NEW WAYS TO PUT FIRES OUT

Stomach acid has been getting a bad rap for years. Witness all the ads for antacids that block its production to ease your pain. Besides easing the symptoms of indigestion, use of antacids was supported by studies that associated a chronic condition of "too much stomach acid" with stomach cancer. Nonetheless, longtime Daily Health News readers have seen us write repeatedly about the importance of healthy complete digestion and how an adequate level of stomach acid is critical to that process. So it didn't surprise me too much when researchers at the University of Michigan Medical School discovered that too little stomach acid also can lead to stomach cancer.

The study author was Juanita L. Merchant, MD, PhD, professor of internal medicine and of molecular and integrative physiology. When discussing the findings with her, she explained that stomach inflammation -- whatever its cause -- can lead to the development of stomach cancer, and this study revealed that chronic inflammation can result from too little acid. Her study was performed on a group of mice that had been genetically engineered so that they no longer had the gene that is responsible for gastrin, the hormone that stimulates the production of hydrochloric acid (which is stomach acid). Without gastrin, of course, the mice ended up with almost no gastric acid. As a result, they developed chronic gastritis (inflammation of the stomach). Their condition progressed to atrophy of the stomach lining, which eventually led to gastric cancer.

THE CYCLE OF STOMACH ACID

The role of acid in the stomach, says Dr. Merchant, is actually more of a security guard, helping protect the stomach from invading microorganisms, than it is a tool for breaking down food for digestion (though some fats, salts and nutrients do enter the body directly from the stomach). Food coming into the stomach is far from sterile. Acid protects the stomach lining from microorganisms that are ingested with the food, while starting the process of sterilizing food so that by the time it gets into the small intestine, it is relatively clean. With too little acid, bacteria enters the stomach, causing the immune system to respond by sending in inflammation to kill the "invaders."

IMPACT OF INFLAMMATION

Researchers are now discovering that the inflammatory response also attacks certain stomach cells, one of which makes the hydrochloric acid or possibly gastrin. When inflammation becomes a chronic condition, the acid-producing cells may be lost to the stomach, which then leaves it vulnerable to abnormal cell formation and tumor growth.

THE ROOT OF STOMACH CANCER

There is no way to know when stomach cancer starts to develop in a person, says Dr. Merchant, but it takes from 20 years to 40 years to do so. (Most people are between the ages of 50 and 70 when diagnosed.) It appears that many people who develop stomach cancer ingested something at some point in the past that carried destructive bacteria, most often the Helicobacter pylori bug that is responsible for up to 90% of stomach ulcers. Once H. pylori and possibly other bugs settle in, the immune system sends antibodies into the bloodstream, but it can't destroy H. pylori because the bug stays in the stomach lining. The immune system doesn't give up, however, and the consequence is chronic inflammation. Why H. pylori creates this situation in some people and not in others is something that just isn't known at this point.

WHAT THIS MEANS TO YOU

This research has several implications for humans, says Dr. Merchant. She notes that antacids have their place in the easing of acid reflux as well as to aid in healing ulcers and addressing its symptoms, and they are safe for very short-term, intermittent use. However, ongoing use of antacids leaves the stomach vulnerable to irritation from these outside invaders.

Doctors are particularly concerned about the obese pediatric population, where many cases of acid reflux have already developed. The children treat the condition with higher-powered antacids called proton-pump inhibitors (PPI) -- esomeprazole (Nexium), lansoprazole (Prevacid) and omeprazole (Prilosec) -- that can make them vulnerable to inflammation. Doctors are concerned about the long-term risk of taking the PPIs.

Looking to the future, Dr. Merchant points out the need for a diagnostic tool that will reveal abnormal changes early while there is still time to intervene and correct the problem. By identifying pre-cancerous conditions, doctors could investigate tissue samples and if necessary treat the cancer before it takes hold. She adds that achieving this goal is still far away, but this study has made important steps toward that end. In the meanwhile, go easy on the antacids. For more on the impact excessive use of antacids can have on you, see Daily Health News, June 2, 2004.

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LENA'S COMMENT:  Instead of changing treatments they are simply looking for a way to identify the problems created from the lack of acid? Commons sense still lacks thought in the medical profession. I like prevention rather than treating the side effects! A real reason not to take the drugs given so freely for GERD and other acid reflux problems... Turning on the television or reading the newspaper is becoming an exercise in anxiety. If it's not the war and its aftermath, it's Bird Flu or the struggling economy. All this stress is sending lots of you to your medicine chests to calm your nervous stomachs. And what do we usually reach for? That old standby -- an over-the-counter (OTC) antacid. Advertising claims would lead you to believe that any OTC antacid, such as Tums, Rolaids, Maalox or Pepcid, is harmless enough. How about those commercials for the stronger prescribed drugs such as Nexium, Prilosec, etc.? Little did you know that taking an antacid actually can make your stomach problems worse!
 

Conclusion of Hidden Downside of Mammography!

MAMMOGRAPHY – THE HIDDEN DOWNSIDE, PART SIX

Alternatives and Adjuncts to Mammography

Thermography, or digital infrared imaging (DII), is a technique that uses infrared technology to identify abnormalities. It is able to detect subtle differences in the heat emitted by different areas within the breast tissue. Because malignant tissue has a higher metabolic rate than normal tissue, thermography picks up these areas even when they are extremely tiny – long before they are detectable on mammography, in fact.

As a screening method, thermography is not a replacement for mammography, but a useful adjunct to it. As noted earlier in this series, screening and diagnosis are two different things. Screening is intended to pick up possible abnormalities in otherwise healthy individuals, whereas diagnosis is the method whereby an abnormality, often initially detected by screening, is more closely examined in order to identify its true nature (i.e., what its origins are, and whether the abnormality is benign or malignant, for example). The characteristics that make a good screening test are not by any means the same as those that are needed for diagnostic purposes.

The major advantages of thermography are that it does not involve compressing the breasts, and that it does not use ionizing radiation. As noted above, it can also detect abnormalities at an earlier stage than mammography. However, heat changes in breast tissue can result from many different processes, not just from malignancy, and a positive thermogram is not specific for cancer. False positives, in other words, are an inherent problem with thermography just as they are with mammography. Another problem is the fact that thermography cannot locate the precise anatomical position of a lesion with accuracy; it still takes a mammogram or other diagnostic technique to pinpoint the exact site of an abnormal area within the breast.

The best use of thermography is therefore as a technique that can be used in conjunction with mammography and CBE/BSE. Because it can detect abnormalities earlier than mammography, it is particularly useful in identifying the need for further investigations (including mammography), and since it is so non-invasive and so safe, it is an ideal method for routinely monitoring women who are at added risk for breast cancer. It is particularly useful, too, for younger women and those with dense breast tissue. For such women mammography is not only an inadequate imaging technique but also carries added risks, including lifetime cumulative radiation exposure, and the danger of an increased, rather than a decreased, risk of death from breast cancer (the so-called 'mammography paradox').

Although thermography has been approved by the US Food and Drug Administration (FDA), relatively few doctors know about it and the profession as a whole is not yet generally willing to accept its conclusions. In addition, few insurance companies will pay for this procedure.

Ultrasound, or sonography, which uses sound waves to create an image of the internal structure of the breast, is again typically used a diagnostic rather than a screening tool, although clinical trials are currently in progress to assess its value in screening. One of the drawbacks of older ultrasound techniques was that the hallmark 'microcalcifications' that accompany early breast cancer were not typically visible. However, newer techniques such as Doppler ultrasound have largely overcome this problem. In addition, ultrasound can be very useful not only in imaging dense breast tissue (something mammography does not do well) but also in distinguishing between benign and potentially malignant lesions, thus sparing many women the need for a biopsy. It seems very likely that this non-invasive technique will come to occupy a prominent place in early detection of breast cancer, perhaps even supplanting mammography.

MRI (magnetic resonance imaging) is another technique whose value in breast cancer screening has perhaps still not been fully harnessed. In clinical trials MRI has proved to be more sensitive than mammography, ultrasound or CBE in detecting early cancers. However, it has also proved to be even more susceptible to false positives than mammography. So while MRI, like thermography, has advantages in that it does not involve breast compression or exposure to radiation, it is not a replacement for mammography either. It does, however, have a definite role to play in screening, as an adjunct to CBE and mammography, particularly for younger women with denser breast tissue, and for those whose family history suggests an increased risk of developing breast cancer.

PET (positron emission tomography) scanning has not yet found a definitive place in breast cancer screening. PET is indeed a very sensitive method of detecting aggressive cancers and does not give rise to as many false positives as most of the other imaging methods. In the detection of recurrences in women who have been previously treated for breast cancer it has been shown to be superior to other techniques. However it is still not particularly useful for identifying marginally invasive lesions. In addition, PET involves the use of an injected radioactive contrast medium, and while the half-life of this material is extremely short – i.e., the exposure to radioactivity is relatively small – it is certainly not a procedure to be undertaken on a regular basis for screening purposes. Nor is PET by any means universally available or affordable.

An Ounce of Prevention

While mammography screening is universally portrayed as essentially a preventive practice, it is in fact nothing of the sort. It is a means of detecting lesions that are already present and growing. Before a lesion becomes detectable on a mammogram it has typically been present for an average of 8 years. The best that can be said for the role of mammography is that it is a modestly effective tool in the service of damage control.

Every cancer avoided is a triumph, and every cancer death a tragedy. While mammography may indeed be a useful (though far from perfect) screening tool, it cannot stop women developing breast cancer, and neither can it reliably prevent the majority of deaths from the disease. Yet the American Cancer Society, the National Cancer Institute and the medical profession at large (all of which have strong ties to the multi-billion dollar mammography industry) continue to focus their education efforts exclusively on the detection of existing breast cancer via screening mammography (Epstein 2001). If instead of doing this, they were to throw their considerable political and financial weight wholeheartedly into the effort to find and control the environmental triggers that contribute heavily to the incidence of this dread disease, we might see more substantial progress.


--Ralph W. Moss, Ph.D.

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