Skip to content

Category: breast cancer

Published on

Amazing possibilities, but more studies needed. The key finding: A diversity of the bacterial community in the gut is good, and perhaps can be altered through diet, and so perhaps alter the future risk of developing breast cancer.From Science Daily:

Diverse gut bacteria associated with favorable ratio of estrogen metabolites

Postmenopausal women with diverse gut bacteria exhibit a more favorable ratio of estrogen metabolites, which is associated with reduced risk for breast cancer, compared to women with less microbial variation, according to a new study.

Since the 1970s, it has been known that in addition to supporting digestion, the intestinal bacteria that make up the gut microbiome influence how women's bodies process estrogen, the primary female sex hormone. The colonies of bacteria determine whether estrogen and the fragments left behind after the hormone is processed continue circulating through the body or are expelled through urine and feces. Previous studies have shown that levels of estrogen and estrogen metabolites circulating in the body are associated with risk of developing postmenopausal breast cancer.

"In women who had more diverse communities of gut bacteria, higher levels of estrogen fragments were left after the body metabolized the hormone, compared to women with less diverse intestinal bacteria," said one of the study's authors, James Goedert, MD, of the National Institutes of Health's National Cancer Institute (NCI) in Bethesda, MD. "This pattern suggests that these women may have a lower risk of developing breast cancer."

As part of the cross-sectional study, researchers analyzed fecal and urine samples from 60 postmenopausal women enrolled in Kaiser Permanente Colorado. .

"Our findings suggest a relationship between the diversity of the bacterial community in the gut, which theoretically can be altered with changes in diet or some medications, and future risk of developing breast cancer," Goedert said. 

Published on

Excellent way to lower breast cancer risk. From Science Daily:

Postmenopausal breast cancer risk decreases rapidly after starting regular physical activity

Postmenopausal women who in the past four years had undertaken regular physical activity equivalent to at least four hours of walking per week had a lower risk for invasive breast cancer compared with women who exercised less during those four years, according to new data.

"Twelve MET-h [metabolic equivalent task-hours] per week corresponds to walking four hours per week or cycling or engaging in other sports two hours per week and it is consistent with the World Cancer Research Fund recommendations of walking at least 30 minutes daily," said Agnès Fournier, PhD, a researcher in the Centre for Research in Epidemiology and Population Health at the Institut Gustave Roussy in Villejuif, France. "So, our study shows that it is not necessary to engage in vigorous or very frequent activities; even walking 30 minutes per day is beneficial."

Postmenopausal women who in the previous four years had undertaken 12 or more MET-h of physical activity each week had a 10 percent decreased risk of invasive breast cancer compared with women who were less active. Women who undertook this level of physical activity between five and nine years earlier but were less active in the four years prior to the final data collection did not have a decreased risk for invasive breast cancer

"We found that recreational physical activity, even of modest intensity, seemed to have a rapid impact on breast cancer risk. However, the decreased breast cancer risk we found associated with physical activity was attenuated when activity stopped. As a result, postmenopausal women who exercise should be encouraged to continue and those who do not exercise should consider starting because their risk of breast cancer may decrease rapidly."

Fournier and colleagues analyzed data obtained from biennial questionnaires completed by 59,308 postmenopausal women who were enrolled in E3N, the French component of the European Prospective Investigation Into Cancer and Nutrition (EPIC) study. The mean duration of follow-up was 8.5 years, during which time, 2,155 of the women were diagnosed with a first primary invasive breast cancer.

Published on

This is Part 2 on how lifestyle influences aging. Many recent research reports tell of a link between our lifestyle and how we'll age - whether we'll be active and healthy well into our 80s or in terrible shape and dying young. Mind you, these are not "definites" because nothing can give you a guarantee, but they are ways we can improve our odds in living the long and healthy life that we want. From February 2014 Medscape:

Cancers Caused by Lifestyle Behaviors: Experts Urge Action

In launching the World Cancer Report 2014 earlier this week, the editors emphasized the need for prevention and highlighted lifestyle behaviors that lead to cancer, including smoking tobacco, drinking alcohol, overweight/obesity, and lack of exercise. The report, issued by the International Agency for Research on Cancer (IACR), contains contributions from more than 250 scientists worldwide, many of them leading experts in their fields. 

In the United States, 1 in 3 cancer deaths is related to obesity, poor nutrition, or physical inactivity, and the problem will only increase as more countries and regions adopt the diet and lifestyles of more economically developed economies."

Tobacco, both smoked and smokeless, remains the world's leading cause of cancer morbidity and mortality, the report notes. The IACR and also the US Surgeon General have concluded that the relationship with smoking is causal for cancers of the nasal and oral cavities, hypopharynx, larynx, trachea, esophagus, lung, bronchus, bone marrow (leukemia), stomach, kidney, pancreas, ureter, uterus, bladder, and cervix. The IACR expands this list to also include paranasal sinuses, liver, colon, rectum, and ovary (mucinous), but says it is unclear if there is a link with breast cancer.

Still under-recognized, and not acted on, is the association between drinking alcohol and cancer. The agency says cancers caused by drinking alcoholic beverages include those of the oral cavity, pharynx, larynx, esophagus, liver, colorectum, and female breast.

Excess body fat increases the risk for cancers of the esophagus, colon, pancreas, endometrium, and kidney, as well as postmenopausal breast cancer. The evidence for obesity increasing the risk for these cancers is "convincing," the agency comments, and there is a dose–response relationship, so being overweight is less risky than being obese.

Regular physical activity reduces the risk for multiple cancers by contributing to weight control, and also reduces the risk for colorectal and breast cancer by additional mechanisms. The general consensus among researchers is that exercise should be of moderate intensity and average at least an hour each day.

High consumption of red meat, especially processed meat, is associated with a risk for colorectal cancer. "A diet high in fruit and vegetables and whole grains does not appear to be as strongly protective against cancer as initially believed," the report notes. "However, this dietary pattern is still advisable because of the benefits for diabetes and cardiovascular diseases, and some possible reductions in cancer incidence."

From Science Daily:

Watching too much TV may increase risk of early death: Three hours a day linked to premature death from any cause

Adults who watch TV three hours or more a day may double their risk of premature death from any cause. Researchers suggest adults should consider getting regular exercise, avoiding long sedentary periods and reducing TV viewing to one to two hours a day.

Results of a large study published in the Mayo Clinic Proceedings. From Science Daily:

Large waist linked to poor health, even among those in healthy body mass index ranges

Having a big belly has consequences beyond trouble squeezing into your pants. It’s detrimental to your health, even if you have a healthy body mass index (BMI), a new international collaborative study has found. Men and women with large waist circumferences were more likely to die younger, and were more likely to die from illnesses such as heart disease, respiratory problems, and cancer after accounting for body mass index, smoking, alcohol use and physical activity.

Some good news for those who have to sit for long periods every day at work - being physically fit may help. From Science Daily:

Physical fitness associated with less pronounced effect of sedentary behavior

Physical fitness may buffer some of the adverse health effects of too much sitting, according to a new study. Sedentary behavior has been linked to an increase risk of obesity, metabolic syndrome, type 2 diabetes mellitus, cardiovascular disease, some cancers, and premature death. But previous studies of the association have not taken into account the protective impact of fitness, a strong predictor of cardiovascular disease incidence and mortality.

Published on

Another reason to try to avoid BPA. From Medical Xpress:

BPA stimulates growth of breast cancer cells, diminishes effect of treatment

Bisphenol A (BPA), a chemical commonly used in plastics, appears to increase the proliferation of breast cancer cells, according to Duke Medicine researchers presenting at an annual meeting of endocrine scientists.

The researchers found that the chemical, at levels typically found in human blood, could also affect growth of an aggressive hormone-independent subtype of  cells called inflammatory breast cancer and diminish the effectiveness of treatments for the disease.

"We set out to determine whether routine exposures to common chemicals such as those in plastics, pesticides and insecticides could influence the effectiveness of breast cancer treatments," said corresponding author Gayathri Devi, Ph.D., associate professor of surgery at Duke. "BPA was one of the top chemicals to show growth stimulatory effects in breast cancer cells."

Screenings identified several agents that appeared to increase the proliferation of inflammatory breast cancer cells. Among the most active was BPA, a chemical known to disrupt hormones. The researchers found that it caused breast cancer cells to grow at a faster rate in both estrogen-receptor positive and estrogen-receptor negative breast cancer cells.

The researchers also found that BPA doses in the range observed in human blood lowered the efficacy of FDA-approved anti-cancer drugs used in breast cancer therapy, notably lapatinib.

"These studies provide the foundation for additional research to develop tools that can be used to identify patients who may be at greater risk of developing treatment resistance," Devi said. "The findings could also lead to biomarkers that identify patients who have heavy exposure to compounds that could diminish the effectiveness of their cancer therapy."

Published on

An interesting link. The thinking is that the number of moles (cutaneous nevi) are linked to higher levels of sex hormones. From Medical Xpress:

Moles linked to risk for breast cancer

Cutaneous nevi, commonly known as moles, may be a novel predictor of breast cancer, according to two studies published in this week's PLOS Medicine. Jiali Han and colleagues from Indiana University and Harvard University, United States, and Marina Kvaskoff and colleagues from INSERM, France, report that women with a greater number of nevi are more likely to develop breast cancer.

The researchers reached these conclusions by using data from two large prospective cohorts– the Nurses' Health Study in the United States, including 74,523 female nurses followed for 24 years, and the E3N Teachers' Study Cohort in France, including 89,902 women followed for 18 years. 

In the Nurses' Health Study, Han and colleagues asked study participants to report the number of nevi >3mm on their left arm at the initial assessment. They observed that women with 15 or more nevi were 35% more likely to be diagnosed with breast cancer than women who reported no nevi, corresponding to an absolute risk of developing breast cancer of 8.48% in women with no nevi and 11.4% for women with 15 or more nevi. In a subgroup of women, they observed that postmenopausal women with six or more nevi had higher blood levels of estrogen and testosterone than women with no nevi, and that the association between nevi and breast cancer risk disappeared after adjustment for hormone levels.

In the E3N Study, including mostly teachers, Kvaskoff and colleagues asked study participants to report whether they had no, a few, many, or very many moles. They observed that women with "very many" nevi had a 13% higher breast cancer risk than women reporting no nevi, although the association was no longer significant after adjusting for known breast cancer risk factors, especially benign breast disease or family history of breast cancer, which were themselves associated with nevi number.

These studies do not suggest that nevi cause breast cancer, but raise the possibility that nevi are affected by levels of sex hormones, which may be involved in the development of breast cancer. The findings do suggest that the number of nevi could be used as a marker of breast cancer risk, but it is unclear whether or how this information would improve risk estimation based on established risk factors. The accuracy of the findings is limited by the use of self-reported data on nevus numbers. Moreover, these findings may not apply to non-white women given that these studies involved mostly white participants.

Published on

From Medical Xpress:

Estimated risk of breast cancer increases as red meat intake increases

Higher red meat intake in early adulthood might be associated with an increased risk of breast cancer, and women who eat more legumes—such as peas, beans and lentils—poultry, nuts and fish might be at lower risk in later life, suggests a paper published BMJ today.

So far, studies have suggested no significant association between  intake and breast cancer. However, most have been based on diet during midlife and later, and many lines of evidence suggest that some exposures, potentially including dietary factors, may have greater effects on the development of breast cancer during early adulthood.

So a team of US researchers investigated the association between dietary protein sources in early adulthood and risk of breast cancer. They analysed data from 88,803 premenopausal women (aged 26 to 45) taking part in the Nurses' Health Study II who completed a questionnaire on diet in 1991. Adolescent food intake was also measured and included foods that were commonly eaten from 1960 to 1980, when these women would have been in high school. 

Medical records identified 2,830 cases of breast cancer during 20 years of follow-up.

This translated to an estimate that higher intake of red meat was associated with a 22% increased risk of breast cancer overall. Each additional serving per day of red meat was associated with a 13% increase in risk of breast cancer (12% in premenopausal and 8% in postmenopausal women).

In contrast, estimates showed a lower risk of breast cancer in postmenopausal women with higher consumption of poultry. Substituting one serving per day of poultry for one serving per day of red meat - in the statistical model - was associated with a 17% lower risk of breast cancer overall and a 24% lower risk of postmenopausal breast cancer.

Furthermore, substituting one serving per day of combined legumes, nuts, poultry, and fish for one serving per day of red meat was associated with a 14% lower risk of breast cancer overall and premenopausal breast cancer.

The authors conclude that higher red meat intake in early adulthood "may be a risk factor for breast cancer, and replacing red meat with a combination of legumes, poultry, nuts and fish may reduce the risk of breast cancer." 

Published on

Two studies that look at the role of diet, weight, and obesity in breast cancer. From Science News:

Fighting cancer with dietary changes 

Calorie restriction during treatment for breast cancer changes cellular programming in a way that lowers the chance of metastases in mice. Breast cancer patients are often treated with hormonal therapy to block tumor growth, and steroids to counteract the side effects of chemotherapy. However, both treatments can cause a patient to have altered metabolism which can lead to weight gain. In fact, women gain an average of 10 pounds in their first year of treatment. Recent studies have shown that too much weight makes standard treatments for breast cancer less effective, and those who gain weight during treatment have worse cancer outcomes.

From Medical Daily:

Breast Cancer Patients Suffering From Obesity Face Higher Death Risk Than Healthy-Weight Women

Obesity increases the risk of another cancer, which adds to the long list of life-threatening health hazards that accompany obesity. A new study reveals more evidence that obesity is a risk factor for cancer prognosis and its development, which will be presented at the annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago on May 30.

Researchers found that out of the 80,000 women in the study who had early stage breast cancer, obesity increased the risk of death by 34 percent for women who were pre-menopausal and were susceptible to higher levels of the hormone estrogen.

"No matter how we look at it, obesity is slated to replace tobacco as the leading modifiable risk for cancer," Dr. Clifford Hudis, ASCO president and chief of Memorial Sloan Kettering Cancer Center's Breast Cancer Medicine Service in New York, announced at a news conference.

Fat tissue produces an excess amount of estrogen, and those with increased levels have been associated with the risk of breast cancer. Obese women unquestionably have more fat tissue, which is why their estrogen levels are naturally higher. This leads to a more rapid growth of estrogen-responsive breast tumors. Obese patients also have increased level of insulin and insulin-like growth factor-1, which has been known to promote the development of tumor tissue.

They did find, as they had expected, there was no link between obesity and breast cancer death risk among women who were postmenopausal and either had an estrogen receptor positive or estrogen receptor negative breast cancer. This meant the tumors did not rely on estrogen to grow at a time in a woman’s life when her estrogen levels are fairly low.

Obesity has been linked to an increased risk of many other common cancers as well, which include colon, pancreas, esophagus, kidney, thyroid, gallbladder, and endometrium. Endometrial cancer is found within the lining of the uterus, and those who are obese increase risk by up to 40 percent.

Published on

Finally, a paper on some (but only some) of the chemicals linked to breast cancer and how to measure them in a woman's body. From Medical Xpress:

Study lists dangerous chemicals linked to breast cancer

Certain chemicals that are common in everyday life have been shown to cause breast cancer in lab rats and are likely to do the same in women, US researchers said Monday. The paper in the peer-reviewed journal Environmental Health Perspectives lists 17 chemicals to avoid and offers women advice on how to minimize their exposure. They include chemicals in gasoline, diesel and other vehicle exhaust, flame retardants, stain-resistant textiles, paint removers, and disinfection byproducts in drinking water.

Some of the biggest sources of mammary carcinogens in the environment are benzene and butadiene, which can come from vehicle exhaust, lawn equipment, tobacco smoke and charred food.

Other concerns are cleaning solvents like methylene chloride, pharmaceuticals used in hormone replacement therapy, some flame retardants, chemicals in stain-resistant textiles and nonstick coatings, and styrene which comes from tobacco smoke and is also used to make Styrofoam, the study said. Carcinogens can also be found in drinking water, researchers said.

"Unfortunately, the link between toxic chemicals and breast cancer has largely been ignored. Reducing chemical exposures could save many, many women's lives." Brody described the paper as the first to comprehensively list potential breast carcinogens and detail ways for experts to measure them in women's blood and urine.

The study also recommends seven ways for women to avoid these chemicals:

1) Limit exposure to exhaust from vehicles or generators, don't idle your car, and use electric lawn mowers, leaf blowers and weed whackers instead of gas-powered ones. 2) Use a ventilation fan while cooking and limit how much burned or charred food you eat. 3) Do not buy furniture with polyurethane foam, or ask for furniture that has not been treated with flame retardants. 4) Avoid stain-resistant rugs, furniture and fabrics. 5) If you use a dry-cleaner, find one who does not use PERC (perchloroethylene) or other solvents. Ask for "wet cleaning." 6) Use a solid carbon block drinking water filter. 7) Keep chemicals out of the house by taking off your shoes at the door, using a vacuum with a HEPA (high-efficiency particulate air) filter, and cleaning with wet rags and mops.

Published on

Interesting article about potential low-cost effective cancer treatments that Big Pharma is not researching because there is no profit in it for them. From Pacific Standard:

The War on Cancer: Big Pharma Is Keeping Us From Developing Low-Cost Treatments

Big Pharma’s focus on blockbuster cancer drugs squeezes out research into potential treatments that are more affordable. Says one researcher: “What is scientific and sexy is driven by what can be monetized.”

Numerous laboratory, animal, and small human studies suggest that low-dose, continuous chemotherapy holds promise in shrinking tumors and preventing cancer’s recurrence. But the next step—testing what Retsky did in a large-scale clinical trial—is a long shot given the way cancer treatments are developed today.

Take Michelle Holmes, an associate professor of medicine at Harvard Medical School. She’s been trying for years to raise money for trials on the effects of aspirin on breast cancer. Animal studies, in vitro experiments, and analysis of patient outcomes suggest that aspirin might help inhibit breast cancer from spreading. Yet even her peers on scientific advisory boards appear uninterested, she says. “For some reason a drug that could be patented would get a randomized trial, but aspirin, which has amazing properties, goes unexplored because it’s 99 cents at CVS,” says Holmes.

Increasingly, Big Pharma is betting on new blockbuster cancer drugs that cost billions to develop and can be sold for thousands of dollars a dose. In 2010, each of the top 10 cancer drugs topped more than $1 billion in sales, according to Campbell Alliance, a health-care consulting firm. A decade earlier, only two of them did. Left behind are low-cost alternatives—therapies like Retsky’s or existing off-label medications, including generics—that have shown some merit but don’t have enough profit potential for drug companies to invest in researching them.

The newer drugs have in some cases shown dramatic life-extending results for patients. Yet cancer remains the second-most-common cause of death in the U.S. after heart disease, killing about 580,000 people a year. Worldwide, 60 percent of all cancer deaths occur in developing countries, where experts say the incidence of the disease is growing rapidly, as is a desperate need for affordable care. That has added urgency to an active debate about whether efforts to combat cancer—and where to put scarce research dollars—need to be rethought.

Sukhatme and his wife Vidula, an epidemiologist, are among those trying to do something about it. They have spearheaded a new non-profit,  Global Cures, to promote alternative treatments that are unlikely to attract commercial interest from drug companies. Global Cures calls these forsaken therapies “financial orphans". To help patients and their doctors, the non-profit is producing reports that explain the science behind promising orphan therapies—those that have shown merit in animal studies and limited human data. And Global Cures also has set itself a more challenging goal—to find the money for clinical trials.

Creating an innovative new drug—including everything from early research to late stage trials—costs on average of $1.3 billion, according to the Tufts Center for the Study of Drug Development. Nonetheless, drug development in the United States, even when it is funded in part by taxpayer dollars and encouraged by federal bureaucracies, isn’t geared toward inexpensive alternative treatments.

The NIH, particularly through the National Cancer Institute, contributes to about 15 percent of all clinical trials related to cancer, but the amount it gives is in decline. The agency instead partners with pharmaceutical companies or academic institutions, and the trials the NCI does support usually are for new drugs, not for re-purposing existing ones. 

Low-cost alternatives like aspirin must fight for consideration within a scientific community that is producing effective cancer drugs that can command $100,000 or more for a course of treatment. The escalating prices for these drugs worry many involved in the fight against cancer. Some of the new drugs will eventually be used in combination, a step that could push cost of treatment into the hundreds of thousands, says Lichter.

Published on

This study suggests another reason to avoid Triclosan. From Science Daily:

In lab tests, the antimicrobial ingredient triclosan spurs growth of breast cancer cells

Some manufacturers are turning away from using triclosan as an antimicrobial ingredient in soaps, toothpastes and other products over health concerns. And now scientists are reporting new evidence that appears to support these worries. Their study, published in the ACS journal Chemical Research in Toxicology, found that triclosan, as well as another commercial substance called octylphenol, promoted the growth of human breast cancer cells in lab dishes and breast cancer tumors in mice.

Kyung-Chul Choi and colleagues note that hormonal imbalances seem to play a role in the development of breast cancer. Given that link, researchers are investigating whether endocrine-disrupting chemicals (EDCs), which are compounds that act like hormones, might spur cancer cell growth. EDCs have become ubiquitous in products, in the environment and even in our bodies. Research has found that two EDCs -- triclosan, an antimicrobial ingredient in many products, including soaps, cosmetics and cutting boards; and octylphenol, which is in some paints, pesticides and plastics -- have accumulated in the environment. Additionally, triclosan is reportedly in the urine of an estimated 75 percent of Americans. Choi's team wanted to see what effect the two compounds have on breast cancer cells.

In tests on human breast cancer cells and in special immunodeficient mice with tissue grafts, the scientists found that both agents interfered with genes involved with breast cancer cell growth, resulting in more cancer cells. Mice that were exposed to the two compounds had larger and denser breast cancer tumors than the control group. "Although the doses of EDCs were somewhat high, we did this to simulate their effects of daily exposure, as well as body accumulation due to long-term exposure, simultaneously in animal experiments," said Choi. "Thus, exposure to EDCs may significantly increase the risk of breast cancer development and adversely affect human health," the researchers state in the paper.