammography screening rose from 1980 until 1993, then remained stable through 2006. Hormone therapy use increased from 1988 to 2002, when it dropped by 75%.
"This rise [from the early 1980s to 2001] seemed to occur in two phases, the first during the 1980s, coinciding with the progressive adoption of screening mammography by 75%-79% of eligible women in the plan, and the second corresponding to increases in menopausal hormone use, particularly combined therapy, throughout the 1990s," the authors write.
In an accompanying editorial, Donald Berry, Ph.D., and Peter Ravdin, M.D., of the University of Texas M. D. Anderson Cancer Center in Houston suggest that hormone therapy itself may not cause breast cancer. Instead it could promote tumor growth while its withdrawal may slow or stop it. They add that using individual-based--in addition to population-based--data would give researchers a better picture of relationship between hormone therapy use and breast cancer.
"These additional analyses will be hopefully forthcoming from registries and data resources like those of the [Kaiser Permanente Northwest] group and might allow new insights into how to use menopausal hormone therapy with the lowest risk of negative effects and to the greatest advantage," the editorialists write.
- Article: Terry Fitzpatrick, communications manager, Kaiser Permanente Center for Health Research, Terry.Fitzpatrick@kpchr.org, (503) 335-6602
- Editorial: Donald Berry, firstname.lastname@example.org, (713)794-4141
Postmenopausal Sex Hormones and Breast Density Are Each Associated with Breast Cancer Risk
Sex hormone levels and breast density are independent risk factors for breast cancer in postmenopausal women.
Breast density and hormone levels are both well-known predictors of breast cancer, but it is unclear whether hormone levels regulate breast density.
Rulla Tamimi, Sc.D., of Brigham and Women's Hospital in Boston and colleagues measured breast density and estrogen and testosterone levels in postmenopausal women who later developed breast cancer and those who did not. They found that sex hormone levels and breast density are strongly and independently associated with breast cancer risk.
"Thus, levels of circulating sex steroid hormones and mammographic density may increase breast cancer risk through different mechanisms," the authors write.
Contact: Kevin Myron, media relations, Brigham and Women's Hospital, email@example.com, (617) 534-1605
Broccoli and Other Vegetables Linked with Decreased Risk of Aggressive Prostate Cancer
Eating more cruciferous vegetables like broccoli and cauliflower is associated with a reduced risk of aggressive prostate cancer.
Several studies have demonstrated an association between eating vegetables and a reduced risk of prostate cancer, but study results have not been consistent and many have not investigated the association among patients with aggressive prostate cancer.
Victoria Kirsh, Ph.D., of Cancer Care Ontario in Toronto and colleagues evaluated the possible association in 1,338 prostate cancer patients diagnosed in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Each of the men completed a 137-item food-frequency questionnaire.
They found that eating fruits and vegetables was not associated with decreased prostate cancer risk in general. But greater consumption of dark green and cruciferous vegetables, especially broccoli and cauliflower, was associated with a decreased risk of aggressive prostate cancer.
"Aggressive prostate cancer is biologically virulent and associated with poor prognosis. Therefore, if the association that we observed is ultimately found to be causal, a possible means to reduce the burden of this disease may be primary prevention through increased consumption of broccoli, cauliflower, and possibly spinach," the authors write.
Also in July 24 JNCI:
eurekalert. org/ emb_releases/ 2007-07/ jotn-mr071907. php
eurekalert. org/ emb_releases/ 2007-07/ jotn-rf071907. php
eurekalert. org/ jrnls/ jnci/ 99-15Nummer.
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