Combined HRT increases risk of lobular breast cancer fourfold after just 3 years of use

[Guest guest]

Colleagues, the following is FYI and does not necessarily reflect my own

opinion. I have no further knowledge of the topic. If you do not wish to

receive these posts, set your email filter to filter out any messages

coming from @nutritionucanlivewith.com and the program will remove

anything coming from me.

---------------------------------------------------------

Public release date: 15-Jan-2008

http://www.eurekalert.org/pub_releases/2008-01/fhcr-chi010908.php

Contact: Woodward

kwoodwar@...

Fred Hutchinson Cancer Research Center

Combined HRT increases risk of lobular breast cancer fourfold after just

3 years of use

First study designed to evaluate the association between combined HRT

use and the risk of lobular breast cancers

SEATTLE – Postmenopausal women who take combined estrogen/progestin

hormone-replacement therapy for three years or more face a fourfold

increased risk of developing various forms of lobular breast cancer,

according to new findings by researchers at Fred Hutchinson Cancer

Research Center.

“Previous research indicated that five or more years of combined

hormone-therapy use was necessary to increase overall breast-cancer

risk,” said I. Li, M.D., Ph.D., the lead author of the

report, published in the January issue of Cancer Epidemiology,

Biomarkers and Prevention. “Our study, the first specifically designed

to evaluate the relationship between combined HRT and lobular breast

cancers, suggests that a significantly shorter length of exposure to

such hormones may confer an increased risk.”

The study, which confirms previous reports of the association between

combined hormone-therapy use and increased risk of lobular breast

cancers, is the largest study of combined HRT and lobular cancer risk in

the United States. It is also the first such study to take into account

the recency and duration of hormone use and the first to include a

centralized pathological review of tumor specimens to confirm their

histological type: ductal, lobular or mixed ductal-lobular.

Lobular cancer involves the lobules, or chambers, in the breast that

contain milk-producing glands. While lobular carcinoma accounts for only

about 15 percent of all invasive breast cancers, it is hormonally

sensitive and therefore more treatable than the more common ductal

variety, which arises in the ducts that carry milk from the lobules to

the nipple. However, lobular breast tumors also present a clinical

challenge because they are more difficult to detect both by clinical

examination and by mammography than ductal cancers, which account for

about 70 percent of invasive breast cancers in the United States.

The study assessed hormone-replacement status in more than 1,500

postmenopausal women in western Washington – 1,044 breast-cancer cases

(324 lobular, 196 mixed ductal-lobular and 524 ductal) and 469 controls.

The researchers also confirmed tumor status through centralized

examination of breast tissue.

The researchers found that current users of combined HRT had a 2.7-fold

and 3.3-fold elevated risk of lobular and ductal-lobular cancer,

respectively, regardless of tumor stage, size or number of lymph nodes

involved. Only women who used combined HRT for three or more years faced

an increased risk of lobular cancer. Among mixed ductal-lobular cases,

hormone therapy increased the risk of tumors that were predominantly

lobular but not tumors that had predominantly ductal characteristics.

The incidence of invasive lobular and ductal-lobular breast cancers has

risen rapidly in the United States, increasing 52 percent and 96

percent, respectively, between 1987 and 1999, whereas rates of ductal

cancer have increased only 3 percent during this time.

“Our research suggests that the use of postmenopausal

hormone-replacement therapy, specifically the use of combined

estrogen-plus-progestin preparations, may be contributing to this

increase,” said Li, an associate member of the Hutchinson Center’s

Public Health Sciences Division.

While the number of postmenopausal women taking combined HRT long-term

has dropped by about half in recent years due to Women’s Health

Initiative reports of health risks associated with such therapy, such as

an increase in heart-disease and breast-cancer risk, a substantial

number of women are still taking HRT to manage the symptoms of menopause.

“These findings are still of considerable public-health importance

considering the estimated 57 million prescriptions for menopausal

hormone therapy that continue to be filled in the United States,” Li said.

--

ne Holden, MS, RD < fivestar@... >

" Ask the Parkinson Dietitian " http://www.parkinson.org/

" Eat well, stay well with Parkinson's disease "

" Parkinson's disease: Guidelines for Medical Nutrition Therapy "

http://www.nutritionucanlivewith.com/