THE MOSS REPORTS Newsletter (10/09/05)

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THE MOSS REPORTS Newsletter (10/09/05)

 

 

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Ralph W. Moss, Ph.D. Weekly CancerDecisions.com

Newsletter #205 10/09/05

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THE MOSS REPORTS CANCER DECISIONS NEWSLETTER

 

 

http://www.cancerdecisions.com/100905.html

 

 

HERE AT THE MOSS REPORTS

 

It is a modern day mantra, endlessly repeated and unquestioningly

accepted, that screening for cancer offers the best chance of early

detection and therefore saves lives. But is this really true?

 

Over the next few weeks I will be examining the rationale for, and the

scientific basis of, cancer screening in general, and investigating

the under-reported and largely unknown shortcomings of screening for

three of the major cancers – breast, prostate and colon cancer.

 

Over my long career in the field of cancer I have seen many theories

arrive in a blaze of glory only to be discredited and quietly

discarded a short time later. The profit-driven nature of cancer

therapeutics has only added to the confusion. Drug companies and the

manufacturers of expensive scanning and screening equipment have a

strong interest in promoting the sale of their products, and the voice

of reason all too often gets drowned out in the face of their massive

advertising, lobbying and public relations efforts.

 

By going to primary sources and carefully studying the scientific

literature itself, I aim to provide my readers with the best possible

synopsis of the current state of knowledge in the sphere of cancer

prevention and treatment. In my writings, my goal, and that of my

organization, Cancer Communications, Inc., is to maintain the sort of

consistent, reliably objective analytical standard that will allow my

readers to make truly informed decisions.

 

In the past 30 years I have written and published extensively on the

subject of cancer and its treatment, including compiling 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 from our website, www.cancerdecisions.com, or by

calling 1-800-980-1234 (814-238-3367 from outside the US).

 

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. To schedule an appointment, please call 1-800-980-1234

(814-238-3367 from outside the US).

 

We look forward to helping you.

 

MAMMOGRAPHY – THE HIDDEN DOWNSIDE – PART ONE

 

 

Mammography is the term used to describe any imaging technique used

for the screening and diagnosis of breast disease – and in particular,

breast cancer. There are various ways of creating a mammographic image

of the breast – ultrasound, thermography, MRI, etc., but by far the

commonest form of mammography used for mass screening utilizes

ionizing radiation (X-rays) to detect 'lesions' (i.e., areas of

abnormal tissue) that are suspicious for breast cancer. The terms

'mammography' and 'mammogram' as used in this article therefore refer

exclusively to the X-ray imaging technique.

 

There is a widespread belief that screening mammography unequivocally

saves lives. The National Cancer Institute, the American Cancer

Society, and the American College of Radiology recommend annual

mammography for all women over the age of 40. The statistic that is

most commonly quoted is that by detecting breast cancer early, before

it has become large enough to be clinically apparent as an obvious

lump in the breast, mammography reduces the mortality rate from breast

cancer by 20 to 30 percent. So fixed has this statistic become in the

minds of women, the medical profession and the media that by

repetition alone it has now attained the status of unimpeachable fact.

 

How well-founded is this belief? A closer examination of the data

yields a somewhat less optimistic picture.

 

First of all, how much benefit can one truly expect from regular

mammography? Just how effective is it in terms of saving lives?

 

To come to grips with that question it helps to have an understanding

of the concept of absolute risk. Absolute risk is a statistical

concept that expresses the number of people who can be expected to

succumb to a disease over a certain period of time. Women generally

perceive that their risk of developing breast cancer is very high. But

in reality the absolute risk of dying from breast cancer depends on

your age.

 

For a 60 year old woman, the chance of dying from breast cancer in the

next 10 years is 9 in 1,000. Mammography screening has been estimated

to reduce the absolute risk of dying from breast cancer for this 60

year old woman by around one third; i.e., instead of having an

absolute risk of 9 in 1,000 over the next 10 years, her chance might

at best be reduced to around 6 in 1,000 by screening. For younger

women, whose absolute risk of dying of breast cancer is commensurately

lower to start with (around 6 in 1,000), the reduction in risk that

might be conferred by mammography would also be smaller. For 50 year

olds, 10 years of regular mammography might at best be expected to

reduce the absolute risk of dying from 6 in 1,000 to around 4 in 1,000.

 

However, advocates of screening rarely ever talk in terms of absolute

risk. Instead, they prefer to express the benefits of screening in

terms of relative risk, a statistical concept that, because it is

expressed as a percentage, makes the benefits of screening appear much

more dramatic.

 

For example, they will say that mammography reduces your chances of

dying by 30 percent (the relative risk) but will neglect to tell you

that the chance of dying of the disease (the absolute risk) is very

small to start with. The relative risk, expressed as a percentage,

therefore makes screening look dramatically effective, whereas when

expressed in terms of absolute risk the picture is considerably less

persuasive. Which of these two statements sounds more impressive:

mammography saves 2 lives out of 1,000 over 10 years, or mammography

reduces breast cancer deaths by 30 percent? No wonder proponents of

screening are so enamored of quoting relative risk rather than

absolute risk.

 

As Prof. Samuel Epstein, MD, of the University of Illinois and

colleagues have pointed out:

 

" Even assuming that high quality screening of a population of women

between the ages of 50 and 69 would reduce breast cancer mortality by

up to 25 percent, yielding a reduced relative risk of 0.75, the

chances of any individual woman benefiting are remote. For women in

this age group, about 4 percent are likely to develop breast cancer

annually, about one in four of whom, or 1 percent overall, will die

from this disease. Thus, the 0.75 relative risk applies to this 1

percent, so 99.75 percent of the women screened are unlikely to

benefit " (Epstein 2001).

 

Finding Indolent Tumors

 

 

There are other facets of mammography that are seldom discussed by the

many enthusiastic advocates of mass screening. Cancers – even breast

cancers– vary greatly in their malignancy. For any screening technique

to be worthwhile, it should be capable of picking up the most

dangerous kinds of cancer rather than the most indolent. It should

also be highly sensitive, giving few false positives and false

negatives. Sadly, x-ray mammography does not score well on either count.

 

Mammography is undoubtedly good at picking up slow-growing cancers. It

is also good at detecting so-called 'in situ' lesions, that is, the

latent, precancerous lesions that have not yet developed – and might

never develop - into truly invasive cancers. But these are not the

kinds of breast cancer that are most likely to kill. That distinction

belongs to the faster-growing tumors, and it is precisely these faster

growing malignancies that mammography typically fails to catch.

 

Thus, a woman can have a clear mammogram at one annual screening, and

yet, less than a year later, can discover that she has a highly

aggressive form of breast cancer. Women who develop such so-called

'interval cancers' (i.e., cancers that are discovered in the interval

between two screenings) are more than twice as likely to die as are

women whose cancers are detected through routine mammography. Like

most screening tests, therefore, mammography suffers from the drawback

that it misses many of the deadliest cancers entirely, while zealously

identifying slow-growing or latent cancers, a significant proportion

of which might never progress or pose a threat to life. This

accelerates the trend towards finding and curing 'cancers' of dubious

malignancy, thus exaggerating the benefits of both diagnosis and

treatment.

 

Another important aspect of breast tumor growth is the 'doubling time'

of the tumor. This is the time taken for the tumor to double in size.

It has been estimated that there are approximately 40 doublings

between the development of a single malignant cell and the point at

which a patient dies of widely metastatic breast cancer. For a tumor

to be detectable by clinical breast examination (i.e., by the human

hand, feeling for a lump) the tumor needs to be around 1 centimeter in

diameter (i.e., around half an inch across). A mammogram can detect a

tumor at half this size, i.e., 5 millimeters in diameter. This is just

one doubling less than the size at which a small tumor becomes

detectable manually, by self-examination. This single doubling is

probably not a sufficiently wide difference to be able to affect the

overall outcome of the disease very significantly.

 

 

TO BE CONTINUED NEXT WEEK