Caveats and Concerns With New Study on Hormone Therapy and Breast Cancer

Note: references studies - WHI (Women's Health Initiative) and California Teachers Study

Clinicians vary in their approaches to HT, said Dr. Ursin. "Certain gynecologists are very careful with finding the right dose for each woman, and some even prescribe [estrogen] alone for women who have a uterus, but then monitor the uterus carefully. Please keep in mind that the risk of breast cancer associated with EPT is relatively moderate. The risk of endometrial cancer with [estrogen] alone is much higher — a more than 4-fold increase in risk in this same population of California teachers," she said.

media article: New Findings Further Clarify Breast Cancer Risk With Hormone Therapy

“This is evidence that the story is complicated,” said Tanmai Saxena, an M.D./Ph.D. student at the Keck School of Medicine at the University of Southern California. “The benefits of hormone therapy for relief of postmenopausal symptoms among women are clear, but the risks are more complicated than we had previously thought.”

Postmenopausal Hormone Therapy: An Endocrine Society Scientific Statement abstract only/multinational statement - Journal of Clinical Endocrinology & Metabolism

Conclusions: The major conclusions related to the overall benefits and risks of MHT expressed as the number of women per 1000 taking MHT for 5 yr who would experience benefit or harm. Primary areas of benefit included relief of hot flashes and symptoms of urogenital atrophy and prevention of fractures and diabetes. Risks included venothrombotic episodes, stroke, and cholecystitis. In the subgroup of women starting MHT between ages 50 and 59 or less than 10 yr after onset of menopause, congruent trends suggested additional benefit including reduction of overall mortality and coronary artery disease. In this subgroup, estrogen plus some progestogens increased the risk of breast cancer, whereas estrogen alone did not. Beneficial effects on colorectal and endometrial cancer and harmful effects on ovarian cancer occurred but affected only a small number of women. Data from the various Women’s Health Initiative studies, which involved women of average age 63, cannot be appropriately applied to calculate risks and benefits of MHT in women starting shortly after menopause. At the present time, assessments of benefit and risk in these younger women are based on lower levels of evidence.

Hormone therapy, DNA methylation and colon cancer-- Carcinogenesis

Hormone Replacement Therapy: MedlinePlus (update)

New study confirms HRT helps ward off colon cancer | Reuters

 Note: this issue of a protective effect was known at the time the original WHI study information was published but also received very little attention

 New study confirms HRT helps ward off colon cancer

Fri Apr 9, 2010 5:19pm EDT

NEW YORK (Reuters Health) - Hormone replacement therapy (HRT) cuts a woman's risk of developing colon cancer, new research confirms.

Health

Millions of women stopped taking HRT when a Women's Health Initiative study showed in 2002 that the hormones raised the risk of stroke, heart disease and breast cancer.
But the Women's Health Initiative had also found that HRT protected against colon cancer. Some studies have also suggested that oral contraceptives might reduce the risk of the disease, while the fact that women are at lower risk of colon cancer than men also hints at a hormonal role in disease risk.
To investigate ties between HRT and colon cancer further, Dr. Millie D. Long of the University of North Carolina at Chapel Hill and her colleagues matched 443 women diagnosed between 2001 and 2006 with distal large bowel cancer (meaning tumors at the far end of the colon and the rectum) to 405 healthy control women. The average age of the study participants was around 63.
Long's team found that women who had ever used HRT were at half the risk of this type of colon cancer compared to women who'd never used hormone replacement, and the longer a woman was on HRT, the lower the risk.
For example, women who used hormones for less than four years cut their colon cancer risk by about one-quarter; four to eight years of HRT cut risk by a third; nine to 14 years of use halved risk; and 15 years or more of HRT reduced risk by two-thirds. The effects were the same for African-American women and white women.
However, there was no relationship between oral contraceptive use and colon cancer risk, the study team reports in the American Journal of Gastroenterology.
Long-term hormone therapy is no longer recommended for postmenopausal women, Long and her team note, although it is still sometimes prescribed on a short-term basis to help women with menopausal symptoms such as hot flashes. The major drop off in distal large bowel cancer in recent years could have been related to widespread use of HRT, the researchers say.
More research is needed to determine if HRT's protective effects persist after women stop taking hormones, the researchers add, or whether there might be a "rebound" effect with more pre-cancerous polyps developing after a woman halts
HRT.
"It may become important in the future to tailor timing of women's colorectal screening based on cessation of hormonal therapy," Long and her colleagues conclude.

SOURCE: The American Journal of Gastroenterology, online March 30, 2010.

If only WHI was done well -- BMJ (Drug firm conflicting interests)

"Barrington claims that the women’s health initiative (WHI) trial had impeccable standards.1 We recently highlighted some of its shortcomings relating to hormone replacement therapy (HRT). The data and safety monitoring board used a global index of health which was modified on three occasions...."

Hormone replacement therapy (HRT), breast cancer and tumor pathology

Hormone replacement after gynaecological cancer

"However, the majority of the most common gynaecological malignancies like squamous cell carcinomas of the cervix, serous papillary epithelial ovarian carcinomas and squamous cell carcinomas of the vulva are not oestrogen dependent."

(financial news source) Non-Patch, Transdermal Estrogen Products Such as Divigel(R) Are Effective Hormone Therapy Alternatives to Oral Estrogen