Cancer Research Moves Forward by Fits and Starts

I recently returned from the American Association for Cancer Research (AACR) meeting held in Philadelphia. AACR is attended by basic researchers focused on the molecular basis of oncology. Many of the concepts reported will percolate to the clinical literature over the coming years.

There were many themes including the revolution in immunologic therapy that took center stage, as James Allison, PhD, received the Pezcoller Prize for his groundbreaking work in targeting immune checkpoints. The Princess Takamatsu Award given to Dr. Lewis Cantley, recognized his seminal contribution to our understanding of signal transduction at the level of PI3K. A series of very informative lectures were provided on “liquid biopsies” that examine blood, serum and other bodily fluids to characterize the process of carcinogenesis. These technologies have the potential to revolutionize the diagnosis and monitoring of cancers.

The first symposium I attended described the phenomenon of chromothripsis. This represents a catastrophic cellular trauma that results in the simultaneous fragmentation of chromosomal regions, allowing for rejoining of disparate chromosome components, often leading to malignancy and other diseases. I find the concept intriguing, as it reflects the intersection of oncology with evolutionary developmental biology, reminiscent of the outstanding work of Stephen Jay Gould. His theory of punctuated equilibrium, from 1972, challenged many long held beliefs in the study of evolution.

Since the time of Charles Darwin, we believed that evolution was slow and continual.  New attributes were selected under environmental pressure and the population carried those characteristics forward toward higher complexity. Gould and his associate, Niles Eldredge, stated that evolution was anything but gradual. Indeed, according to their hypothesis, evolution occurred as a state of relative stability, followed by brief episodes of disruption. This came to mind as I contemplated the implications of chromothripsis.

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According to the new thinking (chromothripsis and its related fields), cancer may arise as a single cell forced to recover from what would otherwise be catastrophic injury. The reconfiguring of genetic elements scrambled together to avoid apoptosis (programmed cell death) provides an entirely new biology that can progress to full-blown malignancy.

By this reasoning, each patient’s cancer is unique. The results of damage control whereby chromosomal material is rejoined haphazardly would be largely unpredictable. These cancers would have a fingerprint all their own, depending on which chromosome was disrupted.

As high throughput technologies and next generation sequences continue to unravel the complexity of human cancer, we seem to be more and more like those who practice stone rubbing to create facsimiles of reality from the “surface” of our genetic information. Like stone rubbing, practitioners do not create the images, but simply borrow from them.

With each symposium, we learn that cancer biology does not come to be, but is. Grasping the complexity of cancer requires the next level of depth. That level of depth is slowly being recognized by investigators from Harvard University to Vanderbilt as the measurement of humor tumor phenotypes.

Cancer is phenotypic and human biology is phenotypic. Laboratory analyses that allow us to measure, grasp, and manipulate phenotypes are those that will provide the best outcomes for patients. Laboratory analyses like the EVA-PCD.

Is Cancer a Genetic Disease?

I recently had the opportunity to meet two charming young patients: One, a 32-year-old female with an extremely rare malignancy that arose in her kidney and the other a 33-year-old gentleman with widely metastatic sarcoma.

Both patients had obtained expert opinions from renowned cancer specialists and both had undergone aggressive multi-modality therapies including chemotherapy, radiation and surgery. Although they suffered significant toxicities, both of their diseases had progressed unabated. Each arrived at my laboratory seeking assistance for the selection of effective treatment.

With the profusion of genomic analyses available today at virtually every medical center, it came as no surprise that both patients had undergone genetic profiling. What struck me were the results. The young woman had “no measurable genetic aberrancies” from a panoply of 370 cancer-causing exomes, while the young man’s tumor revealed no somatic mutations and only two germ-line SNV’s (single nucleotide variants) from a 50 gene NextGen sequence, neither of which had any clinical or therapeutic significance.

What are we to make of these findings? By conventional wisdom, cancer is a genetic disease. Yet, neither of these patients carried detectable “driver” mutations. Are we to conclude that the tumors that invaded the cervical vertebra of the young woman, requiring an emergency spinal fusion, or the large mass in the lung of the young man are not “cancers”? It would seem that if we apply contemporary dogma, these patients do not have a cancer at all. But nothing could be further from the truth.

Cancer as a disease is not a genomic phenomenon. It is a phenotypic one. As such, it is extremely likely that these patients’ tumors are successfully exploiting normal genes in abnormal ways. The small interfering RNAs or methylations or acetylation or non-coding DNA’s that conspired to create these monstrous problems are too deeply encrypted to be easily deciphered by our DNA methodologies. These changes are effectively gumming up the works of the cancer cell’s biology without leaving a fingerprint.  

I have long recognized that cellular studies like the EVA-PCD platform provide the answers, through functional profiling, that genetic analyses can only hope to detect. The assay did identify drugs active in these patients’ tumor, which will offer meaningful benefit, despite the utter lack of genetic targets. Once again, we are educated by cellular biology in the absence of genomic insights. This leaves us with a question however – is cancer a genetic disease?

In Cancer Research: An Awakening?

In 2005, as the Iraq War reached a low point with casualties mounting and public support dwindling, Sunni tribesman in the Anbar Province arose to confront the enemy. Joining together as an ad hoc army these fighters turned the tide of the war and achieved victories in the face of what had appeared at the time, to be overwhelming odds.

I am reminded of this by an article in The Wall Street Journal by Peter Huber and Paul Howard of the Manhattan Institute that examined the bureaucracy of drug development. It raised the question: Are new cancer treatments failures or is the process by which they are approved a failure? They describe “exceptional responders” defined as patients who show unexpected benefits from drug treatments. Using molecular profiles, they opine, scientists will unravel the mysteries of these individuals and usher in an era of personalized medicine. Thus, rigid protocols that use drugs based upon tumor type e.g. lung vs. colon fail because they do not incorporate the features that make each patient unique – an awakening.

The example cited is from Memorial Sloan-Kettering where a patient with bladder cancer had an unexpected response to the drug Everolimus (approved for kidney cancer). Subsequent deep sequencing identified a genetic signature associated with sensitivity to this drug. While it is a nice story, I already knew it very well because it had been repeated many times before and would in the past have been dismissed as an “anecdote.” It is precisely because of its rarity that it has been repeated so many times.

The WSJ analysis strikes a familiar chord. For decades, we have decried the failure of rigid clinical trials that underestimate a patient’s unique biology yet cost millions, even billions of dollars, while denying worthy candidates new treatments under stultifying disease-specific designs.

We pioneered phenotypic (functional) analyses (the EVA-PCD platform) to examine whole cell models as we explored drug response profiles, novel combinations and new targets. It is regrettable that these WSJ authors, having raised such important issues, then stumble into the same tantalizing trap of molecular diagnostics, and call for bigger, better, faster genomic analyses.

Cancer patients need to receive treatments that work. They do not particularly care why or how they work, just that they work. These authors seem to perpetuate the myth that we must first understand why a patient responds before we can treat them. Nothing could be further from the truth.

Alexander Fleming knew little about bacterial cell wall physiology when he discovered penicillin in 1928, and William Withering knew nothing about the role of muscle enzymes in congestive heart failure when he discovered digoxin extracts in 1785. Would anyone argue that we should have waited decades, even centuries to apply manifestly effective therapies to patients because we did not have the “genes sequenced?’

We may be witness to an awakening in cancer drug development. It may be that a new understanding of individualized patient response will someday provide better outcomes, but platforms with the proven capacity to connect patients to available treatments should be promoted and applied today.

Breakthroughs In Cancer?

Coco Chanel, the icon of 20th century fashion once said, “Only those with no memory insist on their originality.” I am reminded of this quote as I review recent discoveries in cancer, among them, the recognition that cancer represents a dysregulation of cellular metabolism.

The field of metabolomics (the systematic study of cellular energy production), explored by investigators over the last decade is little more than the rediscovery of enzymology (a branch of biochemistry that deals with the properties, activity, and significance of enzymes), biochemistry (the science dealing with the chemistry of living matter) and stoichiometry (the part of chemistry that studies amounts of substances that are involved in reactions), pioneered by investigators like Albert Lehninger, Hans Krebs, Otto Warburg, and Albert Szent-Gyorgyi. These innovators used crude tools to explore the basis of human metabolism as they crafted an understanding of bioenergetics (the study of the transformation of energy in living organisms) and oxidative phosphorylation (processes occurring in the cell’s mitochondrion that produce energy through the synthesis of ATP (energy carrier of the body).

More recently, scientists wedded to genomics have slowly come to recognize the limitations of their approach and have returned to the field of phenotypic (the observable physical or biochemical characteristics of an organism analysis.

While newcomers to the field claim to be the first to recognize the role of cellular biology in tumor biology, a cadre of dedicated investigators had already charted these waters decades earlier. Beginning with the earliest studies by Siminovitch, McCulloch and Till, subsequent investigations by Sydney Salmon and Anne Hamburger, developed the earliest iteration of cellular studies for the examination of cancer biology in primary culture.

Ovarian Cancer

The work of Black and Spear, published in the 1950s similarly explored the study of human cellular behavior for the study of cancer research. While Larry Weisenthal, Andrew Bosanquet and others established useful predictive methodologies to study cellular phenotype, their seminal contributions have gone largely unrecognized.

Today, start-up companies are examining cellular biology to predict cancer outcomes, each claiming to be the first to recognize the importance of cell death events in primary culture. The most recent and widely touted in the literature is the use of mouse avatars. Implanting biopsied explants of tissue from patients into nude mice, they grow the cancers to desired size and then inject the drugs of interest to show tumor shrinkage. To the discerning eye however, it obvious that this represents little more than an expensive, inefficient, and extremely slow way to achieve that, which can be done more easily, inexpensively, and quickly in a tissue culture environment.

When I read the promotional material of some of the new entrants to this field, I am reminded of another quote, that of Marie Antoinette, who said, “There is nothing new except what has been forgotten.”

A New Use for One of the Oldest “New” Drugs

With the profusion of new targeted agents entering the clinical arena, a report from the American Society of Hematology bears consideration.

The trial known as the SORAML trial enrolled 276 patients with newly diagnosed acute myelogenous leukemia. The patients were between the ages of 18 and 60. All patients received a standard chemotherapy regimen. The patients were then randomized to receive Sorafenib or placebo. Patients on the Sorafenib arm then remained on a maintenance therapy for twelve months.

While the achievement of complete remission was almost identical between the two arms at 59% and 60%, the event free survival demonstrably favored the Sorafenib group at 20.5 months versus 9.2 months. At three years of follow-up 40% of the Sorafenib group were well with only 22% of the placebo group still in remission. This corresponds to a three-year relapse free survival of 38% for placebo and 56% for Sorafenib (P=0.017).

The results are of interest on several levels.
1.    Sorafenib a multitargeted tyrosine kinase inhibitor was approved in December 2005 for the treatment of renal cell carcinoma. This makes Sorafenib one of the first targeted agents to achieve FDA approval.

2.     Sorafenib has many modes of action and it is not entirely clear which of its functions were responsible for the superior survival in this AML study.

3.    Sorafenib’s approval reflects a rather convoluted and interesting history. When first developed the drug was designed to target the oncogene B-Raf. As a result the drug was introduced into early clinical trials for the treatment of advanced melanoma, a disease known to be associated with B-Raf mutation. As the drug proved ineffective, it appeared unlikely to gain FDA approval. That is, until it showed cross reactivity with VEGF pathway associated with tumor cell vascularity. A successful trial published in the New England Journal of Medicine then led to the approval.

Now, nine years later this old new drug has gained new life. This time in acute myelogenous leukemia.

The term “dirty drug” refers to agents that target many kinases at the same time. Sorafenib is an example of a “dirty drug.” However it is Sorafenib’s “dirty drug” quality that led first to its approval and most likely now leads to its application in AML. This reflects the fact that Sorafenib may be inhibiting B-Raf signaling associated with the common mutation in Ras upstream of B-Raf or it may reflect Flt3 a secondary activity associated with Sorafenib.

Indeed B-Raf and Flt3 may not be upregulated in every patient, but could serve a function of permissive activity granting an additional survival signal to the AML cells as they go through induction therapy. These subtleties of drug effect may escape genomic analysis as the true “target” may not be mutated, upregulated or amplified. No doubt the investigators in this study will conduct gene sequencing to determine whether there is a driver mutation associated with the advantage reported in this clinical study. What will be intriguing is to determine whether that advantage is an abnormal gene functioning within these cancerous cells or possibly a normal gene functioning abnormally in these cancer cells. More to come.

The Case for the Metabolic Basis of Cancer Gains Traction

Researchers from the Huntsman Cancer Institute at the University of Utah reported an interesting finding with far-reaching implications.

In their study of the rare tumor known as alveolar soft part sarcoma (ASPS), they examined the well-established chromosomal translocation that occurs between chromosomes 17 and X. This results in the production of a fusion protein dubbed ASPSCR1-TFE3. Like other fusion proteins described in malignancies such as lymphoma, acute pro-myelocytic leukemia and chronic myelogenous leukemia, a novel function occurs when two disparate genomic elements are spliced together.

In this instance, the ASPSCR1-TFE3 gene product functions as a lactate transporter. Strikingly, every mouse in which the gene was up regulated developed a tumor. The locations of tumor, in the skull and near the eye, both represented areas of high lactate concentration. In humans, this tumor occurs in skeletal muscle, also associated with high lactate production.

Since 1930, when Otto Warburg first described increased glycolysis (preferential use of sugars) in tumor cells, investigators have pondered the implication of inefficient glucose metabolism in the face of adequate oxygenation.

Human metabolism relies upon mitochondrial function to efficiently liberate the maximum amount of energy in the form of ATP from each glucose molecule. Glycolysis occurring in the cell cytoplasm is highly inefficient and produces only 1/18 of the amount of ATP that a full molecule of glucose can produce through mitochondrial oxidative phosphorylation. Recent molecular biological studies have established that the preferential use of glycolysis may represent the cells need to direct glucose away from energy production and toward the creation of essential structures like amino acids, lipids, and nucleic acids. With the rapid turnover of glucose, cells produce an overwhelming amount of lactate, which is then transported out of the cell. At least this has been the working hypothesis over many years.

More recently, investigators have begun to examine how lactate metabolism may represent the interplay between stromal fibroblast cells and tumor cells. Indeed, many tumor cells are now known to increase lactate uptake reflecting increased lactate production by fibroblasts that have been commandeered in the tumor microenvironment.

Lactate uptake is under the control of a family of transporters known as monocarboxylate transporters, of which nine have been described. These are expressed differently in various tissues, have different affinities for lactate and transport in one direction or another. These processes appear to be under the control of the major regulator of oxygen metabolism known as HIF-1 alpha. As cancer cells adapt to a high lactate environment, they can survive in low oxygen tension.

The preferential use of lactate as a source of energy is contrary to many dictates of current metabolic research that suggest that tumor cells preferentially use glucose and have limited capacity to utilize non-glucose energy sources like the ketone bodies acetoacetate and beta-hydroxybutyrate. Substantial literature on ketogenic diets suggests that these ketone bodies deprive cancer cells of needed nutrition and energy. The current discovery by the Utah investigators, as well as interesting work conducted by researchers in Italy on the prostate cancer, provide a new angle on some of these principles of cancer metabolism.

As the investigators from Utah note, the alveolar soft part sarcoma is a rare tumor, but the implications of these findings could be profound, as they force us to re-think tumorigenesis and the metabolic basis of cancer.

Pigment, Color and Cancer

An interesting story reported by National Public Radio on November 12 described the origins of color in biology. Andrew Parker, a biologist from London’s Natural History Museum, described the development of sightedness in living organisms.

Until 600 million years ago animals were sightless. Then predatory organisms developed vision and used it to pursue prey. From that point color became an integral part of biological existence. Colors could attract mates, serve as camouflage, protect against predators and attract other organisms such as pollinating bees.

One of the more interesting aspects of the discussion was the fact that vertebrates have no capacity to produce the color blue. Indeed green is also quite difficult. So how, one might ask, do butterflies, peacocks and people with blue eyes create the appearance of the color blue? The answer is quite interesting and may be instructive when we examine other biological phenomena.

Pigments, known as biochromes, are substances produced by living organisms that have the capacity to absorb or reflect light of specific wavelengths. Their chemical structure captures the energy of the light wave resulting in the excitation of electrons to higher energy states. Among the colors commonly found are heme porphyrins, chlorophyll, carotenoids, anthocyanins, and betalains. While it is comparatively easy for plants to produce a broad spectrum of colors, animals have a more limited palate. They can borrow pigments from other species, like the flamingo whose pink hue is borrowed from the shrimp it eats. It seems however, that blue and green pose unique problems and must be created through an ingenuous melding of chemical biochromes and what is known as “structural pigmentation.”

The wings of a bluebird or those of a Morpho butterfly use specialized structures that are capable of capturing light at just the right angle. In so doing, they selectively reflect light and combine specific wavelengths with chemical pigments to create the illusion of color. Blue butterflies and green parrots are, in reality, sophisticated illusionists.

So what of other biological phenomena, specifically cancers? Quite a lot it seems. We have come to think of cancer as a product of genetic information. Our linear thinking with origins in cancer biology dating to the 1950s has long held that biological phenomena reflect the presence (or absence) of genes. The principal known as Central Dogma dictated that DNA produced RNA, that RNA produced protein and that protein produced function.

Our tidy principles were dealt their first blow by the discovery of epigenetics and then by small interfering RNAs. Most recently noncoding DNAs have further clouded the picture. It seems that the behavior of cancers may be every bit as deceptive as the bright blue hue that we ascribe to our avian and insect brethren.

Like butterflies or birds, cancers cloak themselves in a mixture of genetic and structural elements. While their behavior may appear to reflect genetic aberrancies, it may be structural (e.g. micro-environmental) perturbations that confer their unique biology. One can no more grind up and extract a parrot’s wings to find blue pigment than can we grind up and extract the genetic information of cancer to recreate its complexity. This however has not prevented the reductionists among us from trying. Unfortunately for them, cancers are demonstrably more complex than their genetic makeup.

Like a bird or a butterfly we must witness the creature in its entirety to grasp its function and behavior. Genomic analyses conducted in a vacuum cannot define the complexity of cancer biology. To create successful cancer treatment outcomes, we need to determine cellular phenotype. And, the EVA-PCD assay is quintessentially phenotypic. This is why the functional profile resulting from the EVA-PCD assay can identify accurate targets and select therapies.

Triple Negative Breast Cancer: Worse or Just Different?

The term “triple negative breast cancer” (TNBC) is applied to a subtype of breast cancers that do not express the estrogen or progesterone receptors. Nor do they overexpress the HER2 gene. This disease constitutes 15 – 20 percent of all breast cancers and has a predisposition for younger women, particularly those of black and Hispanic origin. This disease may becoming more common; although, this could reflect the greater awareness and recognition of this disease as a distinct biological entity.

On molecular profiling, TNBC has distinct features on heat maps. The usual hormone response elements are deficient, while a number of proliferation markers are upregulated.  Not surprisingly, this disease does not respond to the usual forms of therapy like Tamoxifen and the other selective estrogen response modifiers known as SERMs. Nonetheless, TNBC can be quite sensitive to cytotoxic chemotherapy. Indeed, the responsiveness to chemotherapy can provide these patients with complete remissions. Unfortunately, the disease can recur. Complete remission maintained over the first three to five years is associated with a favorable prognosis, with recurrence rates diminishing over time and late recurrences more often seen in estrogen receptor-positive cancers.

Triple negative breast cancer is not one, but many diseases.

Among the subtypes are those that respond to metabolic inhibitors such as the PI3K and mTOR directed drugs. Another subset may respond to drugs that target epidermal growth factor. There are basal-types that may be somewhat more refractory to therapy, while a subset may have biology related to the BRCA mutants, characterized by DNA repair deficiencies and exquisite sensitivity to Cisplatin-based therapies. Finally, a last group is associated with androgen signaling and may respond to drugs that target the androgen receptor.

Some years ago, we used the EVA-PCD platform to study refractory patients with breast cancer and identified exquisite sensitivity to the combination of Cisplatin plus Gemcitabine in this patient group. We published our observations in the Journal of Clinical Oncology and the combination of Cisplatin or Carboplatin plus Gemcitabine has become an established part of the armamentarium in these patients.

The I-SPY-2 trial has now used genomic analyses confirming our observations for the role of platins in TNBC. This in part reflects the DNA repair deficiency subtype associated with the BRCA-like biology. More recently, we have examined TNBC patients for their sensitivity to novel therapeutic interventions. Among them, the PI3K and mTOR inhibitors, as well as the glucose metabolism pathway inhibitors like Metformin. Additional classes of drugs that are revealing activity are the cyclin-dependent kinase inhibitors, some of which are moving forward through clinical trials.

One feature of triple negative breast cancer is avid uptake on PET scan. This reflects, in part, the proliferation rate of these tumors, but may also reflect metabolic changes associated with altered glucose metabolism. In this regard, the use of drugs that change mitochondrial function may be particularly active. Metformin, a member of the biguanide family influences mitochondrial metabolism at the level of AMP kinase. The activity of Metformin and related classes of drugs in triple negative breast cancer is a fertile area of investigation that we and others are pursuing.

When we examine the good response of many triple negative breast cancers to appropriately selected therapies, the potential for durable complete remissions and the distinctly different biology that TNBC represents, the question arises whether TNBC is actually a worse diagnosis, or simply a different entity that requires different thinking. We have been very impressed by the good outcome of some of our triple negative breast cancer patients and believe this a very fertile area for additional investigation

The 2013 Nobel Prize for Medicine and Physiology

On October 7, 2013, in Stockholm, Sweden, the Nobel Committee announced the winners of the Nobel Prize for Medicine and Physiology – two Americans and one German, all now located at institutions in the US. The discovery for which these three investigators share the prize involves their work over three decades studying the transport, packaging and trafficking of cellular proteins.

All cells must communicate and maintain their identity. To do so cells have developed intricate systems whereby neurotransmitters, proteins, hormones, and other species are encapsulated in small vesicles. These vesicles may be utilized to extrude materials into the extracellular domain or may store materials within the cell for later use. Working in model systems including yeast cells, these investigators showed the intricacy of cellular physiology associated with micro-vesicular function.

What makes these investigators’ work so interesting is that it is principally the study of cellular physiology, or what we call cell biology. While many breakthroughs and observations today reflect discoveries at the level of DNA, RNA and the genome, these investigators have pioneered protein kinetics and physiology. What is so exciting about this Nobel Prize is that it returns attention to the intricacies of cellular function at the level of phenotype. Protein biology represents the final common pathway from blueprint (DNA) to function. While genes that are detected within the nucleus (the purview of genomic analyses and many recent Nobel prizes) may or may not ultimately be expressed, depending upon splice variants, DNA methylation, histone acetylation, small interfering RNAs and non-coding DNAs among other phenomena, functional proteins are the active end-product and do very much exist.

We now recognize that cellular signaling, misfolded protein response, autophagy and apoptotic responses are tightly bound together. Among the most toxic phenomena for a cell is the misfolded protein signal, a signal that occurs far from the gene. This represents the target of the newest classes of drugs known as proteasome inhibitors and heat shock protein inhibitors, which function within the cytoplasm, not the nucleus.

It is exciting to imagine a day when physiologist, biochemist, enzymologist, physical chemist, and protein chemist regain their position as leaders in cancer research.

N.B: It should not go unmentioned that the EVA-PCD® assay offered by Rational Therapeutics is based on cellular function.

The Vitamin Myth, Myth

An article by Paul Offit, MD, published in The Atlantic Monthly, July 19, 2013, reports the lack of evidence supporting the use of micronutrient supplements. Dr. Offit is a recognized infectious disease expert, co-developer of the rotavirus vaccine and a professor at the University of Pennsylvania. He is the author of 2013 book, “Do you Believe in Magic, the Sense and Nonsense of Alternative Medicine.”

The article begins by examining the illustrious career of Linus Pauling, PhD. Recipient of two Nobel prizes, Dr. Pauling’s contributions to science cannot be overstated as he is credited with originally describing the ionic bond and the discovery of the molecular basis of sickle cell disease. Later in his career, Dr. Pauling became interested in Vitamin C and its potential for chemo prevention and maintenance of cardiovascular health.

Unfortunately, the article deteriorates from an interesting discussion to a diatribe directed against micro-nutritional supplementation with Dr. Pauling’s focus on vitamin C as the principle point of departure. Where Dr. Offit may have missed his mark isn’t that he raises questions about micro-nutrition but that he selectively utilizes negative studies to support his position to the exclusion of any and all more favorable findings.

To examine but a few of the points: Vitamin C is a profoundly important micronutrient, which is likely deficient in many American’s diets. The USRDA measured in tens of milligrams may well underestimate the human body’s requirements, characterizing instead the minimum amount required to avoid scurvy, that age-old disease of English mariners successfully managed with the consumption of citrus fruit (ergo the moniker of limey). As mankind evolved we lost the capacity to synthesize vitamin C (lacking the enzyme L-gulano-gamma-lactone oxidase) and now must rely on ingestible sources. Thus, Dr. Pauling’s attention to this vital micronutrient served us well in forcing a reexamination of the biologically relevant daily requirements.

Although, Drs. Pauling and Cameron’s (a Scottish surgeon), and Dr. Moertel’s, subsequent American studies did not establish vitamin C as a therapeutic, the choice of oral vitamin C in this pharmacologic application should have been recognized as an inadequate delivery mechanism in light of the diminishing absorptive efficiency of the human gastrointestinal tract associated with high dose oral administration. To wit, the therapeutic application of vitamin C, it could be argued, ultimately requires other vehicles for administration. More to the point, however, was Dr. Pauling’s original examination of primate diets, which included vitamin C rich foods and not vitamin C tablets. Albert Szent-Gyorgi, the co-discoverer of ascorbic acid, long held that the bioflavonoids in Vitamin C rich fruits participated in critical antioxidant reactions.

Above and beyond Dr. Offit’s pillorying of Dr. Pauling, is his inclusion of several ill-conceived clinical-proofs-of-concept that failed to support vitamin supplementation for cancer prevention.  The CARET study, which provided cigarette smokers and patients with asbestos exposure, high doses of beta carotene (30 mg/day) and retinyl palmitate (25,000 IU/day) identified an increased incidence and death rate from of lung cancer. In retrospect, any biochemist should have known that carotenoids serve both as antioxidants and prooxidants depending upon ambient oxygen-free radical conditions. Placing high concentrations of beta carotene into the circulation of cigarette smokers and asbestos exposed individuals was tantamount to throwing gasoline on a fire.

Similarly, the prostate cancer prevention study, SELECT, chose alpha-tocopherol as its vitamin E supplement and went on to report a higher incidence of prostate cancer in the treatment arm. Once again, the choice of a comparatively inactive tocopherol (the alpha form) that, in high doses, diminishes the bioavailability of the more active gamma tocopherol and tocotrienols, reflected a poorly conceived design and an inadequate understanding of the underlying biochemistry.

Dr. Offit’s article adds heat, but little light to this discussion. We should remember that micro-nutritional supplementation is designed to replace those trace elements and chemical species that would normally be found in a human diet. We evolved from scavengers, hunters and gatherers whose diet varied by season and included dozens, even hundreds of foodstuffs that few Western civilizations consume today. It is the intention of intelligently constructed micro-nutritional supplements to replace these deficient nutrients.

There is ample evidence to support intelligent dietary supplementation and a growing body of evidence that suggests that many, if not most, modern human maladies reflect our diets and lifestyles. Epidemiology is a difficult field under the best of circumstances. It took Doll and Peto decades to prove that cigarette exposure caused cancer, a simple fact that today is accepted by every grade school child in America.

It was Mark Twain who quipped that “There are three kinds of lies: lies, damned lies and statistics.” Perhaps he should have considered including nutritional epidemiology as a fourth.