"Chemo Brain" - Brain Scan Study Finds Evidence

Women who survive breast cancer after undergoing chemotherapy may also have to contend with impairments in attention, memory and planning skills, U.S. researchers said Monday.

They said women who had undergone chemotherapy for breast cancer had significantly less activity in parts of the brain responsible for executive functioning tasks compared with breast cancer patients who were not treated with chemotherapy.

Among those treated with chemotherapy, the study also found a strong correlation between women who complained they were having trouble with memory and thinking skills and actual deficits in these regions of the brain.

The study may help explain why many breast cancer patients complain of "chemo brain" -- a term used to describe foggy thinking and memory lapses following treatment with chemotherapy.

"This is a huge validation for these women who are telling their doctors 'something is wrong with me'," said Shelli Kesler of Stanford University School of Medicine in California, whose study appears in the Archives of Neurology.

Kesler said the conventional thinking is that chemotherapy drugs cannot cross a protective membrane called the blood-brain barrier that protects the brain from toxins.

And doctors have dismissed women's complaints of brain deficits after chemotherapy, chalking them up to exaggeration and stress related to the cancer.

"This shows that when a patient reports she's struggling with these types of problems, there's a good chance there has been a brain change," Kesler said.

Her study involved 25 breast cancer patients who had been treated with chemotherapy, 19 breast cancer patients who had surgery and other treatments, and 18 healthy women.

All were asked to perform a card-sorting task that involves problem-solving skills while their brain activity was monitored through functional magnetic resonance imaging or fMRI.

The women also completed questionnaires to assess their own cognitive abilities.

As in prior studies of cancer patients, the team saw significant reductions in activity in two parts of the prefrontal cortex, including one used for working memory, cognitive control and monitoring.

But they also found significantly reduced activation of an additional region of the prefrontal cortex linked with executive function -- the area of the brain needed for planning.

Women in the chemotherapy group were also found to make more errors on the card-sorting task and take longer to complete it than healthy women and cancer patients who were not treated with chemotherapy.

While a finding in 25 women seems small, Kesler said it is large for a brain scan study and points to a need to start identifying which women who undergo chemotherapy are most vulnerable to these types of deficits.

She said future studies should be done in which women are tested before they undergo chemotherapy to determine the impact of treatment on brain function.

Women are increasingly surviving their breast cancer, with breast cancer survivors comprising 22 percent of the nearly 12 million cancer survivors in the United States, according to the Centers for Disease Control and Prevention.

Hot dog! Ready-to-eat meat contains few cancerous compounds

If given the choice between eating a hot dog or enjoying some rotisserie chicken, consider the hot dog.

That’s because hot dogs, as well as pepperoni and deli meats, are relatively free of carcinogenic compounds, according to Kansas State University research. But it’s a not-so-happy ending for bacon and rotisserie chicken — especially chicken skin — because both have higher levels of cancerous material.

J. Scott Smith, professor of food chemistry, and a K-State research team have been looking at such ready-to-eat meat products to determine their levels of heterocyclic amines, or HCAs.

These are carcinogenic compounds found in meat that is fried, grilled or cooked at high temperatures. Studies have shown that humans who consume large amounts of HCAs in meat products have increased risk of stomach, colon and breast cancers.

Ready-to-eat meat products are meat or poultry products that come in edible forms and don’t need additional preparation or cooking. Smith has already researched HCA levels in cooked meat and found that adding certain spices and marinades before cooking can reduce HCA content in the meat.

The ready-to-eat product project was a collaboration with several other K-State researchers, including Terry Houser, assistant professor of meat science; Melvin Hunt, professor of animal sciences and industry; Kanithaporn Puangsombat, December 2010 doctoral graduate in food science, Bangkok, Thailand; and Priyadarshini Gadgil, a K-State graduate who now works as a research scientist at the U.S. Department of Agriculture Center for Grain and Animal Health Research in Manhattan. Their research appears in a recent issue of Meat Science, the journal of the American Meat Science Association.

The study focuses on eight types of ready-to-eat meat products: beef hot dogs, beef-pork-turkey hot dogs, deli roast beef, deli ham, deli turkey, fully cooked bacon, pepperoni and rotisserie chicken.

“These are the most common types of ready-to-eat products, and their use has increased in recent years because of convenience,” Smith said. “For this research, we took each of these products and prepared them as a consumer would.”

The researchers heated up the hot dogs and bacon in a microwave, cooked the pepperoni on a pizza either in the oven or a microwave and used the chicken and deli meat as obtained. After doing so, they studied the meat to determine whether it contained five different types of HCAs according to nanograms per gram, ng/g.

Pepperoni had the least HCA content, 0.05 ng/g, followed by hot dogs and deli meat, 0.5 ng/g). Such amounts are low, and the researchers concluded that consuming such ready-to-eat meat products contributes very little to HCA intake.

Fully cooked bacon, with 1.1 ng/g, and rotisserie chicken meat, with 1.9 ng/g, contained all five types of HCAs tested. Rotisserie chicken skin had significantly higher HCA levels, with 16.3 ng/g. This is because chicken skin contains more fat and protein and less moisture, and HCA levels tend to increase as moisture decreases, Smith said.

“Based on this research, HCA consumption can be reduced by not eating chicken skin,” he said.

The reasons for lower HCA content in some of the other ready-to-eat products may be because of the higher water content in the ready-to-eat products. More moisture prevents many HCAs from forming. Ready-to-eat products are often enhanced products, meaning they have a water solution with flavoring added to them.

“Hot dogs and deli meat may have low HCA levels because they are manufactured at low temperatures,” Smith said. “The low HCA levels may also be from ingredients that are added to the meat and prevent HCAs from forming while the meat is cooking.”

Cancer: A Shot in the Arm or a shot in the Dark?

In 1999, two researchers at the National Cancer Institute (NCI) received a long-awaited green light to launch separate studies on cancer care.

Six months apart, Dr. Douglas Schwartzentruber and Dr. Larry Kwak (what an unfortunate name for a doctor! Change it now, to Dr Cure-all) began enrolling patients/subjects to test an entirely novel weapon in the war on cancer, one which they hoped would bypass the toxic effects of chemotherapy and give patients a new edge in halting the spread of tumours.

Both had the blessings of Dr. Richard Klausner, then NCI director. But even Klausner, a well-respected researcher, had to be persuaded at first. "I came to the NCI being quite skeptical about it," he says of the new strategy.

Unfortunately, he wasn't the only one. What Schwartzentruber and Kwak were hoping to do was prove they could vaccinate a patient against cancer — educate a body to, in essence, recognise and round up tumour cells the same way it polices viruses and bacteria.

It certainly made good biological sense: the immune system is the body's built-in defense mechanism, after all, so why not turn it against one of the most persistent diseases?

One of the problems, is that a tumour is not exactly a pathogen. What it is, at its core, is a collection of aggressively growing cells that can't stop dividing. It is not entirely foreign, in the same way that a virus is; it does not infect healthy cells, as bacteria and viruses do.

Turning the immune system against cancer cells would involve turning the body's defense mechanisms against a part of itself. Designing a vaccine to do this entails creating the biological version of a stealth weapon encased in a smart bomb equipped with a guided missile.

All this was proving to be a bit too challenging. Hundreds of researchers in hundreds of trials had attempted to solve this and nothing had worked. While the vaccine idea made logical sense, the immune system, it seemed, just wasn't designed to battle cancer this way.

Eventually, in June this year, after nearly a decade of carefully inoculating patients suffering from either advanced melanoma or a type of lymphoma, both Schwartzentruber and Kwak announced positive outcomes of their trials, at the American Society of Clinical Oncology meeting in Orlando, Fla.

Their results, along with those of a trial vaccine against prostate cancer and an early candidate against a type of brain cancer, suggest that we might finally be on the way to unleashing the immune system against the disease.