“Targeted therapy.” It’s the holy grail of cancer research these days. If you listen to its most vocal proponents, it’s the path towards “personalized medicine” that improves survival with much lower toxicity. With the advent of the revolution in genomics that has transformed cancer research over the last decade, including the petabytes of sequence and gene expression data that pour out of universities and research institutes, the promise of one day being able to a patient’s tumor, determining the specific derangements in genome and gene expression that drive its uncontrolled proliferation, and finding drugs to target these abnormalities seems more tantalizingly close than ever. Indeed, it seems so close that even dubious practitioners, such as Stanislaw Burzynski, have jumped on the bandwagon, co-opting the terms used by real oncologists and real cancer researchers to sell “personalized gene-targeted cancer therapy,” which in their hands are really no more than a parody of efforts to synthesize the enormous quantity of genomic data each patient’s tumor possesses and figure out how best to take advantage of it, a “personalized genomic therapy for dummies,” if you will.
That’s not to say that there aren’t roadblocks to realizing this vision. The problems to be overcome are substantial, and I’ve discussed them multiple times before. For example, just a couple of weeks ago I discussed an example of just what it takes to apply these new genomic techniques to an individual patient. The resources required are staggering, and, more problematic, there often aren’t any single “magic bullet” molecular pathways identified that can be targeted with existing drugs. The case I discussed was a fortunate man indeed in that such a pathway was identified, but most tumors are driven by many derangements in growth control, metabolism, migration, and the other hallmarks of malignancy described by Robert Weinberg. Worse, in many cases we don’t even have drugs that can attack many of the abnormalities that drive cancer progression. Then there’s the issue of tumor heterogeneity, which comes about because cancer is as good example of a disease as I can think of in which evolution due to natural selection results in incredible differences in the cancer cells in one part of the tumor compared to other parts of the tumor or in the tumor metastases. A “targeted” therapy that targets the genetic abnormalities in one part of the cancer might well fail to target the genetic abnormalities driving another part of the tumor.
Last week, I wrote a magnum opus of a movie review of a movie about a physician and “researcher” named Stanislaw Burzynski, MD, PhD, founder of the Burzynski Clinic and Burzynski Research Institute in Houston. I refer you to my original post for details, but in brief Dr. Burzynski claimed in the 1970s to have made a major breakthrough in cancer therapy through his discovery of anticancer substances in the urine that he dubbed “antineoplastons,” which turned out to be mainly modified amino acids and peptides. Since the late 1970s, when he founded his clinic, Dr. Burzynski has been using antineoplastons to treat cancer. Over the last 25 years or so, he has opened a large number of phase I and phase II clinical trials with little or nothing to show for it in terms of convincing evidence of efficacy. Worse, as has been noted in a number of places, high doses of antineoplastons as sodium salts are required, doses so high that severe hypernatremia is a concern.
Although antineoplastons are the dubious cancer therapy upon which Dr. Burzynski built his fame, they aren’t the only thing he does. Despite the promotion of the Burzynski Clinic as using “nontoxic” therapies that “aren’t chemotherapy” by “natural medicine” cranks such as Joe Mercola and Mike Adams, Dr. Burzynski’s dirty little secrets, at least as far as the “alternative medicine” crowd goes, are that (1) despite all of the attempts of Dr. Burzynski and supporters to portray them otherwise antineoplastons are chemotherapy and (2) Dr. Burzynski uses a lot of conventional chemotherapy. In fact, from my perspective, it appears to me as though over the last few years Dr. Burzynski has pivoted. No longer are antineoplastons the center of attention at his clinic. Rather, these days, he appears to be selling something that he calls “personalized gene-targeted cancer therapy.” In fact, it’s right there in the first bullet point on his clinic’s webpage, underlined, even! Antineoplastons aren’t even listed until the third bullet point.
“Personalized medicine.” You’ve probably heard the term. It’s a bit of a buzzword these days and refers to a vision of future medicine in which therapies are much more tightly tailored to individual patients than they currently are. That’s not to say that as physicians we haven’t practiced personalized medicine before; certainly we have. However it has only been in the last decade or so that our understanding of genomics, systems biology, and cell signaling have evolved to the point where the vision of personalized medicine based on each patient’s genome and biology might be achievable within my lifetime.
I was thinking about personalized medicine recently because of the confluence of several events. First, I remembered a post I wrote late last year about integrating patient values and experience into the decision process regarding treatment plans. Second, a couple of months ago, Skeptical Inquirer published an execrablynihilistic article by Dr. Reynold Spector in Skeptical Inquirer in which he declared personalized medicine to be one of his “seven deadly medical hypotheses,” even though he never actually demonstrated why it is deadly or that it’s even really a hypothesis. Come to think of it, with maybe–and I’m being very generous here–one exception, that pretty much describes all of Dr. Spector’s “seven deadly medical hypotheses”: Each is either not a hypothesis, not deadly, or is neither of the two. Third, this time last week I was attending the American Association for Cancer Research (AACR) meeting in Orlando. I don’t really like Orlando much (if you’re not into Disney and tourist traps, it’s not the greatest town to hang out in for four days), but I do love me some good cancer science. One thing that was immediately apparent to me from the first sessions on Sunday and perusing the educational sessions on Saturday was that currently the primary wave in cancer research is all about harnessing the advances in genomics, proteomics, metabolomics, and systems and computational biology, as well as the technologies such as next generation sequencing (NGS) techniques to understand the biology of each cancer and thereby target therapies more closely to what biological abnormalities drive each cancer. You can get an idea of this from the promotional video the AACR played between its plenary sessions:
Which is actually a fairly good short, optimistic version of my post Why haven’t we cured cancer yet? As I mentioned before, with this year being the 40th anniversary of the National Cancer Act, as December approaches expect a lot of articles and press stories asking that very question, and I’m sure this won’t be the last time I write about this this year. (more…)
A topic of growing interest (and concern) at SBM is laboratory and diagnostic test pseudoscience. Bogus tests are everywhere, and Kimball Atwood recently discussed several of them. But over the past several years, diagnostic tests have emerged that appear to be science-based and offer gene-level insights into your health. And these tests don’t even require a physician’s visit – just a swab of saliva and a credit card get you reams of information on your genetics, traits, and risks of dozens of diseases. It looks like the ultimate in consumer health information, with the potential to offer truly personalized treatment strategies. Companies like 23andme, deCODEme, and Navigenics all promise “genetic insights” to improve your health. How could this information be anything but helpful?
Personalized medicine describes medical practices that use information about a person’s genes, proteins, and environment to prevent, diagnose and treat disease. Science-based practice has routinely incorporated environmental advice (e.g., diet and exercise) into medical management. And there are a number of genetic tests in routine use that are well established, clinical validated, and are highly predictive of future outcomes, such as tests for Huntington’s disease and hereditary breast cancer. (more…)