Early Detection Critical In Treating Pediatric Thyroid Cancer

Daily Science Journal (Feb. 6, 2008) — Efforts to treat pediatric papillary thyroid cancer are greatly improved by detecting the disease as early as possible, making the patient's age the most important factor in determining a prognosis, according to new research published in the February 2008 issue of the journal Otolaryngology -- Head and Neck Surgery.

The study, authored by Italian researchers, evaluated 2,709 patients who underwent a total thyroidectomy to treat papillary thyroid carcinoma (PTC). Among the group's pediatric patients (younger than 18 years old), the cancer was observed to be much more aggressive than that in adult patients. However, despite the aggressive course of the disease, this did not influence the patient's survival rate, since cases of pediatric cancer have a better prognosis than that in adults. As a result, the authors concluded that age of detection is the single most important factor to consider when issuing a prognosis.

Thyroid cancer is the third most common tumor malignancy in children. It is one of the few cancers that has increased in incidence rates over the past several years, with an estimated 11 percent increase from 2006 to 2007. Papillary thyroid cancer occurs in cells that produce thyroid hormones containing iodine. This type, the most common form of thyroid cancer in children, grows very slowly.

The study also confirms that PTC is more prevalent in younger patients, compared with other age groups; these patients also had significantly larger tumors. However, the study's authors concluded that the size of the tumor, which is considered a significant factor in determining prognosis in adult patients, does not play a significant role in a child's prognosis.

The study also suggests a longer period for follow-ups is in order to more accurately measure the success of treatment.

Adapted from materials provided by American Academy of Otolaryngology, Head and Neck Surgery, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

Nanotubes Help Advance Brain Tumor Research

Daily Science Journal (Jan. 30, 2008) — The potential of carbon nanotubes to diagnose and treat brain tumors is being explored through a partnership between NASA's Jet Propulsion Laboratory, Pasadena, Calif., and City of Hope, a leading cancer research and treatment center in Duarte, Calif.

Benham Badie, M.D., director of the Department of Neurosurgery and the Brain Tumor program at City of Hope, performs a minimally invasive procedure to surgically remove a pituitary tumor. Nanotube technology may help in the development of new treatments that would require only minimally invasive procedures no matter the location of the brain tumor. (Credit: City of Hope)

Nanotechnology may help revolutionize medicine in the future with its promise to play a role in selective cancer therapy. City of Hope researchers hope to boost the brain's own immune response against tumors by delivering cancer-fighting agents via nanotubes. A nanotube is about 50,000 times narrower than a human hair, but it length can extend up to several centimeters.

If nanotube technology can be effectively applied to brain tumors, it might also be used to treat stroke, trauma, neurodegenerative disorders and other disease processes in the brain, said Dr. Behnam Badie, City of Hope's director of neurosurgery and of its brain tumor program.

"I'm very optimistic of how this nanotechnology will work out," he said. "We are hoping to begin testing in humans in about five years, and we have ideas about where to go next."

The Nano and Micro Systems Group at JPL, which has been researching nanotubes since about 2000, creates these tiny, cylindrical multi-walled carbon tubes for City of Hope.

City of Hope researchers, who began their quest in 2006, found good results: The nanotubes, which they used on mice, were non-toxic in brain cells, did not change cell reproduction and were capable of carrying DNA and siRNA, two types of molecules that encode genetic information.

JPL's Nano and Micro Systems Group grows the nanotubes on silicon strips a few square millimeters in area. The growth process forms them into hollow tubes as if by rolling sheets of graphite-like carbon.

Carbon nanotubes are extremely strong, flexible, heat-resistant, and have very sharp tips. Consequently, JPL uses nanotubes as field-emission cathodes -- vehicles that help produce electrons -- for various space applications such as x-ray and mass spectroscopy instruments, vacuum microelectronics and high-frequency communications.

"Nanotubes are important for miniaturizing spectroscopic instruments for space applications, developing extreme environment electronics, as well as for remote sensing," said Harish Manohara, the technical group supervisor for JPL's Nano and Micro Systems Group.

Nanotubes are a fairly new innovation, so they are not yet routinely used in current NASA missions, he added. However, they may be used in gas-analysis or mineralogical instruments for future missions to Mars, Venus and the Jupiter system.

JPL's collaboration with City of Hope began last year, after Manohara, Badie and Dr. Babak Kateb, City of Hope's former director of research and development in the brain tumor program, discussed using nanostructures to better diagnose and treat brain cancer. Badie said his team's nanomedical research continues, and the next goal will be to functionalize and attach inhibitory RNA to the nanotubes and deliver it to specific areas of the brain.

The JPL and City of Hope teams published the results of the study earlier this year in the journal NeuroImage.

Badie says that JPL's contribution to City of Hope's nanomedicine research has been invaluable.

"The fact that we can get pristine and really clean nanotubes from Manohara's department is unique," he said. "The fact that we are both collaborating for biological purposes is also really unique."

The collaboration between JPL and City of Hope is conducted under NASA's Innovative Partnership Program, designed to bring benefits of the space program to the public.

Adapted from materials provided by NASA/Jet Propulsion Laboratory.

Read the rest of this entry »

Radio Waves Fire Up Nanotubes Embedded In Tumors, Destroying Liver Cancer

Daily Science Journal (Nov. 3, 2007) — Cancer cells treated with carbon nanotubes can be destroyed by non-invasive radio waves that heat up the nanotubes while sparing untreated tissue, a research team led by scientists at The University of Texas M. D. Anderson Cancer Center and Rice University has shown in preclinical experiments.

Researchers show that the technique completely destroyed liver cancer tumors in rabbits. There were no side effects noted. However, some healthy liver tissue within 2-5 millimeters of the tumors sustained heat damage due to nanotube leakage from the tumor.

"These are promising, even exciting, preclinical results in this liver cancer model," says senior author Steven Curley, M.D., professor in M. D. Anderson's Department of Surgical Oncology. "Our next step is to look at ways to more precisely target the nanotubes so they attach to, and are taken up by, cancer cells while avoiding normal tissue."

Targeting the nanotubes solely to cancer cells is the major challenge in advancing the therapy, Curley says. Research is under way to bind the nanotubes to antibodies, peptides or other agents that in turn target molecules expressed on cancer cells. To complicate matters, most such molecules also are expressed in normal tissue.

Curley estimates that a clinical trial is at least three to four years away.

Curley conducted the research at M. D. Anderson in collaboration with nanotechnology experts at Rice University and with Erie, Pennsylvania, entrepreneur John Kanzius of ThermMed LLC, who invented the experimental radiofrequency generator used in the experiments. Kanzius is a cancer survivor and former radio station owner whose insights into the potential of targeted radio waves inspired this line of research.

At Rice, the work was begun by Nobel laureate Richard Smalley, several months before his untimely death from cancer in October 2005. Smalley was the founder of Rice's Carbon Nanotechnology Laboratory and one of the world's foremost experts on carbon nanotubes. He shared the Nobel Prize for the 1985 discovery of fullerenes, the family of carbon molecules that includes nanotubes. His research in 2005 was concentrated largely on the radiofrequency cancer research project.

Rice materials scientist professor Boris Yakobson, Ph.D., a co-author on the paper, recalled meeting with Smalley in his hospital room at M. D. Anderson five days before his death.

"He looked very ill, breathing heavily through the oxygen mask, but all he wanted to do was talk about the physics of this very phenomenon," Yakobson said. "Oblivious of his ebbing health, Rick was focused in the future. He had told Congress in 1999 that nanotechnology would help revolutionize cancer treatment, and he was a scientist wanting to know whether this technology might be one of the things that would make that possible."

In the liver cancer experiment, a solution of single-walled carbon nanotubes was injected directly into the tumors. Four treated rabbits were then exposed to two minutes of radiofrequency treatment, resulting in thermal destruction of their tumors.

Carbon nanotubes are hollow cylinders of pure carbon that measure about a billionth of a meter, or one nanometer, across.

Control group tumors that were treated only by radiofrequency exposure or only by nanotubes were undamaged.

In lab experiments, two lines of liver cancer cells and one pancreatic cancer cell line were destroyed after being incubated with nanotubes and exposed to the radiofrequency field.

"I'm humbled by the results of this research," says Kanzius. "I realize it's early in the race, but Dr. Curley and his team have moved on this carefully with utmost speed. I look forward to continuing to work with them and hopefully to watching the first person be treated with this procedure. The race isn't over but it needs to be taken to the finish line."

Radiofrequency energy fields penetrate deeply into tissue, so it would be possible to deliver heat anywhere in the body if targeted nanotubes or other nanoparticles can be delivered to cancerous cells, Curley says. Without such a target, radio waves will pass harmlessly through the body.

An invasive technique known as radio frequency ablation is used to treat some malignant tumors, the authors note. It requires insertion of needle electrodes directly into the tumors. ncomplete tumor destruction occurs in 5 to 40 percent of cases, normal tissue is damaged and complications arise in 10 percent of patients who suffer such damage. Radiofrequency ablation is limited to liver, kidney, breast, lung and bone cancers.

This research appeared online ahead of December publication in the journal Cancer.

The research was supported by an American Association of Cancer Research Littlefield Grant, NASA and the Houston-based Alliance for NanoHealth, the National Science Foundation, the Center for Biological and Environmental Nanotechnology and the Fulbright Foundation.

Co-authors with Curley, Smalley, Kanzius and Yakobson are first authors Christopher J. Gannon, M.D., also of M. D. Anderson's Department of Surgical Oncology, and Paul Cherukuri, Ph.D. of Rice's Carbon Nanotechnology Laboratory and Department of Chemistry; Carter Kittrell, Ph.D., R. Bruce Weisman, Ph.D., Matteo Pasquali, Ph.D., and Howard K. Schmidt, Ph.D., all of Rice; and Laurent Cognet, Ph.D., of Rice and the Centre de Physique Moléculaire Optique et Hertzienne, Université Bordeaux, France.

Adapted from materials provided by University of Texas M. D. Anderson Cancer Center.

Read the rest of this entry »

Women With Breast Cancer Have Less Dermatitis When Treated With IMRT

Daily Science Journal (Oct. 30, 2007) — All women treated with radiation therapy for breast cancer are at risk of developing dermatitis--a sometimes-painful skin condition caused by radiation as it makes its way through the skin to the tumor area and tissue within the breast. But researchers at Fox Chase Cancer Center say women being treated with IMRT (intensity-modulated radiation therapy) are less likely to have serious dermatitis.

A reddening of the skin, dermatitis is often likened to a bad sunburn. It can begin in the first weeks of treatment as mild redness, dryness or itching of the skin and progress to a more intense skin reaction by the last week of radiation. When dermatitis is acute and severe, causing peeling, it is can be extremely painful, interfering with normal life activities and sometimes interrupting treatment.

"Dermatitis is a major quality-of-life concern," said Gary Freedman, M.D., a radiation oncologist at Fox Chase Cancer Center who studies the side effects of breast cancer treatment. "It can be so painful that wearing a bra or snug-fitting clothing isn't possible. In the most severe cases, the skin will actually bleed or be at risk of infection."

Freedman says IMRT can reduce the risk of dermatitis. IMRT allows the radiation to be distributed in more beams across the skin, avoiding the full-on assault of conventional radiation.

In this study, Freedman and his colleagues looked at the records of 804 consecutive patients with early-stage breast cancer. The women were treated with breast-conserving surgery and radiation therapy between 2001 and 2006.

In the earlier part of the study period, women were treated with conventional radiation therapy (n=405). Later in the study period, women were primarily treated with IMRT (n=399).

Of those treated with IMRT, 48 percent had grade 0/1 dermatitis and 52 percent had grade 2/3. Of those treated with conventional radiation, 25 percent had grade 0/1 dermatitis and 75 percent had grade 2/3.

"In addition to statistically fewer patients with serious dermatitis, women treated with IMRT who developed dermatitis had it for a shorter time period than those treated with conventional radiation," added Freedman. "These benefits were shown in all patients regardless of breast size."

He concluded, "This study confirms our current practice of recommending IMRT for all patients. The study seeks to provide further evidence for patients, physicians and insurance companies that IMRT should be standard practice."

The research was presented October 28, 2007 at the American Society for Therapeutic Radiology and Oncology's 49th Annual Meeting in Los Angeles.

Fox Chase Cancer Center was founded in 1904 in Philadelphia as the nation's first cancer hospital. In 1974, Fox Chase became one of the first institutions designated as a National Cancer Institute Comprehensive Cancer Center. Fox Chase conducts basic, clinical, population and translational research; programs of cancer prevention, detection and treatment; and community outreach. For more information about Fox Chase activities, visit the Center's web site at http://www.fccc.edu or call 1-888-FOX CHASE.

Adapted from materials provided by Fox Chase Cancer Center, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

Potential New Way Of Treating Inflammatory Diseases Identified

Daily Science Journal (Sep. 19, 2007) — Scientists have shown for the first time that platelets, the cells needed for blood clotting, help white blood cells called neutrophils fight inflammation.

The discovery was made by Ralph Kettritz, Professor of Medicine at the Medical Faculty of the Charite and investigator at the Max Delbrueck Center for Molecular Medicine, Berlin, Germany, and colleagues. The results of the study could lead to new anti-inflammatory compounds for the treatment of inflammatory vascular injury.

"We found an entirely new mechanism by which neutrophils induce inflammation," Kettritz says. "So far, scientists have shown that platelets form clots and neutrophils can cause symptoms of inflammation, such as swelling, redness, and heat. In this study, we show that platelets and neutrophils sometimes work together to heal a wound or fight an infection."

During inflammation -- a protective reaction from the tissues following a wound or infection -- white blood cells attack bacteria and platelets form clots that close any potential wound. White blood cells called neutrophils are the first to launch an attack against the bacteria. They are attracted by substances, such as granulocyte-macrophage colony-stimulating factor (GM-CSF), that are released at the early stages of inflammation. Once activated, neutrophils engulf and destroy bacteria and damaged tissue.

In addition to neutrophils, two other types of white blood cells, called macrophages and lymphocytes, also engage in the fight against bacteria. These cells are activated by a chemical compound called tumor necrosis factor (TNF) released by the neutrophils. Although there are several ways by which neutrophils release TNF, Kettritz and colleagues found that neutrophils can be stimulated to produce TNF in a totally new and different way.

"Usually, TNF is produced when specific chemicals bind to proteins called receptors on the surface of a neutrophil, which tells the cell that it should make TNF," Kettritz says. "This time, we found that a neutrophil can acquire receptors that are not already present on its surface and use them to stimulate the production of TNF."

The receptors, called GPIIb/IIIa, are sent to neutrophils by platelets. Like a letter sent in an envelope, these receptors are packaged in vesicles called microparticles that, when they reach a neutrophil, bind to its surface and release the receptors. Once released, the receptors are incorporated into the neutrophil's cell membrane.

Kettritz and his team also found that these newly-acquired receptors did not work alone. To stimulate neutrophils to produce TNF, the GPIIb/IIIa receptor works in tandem with the receptor for GM-CSF (the substance produced during the early stages of inflammation). The scientists found that the neutrophil produces TNF both when GPIIb/IIIa binds to a protein outside the cell called fibronectin and when the GM-CSF receptor binds to GM-CSF.

"We have shown for the first time that platelets can, by using microparticles, help other cells -- in this case, neutrophils -- respond to inflammation," Kettritz says. "We also found for the first time that receptors involved in blood clotting also trigger an inflammatory response."

These results may help devise new drugs against several types of inflammation by targeting the GPIIb/IIIa receptors acquired by neutrophils. In particular, drugs currently used to prevent blood clotting by inhibiting GPIIb/IIIa receptors on platelets may be used against inflammation.

Kettritz and colleagues tested three of these drugs -- abciximab, epifibatide, and tirofiban -- on cell cultures in which neutrophils had received the GPIIb/IIIa receptors from platelets and confirmed the drugs' effects on inflammation. The scientists showed that all three drugs inhibited the production of TNF, which reduced inflammation in these cells. These results also led the researchers to speculate that some of the beneficial effects of the three drugs on patients with acute coronary syndrome result from their anti-inflammatory properties.

If the drugs' effects are confirmed in clinical trials, they could be used against several types of inflammation that include acute vasculitis, an inflammation of blood vessels that can affect any organ in the body. Also, the drugs have been used successfully to treat acute coronary syndrome, which refers to certain types of heart attack and unstable angina. The new results show that these beneficial effects may be due not only to their anti-clotting properties, but also to their anti-inflammatory qualities.

"The results of this study are very encouraging," Kettritz says. "Although specific drugs that target GPIIb/IIIa receptor actions on neutrophils may need to be developed in the future, these three drugs can now be tested in clinical trials, which could make them -- or modified versions of them -- new anti-inflammatory drugs."

The new study, to be published in the September 21 issue of the Journal of Biological Chemistry, was selected as a "Paper of the Week" by the journal's editors, meaning that it belongs to the top one percent of papers reviewed in significance and overall importance.

Article: "Beta 2-integrins and acquired GPIIb/IIIa receptors cooperate in NF-KB activation of human neutrophils," by Birgit Salanova, Mira Choi, Susanne Rolle, Maren Wellner, Friedrich C. Luft, and Ralph Kettritz

Adapted from materials provided by American Society for Biochemistry and Molecular Biology, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

New Chemical Effective Against Anthrax

Daily Science Journal (Jul. 23, 2007) — Scientists have identified a chemical that could be used as a new drug against anthrax.

Anthrax is a deadly disease caused by spores that germinate into bacteria, which then release a deadly toxin. Spores that are inhaled by animals or people germinate in the lungs to form bacteria, which then spread throughout the body, releasing the toxin and triggering the disease. Since spore germination is needed to cause infection, preventing germination is a potentially efficient way to stop the infection.

Jurgen Brojatsch, Ernesto Abel-Santos, and colleagues identified seven chemicals that block the germination of cultured anthrax spores. They also showed that one of these compounds, 6-thioguanosine, blocked the spores' germination inside mammalian cells, thus blocking anthrax infection. The scientists are now planning to test 6-thioguanosine in mice infected with the anthrax bacterium. This compound is a known anticancer agent with well-studied pharmacological properties, which could help save time and money if it is used in clinical trials.

Article: "Identification of an in Vivo Inhibitor of Bacillus anthracis Spore Germination" by Monique Akoachere, Raynal C. Squires, Adel M. Nour, Ludmyl Angelov, Jurgen Brojatsch, and Ernesto Abel-Santos

Adapted from materials provided by American Society for Biochemistry and Molecular Biology, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

Vitamin D And Flavonoids Examined For Impact On Breast And Ovarian Cancers

Daily Science Journal (Jul. 7, 2007) — While risk factors for breast and ovarian cancers include menopause, obesity, family history and specific genetic mutations, researchers also are looking at the role of diet in the development, as well as the treatment and prevention of these tumors. At the 97th Annual Meeting of the American Association for Cancer Research, two groups of scientists using sophisticated statistical techniques report their findings of possible preventive properties of Vitamin D against breast cancer. Two other groups of scientists present their work analyzing the possibility that natural antioxidants found in plants, substances called flavonoids, could play a powerful role in preventing both breast and ovarian cancer.

Potential Reduction in Breast Cancer Risk Associated with Vitamin D: Abstract No. 4009

Though scientists have suspected that Vitamin D helps to prevent and possibly even treat breast cancer, population-based studies on the possible link have been few and of limited scope.

Now, new studies by researchers at the Samuel Lunenfeld Research Institute at Mount Sinai Hospital in Toronto suggest the "sunshine" vitamin may play a significant role in reducing breast cancer risk. The results, based on population data, found the reduction was most apparent among subjects exposed to the highest levels of vitamin D when they were young.

By interviewing about 576 patients who had been diagnosed with breast cancer and 1,135 people who had no cancer, the scientists discovered that significant reductions in breast cancer were found in those who had either worked in an outdoor job, had taken part in outdoor activities when young, or consumed cod liver oil or milk.

Working an outdoor job between ages 10 to19 resulted in an estimated 40 percent reduced risk of breast cancer, while frequent outdoor activities between ages 10 to 29 lowered breast cancer risk by an estimated 35 percent.

"These outdoor activities included those that didn't involve physical activity," said Julie Knight, who headed the Mount Sinai research team. "And so we believe that this is evidence of a reduction of breast cancer risk, associated with earlier exposure to the sun."

For dietary influences on cancer development, taking cod liver oil between ages 10 to 19 reduced breast cancer risk by about 25 percent, and consuming at least nine glasses of milk every week between the ages of 10 to 29 reduced the risk by 35 percent. The dietary and lifestyle reductions were significant, even when adjusted for other risk factors for breast cancer such as age, ethnicity, close relatives with breast cancer, age at menarche and age at a woman's first birth.

"What you are exposed to during breast development may be particularly important in determining future breast cancer risk," Knight said. "Current thinking is that exposures during adolescence or before a full-term pregnancy may have a greater effect, as that is when breast tissue is going through the most rapid development."

Knight emphasizes that these findings are preliminary estimates of the risk reduction of breast cancer brought about by Vitamin D. The researchers are now looking to solidify these findings, and determine whether physical exercise while outdoors is in any way associated with breast cancer.

Evidence of Need for Increased Vitamin D Fortification of Food Based on Pooled Analysis of Studies of Serum 25-hydroxyvitamin D and Breast cancer: Abstract No. 4008

Increasing doses of dietary Vitamin D may help prevent breast cancer, with the optimal level of intake of Vitamin D more that three times the current average for Americans, according to a study conducted at the University of California, San Diego.

Previous studies have suggested a link between Vitamin D deficiency and higher incidence of breast cancer. Cedric Garland, Dr. P.H., and Edward Gorham, Ph.D., of UCSD, and their colleagues examined existing cancer studies to determine if higher Vitamin D levels in the blood could reduce the risk of cancer.

"There is a strong inverse dose-response relationship between the serum concentration of 25-hydroxyvitamin D and the risk of breast cancer," Garland said. "It's a close fit to a linear model," meaning that higher amounts of 25-hydroxyvitamin D in the serum resulted in decreased risk of breast cancer. The evidence further pointed to a level of Vitamin D measured in blood that correlated with a 50 percent reduction in the incidence of breast cancer.

Garland, Gorham and their colleagues studied a serum Vitamin D metabolite known as 25 hydroxyvitamin D and its association with breast cancer occurrence in a pooled study that included 1,760 women. The studies that provided the data for the pooled analysis were conducted by Elizabeth R. Bertone-Johnson and colleagues at Harvard, and L.C. Lowe and associates at Saint George's Hospital Medical School in London.

According to the pooled analysis, Vitamin D in blood serum equal to 52 nanograms per milliliter was associated with a 50 percent reduced risk of breast cancer. To move closer to a serum concentration of 52 nanograms/milliliter, a typical individual would have to consume no less than 1,000 International Units (IU) of Vitamin D every day, through supplements or vitamin D-fortified foods. Currently, a typical American consumes only 320 International Units of Vitamin D a day. The upper limit for vitamin D intake established by the National Academy of Sciences is 2,400 IU/day, but no toxic effects of vitamin D intake have been reported for intakes below 3,800 IU per day.

"There is no substantial downside to a serum level of 52 nanograms per milliliter of Vitamin D," said Gorham. "Such levels are common in sunny climates. There is no known adverse effect of serum levels below 160 nanograms per milliliter."

However, since many people use sunscreens and are involved in indoor occupations or shift work, dietary supplements and vitamin D fortified foods are necessary to maintain optimal levels of Vitamin D, the scientists noted.

High intakes of calcium, which could occur with intake of Vitamin D supplements containing calcium, could increase the risk of kidney stones, they warn. However, the dosage level of vitamin D associated with kidney stones in patients far exceeded 3,800 IU/day. Until more studies are completed, the scientists recommended that everyone consume at least 1,000 IU/day of vitamin D3.

Dietary Flavonoid Intake and Breast Cancer Risk among Women in the Long Island Breast Cancer Study Project: Abstract No. 4014

Flavonoids, a class of antioxidants found in plants, is associated with a reduced risk of breast cancer among post-menopausal women, according to results of the Long Island breast cancer study project. The results are one of the first epidemiologic studies to suggest that these compounds could have a chemoprotective effect among women.

Brian Fink, Susan Steck and Marilie Gammon of the University of North Carolina, Chapel Hill, and other colleagues studied data from a large study of breast cancer incidence and risk factors conducted among women living during the mid-1990s on Long Island, N.Y.

Breast cancer risk was reduced for the highest percentages of total flavonoid intake, compared to the lowest intake of the plant antioxidants. The decreased risk was about 45 percent among post-menopausal women. Risk decreases were not seen in pre-menopausal women. Specific flavonoids -- including flavones, flavan-3-ols and lignans -- were associated with reduced cancer risks ranging from 26 to 39 percent; other flavonoids, such as flavanones, isoflavones and anthocyanidins, showed no relationship with reduced cancer risk.

"These results are consistent with other studies conducted among Mediterranean women," said Fink. "Few epidemiologic studies have examined whether there is a relationship between breast cancer and dietary flavonoids. Our study proposes that dietary flavonoids can help American post-menopausal women reduce their risk of breast cancer."

The researchers examined data from the Long Island study, which was conducted by Dr. Gammon and colleagues between August 1996 and July 1997. The team compared data from 1,434 women with breast cancer to data from 1,440 women who were not diagnosed with the disease.

Flavonols, flavones, lignans and anthocyanidins are all flavonoids, molecules that give plants protection from oxidative damage due to disease and environmental stresses. Flavonoids are classified according to chemical structure, and have been studied for their varying degrees of effectiveness against human diseases, both in treatment and prevention. They are found in green tea, red wine, soybeans, fruit and vegetables.

"There are no recommended dietary standards for ingestion of flavonoids, and we do not know exactly how these chemicals may work on a cellular level," said Fink, whose work was supported with funding from the National Institutes of Health and the Lance Armstrong Foundation. "Minute differences in chemical structure could determine how a certain natural antioxidant may work to prevent disease, including cancer. More study is needed to determine why certain flavonoids appear to be effective at reducing cancer risk, and others do not appear to have these properties."

A Prospective Analysis of Dietary Flavonoid Intake and Epithelial Ovarian Cancer Incidence: Abstract No. 4013

The incidence of ovarian cancer may be reduced with increased consumption of dietary flavonoids, plant chemicals that are found in tea, red wine, fruits and vegetables, according to researchers from Brigham and Women's Hospital and the Harvard School of Public Health.

The study, conducted by Margaret Gates, a doctoral candidate at the Harvard School of Public Health, looked at food intake surveys and ovarian cancer data from 66,384 participants in the Harvard Nurses' Health Study, which collected health data from 121,700 women over a period of 30 years. "This is the first prospective analysis of flavonoid intake and ovarian cancer incidence," Gates said.

Gates studied the association between flavonoid intake from food frequency questionnaires completed by the women in 1984, 1990, 1994 and 1998; and 344 confirmed cases of ovarian cancer diagnosed between 1984 and 2002. While there was a significant trend toward decreasing incidence of ovarian cancer with increasing total flavonoid intake, Gates warned that "because this is one of the first studies of the topic, this association needs to be evaluated in another prospective study population before conclusions can be made."

Gates also analyzed individual flavonoids to evaluate their impact on ovarian cancer incidence. The flavonoid kaempferol, which the nurses consumed primarily from caffeinated tea, broccoli and kale, was associated with decreased ovarian cancer risk. Women with the highest levels of kaempferol intake had a significant 38 percent decrease in ovarian cancer incidence, compared to women with the lowest levels of intake. Two other flavonoids, myricetin and quercetin, showed a possible inverse association with ovarian cancer risk, although the results were largely non-significant.

"The associations were stronger when exposure was defined as cumulative average flavonoid intake over a period of 14 years, which suggests that long-term intake of flavonoids may be important," Gates said.

But she cautioned that "these findings need to be confirmed by others before any public health recommendations can be made. However, if confirmed, consumption of flavonoids would provide another means for women to decrease their risk of ovarian cancer."

Adapted from materials provided by American Association for Cancer Research.

Read the rest of this entry »