SAN DIEGO — The American Association for Clinical Chemistry (AACC; Washington) kicked off its annual meeting here at the San Diego Convention Center Sunday as its opening plenary session featured a video montage outlining the "paradigm shifts" that the profession is facing as new tests are developed that require additional skills, namely genetic testing. And as the booming voice suggested, one of the important themes at this event is the strategic development of a whole new range of diagnostics.
These "companion" diagnostics come in a variety of types.
One is to detect the presence of disease even before the disease has presented with symptoms, so that by diagnosing early, there is more chance of successful therapy.
Another is to identify those patients who are at highest risk for a disease and therefore enable the launch of preventive therapy.
These diagnostic strategies come with a variety of names, thus far: "predictive" medicine, "preemptive" medicine, and the catch-all "personalized" medicine.
An additional focus of these diagnostic strategies is a corollary effort being hyped by drug companies and those closely monitoring drug effects: that the sector ultimately will produce a range of tests that will identify those patients who should not receive a drug because likely to experience adverse reactions (thus reducing the risks in the risk/benefit ratio), and those most likely to benefit from a particular drug.
In parallel with the increased emphasis on personalized medicine, the guest speaker for the kickoff event — and the recipient of The AACC Lectureship Award — was someone who has spent much of his career studying the impact of therapy on different patients suffering from acute lymphoblastic leukemia (ALL) at St. Jude Children's Research Hospital (Memphis, Tennessee).
William Evans, PharmD, CEO and director at St. Jude, said his quest in what is now known as pharmacogenomics, or alternatively as pharmacogenetics, began in the 1970s when he began tracking the fact that different patients, in his practice, children, despite being given the same dose of chemotherapy for ALL according to their body weight, responded to the chemotherapy in different ways with no known reason.
"We became interested in that variability" and how it could impact the success of the treatment, he told his audience.
The search to find the answer to that question has made him internationally known. Evans has received three Merit Awards from the National Institutes of Health and has authored more than 300 book chapters and scientific articles.
Today, pharmacogenomics has become something of a buzzword in laboratory medicine, and acknowledging a great deal of "hype" surrounding the concept, Evans also admitted to considerable uncertainty concerning where this effort ultimately will lead.
Thus far, though, both the science and the technology to enable pharmacogenomics have "progressed" in promising fashion, according to Evans.
Evans noted that cancer is the leading cause of death in children, and his work at St. Jude's demonstrated something other than what was originally thought: that is, that a particular child's cancer was resistant to chemotherapy.
His work demonstrated instead that it was not the particular cancer that was resistant but rather the particular child's genetic makeup. And that genetic makeup was the key to determining therapeutic response.
Thus, some children were not receiving enough chemotherapy, compared to those who might suffer severe toxicity from the same dose.
Evans suggested his experience with treating ALL might serve as an example to other researchers attempting to develop tests in pharmacogenomics — by "getting all the smart people you can in a room" and starting with some basics: how patients with specific diseases are treated with what therapy and determining the genetic differences of these patients and how these differences determine different responses to the same drugs.
For example, at St. Jude's, he said, "We have moved from giving every child the same amount of drug based on their body surface," to more tailored drug choices and regimens.
"Can pharmacogenomics lead to further improvements in treatment outcomes?" he asked.
He answered by saying that more research is likely to lead to better understanding of the etiology of cancer in adults, as well as the etiology of other diseases, from diabetes to obesity.
However, he cited the "complexities of pharmacogenomics" as a caution going forward.
For example, he noted the fact that "multiple genetic mechanisms may influence a single gene and single pharmacogenomics treatment."
Another of the complexities with cancer is that "cancer cells often have chromosomal abnormalities, e.g. extra copies of specific chromosomes."
Still, it can only be concluded that the pharmacogenomics efforts will be worth the findings, if Evans' work is any model.
And that is what doctors currently say they are seeing on the horizon the possibility of "surpassing the 90% cure" rate in ALL, he said.
But the promise of pharmacogenomics will involve many disciplines and much study.
"Pharmacogenomics," Evans said, "is a team sport."
All told, about 20,000 participants from 100 countries are swarming the exhibit and presentation spaces this year, reflecting the fact that one-third of the organization's membership is international — and representing the increasing globalization of medicine, just as in other healthcare sectors.