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AMAS: A Blood Test for Detecting Cancer (has proved to be not effective for Prostate Cancer, with a very high percentage of false negatives). See instead, the very effective PCD Sonograms
By Jonathan McDermed, Pharm.D.
A Malignin is a 10,000 Dalton (unit of atomic size) polypeptide that
is found in most cancerous cells regardless of their cell type or
location.
The AMAS (Anti-Malignin Antibody in Serum) test measures the amount
of an IgM antibody in the blood that the cancer patient's immune system
produces against this "antigen" (an antigen is recognized
by the immune system as "foreign" because it is not part
of the body's normal biology). AMAS is activated early in the course
of cancer when patients are asymptomatic and during their course of
illness, but is not activated in patients with terminal cancer.
Diagnosing Early Stage Cancer
This anticancer antibody was discovered 21 years ago by the neurochemist,
Samuel Bogoch, M.D., Ph.D., who evaluated this test on more than 6,000
patients. The AMAS test was subsequently patented by Oncolab, Inc.
and approved for use by the FDA.
According to Oncolab, AMAS levels higher than 135 micrograms per
milliliter (mcg/mL) are detected in patients with cancer 95% to 99%
of the time. On the other hand, the AMAS level in the blood is below
135 mcg/mL if there is no cancer, or if cancer has been treated and
cured. The AMAS test has been used two ways: for cancer screening
and to monitor patients for possible recurrence of cancer after treatment.
Cancer is not detectable in its early stages by conventional methods,
and early diagnosis offers the best chance for cure. The AMAS test
has been effective in detecting early-stage cancer.
Researchers at the San Francisco Medical Research Foundation, which
has been monitoring development of this test for years, claim that
"the AMAS may dramatically reduce the need for invasive biopsies
of suspicious lesions found on CT scans, MRI's or needle biopsies.
AMAS may also help patients avoid needless pain and suffering, and
reduce the cost of medicine."
In a 1990 abstract published in the Proceedings of the American Association
for Cancer Research, AMAS was used to evaluate patients with suspicious
mammograms. In addition to AMAS, patients had serum levels obtained
for four other tumor markers - CEA, CA 15-3, CA 19-9 and CA 125. The
average AMAS level in 154 control subjects (women who did not have
cancer) was 77 mcg/mL. Three of these patients had positive AMAS levels
135 mcg/mL. Subsequently, one was diagnosed as having in situ (microscopic
malignant cells which is curative) cancer of the cervix, another had
basal cell cancer (curable skin cancer), and the third had ulcerative
colitis (inflammation of the colon), but did not have cancer.
Twenty patients with biopsy-positive breast cancer had an average
AMAS level of 220 mcg/ml prior to surgery, and many of the tumors
removed were of millimeters in size. In this study, the sensitivity
of the AMAS test for breast cancer was 95% compared to 0% for CEA,
11% for CA 15-3, 5% for CA 19-9 and 16% for CA 125 (ref. 1).
Monitoring Post-Treatment
For cancer patients who have completed treatment, the AMAS test has
been promoted as a component of ongoing monitoring to be sure that
cancer hasn't recurred. In the breast cancer abstract cited above,
AMAS levels returned to normal in 18 of the 20 women following mastectomy.
One of these patients developed lymphoma (a cancer which has spread
to the lymph nodes), 3 months after her AMAS test abnormality was
found (48 days after breast surgery). The remaining patient had a
persistent elevation of AMAS for more than 6 months after mastectomy
without full diagnostic work-ups revealing any evidence of cancer.
In another study, AMAS was found to be elevated in 21 of 118 patients
screened, all of whom had documented cancer. The AMAS test was negative
in the remaining 97 patients, all of whom had benign diseases. In
56 patients who were undergoing treatment, changes in AMAS test results
were consistent with the clinical course in 94.1% of patients (ref.
2). In other words, these 56 patients who had elevated AMAS levels
before treatment showed a response to the treatment, and their AMAS
levels returned to normal. Supporters for this test claim that AMAS
will allow cancer specialists to more precisely recommend radiation
and/or chemotherapy for only those patients with recurrent cancer
who need the treatment.
Dr. Bogoch and his fellow evaluators see the AMAS test as invaluable
in the ongoing war against prostate and all other forms of cancer.
The San Francisco group believes that the most likely use for the
test in the future will be as an annual cancer screening tool for
all adults, beginning as early as age 35, particularly if there is
a history of cancer in the patient's family.
Source: "An Accurate Blood Test For Cancer." The San Francisco
Medical Research Foundation, Seattle, WA.
Ref. l : Thornwaite J.T., Derhagopian R. and Riemer
W.: Determination of antinmlignin in patients with suspicious mammograms.
Proceedings of the American Association for Cancer Research (31 :A
1550, 1990.)
Ref. 2: Abrams M.B., Bekarek K.T., Bogoch S., et al:
Early detection and monitoring of cancer with the anti-malignin test.
Cancer Detection and Prevention 18(1): pp. 65-78, 1994.
How Should You Use This Information?
The PSA blood test and digital rectal examination (DRE) remain the
foundation for the current screening of patients for prostate cancer.
Note: The preceding article was reviewed by Stephen B. Strum, M.D.
His comments are as follows:
New diagnostic tests that accurately detect cancer before it becomes
clinically apparent are welcomed by all medical oncologists. When
the AMAS test was being formally evaluated by the FDA in 1994 and
1995, I enthusiastically supported AMAS by offering blood samples
from more than 40 patients in my medical practice for testing, the
vast majority of whom had prostate cancer.
Using medically-accepted terminology, we found the AMAS test to have
a relatively high degree of specificity and positive predictive value
(both 80%) in all of the patients that we evaluated. Dr. Avrum Bluming,
another medical oncologist in Southern California, has done AMAS tests
in over 60 patients in his practice. His data indicated a false positive
rate of <5% and a false negative rate of approximately 7% for AMAS.
Clearly, the AMAS test has demonstrated clinical usefulness for the
diagnosis of cancer. Therefore, we ask how does AMAS improve upon
or add to diagnostic or prognostic information for prostate cancer
patients that can already be obtained by physicians using PSA and
other diagnostic tools? For the moment, the answer is "we still
don't know." However, we are currently working closely with Dr.
Bogoch to answer these questions.
To definitively diagnose prostate cancer, PSA and certain other tumor
markers should always be used in conjunction with a DRE (digital rectal
examination) and TRUSP (trans-rectal ultrasound of the prostate) with
needle biopsies. A single blood test result (PSA, AMAS or any other)
should never be used alone to establish or refute the possible diagnosis
of cancer.
Research continues to decipher the relationships between the immune
system and the onset and growth of cancer cells. In the near future,
more specific immunologic treatments will be discovered that will
likely be more effective than AMAS to diagnose and treat human cancers.
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