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CHAPTER II
INTRODUCTION
AMYGDALIN, A NEW ANTICANCER AGENT
Dr. Jose Ernesto
Contreras Pulido, M.D.
A lecture given by our
Medical Director in the Xl Conference of the
Northwest Medical Confederation of the
Mexican Republic and the X Conference of the
Medical Federation of Baja California. July
15, 1980.
Chemotherapy for
cancer developed rapidly from 1945 when
nitrogen mustard was first used and is
considered to be the number one method of
systemic treatment of malignant neoplasms.
Its history goes back to Egyptian writings
in which is mentioned the use of caustic
substances in treating tumors of the skin
and also in the last century, to the use of
potassium arsenita (Fowler's solution) as an
anticancer agent, by Lissauer, in the 19th
century.
Although hope was
high, the general use of chemotherapy has
not improved the death rate for cancer in
the world with the exception of some 10
malignant neoplasms in which cures are
reported through the use of different
chemotherapeutic agents. The principal value
of chemotherapy has been that of a
predominantly palliative cancer treatment,
although it has proven to be curative in
some patients.
It is generally
accepted that the principal limitation to
chemotherapy in cancer treatment is the
enormous "tumoral load" that the majority of
the patients have at the time of diagnosis;
a tumoral load that exceeds that level which
can be effectively eliminated with tolerable
doses of cytotoxic and an tineoplastic drugs
currently available.
Therefore, the factor
which has had the most positive influence in
the cure rate of patients with cancer is the
early and accurate diagnosis of malignant
neoplasms.
More than 60% of those
patients who are diagnosed as having cancer
are only candidates for paliative treatment
through surgery, radiation, chemotherapy
and/or immunological therapy and in many of
them these forms of treatment are limited or
contraindicated because of their
ineffectiveness and toxicity.
During the last 10
years, the discovery of antiestrogens and
progestagens that have antitumoral value in
a practically nontoxic dosage has allowed
paliative treatment for some patients who
are not candidates for more aggressive and
toxic forms of treatment, and also, it has
been proven that the aphorism "In order for
a substance to be valuable as an
antineoplastic agent, it must be toxic," is
not valid in all cases. Now a nontoxic
substance in therapeutic dosage can have a
useful antineoplastic effect.
The search for more
nontoxic antineoplastic substances in
therapeutic dosages is justified and today I
wish to introduce one of them which is
AMYGDALIN, better known as Laetrile.
AMYGDALIN is a
substance of vegetable origin, frequently
extracted from the apricot pit and whose
physical and chemical identification has
been perfectly defined since the decade of
the 50's.
Since the decade of
the 60's the preclinical studies of toxicity
and antineoplastic effect on implanted and
spontaneous tumors in animals gave results
that allowed its experimental use in humans.
Since early 1970,
El Centro Medico y Hospital Del Mar has
carried out the studies of Phase I which
proved AMYGDALIN's nontoxicity in
therapeutic dosage through intravenous and
oral application. Phase II studies performed
on 1,200 cancer patients, the majority of
whom were not considered candidates for
conventional treatment, proved objectively
and subjectively, the anti-tumor effect of
AMYGDALIN already suggested by Phase I
studies. Several Phase III type studies are
currently being completed. The research
performed on patients with inoperable lung
cancer has shown that apart from reporting
well documented complete and partial
remission and stabilization, the average
survival of the patients was increased to
more than 59 weeks
from the diagnosis and more than 35 weeks
from the initial application of AMYGDALIN.
These figures compare favorably with the 25
weeks that is the average survival rate of
these patients from diagnosis.
We must emphasize that the subjective
benefits, primarily in tumor caused pain,
was present in more than 65% of the
patients. Practically 100% of the patients
who were using morphine derivatives were
able to substitute them for non-narcotic
analgesics after several weeks of using
AMYGDALIN.
We will soon have
results from Phase Ill research in patients
with breast, prostate and digestive tract
adeno-carcinoma which will increase our
experience with the clinical use of
AMYGDALIN.
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