Hormone therapy increases invasive breast cancer and mortality, WHI 11-year follow up finds
Results of a new Women's Health Initiative (WHI) report show that hormone therapy is associated with an increased the risk of death from breast cancer, as well as an increased risk of developing invasive breast cancer in postmenopausal women. Jean Wactawski-Wende, PhD, professor of social and preventive medicine at the University at Buffalo and one of the primary authors on the paper, published today in JAMA, says the breast cancers found in these women also tended to have more lymph node involvement, indicating a poorer prognosis.
"This report, which expands on earlier results of the WHI study, followed these women for an average of 11 years," says Wactawski-Wende. "The data show that, with further follow-up, there remains an increased incidence of breast cancer in women taking estrogen plus progestin.
"In fact, women taking estrogen plus progestin are more likely to die from breast cancer and from other causes than women who did not take these hormones."
The paper was posted online Oct. 19 at http://jama.ama-assn.org/cgi/reprint/304/15/1684.
Wactawski-Wende was co-PI at UB's WHI Vanguard Center, one of 16 that helped develop the initial protocols for the study, which began in 1993 and eventually included 40 clinical centers across the U.S. Initially planned to continue until 2005, the hormone trial was halted in 2002 because preliminary analysis of the data showed estrogen plus progestin increased the risk of heart disease, stroke and invasive breast cancer. Prior to WHI, scientists speculated that hormone therapy reduced heart disease risk.
The WHI continued to follow these women after the main trial ended. The current JAMA paper reports the results of research conducted during this WHI extension phase. Most of the earlier observational studies, which follow participants over time and collect health information at specific intervals, had suggested that breast cancers that develop in women taking hormone therapy were less advanced and had a lower risk of death.
However, the WHI researchers note in the JAMA paper that the influence of estrogen plus progestin on breast cancer mortality had not been addressed in the context of a randomized clinical trial, prior to WHI.
Their current study to answer that question was based on 12,788 surviving postmenopausal women who took part in the initial trial.
Results showed that combined hormone therapy increases the incidence of invasive breast cancer and that, more commonly, the cancers had spread to the lymph nodes. There also were more deaths attributed to breast cancer in those taking hormone therapy -- 2.6 versus 1.3 per 10,000 women. There also were more deaths from all causes in the women who had been diagnosed with breast cancer who were on hormone therapy -- 5.3 versus 3.4 per 10,000.
The trial also found that hormone therapy interfered with detection of breast cancer, leading to cancers being diagnosed at a more advanced stage.
"These findings related to increased mortality in estrogen plus progestin users were surprising," says Wactawski-Wende. "Prior studies had suggested that, although these women were diagnosed with breast cancer, their prognosis was more positive than those who were not on hormone therapy when diagnosed. This study emphasizes the importance of clinical trial data to understand the risks and benefits of taking hormone therapy."
Source: University at Buffalo
Articles on the same topic
- Estrogen replacement therapy speeds ovarian cancer growth, new study reportsWed, 20 Oct 2010, 16:03:28 EDT
- Women fight the effects of chemotherapy long after treatment endsWed, 20 Oct 2010, 12:35:43 EDT
- Hormone therapy use by postmenopausal women may increase incidence of more advanced breast cancerTue, 19 Oct 2010, 16:36:09 EDT
- Soy intake associated with lower recurrence of breast cancer in hormone-sensitive cancersMon, 18 Oct 2010, 12:35:09 EDT
- Hormone therapy use by postmenopausal women may increase incidence of more advanced breast cancerfrom Science CentricFri, 22 Oct 2010, 15:00:30 EDT
- Women fight the effects of chemotherapy long after treatment endsfrom Science CentricFri, 22 Oct 2010, 14:20:21 EDT
- Breast cancer study finds prolonged hormone therapy riskfrom LA Times - HealthFri, 22 Oct 2010, 12:30:56 EDT
- Five-day breast cancer treatment now availablefrom PhysorgFri, 22 Oct 2010, 11:01:25 EDT
- Estrogen replacement therapy speeds ovarian cancer growth, new study reportsfrom Science BlogWed, 20 Oct 2010, 17:00:37 EDT
- Estrogen replacement therapy speeds ovarian cancer growth, new study reportsfrom PhysorgWed, 20 Oct 2010, 16:00:41 EDT
- Women fight the effects of chemotherapy long after treatment endsfrom Science DailyWed, 20 Oct 2010, 13:30:27 EDT
- Women fight the effects of chemotherapy long after treatment endsfrom PhysorgWed, 20 Oct 2010, 13:01:49 EDT
- Women fight the effects of chemotherapy long after treatment endsfrom Science BlogWed, 20 Oct 2010, 13:01:03 EDT
- Hormone therapy raises breast cancer deaths: studyfrom Reuters:ScienceWed, 20 Oct 2010, 10:00:29 EDT
- Breast cancer study finds prolonged risk to hormone therapyfrom LA Times - ScienceWed, 20 Oct 2010, 0:31:08 EDT
- Hormone therapy use by postmenopausal women may increase incidence of more advanced breast cancerfrom Science DailyTue, 19 Oct 2010, 23:30:28 EDT
- Hormone therapy use by postmenopausal women may increase incidence of more advanced breast cancerfrom PhysorgTue, 19 Oct 2010, 19:30:22 EDT
- Hormone Therapy Raises Cancer Risks, Study Findsfrom NY Times ScienceTue, 19 Oct 2010, 17:50:11 EDT
- Hormones for Menopause Increase Breast Cancer Hazardfrom Live ScienceTue, 19 Oct 2010, 17:00:38 EDT
- Hormones Amplify Cancer Risks, Study Findsfrom NY Times HealthTue, 19 Oct 2010, 17:00:09 EDT
- Hormone therapy linked to deadlier breast cancerfrom CBC: HealthTue, 19 Oct 2010, 16:31:44 EDT
- Soy intake associated with lower recurrence of breast cancer in hormone-sensitive cancersfrom Science DailyMon, 18 Oct 2010, 14:34:01 EDT
- Soy intake associated with lower recurrence of breast cancer in hormone-sensitive cancersfrom PhysorgMon, 18 Oct 2010, 13:00:38 EDT
- High Soy Intake May Reduce Risk of Breast Cancer Recurrencefrom Live ScienceMon, 18 Oct 2010, 12:32:54 EDT
- Prolonging first-line chemotherapy improves outcomes for patients with metastatic breast cancer, meta-analysis showsfrom Science DailySun, 17 Oct 2010, 22:41:04 EDT
Latest Science NewsletterGet the latest and most popular science news articles of the week in your Inbox! It's free!
Learn more about
Check out our next project, Biology.Net
From other science news sites
Popular science news articles
- Climate affects the development of human speech
- Why all-nighters don't work: How sleep and memory go hand-in-hand
- Did genetic links to modern maladies provide ancient benefits?
- Researchers identify brain circuit that regulates thirst
- Anthropology: Ancient skull from Galilee cave offers clues to the first modern Europeans