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Daily sitting for hours on end is no damn good. From Medical Daily:

Too Much Sitting And Watching TV Increases Your Risk Of Certain Cancers: Why Sitting Is The New Smoking

Or the nice scientific write-up of the same study. Bottom line: to lower the risk of cancer, sit less and move more. From Science Daily:

Sedentary behavior increases risk of certain cancers

Physical inactivity has been linked with diabetes, obesity, and cardiovascular disease, but it can also increase the risk of certain cancers, according to a study published June 16 in the JNCI: Journal of the National Cancer Institute.

To assess the relationship between TV viewing time, recreational sitting time, occupational sitting time, and total sitting time with the risk of various cancers, Daniela Schmid, Ph.D., M.Sc., and Michael F. Leitzmann, M.D., Dr.P.H., of the Department of Epidemiology and Preventive Medicine, University of Regensburg, Germany, conducted a meta-analysis of 43 observational studies, including over 4 million individuals and 68,936 cancer cases

When the highest levels of sedentary behavior were compared to the lowest, the researchers found a statistically significantly higher risk for three types of cancer -- colon, endometrial, and lung. Moreover, the risk increased with each 2-hour increase in sitting time, 8% for colon cancer, 10% for endometrial cancer, and 6% for lung cancer, although the last was borderline statistically significant. The effect also seemed to be independent of physical activity, suggesting that large amounts of time spent sitting can still be detrimental to those who are otherwise physically active. TV viewing time showed the strongest relationship with colon and endometrial cancer, possibly, the authors write, because TV watching is often associated with drinking sweetened beverages, and eating junk foods.

The researchers write "That sedentariness has a detrimental impact on cancer even among physically active persons implies that limiting the time spent sedentary may play an important role in preventing cancer…."

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.

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." 

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.

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 MondayThe 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 retardants4) Avoid stain-resistant rugs, furniture and fabrics5) 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.

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.

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.

An excellent reason to listen to your mother and eat your vegetables. From the U.S. Department of Health and Human Services site healthfinder.gov:

Vegetables in Childhood May Benefit Breast Health

Girls who ate the most fruits and vegetables rich in carotenoids were less likely to get benign breast disease, a new study suggests.

Carotenoids are a group of pigments that typically produce an orange, red or dark green color. They are believed to have antioxidant properties that may guard against disease. Benign breast disease describes a variety of noncancerous conditions of the breast; some forms raise the risk of breast cancer. 

For her study, Boeke and her colleagues looked at food reports from 1996 through 1998 and then evaluated reports in 2005, 2007 and 2010 from girls who got a diagnosis of benign breast disease from a doctor after having a biopsy. In all, Boeke studied nearly 6,600 girls, and 122 reported a diagnosis of benign breast disease.

When she looked at carotenoid intake, she found high intakes were protective. "The odds of benign breast disease in those who consumed the most beta carotene were about half that of those who consumed the least," she said. Girls in the highest intake group ate two to three servings of carotenoid-rich foods weekly, she said.

She did take into account other factors that might affect the risk of benign breast disease, such as alcohol intake, physical activity, family history and body mass index (a measure of body fat using height and weight).

Why might the fruits and vegetables help? It's not known for sure, but Boeke said it may be due partly to their antioxidant properties. Carotenoids absorb harmful substances known as free radicals which can harm cells.

The study looked only at food intake, not supplements, and Boeke said she would not recommend supplements since other research has found some harmful effects with supplement use. Other foods that are rich in carotenoids include yams, melons, spinach and kale.

The period of time between the start of a girl's period and the first birth is a sensitive one for the breasts, as they are very vulnerable to environmental exposures, according to background information in the study.

Again, more support for eating a mainly plant based diet and lowering intake of saturated fat. From MedlinePlus:

High-Fat Diet May Boost Breast Cancer Risk

For more than three decades, experts have debated whether eating a high-fat diet increases breast cancer risk. Now, new research suggests it might boost the chances of three common types of breast cancer.

In a large European study evaluating more than 337,000 women in 10 countries over 11 years, researchers found that women who ate the most saturated fat were about 30 percent more likely to develop breast cancer than those who ate the least. The study is published April 9 in the Journal of the National Cancer Institute.

Sieri and her team found that a high intake of total fat and saturated fat was linked to an increased risk of breast cancer subtypes known as estrogen receptor-positive (ER-positive) and progesterone receptor-positive (PR-positive). High-fat diets also were tied to a raised risk of developing HER2-negative breast cancer, the investigators noted.

The breast cancer subtypes linked with fat intake are common, she said. "The majority of breast cancers in the U.S. and Europe are ER-positive, PR-positive, HER2-negative," she noted.

In the new study, women answered questions about their fat intake and other habits that could affect risk, including smoking, age at first period, pregnancy history, use of hormone therapy and their body mass index (a measurement of body fat based on height and weight). To correct for measurement errors in the diet questionnaire, the researchers interviewed a random sample of 8 percent of the women, asking for a 24-hour dietary recall.

After an average follow up of 11.5 years, just over 10,000 women were diagnosed with breast cancer.When the cases of cancer were compared with fat intake, "we found an association between exposure to saturated-fat intake and breast cancer," Sieri said.

Women in the group eating the most saturated fat averaged 48 grams a day, compared to 15 grams in the group eating the least. The link can't be explained with certainty, Sieri said, but it's possible that the high-fat intake raises the levels of the body's own estrogen, which can stimulate the growth of breast cancer cells.

Until more study is done, Sieri tells women: "In general, it is recommended that the percent of total calories from saturated fat should not exceed 10 percent for women." Gaudet agreed. "If you have a mainly plant-based diet, that is going to help you keep your fat intake low."

Paternal age of 25 to 29 at conception resulted in the lowest risk of adult-onset hormone related cancers in their daughters. From Science Daily:

Father's age at birth may affect daughter's cancer risk

Paternal age and the health effects it has on potential offspring have been the focus of many studies, but few have examined the effect parental age has on the risk of adult-onset hormone-related cancers (breast cancer, ovarian cancer and endometrial cancer).

A team of City of Hope researchers, lead by Yani Lu, Ph.D., explored this relationship and found that a parent’s age at birth, particularly a father’s age, may affect the adult-onset cancer risk for daughters — especially for breast cancer.

“Our findings indicate that parental age, especially paternal age, at conception appears to be associated with a wide range of effects on the health and development of the offspring,” Lu said.

To help determine the effects of parental age on the risk of adult-onset hormone-related cancers, Lu and her colleagues examined a cohort of 133,479 female teachers and administrators from the California Teachers Study. Between 1995 and 2010, 5,359 women were diagnosed with breast cancer, 515 women were diagnosed with ovarian cancer and 1,110 women were diagnosed with endometrial cancer.

While the team of researchers did not find an association for maternal age at birth for any type of cancer, they found that paternal age is linked to an increased adult-onset cancer risk for daughters – and the link was not only to advanced paternal age.

Women born to a father under the age of 20 had a 35 percent greater risk of breast cancer and more than two times greater risk of ovarian cancer, when compared to those born to a father whose age at his daughter’s birth was 25 to 29 years old.

Women born to a father whose age at childbirth was 30 to 34 years had a 25 percent greater risk of endometrial cancer than those born to a father age 25 to 29.

Lu and her team were not surprised to find a relationship between older fathers and an increased risk of hormone-related cancers, especially since there has been increasing evidence suggesting that daughters born to older fathers have increased risk of breast cancer, noted Lu.

“We observed that young paternal age, as well as advanced paternal age, increase the risk of breast cancer,” said Lu. “We also found that young paternal age increases the risk of ovarian cancer.”