Cancer Decisions - Free Newsletter

HERE AT THE MOSS REPORTS

When apparently good news about cancer can be transmitted around the globe at the click of a mouse, it doesn't take long for enthusiasm to mount and hopes to be raised sky-high. Such was the case two weeks ago, when an article appeared in the magazine New Scientist, under the arresting headline "Cheap, safe drug kills most cancers."

The article concerned research showing that an inexpensive laboratory chemical known as DCA (dichloroacetate) was capable of killing experimental cancer cell lines in vitro, and causing tumor shrinkage in laboratory animals. However, encouraging though this research is, it is a very far cry indeed from an available, clinically tested treatment for cancer.

As I pointed out in a letter to the editor of New Scientist (published in this week's issue of the magazine), as a result of the article, and in particular as a result of the carelessly worded headline, "my medical information service [The Moss Reports ed.] was deluged with demands from desperate patients for what you call a 'too good to be true' wonder drug. We had to inform them that DCA had never been tested in humans, only in cell lines and experimental animals, and that it was totally unavailable to today's patients.

"You did explain that it is too early to draw therapeutic conclusions, despite the promising lab work," I continued. "But the magazine headline 'Cheap, safe drug kills most cancers' implies that DCA is known to destroy actual tumors in humans. This continues to generate waves of unwarranted expectation among many patients and has already resulted in severe disappointment for people seeking a solution to life-threatening cancers."

(The full letter can be found in New Scientist magazine, 3 February, 2007.)

This is not to say that this work on DCA lacks potential. To the contrary: early indications are that it may prove to be an important development. This research has also helped to illuminate the peculiar metabolism of the cancer cell, a phenomenon which was first explained by Nobel laureate Otto Warburg in the 1920s. I am currently working on a full-length report on this subject. This report will be published in our Current Topics series in the near future.

By carefully monitoring the medical literature and mainstream media reports on medical issues I am able to keep abreast of important issues and to provide my readers with accurate news on exciting developments that are taking place in medical research.

During my long career I have written and published extensively on the subject of cancer and its treatment, and have compiled a comprehensive series of individual reports on more than 200 different cancer diagnoses - The Moss Reports - each one of which examines both the standard treatment options that are likely to be offered for a particular cancer diagnosis, and the possible alternative and complementary approaches to that disease.

If you would like to order a Moss Report for yourself or someone you love, you can do so securely from our website, www.cancerdecisions.com.

Also available from our website, at a cost of $9.95 each, are the following in our Current Topics series, focusing on issues of interest in the field of cancer prevention and treatment:

Do Antioxidants and Chemotherapy Conflict?
Mammography, Biopsy and the Diagnosis of Breast Cancer
Herceptin or Deceptin? (An evaluation of the use of Herceptin in breast cancer)
Avastin: Your Money Or Your Life. (A clear-eyed look at the 'targeted' drug Avastin)
The Politics of Hope: Andrew von Eschenbach and the Decline of the National Cancer Institute
The Mexican Cancer Clinics in the Era of Evidence-Based Medicine

I also offer phone consultations to clients who have purchased a Moss Report. A phone consultation can be enormously helpful in drawing up an effective treatment strategy and getting one's options clearly prioritized. A recent client wrote:

"I had often wondered what it would be like to sit down and talk with a friend, or an acquaintance who had knowledge about the internal workings of the cancer field...What would it be like to have someone - someone who actually knew what they were talking about, someone who had done their homework - tell you what they really thought, instead of holding back for fear of consequences? For us, Dr. Moss was that courageous voice. We're so grateful to have had someone like him to turn to." — M.M.

To schedule a phone consultation, please call 1-800-980-1234 (814-238-3367 from outside the US) or send an email to Jacquie@cancerdecisions.com

We look forward to helping you.

NEW! AUDIO NEWSLETTER NOW AVAILABLE

This week, and whenever possible in future, we are making an audio version of the newsletter available. To hear me read this week's Cancer Decisions newsletter please click or go to:
http://www.cancerdecisions.com/audio/cd020407.mp3

BENEFIT OF EARLY MAMMOGRAPHY DIFFICULT TO PROVE

Screening for early-stage cancer seems like such a logical idea that some people develop an almost religious belief in its utility. Put this together with the fact that there are indeed some Scrooge-like politicians who would cheerfully deny women the benefit of even inexpensive public health measures, and this makes for an atmosphere not conducive to calm discussion and reflection. At the end of the day, though, the only thing that matters is not medical ideology, but what actual benefit, if any, the masses of people are likely to derive from a large cancer screening campaign.

Since 1997, the American Cancer Society (ACS) has repeatedly urged women to start annual mammography screening at age 40. "This new guideline is based on research evidence, which overwhelmingly points to a benefit from annual mammographic screening for women beginning at age 40," said Myles Cunningham, MD, then President of ACS.

But, in fact, things have not proved so clear-cut. Many prominent experts believe that age 50 is soon enough to begin. It has turned out to be unexpectedly difficult to prove in a scientific way that mammograms given during a woman's 40s actually improve her chances of survival. The evidence from research remains conflicting.

The latest blow to the "start-at-40" school was a London Institute of Cancer Research study that tracked 160,900 women over an average of 11 years. The women were divided into two groups. One group was offered annual mammography screening starting at age 40, while the other group was offered annual screening starting at age 50. While there was a decrease of 17 percent in breast cancer deaths in the younger women, this figure turned out not to be statistically significant – which is another way of saying that it very well may have been due to chance. Meanwhile, among the women in their 40s who received regular screenings, 23 percent had at least one false positive result compared to 12 percent of the women in their 50s. This was probably a reflection of the fact that younger women tend to have denser breast tissue, which makes early breast cancer lesions far more difficult to discern on x-rays.

A false positive is an aberrant finding that after further investigation turns out not to be breast cancer. But this "scare" can be psychologically traumatizing: undergoing a biopsy procedure and then waiting days - or sometimes weeks - for the results can be extremely stressful. These false positives also waste a lot of a hospital's scarce medical resources, as doctors try to chase down illusory 'tumors' that turn out to be either benign growths or radiological glitches.

Another consideration is that mammography involves repeated exposure to radiation. Despite assurances of how safe mammography now is, it is acknowledged by experts that the procedure (like all exposure to ionizing rays) does somewhat heighten the risk of radiation-induced cancer. This is particularly so when a mammogram has to be repeated because of questionable readings. The danger begins to add up when hundreds of thousands of women are being screened annually. According to the authors of the London study, the risk of radiation-induced cancer rarely outweighs the benefit. This is reassuring, unless you happen to be in that small percentage. The risk of radiation-induced cancer needs to be taken into account in making the decision as to when to begin regular screening mammography.

The London study was published in the December 9, 2006 issue of the Lancet, a weekly journal notable for its objective reports on the benefits of cancer treatments. The lead author was Sue M. Moss (no relation), while Benjamin Djulbegovic, of the H. Lee Moffitt Cancer Center and Research Institute in Tampa, Fla., wrote an accompanying comment to the study.

In a prepared statement, he said: "...the decision of whether to recommend screening mammography crucially depends on estimates of harm, which will never be zero."

"Although the best estimates of harms from screening mammography seem to be less than the benefits, they remain too uncertain to conclude that screening mammography in this age-group is associated with a net benefit," he noted (emphasis added).

"Benefit and harms need to be contrasted with each woman's individual risks for development of breast cancer," Djulbegovic concluded. "Every woman, with her physician's guidance, should decide whether regret will be greater if she develops breast cancer that could have been detected earlier by screening mammography, or if she develops breast cancer later in life as a result of screening mammography itself."

After initial opposition, the National Cancer Institute finally agreed with the American Cancer Society in recommending mammography screening in younger women. But the United States Public Health Service (USPHS) task force continues to hedge its bets:

"The precise age at which the benefits from screening mammography justify the potential harms is a subjective judgment and should take into account patient preferences," says the task force. "Clinicians should inform women about the potential benefits (reduced chance of dying from breast cancer), potential harms (e.g., false-positive results, unnecessary biopsies), and limitations of the test that apply to women their age. Clinicians should tell women that the balance of benefits and potential harms of mammography improves with increasing age for women between the ages of 40 and 70."

But notice how the USPHS leaves radiation-induced cancers out of the equation! It is to the credit of the Lancet authors that they take this danger seriously. When you add the risk of radiation-induced cancer into the mix, I think it tips the scales against beginning mammographic screening for the average women in her 40s. (However, those at high risk of breast cancer, such as those who have BRCA 1 and 2 mutations, and those with first-degree relatives who have developed the disease, may decide that the risk-benefit ratio favors annual mammography starting before age 50.)

This paper illustrates that the debate over the merits of screening mammography, especially for younger women, is still an open question, despite the sometimes dogmatic statements to the contrary that come from US cancer agencies.

IN THE MAILBAG

Last week's newsletter concerning the announcement by the ACS of another minuscule drop in the annual number of US cancer deaths prompted some interesting and insightful comments from readers. For example:

"You could usefully have pointed out that a change as small as the one so rapturously received has no statistical significance at all. Basically, it indicates "no change" - in effect, "no information." This would have been the correct way to report it. Statistically speaking, there were no conclusions to draw, no grounds for hope or despair, just... let's see what happens next. But tell that to a journalist (or president) hell-bent for a story. You said this, of course; it was the point of your piece; but you could have given it a solider base in the statistics."

This reader is absolutely correct: the only true yardstick by which to judge any change in mortality figures is to submit them to statistical analysis. The fact that the ACS announcement conspicuously failed to make any claim of statistical significance is itself revealing. In general, reports of the announcement were careful not to make any explicit claim of statistical significance per se, yet still managed convey the impression that the drop in cancer deaths was unequivocally a milestone of great importance. The cancerfacts.com Web site, for example, put it this way:

"This year's report shows a ten-fold increase in the drop between 2003 and 2004, which indicates a significant trend rather than a statistical anomaly" (emphasis added).

Several readers pointed out that the way cancer deaths are recorded is so open to errors of interpretation and classification that the official figures for cancer deaths cannot be relied upon. For example:

"My father was diagnosed in April with stomach cancer and died in October. When I saw his death certificate it said he had died of pneumonia. I talked with a woman who said she never looked at her husband's death certificate [at the time of his death from cancer] and was [later] stunned to see that he apparently did not die of cancer but of pneumonia. Statistical deceptions? If you die within 5 years of a cancer diagnosis shouldn't cancer be listed as the cause if nothing unrelated, like an accident, takes your life?"

Another reader wrote:

"After reading your article on the death rate in cancer I wanted to say that my husband recently died of pancreatic cancer and he was listed as death by heart attack because he was in the end stages of his cancer and his heart gave out. Statistics can be what ever the people keeping the results want them to be."

We are grateful to the many readers who have written to us on this and other subjects. We consider ourselves profoundly privileged to have such an intellectually lively and astute readership.

--Ralph W. Moss, Ph.D.

References:

Djulbegovic B, Lyman GH. Screening mammography at 40-49 years: regret or no regret? Lancet 2006; 368(9552):2035-7.

Moss SM, Cuckle H, Evans A, et al. Effect of mammographic screening from age 40 years on breast cancer mortality at 10 years' follow-up: a randomized controlled trial. Lancet 2006; 368(9552):2053-60.

American Cancer Society press release on recommendations for changes to mammography guidelines:
http://www.cancer.org/docroot/MED/content/MED_2_1X_American_Cancer_Society_Re
commends_Annual_Mammography_StartingAt_Age_40_.asp

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IMPORTANT DISCLAIMER

The news and other items in this newsletter are intended for informational purposes only. Nothing in this newsletter is intended to be a substitute for professional medical advice.