I thought I’d cover some medical topics today since that folder is beginning to bulge. There’s new statistics out that predict that soon cancer will become the number one killer so we’ll start with two articles that could be very important to you.
Researchers have recently discovered that a commonly used chemotherapy drug causes healthy brain cells to die off long after treatment has ended and may be one of the underlying causes of "chemobrain" a condition that many cancer patients experience. Chemobrain can cause patients to lose cognitive skills.
Researchers from the University of Rochester Medical Center (URMC) and Harvard Medical School have linked the widely used chemotherapy drug 5-fluorouracil (5-FU) to a progressing collapse of populations of stem cells and their progeny in the central nervous system. The drug apparently causes global disruption of the myelin-forming cells that are essential for normal neuronal function. The researchers say they are now beginning to understand and define the molecular mechanisms behind the cognitive difficulties that linger and worsen in a significant number of cancer patients.
Cancer patients have long complained of chemotherapy side effects like short-term memory loss and, in extreme cases, seizures, vision loss, and even dementia. Until very recently, these side effects were often dismissed as the byproduct of fatigue, depression, and anxiety related to cancer diagnosis and treatment. Now a growing body of evidence has documented the scope of these conditions, collectively referred to as chemobrain.
Virtually all cancer survivors experience short-term memory loss and difficulty concentrating during and shortly after treatment. A study two years ago by researchers with the James P. Wilmot Cancer Center at the University of Rochester showed that upwards of 82% of breast cancer patients reported that they suffer from some form of cognitive impairment.
While these effects tend to wear off over time, some patients, particularly those who have high doses of chemotherapy drugs, continue to experience the cognitive side effects long after treatment has stopped and the drugs are no longer in their systems. For example, a recent study estimates that somewhere between 15 and 20 percent of the nation’s 2.4 million female breast cancer survivors have lingering cognitive problems years after treatment. Another study showed that 50 percent of women had not recovered their previous level of cognitive function one year after treatment.
Two years ago, researchers showed that three common chemotherapy drugs used to treat a wide range of cancers were more toxic to healthy brain cells than the cancer cells they were intended to treat. While these experiments were among the first to establish a biological basis for the acute onset of chemo brain, they did not explain the lingering impact that many patients experience.
In the current research, scientists exposed both individual cell populations and mice to doses of 5-fluorouracil (5-FU) in amounts comparable to those used in cancer patients. 5-FU belongs to a class of drugs called antimetabolites that block cell division. Antimetabolites have been used in cancer treatment for more than 40 years. These drugs are often administered in a "cocktail" with other chemotherapy drugs, and they are currently used to treat breast, ovarian, stomach, colon, pancreatic and other forms of cancer.
The researchers discovered that months after exposure, specific kinds of nerve cells called oligodendrocytes were so damaged that after 6 months the cells had all but disappeared in the mice.
Oligodendrocytes play an important role in the central nervous system and are responsible for producing myelin, the fatty substance that, like insulation on electrical wires, coats nerve cells and enables signals between cells to be transmitted rapidly and efficiently. The myelin membranes are constantly being turned over, and without a healthy population of oligodendrocytes, the membranes can’t be renewed and eventually break down, resulting in a disruption of normal impulse transmission between nerve cells.
The scientists point out that not all cancer patients experience these cognitive difficulties, and determining why some patients are more vulnerable may be an important step in developing new ways to prevent these side effects. We may be working to prevent the side effects, but is there help for those who suffer from the ravages of chemotherapy now?
Cancer patients have complained for years about the mental fog known as chemobrain. Now in animal studies at West Virginia University (WVU), researchers have discovered that injections of N-acetyl cysteine (NAC), an antioxidant, can prevent the memory loss that breast cancer chemotherapy drugs sometimes induce. NAC is a modified form of the dietary amino acid cysteine.
In the WVU researchers’ study, rats were given the commonly used chemotherapy drugs adriamycin and cyclophosphamide. When on the drugs, rats that were trained to prefer a light room to a dark room forgot their training.
“When animals are treated with chemotherapy drugs, they lose memory,” said Gregory Konat, Ph.D., professor of neurobiology and anatomy at WVU. “When we add NAC during treatment, they don’t lose memory.”
Jame Abraham, M.D., director of the Comprehensive Breast Cancer Program at WVU’s Mary Babb Randolph Cancer Center, said as “chemobrain” entered the national lexicon, many patients expressed frustration about doctors not taking the complaints seriously.
“In the past, there was a lot of ignorance among doctors about chemo-induced cognitive problems,” Dr. Abraham said. “In some patients, problems can persist for up to two years.”
The WVU authors say as many as 40 percent of cancer patients undergoing chemotherapy complain of symptoms such as severe memory loss and attention deficits. Previously, scientists suspected the cancer, rather than chemo drugs, might be the cause.
Earlier this year, Dr. Abraham’s team of researchers used MRI scans to document the extent of changes to the brain in women who received chemotherapy for breast cancer. Now the connection between drugs and memory loss is clear, and a potential remedy is suggested as well.
“At this point, we have no evidence to say that NAC is safe in patients who are getting chemotherapy,” Abraham said. “We need more studies to confirm the role of NAC in patients.”
Of course, there’s no mention of 5 FU (an appropriate acronym if I ever saw one!) in the previous article. Clearly, many cancer patients are literally being given a choice of dying smart or living stupid. Here’s hoping that the research that makes the cure better than the disease is carried out as fast as the research on the disease!
Cancer isn’t the only disease facing us here in the Marianas. Because we have such a high percentage of smokers, all the ills wrought by that particular addiction are taking a heavy toll on our populations. But a new study shows that something that also isn’t very common here may be the very thing to prevent some of those tobacco-induced diseases.
COPING WITH COPD
Although most of us have heard of lung cancer, there’s yet another acronym that represents a disease many of us are unfamiliar with. The acronym is COPD and it stands for Chronic Obstructive Pulmonary Disease. It may not be very well known, but it stands a really good chance of killing you, especially if you’re a heavy smoker. COPD is the fourth-leading cause of death in the U.S. and affects more than 16 million Americans.
Recent research from Johns Hopkins Medical School, shows that a class of antioxidants (called NRFP) are key components of the lung’s defense system against inflammato
ry injury. A deficit in these antioxidants is linked to the severity of COPD in smokers.
In this study, researchers examined tissue samples from the lungs of smokers with and without COPD to determine if there were differences in the measured levels of these antioxidants. Previous research had revealed that if the antioxidant wasn’t able to work, mice exposed to cigarette smoke developed severe emphysema. The researchers found that the lungs from patients with COPD had significantly less antioxidants than the lungs from patients without COPD
So how do you get significant amounts of this antioxidant? Well, you’ll be thrilled to death about one method and probably not so happy with the other. No, it doesn’t involve expense drugs or time consuming treatments. To elevate your body’s level of NRFP, you just need to eat your veggies. Specifically, your broccoli, because broccoli contains a compound called sulforapane that prevents the degradation of NFRP.
So . . . your mom never made you eat your veggies and you hate broccoli? Sulforapane is also found in something you eat a lot more of. Wasabi. However, since that sashimi may contain high levels of mercury, you might want to learn to love your vegetables after all.
Fighting cancer, fighting chemobrain, fighting lung disease.