by Don Benjamin, Cancer Information and Support Society
In this article I am trying to answer several questions
related to chemotherapy:
1. What is the rationale for the use of chemotherapy?
2. What is the scientific evidence for its efficacy?
3. How much harm does it do?
4. What are the opinions of practising oncologists about its efficacy?
1. Chemotherapy - A Rationale
Chemotherapy acts differently from surgery and radiotherapy. It is designed
to kill off fast-growing cancer cells, but it also kills many fast-growing
healthy cells. In addition it damages the immune system (see below)
and is toxic. Also unlike surgery and radiotherapy, chemotherapy is
a systemic therapy (as is hormone therapy). If cancer is a systemic
disease, as claimed by most alternative practitioners, chemotherapy
is the most likely of the orthodox therapies to be effective if only
its toxicity could be reduced.
2. What is the Scientific Evidence for its
Efficacy?
Proof of efficacy of a cancer treatment such as chemotherapy requires
a randomised trial in which it has been shown that the group treated
with chemotherapy experienced significantly increased survival when
compared with that of an untreated group. This has never been done.
Unfortunately, most claims for the efficacy of chemotherapy come from
trials showing shrinkage of tumours; or from comparison of survival
rates of unmatched groups over time.
Tumour response trials assume a particular paradigm, namely, that the
tumour is the disease. If this paradigm is wrong and the tumour is only
a symptom of a systemic disease, then the symptom can be removed, destroyed
or shrunk without affecting the course of the disease. Unless tumour
shrinkage is accompanied by evidence of increased survival, the treatment
cannot be claimed to be effective. Tumour- response trials rarely produce
such evidence of increased survival. (1) Tumour shrinkage can however
reduce pain.
Comparison of unmatched groups over time can be valid if a very large
increase in survival is observed and this cannot be attributed to other
factors. For example, when used to treat acute lymphocytic leukemia
(ALL) in children, chemotherapy using different types of drugs has been
shown to increase 10-year survival from less than 10% of patients in
the 1950s to about 60% in the 1980s. (2) Part of this increase is only
apparent because it is due to earlier diagnosis extending the survival
starting time and the increasing incidence of less-fatal forms. However,
it is unlikely that more than a third of this improvement is due to
these factors. The percentage survival has continued to increase steadily
over this thirty-year period, whereas improvements in diagnostic methods
and an increase in less-fatal forms are unlikely to have developed in
this way.
For other forms of leukemia the evidence is questionable. An analysis
of 3-year survival rates between the 1950s and 1960s showed increased
3-year survival rates over this period for all forms of leukemia, yet
for all forms combined the survival remained unchanged. (3) Unlike the
case of ALL above, all of this increase can be attributed to the effects
of earlier diagnosis extending the survival starting time and the reduced
proportion of the more fatal forms in the total cases.
A small improvement in survival has been observed for some lymphomas.
(1) However much of this increase can again be attributed to poor methodology.
According to a leading epidemiologist, “For most cancers in adults,
and particularly for epithelial cancers, there has been so little progress
that it is difficult to distinguish any real improvement in survival
rates from artefacts due to improvements in diagnosis and cancer registration.”
(4) (Survival is slightly prolonged using Tamoxifen for breast cancer;
oestrogens for prostatic cancer; cytotoxic chemotherapy for small-cell
lung cancer and ovarian cancer; adjuvant therapy for resected breast
cancer and possibly colorectal cancer.)
“The efficacy of most other treatments is not established, however,
and a small proportion of patients are certainly killed by the short-
or long-term effects of cytotoxic treatment.” (4)
“There have been considerable advances in avoiding disfigurement
by radical surgery, limiting tissue damage by radiotherapy and controlling
chemotherapeutic toxicity, but for the majority of adult epithelial
cancers, it is not clear whether the withdrawal of all cytotoxic therapy
would measurably alter the annual number of cancer deaths...”
“... In the many situations where it is still not known whether
treatment will prolong remission or survival, the oncologist is therefore
in the invidious position of having to weigh the cost, inconvenience
and toxicity of treatment against its unknown clinical benefit. Not
surprisingly, many clinicians respond by developing a set of firmly
held but unsupported beliefs in the merits of particular regimens. The
primary treatment of advanced non-metastatic laryngeal (voice box) cancer,
for example, will usually be by surgery at certain treatment centres
and by radiotherapy at others. Whether chemotherapy is given as well
and, if so, what form it will take, are also determined more by the
idiosyncrasies and outpatient arrangements of the particular treatment
centre than by objective evidence of long-term efficacy. Similar examples
could be taken from most areas of cancer therapy.” (4)
Similarly, claims that chemotherapy has produced increased percentage
5-year survival for other cancers, such as cancer of the large bowel,
(1) could be attributed to poor methodology because none of these cancers
exhibited an increasing difference between incidence and mortality rates
over time. (5)
Ulrich Abel reviewed the evidence for the efficacy of chemotherapy for
invasive epithelial cancers (6), the type of cancer for which chemotherapy
is most commonly used. He concluded that there was some evidence from
randomised trials that chemotherapy increased survival only for small-cell
lung cancer. Yet even here the gain in survival was measured in weeks
or months.
Adjuvant Chemotherapy for Breast Cancer
It is widely claimed that adjuvant (add-on) chemotherapy extends survival
with late-stage breast cancer. For example, in a letter in the Sydney
Morning Herald of 22 November, 1996, Professor Allan Langlands claimed
that the results of a meta- analysis of more than 100 trials of adjuvant
systemic therapy in many thousands of women with breast cancer have
confirmed a reduced risk of death by more than 20% over the next 10
years. Presumably he was referring to the results of 133 randomised
trials involving 75,000 women published in The Lancet in 1992.
There were 11,041 women in these trials who were randomised to long-term
polychemotherapy vs. no chemotherapy. This was the chemotherapy with
the best results. Looked at ten years after the randomised controlled
trial, these women seemed to show a 6.3% survival advantage (51.3 %
vs. 45.0%). For node-negative women, the advantage was just 4% (67.2%
vs. 63.2%). For node-positive women, it was 6.8% (46.6% vs. 39.8%).
These small differences led two researchers from Manitoba to write in
The Lancet that “No overall survival advantage has been seen so
far.”
Before these figures can be relied on, the original trials need to be
analysed to see if they were methodologically sound. It is likely that
they contain results from many trials that have since been found to
be flawed. The history of randomised trials of adjuvant therapy for
breast cancer is dotted with examples of fraud and poor methodology.
In Italy, where the first positive survival effect was seen using the
combination chemotherapy of cyclophosphamide plus metho-trexate plus
fluorouracil (CMF), later analyses revealed that many patients had been
excluded because they could not complete the rather arduous treatment.
So the randomised comparisons were of healthier treated women against
all the controls, rendering the trial results invalid.
In the US randomised trials of chemotherapy were begun in earnest in
1957 under the auspices of the National Institutes of Health (NIH).
This program eventually became the National Surgical Adjuvant Project
for Breast and Bowel Cancer (NSABP), headed by Bernard Fisher. In 1994
Fisher was sacked from the program because he had failed to notify the
National Cancer Institute (NCI) of enrolment of inappropriate patients,
a fact that had been known for three years. Further irregularities were
then discovered in data from 12 other treatment centres. Some of the
earlier NSABP trials had also involved exclusions that would have affected
the results, as in the Italian trial.
The results referred to by Professor Langlands include the results of
both the Italian and NSABP Trials.
Adjuvant treatment of breast cancer with cytotoxic drugs is one of the
lynch pins of chemotherapy, and the NSABP was the key element within
that program for more than 40 years. According to Irwin D. Bross, writing
in the New England Journal of Medicine in 1994, “... the statistical
quality control was grossly inadequate in the NSABP studies. Hence,
whether or not some fraudulent cases are eliminated post hoc, any findings
lack scientific validity.” (7)
Ulrich Abel makes the following points about claims of efficacy in adjuvant
breast cancer therapy (6):
1. Good and consistent evidence of beneficial effects of adjuvant systemic
chemotherapy on survival exists only for breast cancer, and more specifically,
for patients with at most three positive lymph nodes.
2. So far no positive results seem to have been published for definitely
postmenopausal patients.
3. The restriction of beneficial effects to this small group appears
somewhat strange.
4. It is probable therefore that the effect is not due to the direct
cytotoxic effects on the tumour but rather to treatment-related suppression
of the ovarian function.
Chemotherapy for Invasive Cervical Cancer
Claims have recently been made that chemotherapy helps with invasive
cervical cancer. In fact, the US National Cancer Institute is claiming
a breakthrough in the treatment of late-stage invasive cervical cancer
according to a news item in the Sydney Morning Herald of 24 February,
1999. They claim this is the first breakthrough in the treatment of
this type of cancer in more than 40 years. (Many years ago it was being
claimed that surgery was effective. This claim has now been abandoned.)
However, this new evidence warrants closer consideration because it
is based on the results of randomised trials. The evidence found from
5 randomised trials is that adding chemotherapy in the form of cisplatin
at the same time as radiotherapy, following hysterectomy, increased
the 3-year survival rate by about 10 to 12%.
Thus for women with Stage IIB, III and IVA cancer, survival increased
from 63% to 75%. For women with earlier invasive cancer, Stage IA2,
IB and IIA, survival increased from 77% to 87%. This suggests that chemotherapy
and radiotherapy have a synergistic effect when used together, and possibly
that chemotherapy stops cancer cells from repairing the damage caused
by radiation.
Unfortunately, trials comparing these types of treatment with no treatment
have never be carried out, so it is also possible that percentage survival
is increasing towards what it would otherwise be without treatment.
Radiotherapy has been found to increase deaths in many types of cancer,
so it is possible that the same result could have been achieved simply
by eliminating the radiotherapy.
After considering these developments, there is no reason for changing
my original estimate that fewer than 6% of cancer cases would benefit
from chemotherapy.
Chemotherapy for Neuroblastoma in Children
A recent case involving a court ordering chemotherapy against the parents’
wishes for a child with a neuroblastoma raises the question - is chemotherapy
effective against this type of tumour? Neuroblastomas are tumours that
can occur anywhere in the sympathetic nervous system, as well as the
adrenal gland, the chest or pelvis. The response rate is said to be
59% with cyclophosphamide and combinations involving high-dose cisplatin,
vincristine and other drugs. (1) For high-risk patients, the survival
rate is said to be 15% “despite several therapeutic approaches”.
(1)
This contrast between response rate and survival rate is a good example
of the invalidity of most claims for efficacy with chemotherapy. This
low survival rate is confounded by the fact that neuroblastomas sometimes
regress spontaneously.
3. How Much Harm Does Chemotherapy Do?
There are three main areas of harm:
Weakening the body’s natural defences Increasing mortality Decreasing
the quality of life
Weakening the Immune System
Chemotherapy has been found to reduce the activity of the immune system’s
natural killer cells by 96%. (8) So if there are tumours growing elsewhere
in the body and if the immune system helps to control tumour growth,
then chemotherapy could make things worse by allowing more rapid growth
of the other tumours. However there is little hard evidence from orthodox
immunotherapy that the immune system is a major controlling factor.
In fact, a recent editorial reporting an immunotherapy conference in
Canberra in September 1998 suggests it might be a major factor only
in cancers of viral origin. (9)
On the other hand, immune-boosting therapy as practised at the Immuno-
Augmentative Therapy Clinic in the Bahamas, appears to produce between
15% and 18% 5-year survival with late-stage cancer patients. (10) Similarly
the Issels Wholebody Therapy produced 16.6% 5-year survival among late-stage
cancer patients. (11) (Expected 5-year survival for late-stage cancer
patients using orthodox therapies is less than 2%.) These two therapies
are based on boosting the immune system using natural methods, so it
appears that orthodox immunotherapy and alternative immune-boosting
techniques must be different and produce different results.
Increasing Mortality
By analysing non-cancer deaths among cancer patients it becomes clear
that orthodox therapies often do more harm than good. Doing this helps
explain certain claims of apparently effective treatments. (For example,
cancer treatment can damage the heart and cause deaths from heart failure.
This means fewer deaths from cancer.) As there is little evidence that
surgery causes harm other than temporarily suppressing the immune system,
(8) it would appear that most of the harm is done by radiotherapy and
chemotherapy.
Analysis of the records of 1.2 million cancer cases in the US SEER (Surveillance,
Evaluation and End Results) database showed that non-cancer deaths accounted
for 21% of all deaths. These deaths were in excess of the rate expected
for such patients. This excess was observed in all types of cancer with
an overall figure of 37%. The excess ranged from 9% for breast cancer
to 173% for lung cancer. (12) During the year following diagnosis, this
excess was about 5 times higher, so it ranged from about 50% for breast
cancer to about 800% for lung cancer. The authors attributed this effect
to the damage caused by cancer treatment (presumably mainly radiotherapy
and chemotherapy).
Decreasing the Quality of Life
There is no shortage of evidence that chemotherapy usually causes a
serious reduction in the quality of life. The only question is whether
or not the worsening in the quality of life is justified in view of
the very limited claimed increased survival.
4. What Are the Opinions of Practising Oncologists
About the Efficacy of Chemotherapy?
The following are extracts from the Home Page of the Burzynski Research
Institute on the World Wide Web (13):
“... In an article entitled “Chemotherapy: Snake-Oil Remedy?”
that appeared in the Los Angeles Times of 1-9-87, Dr. Martin F. Shapiro
explained that while “some oncologists inform their patients of
the lack of evidence that treatments work... others may well be misled
by scientific papers that express unwarranted optimism about chemotherapy.
Still others respond to an economic incentive. Physicians can earn much
more money running active chemotherapy practices than they can providing
solace and relief... to dying patients and their families.”
“Dr. Shapiro is hardly alone. Alan C. Nixon, PhD, Past President
of the American Chemical Society, wrote that, “As a chemist trained
to interpret data, it is incomprehensible to me that physicians can
ignore the clear evidence that chemotherapy does much, much more harm
than good”.”
“In 1986, McGill Cancer Centre scientists sent a questionnaire
to 118 doctors who treated non-small-cell lung cancer. More than 3/4
of them recruited patients and carried out trials of toxic drugs for
lung cancer. They were asked to imagine that they themselves had cancer,
and were asked which of six current trials they themselves would choose.
Sixty-four of the 79 respondents would not consent to be in a trial
containing cisplatin, a common chemotherapy drug. Fifty-eight found
all the trials unacceptable. Their reason? The ineffectiveness of chemotherapy
and its unacceptable degree of toxicity.” (14)
The more familiar these doctors were with the treatment, the less likely
they were to accept it for themselves.
Similar findings came from two other studies published in 1987. (15,
16)
A study of how expert physicians would wish to be treated for genito-urinary
cancer found a similar situation in 1988. (17)
In relation to the treatment of 252 advanced breast-cancer patients,
one author observed that the “risk” of being treated by cytotoxic
therapy was three times as high in patients in the terminal stage as
in the remainder of the patients. (18) As Abel points out, this does
not point to the use of a therapy that is particularly geared to patients’
well-being. (6)
In March 1989, the German biostatistician, Dr Ulrich Abel, investigated
physicians’ choices in cancer treatment. He received 150 replies
to a questionnaire sent to oncologists and research units around the
word, trying to gauge these doctors’ feelings about the use of
chemotherapy in advanced carcinoma. He reported that, “The personal
views of many oncologists seem to be in striking contrast to communications
intended for the public”. (1, 6)
5. And Some Other Opinions:
“... The failure of chemotherapy to control cancer has become apparent
even to the oncology establishment. Scientific American recently featured
a cover story entitled: ‘The War On Cancer - It’s Being Lost.’
In the article, eminent epidemiologist, John C. Bailar III, MD, PhD,
Chairman of the Department of Epidemiology and Biostatistics at McGill
University, cited “the relentless increase in cancer deaths in
the face of growing use of toxic chemotherapy”. He concluded that
scientists must look in new directions if they are ever to make progress
against this unremitting killer.” (13)
In a 1997 reassessment of the situation, Bailar’s view had not
changed. (19)
“... John Cairns, professor of microbiology at Harvard University,
published a devastating 1985 critique in Scientific American. “Aside
from certain rare cancers, it is not possible to detect any sudden changes
in the death rates for any of the major cancers that could be credited
to chemotherapy. Whether any of the common cancers can be cured by chemotherapy
has yet to be established”. (13)
“... Why so much use of chemotherapy if it does so little good?
Well for one thing, drug companies provide huge economic incentives.
In 1990, $3.53 billion was spent on chemotherapy. By 1994 that figure
had more than doubled to $7.51 billion. This relentless increase in
chemo use was accompanied by a relentless increase in cancer deaths.”
(13)
Oncologist, Albert Braverman, MD, wrote in 1991 that, “No disseminated
neoplasm (cancer) incurable in 1975 is curable today... Many medical
oncologists recommend chemotherapy for virtually any tumour, with a
hopefulness undiscouraged by almost invariable failure.” (13)
The main problem with chemotherapy is that the large majority of people
is generally unaware that in most cases chemotherapy does more harm
than good. Most doctors who are knowledgeable in the area know this
and will admit it in private. When an oncologist is asked what he or
she can do for a patient’s cancer, it is difficult for them to
say - “Chemotherapy is unlikely to help you”!
References:
1. Moss, R.W., Questioning Chemotherapy, (Equinox Press, New York, 1995).
2. Lilleyman, J.S., Childhood Leukemia - the facts, (Oxford University
Press, Oxford, 1994).
3. Enstrom, J.E. & Austin, D.F., 'Interpreting Cancer Survival
Rates', Science, 1977; 195: 847-851.
4. Peto, J. & Easton, D., 'Cancer Treatment Trials - past failures,
current progress and future prospects', Cancer Survey, 1989; 8:
513-533.
5. Benjamin, D.J., 'The Efficacy of Surgical Treatment of Cancer',
Medical Hypotheses, 1993; 40 (2): 129-138.
6. Abel, U., 'Chemotherapy of Advanced Epithelial Cancer: a critical
review', Biomedicine and Pharmacotherapy, 1992; 46: 439-452.
7. Bross, I.D. New England Journal of Medicine, 1994; 331: 809.
8. Beitsch, P. et al., 'Natural Immunity in Breast Cancer Patients
During Neoadjuvant Chemotherapy and After Surgery', Surgical Oncology,
1994; 3 (4): 211-219.
9. Goodnow, C.C., Editorial. MJA, 1998; 169: 570.
10. Walters, R. Options - The Alternative Cancer Therapy Book, (Avery
Publishing, New York, 1993).
11. Issels, J., 'Immunotherapy in Progressive Metastatic Cancer
- A Fifteen-Year Follow-up', Clinical Trials Journal, August 1970:
357-365 with editorial on pp 355- 356.
12. Brown, Barry W. et al., 'Non-cancer Deaths in White Adult Cancer
Patients', JNCI, 1993; 85 (12): 979-987.
13. Chemotherapy Report, 'Do We Need A New Approach to Cancer?',
Burzynski Research Institute Home Page, www.cancermed.com/chemo.htm
14. McKillop, W.J., et al., 'The Use of Expert Surrogates to Evaluate
Clinical Trials in Non-small Cell Lung Cancer', Br J Cancer, 1986;
54: 661-667.
15. Hansen, H.H., 'Advanced Non-small-cell Lung Cancer: to Treat
Or Not to Treat?', Journal of Clinical Oncology,1987; 5: 1711-12.
16. Anonymous. 'Ein gnadenloses Zuviel an Therapie. Teil I. Zweifel
an den chemischen Waffen', Der Spiegel, 1987; 26, 128-47.
17. Moore, M.J., Tannock, I.F., 'How Expert Physicians Would Wish
to Be Treated If They Developed Genito-urinary Cancer', Abstract
No. 455. Proc. American Society of Clinical. Oncology, 1988; 7: 118.
18. Holli, K., Hakama, M., 'Treatment of the Terminal Stages of
Breast Cancer' British Medical Journal, January 7, 1989; 298(6665):13-14.
19. Bailar J.C. & Gornik H.L., 'Cancer Undefeated', New
England Journal of Medicine, 1997; 336 (22): 1569-1574.
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