By Dr. Ed Taubman Olney, Maryland 301-774-5400
As previously reported by me there continues to be controversy about the idea that those of us who have NOT had a heart attack or stroke should be taking a daily aspirin to prevent one. Bayer recently submitted an application to the FDA to receive permission to promote daily aspirin for this purpose. Many people take a baby aspirin daily because they have heard it is a good thing to do and believe that since it is non prescription must be safe. Many cardiologists recommend daily aspirin to people who have not had a heart attack. Their reasoning is that since aspirin has been shown to benefit people who have had heart attacks or strokes why not give it to healthy people so they don’t develop heart disease or stroke? Similarly since diabetics have a higher risk of heart disease and stroke, endocrinologists often promote daily aspirin to their diabetic patients for the same reasons.
The problem remains, however, that there are no definitive studies that show this to be true. And unfortunately aspirin, though not a prescription drug, can have two very serious side effects. First, it can cause a bleeding ulcer without any warning, which can land people in the hospital with life threatening internal bleeding. Secondly, if a person does get a stroke, those on aspirin are more likely to have a more severe form of stroke known as a hemorrhagic stroke than people not taking aspirin. In fact in 5 studies reviewed by the FDA, 4 studies actually showed an increase in fatal strokes among those taking daily aspirin.
Based on its review the FDA denied Bayer’s request to allow it to promote daily aspirin use for the prevention of heart attack and stroke in those who have never had a heart attack or stroke. For most people the small benefits, if they exist, are probably outweighed by the small but real and potentially serious risks. Nonetheless, there may be a smaller number of patients who are at particularly higher risk for these events and for whom the benefits from daily aspirin outweigh the risks. The challenge is how to identify who those people might be. In future posts we will examine some emerging technologies that propose to do so.
In case you missed the media hype, recent studies in mice have raised the possibility that someday some of the effects of aging might be reversed. Preliminary research along three tracks in mice suggests that factors found younger blood might have such potential. First researchers joined the circulatory systems of older and younger mice and found that the older mice showed improvements in muscle, heart, liver, spinal cord, and brain tissues. Next, researchers in Boston identified a rejuvenating protein in mouse blood known as growth differentiation factor 11 (GDF11) that may be partially responsible. Recently researchers have found that simply giving older mice transfusions with blood products from younger mice can have a similar effect. So where will all this lead us? Will these concepts work in humans? If it does work, will it be safe or create unanticipated side effects? The field of rejuvenative medicine is in its infancy, so don’t expect fountain of youth treatments any time soon. Normally to take a concept like this, fully understand it, and create a drug that is safe and effective can take a couple of decades. However, since blood products are already given routinely in hospitals for all sorts of reasons, the potential to do trials, say, in Alzheimer’s patients might be considerably sped up. Is it a story that’s too good to be true? Probably, but certainly a story worth following and maybe a classic movie-to-be.
By Dr Ed Taubman, Olney Md 301-774-5400
With genetic causes of cancer in the general population proving elusive, our focus is increasingly moving towards lifestyle contributions. Increasingly obesity, poor nutrition choices, lack of exercise and alcohol use are being linked to cancer risks. Some experts feel that 1 in 3 cancers in the United States is linked to the above lifestyle issues. Worldwide smoking remains the number one contributor to cancer; but in the United States, as fewer and fewer people smoke and more and more people become overweight, the trend at home has made obesity the number one contributor. And how about alcohol? Alcohol has been declared a carcinogen by the International Association of Research in Cancer. Its breakdown products include 15 known carcinogens from arsenic to formaldehyde. A recent study in the American Journal of Public Health estimated that about 1 in 30 cancer deaths in the United States can be linked to alcohol. Alcohol can raise estrogen levels, and studies have linked three or four drinks a day to increases in breast cancer risk by 40-50%. But surely small amounts of alcohol are okay? Unfortunately, when it comes to cancer, evidence seems to be accumulating that the more one drinks, the greater the risk and that likely there is no amount of alcohol that is safe. Just one drink a day is thought to increase breast cancer risk by about 4%.
So what does the public think about lifestyle change to prevent cancer? In one recently published study 1700 women were asked if they were interested in learning about lifestyle changes to reduce their risk of breast cancer. Of the respondents 41% were interested in learning more about how exercise could reduce their risk, 35% for weight loss, 30% by diet and only 12% were interested in learning about reducing alcohol consumption to cut their risk. Why the disconnect with alcohol? Perhaps it is because alcohol use is so woven into our society as a fun thing to do and its cardiovascular benefits have long been touted. However, for those worried about their cancer risk, lifestyle changes including reducing alcohol consumption to a minimum, becoming more vegetarian, losing weight and exercising seem reasonable and prudent.
It has been two decades since researchers were able to identify two genes, BRCA1 and then BRCA2. These so-called “breast cancer genes,” when inherited with a faulty copy, would confer very high risks of breast and also ovarian cancers. The thinking was that with time, and as modern genetic tools evolved, researchers would find other genes equally as powerful in causing these and other cancers. Knowing one’s genetic risk might help decide who might need frequent mammograms or MRI’s and who might be able to safely forgo such testing or conversely benefit from preventative measures. Since the discovery of BRCA1 and BRCA2, a few additional high risk breast cancer genes have been discovered such as PALB2, LKB1, and CDH1; but these are very rare. Unfortunately, mother nature has not cooperated with science, and a BRCA3 or BRCA4 has yet to be discovered and may not exist. Instead of a handful of genes that confer great risk, it increasingly looks as if our genetic risk for cancer may be the sum total of hundreds of genes, some of which slightly increase risk, and some of which slightly lower risk.
Though panels of multiple genes to predict one’s risk are being developed and a few are already commercially available, each of us has over twenty thousand genes and over a million genetic variations are known to occur. So an individual’s risk of developing cancer will likely be a complex and nuanced interplay of subtle genetic variations inherited from one’s mom and dad, which will take a long time to fully understand.
While the scientists are struggling with unraveling our genetic predispositions to cancer, lifestyle issues such as exercise, weight, and alcohol use are increasingly being recognized as contributing as much or more to cancer risk and over which we as individuals have some control. Next week – how interested is the public in reducing cancer risk through lifestyle changes? – Stay tuned for the surprising answer.
Not all breast cancers are the same. Some start in the part of the breast where milk is manufactured (lobular) and others start in the ducts that carry the milk to the nipple (ductal). Some breast cancers grow very slowly and respond to relatively gentle oral medications, while others are more likely to spread beyond the milk ducts into the surrounding breast or to other parts of the body and require harsh, yet potentially lifesaving chemotherapy. As mammography has over the years become more and more sensitive, a particular kind of breast cancer called ductal carcinoma in situ, or DCIS for short, is being diagnosed much more frequently. These very early cancers are often being diagnosed as tiny specks of calcium on a mammogram that require a magnifying glass to see, and are found so early that, if left untreated, more than half might never cause more serious illness. The challenge is to figure out which women with these very early cancers could forgo radiation, or even surgery, and which are destined to suffer a much more serious problem that needs more aggressive and perhaps life – saving treatment.
As outlined in a recent review in “Science” magazine, some researchers are looking at ways to figure out who might really benefit from treatment. Studies are now underway to use new diagnostic tests known as gene array analysis to see who is likely to benefit the most from surgery and radiation and who might just require monitoring. DCIS now accounts for about a third of new breast cancer cases, and by one estimate more than a million women will be diagnosed with DCIS by 2020. In the meantime a healthy lifestyle including eating as little food from animal sources as possible, minimizing alcohol, and getting regular mammograms remain one’s best defense.
And what about the role of genetics? Two decades have passed since the strong breast cancer genetic link between an inherited abnormal BRCA1 or BRCA2 gene was discovered – yet the BRCA genes only account for about 5% of breast cancers. What is the role, if any, of other discovered breast cancer predisposing genes? Next week: Beyond BRCA Gene Testing.