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In a puzzling twist, women who have a history of migraine headaches are far less likely to develop breast cancer than other women, U.S. researchers said on Thursday.

The study is the first to look at the relationship between breast cancer and migraines and its findings may point to new ways of reducing a woman’s breast cancer risk, they said.

“We found that, overall, women who had a history of migraines had a 30 percent lower risk of breast cancer compared to women who did not have a history of such headaches,” said Dr. Christopher Li of the Fred Hutchinson Cancer Research Center in Seattle, whose findings appear in the journal Cancer Epidemiology, Biomarkers and Prevention.

Li said the reduction in risk was for the most common types of breast cancers — those driven by hormones, such as estrogen-receptor positive breast cancer, which is fueled by estrogen, and progesterone-receptor positive breast cancer, which is fueled by progesterone.

Hormones also play a role in migraines, a brutal type of headache often accompanied by nausea, vomiting and heightened sensitivity to light and sound. Women are two to three times more likely than men to get migraines.

While it is not exactly clear why women with a history of migraines had a lower risk for breast cancer, Li and colleagues suspect hormones are playing a role.

“Women who have higher levels of estrogen in their blood have higher levels of breast cancer,” Li said in a telephone interview.

And he said migraines are often triggered by low levels of the hormone estrogen, such as when estrogen levels fall during a woman’s menstrual cycle.

Women who get migraines “may have a chronically lower baseline estrogen. That difference could be what is protective against breast cancer,” Li said.

For the study, Li and colleagues analyzed data from two studies of 3,412 post-menopausal women in the Seattle area, 1,938 of whom had been diagnosed with breast cancer and 1,474 of whom had no history of breast cancer. Women in the study provided information on their migraine history.

They found women who had reported a clinical diagnosis of migraine had a 30 percent reduced risk of developing hormonally sensitive breast cancers.

“Migraines are typically most severe among pre-menopausal women,” Li said. “This study was all post-menopausal women.”

He said that suggests the protective effect seen in women who get migraines may have a lasting effect at reducing breast cancer risk.

“While these results need to be interpreted with caution, they point to a possible new factor that may be related to breast-cancer risk,” Li said in a statement.

Breast cancer is the leading cause of cancer death among women worldwide, with an estimated 465,000 deaths annually, according to the American Cancer Society.
By: Reuters

Obesity can wreck a person’s health for many reasons. But for women, too much weight tacks on an additional danger: Studies have linked obesity and breast cancer in a variety of ways.

Doctors aren’t sure why this link exists and are trying to figure out what ties weight gain to breast cancer. But they are more and more convinced the link is there, and they are urging women to watch their weight and increase their exercise to help stave off what is the most common cancer among females, nonmelanoma skin cancer aside.

“There are a lot of factors we need to figure out,” said Dr. Jennifer A. Ligibel, of the Dana-Farber Cancer Institute in Boston. “There are a lot of things we don’t know.”

An estimated 182,500 women in the United States will be found to have invasive breast cancer in 2008, according to the American Cancer Society, and about 40,480 women will die from the disease this year. Currently, there are about 2.5 million breast cancer survivors in the United States.

Studies have found that, in general, obesity is linked to cancer. The higher a person’s body-mass index (BMI, a ratio of weight to height), the more likely she or he will develop cancer, according to recent research by scientists at the University of Manchester in England. Other studies have found similar links to increased body fat.

Still other studies have found that women with breast cancer are more likely to live shorter lives and suffer a recurrence of their cancer if they are overweight.

For example, in a recent study conducted at the University of Texas M.D. Anderson Cancer Center in Houston, more than two-thirds of women with stage III locally advanced breast cancer were either overweight or obese. The study also found that a greater proportion of obese patients were likely to be diagnosed with a rare and more deadly form of breast cancer, known as inflammatory breast cancer.

Scientists vary in their opinions on why this link exists, and what it means.

Some believe that obesity may make tumors harder to detect, so a woman’s breast cancer will be further developed before it is discovered.

“It could be because there’s more breast tissue, a lump would be less evident,” Ligibel said.

Researchers also believe that the systemic effects of obesity might do something to spur cancer on. For example, obesity or overweight can lead to fluctuations in hormone levels in the body.

“When women are heavier, their estrogen levels are higher,” Ligibel said. “That could be a pathway through which weight affects breast cancer. Other studies have shown that when insulin levels are high, there’s more chance a cancer will come back.”

Another link to obesity was found in a study from the University of North Carolina at Chapel Hill that showed that obese women are more likely to skip screenings for breast and cervical cancer. Without those screenings, women are less likely to catch breast cancer at a more treatable stage.

Debbie Saslow, director of breast and gynecologic cancer at the American Cancer Society, said it’s not completely clear what role obesity plays in breast cancer risk.

“For obesity, which is independent of breast size, I would think two factors would come into play,” Saslow said. “One, a positive, is that the breasts may be fattier, which would make a mammogram easier to read. The second, a negative, is indirect: Obese women are less likely to go to a doctor.”

Menopause appears to be a critical time, Ligibel said. Obesity creates a greater risk for breast cancer post-menopause, while pre-menopausal women actually have a reduced risk.

“Gaining weight around the time of menopause is a risk factor in developing breast cancer,” Ligibel said.

The increased risk of developing breast cancer and dying of it after menopause is believed due to increased levels of estrogen in obese women, said Colleen Doyle, director of nutrition and physical activity with the American Cancer Society.

There is good news. Studies have shown that exercise — 30 minutes to 60 minutes a day of moderate-to-high intensity physical activity — decreases breast cancer risk, Doyle said.

“Physical activity reduces breast cancer risk both directly, by decreasing circulating estrogens, and also indirectly, by helping with weight control,” she said. “Women are so concerned about breast cancer risk. Communicating that there are key things you can do to reduce risk — watch your weight and be more active — are valuable messages.”

Ligibel agreed, noting that exercise might be valuable enough to counteract the strain on the body caused by obesity.

“You might not need to lose weight if you exercise,” Ligibel said. “Exercise could affect the hormone levels and help keep cancer from occurring or recurring.”

By HealthDay

Women who were bigger and longer babies may be more likely to develop breast cancer, researchers reported on Tuesday.

The study adds to evidence that, at least in some cases, something that happens in the womb may cause cancer later in life.

Previous research into links between birth size and breast cancer have proved inconsistent, but the findings published in the Public Library of Science journal PLoS Medicine are strong evidence that the two may be related.

“These findings provide strong evidence that birth size — in particular birth length — is a marker of a woman’s breast cancer risk in adulthood, although the mechanisms underlying this association are unclear,” Isabel dos Santos Silva of the London School of Hygiene and Tropical Medicine and colleagues wrote.

Breast cancer is the leading cause of cancer deaths among women worldwide, according to the American Cancer Society. The group estimates about 465,000 women died of breast cancer globally in 2007, and 1.3 million new cases were diagnosed.

Declining death rates from breast cancer in developed countries have been attributed to early detection through mammography screening and to improved treatment.

Dos Santos Silva and colleagues examined 32 studies comprising 600,000 women, mainly in developed countries. Their analysis included more than 22,000 women who had breast cancer.

After considering established risk factors such as age and late menopause, the researchers found a strong association with birth size, birth length and head circumference. Of the three, birth length showed the strongest link.

“The amount by which birth size affected breast cancer risk was not affected by allowing for other established risk factors,” the researchers wrote.

For example, women with recorded birth weights of 4 kilograms or more had a 12 percent higher chance of breast cancer than babies weighing 3 to 3.5 kilograms at birth, the study found.

The link between breast cancer and birth size appeared smaller when compared with other risk factors. The researchers estimated that birth size may be responsible for up to 5 percent of all women who develop breast cancer by the age of 80.

Some research has linked hormones such as estrogen and human growth hormone with cancer.

The researchers noted age of puberty and adult height are also associated with breast cancer risk, and growth as a fetus can predict a girl’s growth, so there could be a link there.

“The maternal and/or foetal hormonal environment associated with large birth size may alter programing of the breast, making it more susceptible to cancer,” the researchers wrote.

by Michael Kahn | Maggie Fox and Tim Pearce ( LONDON Reuters )

A recent study by Kaiser Permanente Researchers has found that the effects of alcohol on breast cancer are the same, regardless of whether a woman drinks wine, beer, or liquor. The ethyl alcohol found in those drinks and the quantity consumed are the factors that weigh heavily on breast cancer risk. Researchers believe the increased risk from three or more drinks a day is similar to the increased breast cancer risk from smoking a pack of cigarettes a day or more. They claim that “Population studies have consistently linked drinking alcohol to an increased risk of female breast cancer, but until now there has been little data, most of it conflicting, about an independant role played by the choice of beverage type.”

The team of Kaiser Permanente researchers studied the drinking habits of over 70,000 women of varying ethnicities who had supplied information during health exams between 1978 and 1985. By the year 2004, 2,800 of these women were diagnosed with breast cancer. Researchers analyzed three aspects of the records; they compared alcohol intake among women who favored specific beverages, the frequency of drinking each beverage type, and the role of total alcoholic intake compared with women who drank less than one drink a day.

The results found no difference among the varying types of alcoholic beverages, even when wine was divided into red and white. Researchers found the risk of breast cancer rose by 30 percent in women who drank more than three drinks a day. They claim that “We think that the heart protection benefit from alcohol is real, and is probably derived largely from alcohol-induced higher HDL or “good” cholesterol, reduced blood clotting and reduced diabetes.” However, they warn “Our findings provide more evidence for why heavy drinkers should quit or cut down.
by FRANCISCO MEJIAS

A large US study suggests that it did not matter whether women drank beer, wine or spirits, they all raised the risk of breast cancer to the same extent. And more than three alcoholic drinks a day raised breast cancer risk by 30 per cent, compared to women who had less than one drink a day, said the researchers.

The study, one of the largest of its kind, was presented yesterday, Thursday, at the European Cancer Conference (ECCO 14) in Barcelona, Spain, and is the work of Dr Arthur Klatsky, adjunct investigator in the Division of Research, Kaiser Permanente Medical Care Program, Oakland, US, and colleagues.

Klatsky and colleagues showed that it made no difference what type of alcoholic drink the women had, it was the fact they contained ethyl alcohol that mattered, and how much was consumed.

The increase in breast cancer risk due to three or more alcoholic drinks a day is similar to that posed by smoking a pack of cigarettes or more a day said Klatsky. It is also similar to the risk posed by taking oestrogenic hormones he added.

Speaking at a news briefing, Klatsky explained that:

“Population studies have consistently linked drinking alcohol to an increased risk of female breast cancer.”

“But there has been little data, most of it conflicting, about an independent role played by the choice of beverage type,” said Klatsky.

The researchers studied the drinking habits of 70,033 women of different ethnic origin who underwent health exams during the period 1978 to 1985 and looked at the breast cancer incidence in the cohort in subsequent years.

They found that 2,829 of the women had been diagnosed with breast cancer by 2004.

The results showed that:

• There was no difference in breast cancer risk between wine, beer and spirit consumption.
• Even between red and white wine, the impact was the same.
• In terms of overall alcohol intake, women who had between one and two drinks a day had a 10 per cent higher breast cancer risk compared to those who had one drink a day.
• The risk went up to 30 per cent for women who had more than three drinks a day.
• The results were the same for all age and ethnic groups.

Commenting on the results, Klatsky said that:

“Statistical analyses limited to strata of wine preferrers, beer preferrers, spririts preferrers or non-preferrers each showed that heavier drinking, compared to light drinking, was related to breast cancer risk in each group.”

“This strongly confirms the relation of ethyl alcohol per se to increased risk,” he added.

Although only a small proportion of women are heavy drinkers, and the risk of breast cancer varies among different groups, a 30 per cent increase in relative risk from drinking heavily probably translates to 5 per cent of all breast cancers being due to this habit.

Klatsky and colleagues have previously linked red wine to reduced heart attack incidence, and he said that different biological mechanisms probably explain the different effects.

The protective effect on the heart from red wine is probably due to increased HDL (”good”) cholesterol, reduced blood clotting and reduced diabetes. But none of these has been shown to have anything to do with breast cancer, he said.

“The coronary benefit from drinking red wine may also be related to favourable drinking patterns common among wine drinkers or to the favourable traits of wine drinkers, as evidenced by US and Danish studies,” said Klatsky.

Emphasizing that all medical advice should be tailored to the individual patient, Klatsky added that the only general statement that could be made from the findings was that it showed more reasons why “heavy drinkers should quit or cut down”.

Klatsky concluded his conference presentation:

“This has been fascinating research. Our group has been involved in studies of alcohol drinking and health for more than three decades, including in the area of heart disease. We are fortunate to have data available about a large, multi-ethnic population with a variety of drinking habits.”

According to a report in WebMD, Dr Shumin Zhang, associate professor of medicine at Brigham and Women’s Hospital and Harvard Medical School, said the findings were “generally consistent with previous research”.

Zhang, who did not take part in the research conducted by Klatsky and colleagues, has also found a link between frequent alcohol consumption and elevated breast cancer risk, said WebMD

Written by: Catharine Paddock
Source: Medical News Today

WASHINGTON (Reuters) - Overweight and obese women have a lower risk of breast cancer prior to menopause, researchers said on Monday in a finding they said both puzzles them and contradicts conventional wisdom.

The researchers admitted they do not know why the extra pounds (kg) may protect premenopausal women from breast cancer, but noted obesity actually greatly boosts breast cancer risk after menopause, when the disease more often is diagnosed.

“It is so puzzling. And it is not a good public health message,” said Karin Michels, associate professor of obstetrics, gynecology and reproductive biology at Harvard Medical School and lead researcher in the study.

“I don’t want women to use this as an excuse to be overweight. Therefore, it’s even more important for us to find out what the mechanisms are. I mean, the last thing we want is, in this day and age, to advise people to gain weight,” Michels said in a telephone interview.

The findings, published in the Archives of Internal Medicine, were based on medical data from 113,130 premenopausal registered nurses tracked from 1989 to 2003. During that time, 1,398 cases of invasive breast cancer were diagnosed.

Women with a body mass index (a weight-for-height scale) of 30 or above — considered obese by the U.S. Centers for Disease Control and Prevention — had a 19 percent lower risk of premenopausal breast cancer than women in a normal weight range (body mass index between 20 and 22.4), the study found.

The lower risk was especially evident in young adults. Those with a body mass index at age 18 of 27.5 or higher, which makes them overweight or obese, had a 43 percent lower risk of breast cancer before menopause than women of normal weight at the same age.

Being overweight is linked to a broad range of health risks. The World Health Organization describes obesity as a growing problem in high-income nations as well as increasing numbers of low- and middle-income nations.

OVULATION FACTORS

Michels said some experts had suspected the reduced premenopausal breast cancer risk was the result of these women not ovulating as much due to their larger body size.

Some overweight women have irregular or long menstrual cycles, or develop a condition called polycystic ovary syndrome in which ovaries malfunction. These are linked to disruptions in ovulation that lower levels of certain hormones.

The suspicion had been that these lower hormone levels might explain the diminished breast cancer risk. But the researchers weighed these factors and concluded that they did not appear to be the cause.

“Now we’re back to square one in trying to explain with which kind of mechanisms a larger body size might protect women from breast cancer,” Michels said, adding she plans further research.

She speculated the findings might be explained by the fact that obese women are less likely to be screened for breast cancer, and that is harder to detect tumors in these women.

“If we just detect the cancer later and therefore delay the time of diagnosis of the cancer into their post-menopausal years, then that might be an explanation,” Michels said.

Michels said the link between weight and breast cancer risk varies by age. High weight at birth and then after menopause is linked to a heightened risk, while high weight in young adulthood is associated with a reduced risk, she said.

Source: Yahoo News

cancer in women at high risk for the disease.

New research finds the chemical compound in RU486 prevented tumors from growing in mice that were genetically engineered to carry the BRCA1 breast cancer gene.

RU486, or mifepristone, blocks the production of the hormone progesterone, and this anti-progesterone effect could have prevented the growth of tumors in these mice, the authors speculated. RU486 aborts a pregnancy via the same mechanism.

Still, all this is a far cry from recommending RU486 as breast cancer therapy in people, experts cautioned.

“It’s an interesting observation,” said Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System, in Baton Rouge, La. “It’s basically showing that this particular agent can change some of the mammary function, but it’s a real leap to say that it may be useful in cancer prevention.”

The study appears in the Dec. 1 issue of Science.

Genes can greatly influence breast cancer risk. Experts have long known that women with mutations in the BRCA1 gene are at a much higher risk of developing both breast and ovarian cancer. The mutations mainly affect hormone-responsive tissues, although experts have been unclear as to why.

For this study, researchers studied mice that carried the mutated form of BRCA1, causing them to be highly susceptible to breast cancer.

As it turned out, the mice’s mammary epithelial cells accumulated high levels of progesterone receptors and then divided and proliferated at an abnormally rapid rate.

However, Mice treated with RU486 did not develop breast tumors by the time they reached 1 year of age. On the other hand, untreated mice developed tumors by eight months.

Progesterone may encourage the proliferation of mammary cells that carry a breast cancer gene, the researchers said.

Although the study was done in mice, the same mechanism occurs in human cells, said study author Eva Lee, a professor of developmental and cell biology and biological chemistry at the University of California, Irvine.

She speculated that clinicians may one day be able to use progesterone-blocking compounds to prevent breast cancer in women with a genetic predisposition.

But RU486 may not be the best candidate, however.

“It is the most widely available anti-progesterone drug,” Lee said. “We are currently testing a more specific anti-progesterone drug to see whether it has the same effect and if that’s proven, we’ll go to a small clinical trial to see if that anti-progesterone is effective in a high-risk population.”

by: HealthDay .

Postmenopausal women who want to significantly decrease their breast-cancer risk would be wise to exercise regularly and keep their weight within a normal range for their height, according to new findings from the Women’s Health Initiative to be published in the journal Obesity.

The multicenter team of researchers, led by Anne McTiernan, M.D., Ph.D., of Fred Hutchinson Cancer Research Center, found that women who had the lowest body-mass index, or BMI, and the highest physical-activity levels had the lowest levels of circulating estrogens, sex hormones that can fuel breast-cancer growth.

Specifically, they found a significant decrease in the two most common, biologically active forms of estrogen, estrone and estradiol, among the most active, lean women studied. The researchers found that women with high BMI and low physical-activity had mean estrogen concentrations that were 50 percent to 100 percent higher than that of women with low BMI and high activity levels.

“Women with high levels of estrogens have a two-to-four-times-higher risk of breast cancer than women with very low levels,” said McTiernan, a member of the Hutchinson Center’s Public Health Sciences Division and co-investigator of the Women’s Health Initiative Clinical Coordinating Center, which is based at the Center. “If a woman can keep her own natural estrogens lower after menopause, it is probably going to be beneficial in terms of reducing her risk of breast cancer.”

The study, based on a random sample of 267 postmenopausal women nationwide selected from the WHI Dietary Modification Trial, is the first of its kind to examine the dual impact of body weight and physical activity on levels of various circulating sex hormones thought to impact cancer risk.

“Other studies have looked at the impact of body weight by itself or physical activity by itself but this is the first to look at both together regarding their influence on hormone levels,” McTiernan said. “This gives us a new understanding that combining weight control with high levels of physical activity is necessary for keeping estrogens at a healthy level in postmenopausal women.” Exercising vigorously for 30 to 60 minutes a day, five days a week would achieve this benefit, McTiernan said.

Women Should Not Neglect Screening
Women whose mothers took the drug DES during pregnancy may have a higher risk for breast cancer than women not exposed to the drug in utero. The new finding suggests these women should be especially vigilant about breast cancer screening, researchers at Boston University School of Public Health say. Their work appears in the journal Cancer Epidemiology, Biomarkers, and Prevention.

Why it’s important: DES, or diethylstilbestrol, was commonly given to pregnant women in the 1940s, ’50s, and ’60s to prevent miscarriage. As many as 2 million women may have been exposed to the drug while still in the womb. Those women are now at the age where breast cancer becomes more common, and thus may be at even higher risk than previously believed.

What’s already known: Use of DES was stopped in 1971 after research found that the drug could interfere with the development of the reproductive system of a fetus. Since then, other negative health effects have been identified. Women who took DES while pregnant are known to have a slightly higher risk of breast cancer than women who never used the drug. But it’s not clear if daughters exposed to DES in the womb also have an increased risk. However, exposed daughters do have a higher risk of developing a very rare cancer called clear cell adenocarcinoma in the vagina or cervix. They may also have problems getting pregnant and maintaining a healthy pregnancy.

How this study was done: To better understand if women exposed in the womb had a higher breast cancer risk, epidemiology professor Julie Palmer, Sc.D. and her colleagues compared breast cancer risk factors and diagnoses in 4,817 women who had been exposed in the womb and 2,073 similar women whose mothers did not take DES while pregnant. The women had all taken part in previous studies of the health effects of DES. Nearly all of the participants were white. They were followed for 22-24 years.

What was found: There were 76 cases of breast cancer among DES daughters and 26 among unexposed women. After controlling for other risk factors like age, family history of breast cancer, use of oral contraceptives and hormone therapy, number of children, weight and others, the researchers saw differences between the two groups. Women age 40 or older who were exposed to DES in the womb had nearly double the risk of developing breast cancer as unexposed women. Women who were 50 or older had an even higher risk, but there were too few women in the study to determine if that difference was statistically significant. Women younger than 40 did not seem to have any higher risk of breast cancer because of DES exposure. Breast cancer risk seemed to increase more in daughters of women given higher doses of DES.

The bottom line: Although the number of breast cancer cases in the study was small, it provides important information to women whose mothers took DES during pregnancy, said Heather Spencer Feigelson, PhD, MPH, senior epidemiologist at the American Cancer Society.

“These women should continue to be studied,” she said. “Most of the women in this cohort are now in their 40s and early 50s, and we do not know whether their breast cancer risk will continue to rise.”

Palmer and her colleagues say women whose mothers took DES while pregnant should be especially careful to keep up with their mammograms and clinical breast exams. Breast cancer screening can find the disease at its earliest stages when it is easier to treat. They also say DES daughters should think twice about using postmenopausal hormone therapy.

“Because the commonly used female hormone supplements have been shown to independently increase risk of breast cancer, it might be wise for exposed women to avoid such supplements whenever possible.”

Feigelson agrees with that advice. And she says women can take steps to address certain other breast cancer risk factors.