What if Sen. Edward Kennedy — or any person — could have taken a simple blood test that would have revealed a growing brain cancer long before the symptomatic seizure occurred? Could an earlier diagnosis improve a prognosis? More than likely.
Surprisingly, a test to do such early stage checking for cancer has been available for three decades. That test, ironically developed in collaboration with the institution that is treating Kennedy, Massachusetts General Hospital (Boston), now is the subject of a reinvented marketing effort by Oncolab (also Boston).
"Its been a sleeper," Oncolabs founder, Samuel Bogoch, MD, PhD, told Medical Device Daily. "Its been available and permitted by the FDA since 1977. But nobody noticed that it was available and we werent particularly good at marketing. We were basically an R&D group and hadnt marketed at all."
Amas allows early detection of a wide range of human cancers. It detects a circulating, cancer-specific antibody, the anti-malignin antibody, in human serum. Anti-malignin is a normal antibody in humans which has been found to increase with age, as the risk of cancer increases. During the early stages of cancer, the anti-malignin antibody increases markedly in concentration.
Determining the concentration of this antibody is the basis for Amas.
"It was originally discovered for glioblastoma [brain cancer] and then we found out it was a general marker for any transformed or malignant cell," Bogoch said. "We figured out that its measuring rapid replication. When cells replicate more rapidly than usual, they produce a peptide called a replicon and these replicons increase in concentration in cells. So when these increase in concentration, the body makes antibodies against them. Our test measures the antibodies. Its quite unique."
There are other blood tests that help to diagnose cancer, but those tests measure carcinoembryonic antigen (CEA), which measure less well-defined antigens whose serum levels tend to be inconstant but elevated late in the disease. Alternately, the Amas test measures a well-defined antibody whose serum levels rise early in the course of the disease.
In some cases, the Amas test has been positive early, one to 19 months before clinical detection of cancer
But it only works if the cancer is active and rapidly replicating. "A lot of cancers go through periods that are dormant. For example in prostate cancer, 80% to 90% dont do much early on, but 10% replicate," Bogoch said. "The same holds true with breast cancer; it doesnt get very active early.
"The usefulness of our test is that it measures early. After cancer advances, the antibodies are knocked out," he said. "So, all of the existing tests are good for middle- and late-stage cancers when ours is not good."
Because it monitors an aspect of the bodys immune response to cancer, rather than cancer antigens or cancer cells in the bloodstream, the Amas test is especially accurate early in the recurrence or first occurrence of cancer, when clinical signs of the disease may not be evident or may just be emerging.
Patients in remission after successful cancer therapy, or a healthy normal population, generally have normal circulating levels of the antibody assayed in the test. Amas false positive rate, shown to be 5% in double-blind clinical studies, means that elevated results on the test are highly suspicious for a recurrence or unrelated new occurrence of cancer, and warrant further clinical investigation.
So, is it time to incorporate the Amas test into every persons physical, along with other standard blood work-ups?
"Nobody disagrees that if you are at high risk, you should take the test," Bogoch said. "If you had cancer before or are at high risk, with a heavy genetic load, it should be taken. Its being ordered by doctors every three to six months in high-risk patients.
"Ten years ago," he said, "nobody talked about early detection, and nobody thought antibodies were important to cancer. Only in the last three to four years have antibodies been used in therapy."
Bogoch said, "Theres been a marked change in the environment. Early detection is important and better for treatment. And antibodies seem to be more important in cancer."
The $165 test already is approved for reimbursement via Medicare.
Oncolab has launched a new sales and marketing campaign as the company tries to get the word out about its previously unknown test to detect cancer at its earliest stages.