HERE AT THE MOSS REPORTS
People facing a diagnosis of cancer often must make a series
of crucial treatment decisions in very short order. It can
be hard to make informed choices at a time when one is under
such intense pressure. The widely praised Moss
Reports are an invaluable source of information on
currently available treatments for more than 200 different
types of cancer. Each Moss Report
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.
For the cancer patient, a Moss Report
offers a truly comprehensive resource and reference work.
These reports can be ordered and downloaded directly from
our Web site, www.cancerdecisions.com.
For those who have already purchased a Moss
Report on their specific cancer diagnosis, I offer
phone consultations. A phone consultation
can be enormously helpful in narrowing down the options and
arriving at a coherent treatment strategy. If you are a Moss
Report client and would like to schedule a consultation,
please contact Jacquie by email: Jacquie@cancerdecisions.com.
We also offer downloadable special reports on specific cancer-related
subjects. Currently available from our Web site www.cancerdecisions.com
are the following:
- Mammography, Biopsy and the Diagnosis of Breast Cancer
- Herceptin – or Deceptin?
- Do Antioxidants and Chemotherapy Conflict?
- Mexican Cancer Clinics in the Era of Evidence-Based
Medicine
We look forward to helping you.
ARTICLE ON HERCEPTIN APPEARS IN NEW SCIENTIST MAGAZINE
The New Scientist, a British-based science and technology
weekly with an international readership of 780,000 and a Web
readership of 1.6 million, has published an article that I
wrote on the subject of the breast cancer drug Herceptin.
The article can be accessed online by clicking or going to:
http://www.newscientist.com/channel/health/mg18925415.800.html
(Note: Access to the full article requires
a trial subscription to the magazine.)
This article is a summary of a much longer paper I have written
on the subject of Herceptin - "Herceptin – or Deceptin?"
– copies of which can be purchased for $9.95 and downloaded
directly from our Web site, www.cancerdecisions.com
AUSSIE ONCOLOGISTS CRITICIZE CHEMOTHERAPY - PART ONE
An important paper has been published in the journal Clinical
Oncology. This meta-analysis, entitled "The Contribution
of Cytotoxic Chemotherapy to 5-year Survival in Adult Malignancies"
set out to accurately quantify and assess the actual benefit
conferred by chemotherapy in the treatment of adults with
the commonest types of cancer. Although the paper has attracted
some attention in Australia, the native country of the paper's
authors, it has been greeted with complete silence on this
side of the world.
All three of the paper's authors are oncologists. Lead author
Associate Professor Graeme Morgan is a radiation oncologist
at Royal North Shore Hospital in Sydney; Professor Robyn Ward
is a medical oncologist at University of New South Wales/St.
Vincent's Hospital. The third author, Dr. Michael Barton,
is a radiation oncologist and a member of the Collaboration
for Cancer Outcomes Research and Evaluation, Liverpool Health
Service, Sydney. Prof. Ward is also a member of the Therapeutic
Goods Authority of the Australian Federal Department of Health
and Aging, the official body that advises the Australian government
on the suitability and efficacy of drugs to be listed on the
national Pharmaceutical Benefits Schedule (PBS) – roughly
the equivalent of the US Food and Drug Administration.
Their meticulous study was based on an analysis of the results
of all the randomized, controlled clinical trials (RCTs) performed
in Australia and the US that reported a statistically significant
increase in 5-year survival due to the use of chemotherapy
in adult malignancies. Survival data were drawn from the Australian
cancer registries and the US National Cancer Institute's Surveillance
Epidemiology and End Results (SEER) registry spanning the
period January 1990 until January 2004.
Wherever data were uncertain, the authors deliberately erred
on the side of over-estimating the benefit of chemotherapy.
Even so, the study concluded that overall, chemotherapy contributes
just over 2 percent to improved survival in cancer patients.
Yet despite the mounting evidence of chemotherapy's lack
of effectiveness in prolonging survival, oncologists continue
to present chemotherapy as a rational and promising approach
to cancer treatment.
"Some practitioners still remain optimistic that cytotoxic
chemotherapy will significantly improve cancer survival,"
the authors wrote in their introduction. "However, despite
the use of new and expensive single and combination drugs
to improve response rates...there has been little impact from
the use of newer regimens" (Morgan 2005).
The Australian authors continued: "...in lung cancer,
the median survival has increased by only 2 months [during
the past 20 years, ed.] and an overall survival benefit of
less than 5 percent has been achieved in the adjuvant treatment
of breast, colon and head and neck cancers."
The results of the study are summarized in two tables, reproduced
below. Table 1 shows the results for Australian patients;
Table 2 shows the results for US patients. The authors point
out that the similarity of the figures for Australia and the
US make it very likely that the recorded benefit of 2.5 percent
or less would be mirrored in other developed countries also.
(NB: We apologize for the poor image
quality of these tables. The blanks in the columns represent
zero, i.e. no direct benefit can be attributed to chemotherapy;
no patients in that category achieved an increased 5-year
survival due to chemotherapy.)
Table 1
Table 2
Basically, the authors found that the contribution of chemotherapy
to 5-year survival in adults was 2.3 percent in Australia,
and 2.1 percent in the USA. They emphasize that, for reasons
explained in detail in the study, these figures "should
be regarded as the upper limit of effectiveness" (i.e.,
they are an optimistic rather than a pessimistic estimate).
Understanding Relative Risk
How is it possible that patients are routinely offered chemotherapy
when the benefits to be gained by such an approach are generally
so small? In their discussion, the authors address this crucial
question and cite the tendency on the part of the medical
profession to present the benefits of chemotherapy in statistical
terms that, while technically accurate, are seldom clearly
understood by patients.
For example, oncologists frequently express the benefits
of chemotherapy in terms of what is called "relative
risk" rather than giving a straight assessment of the
likely impact on overall survival. Relative risk is a statistical
means of expressing the benefit of receiving a medical intervention
in a way that, while technically accurate, has the effect
of making the intervention look considerably more beneficial
than it truly is. If receiving a treatment causes a patient's
risk to drop from 4 percent to 2 percent, this can be expressed
as a decrease in relative risk of 50 percent. On face value
that sounds good. But another, equally valid way of expressing
this is to say that it offers a 2 percent reduction in absolute
risk, which is less likely to convince patients to take the
treatment.
It is not only patients who are misled by the overuse of
relative risk in reporting the results of medical interventions.
Several studies have shown that physicians are also frequently
beguiled by this kind of statistical sleight of hand. According
to one such study, published in the British Medical Journal,
physicians' views of the effectiveness of drugs, and their
decision to prescribe such drugs, was significantly influenced
by the way in which clinical trials of these drugs were reported.
When results were expressed as a relative risk reduction,
physicians believed the drugs were more effective and were
strongly more inclined to prescribe than they were when the
identical results were expressed as an absolute risk reduction
(Bucher 1994).
Another study, published in the Journal of Clinical Oncology,
demonstrated that the way in which survival benefits are presented
specifically influenced the decision of medical professionals
to recommend chemotherapy. Since 80 percent of patients chose
what their oncologist recommends, the way in which the oncologist
perceives and conveys the benefits of treatment is of vital
importance. This study showed that when physicians are given
relative risk reduction figures for a chemotherapy regimen,
they are more likely to recommend it to their patients than
when they are given the mathematically identical information
expressed as an absolute risk reduction (Chao 2003).
The way that medical information is reported in the professional
literature therefore clearly has an important influence on
the treatment recommendations oncologists make. A drug that
can be said, for example, to reduce cancer recurrence by 50
percent, is likely to get the attention and respect of oncologists
and patients alike, even though the absolute risk may only
be a small one - perhaps only 2 or 3 percent - and the reduction
in absolute risk commensurately small.
TO BE CONCLUDED, WITH REFERENCES,
NEXT WEEK
--Ralph W. Moss, Ph.D.
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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.
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