Our Blog’s 2013 Year in Review

WordPress.com came up with this nifty report of our blog’s progress for 2013. We thought we’d share it with you. Do you have anything to add? Tell us what you would like to see during the coming new year.

Wishing you good health and much happiness in 2014.

Here’s an excerpt:

The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 22,000 times in 2013. If it were a concert at Sydney Opera House, it would take about 8 sold-out performances for that many people to see it.

Click here to see the complete report.

Cancer Patients, Genetic Testing and Clinical Outcomes

Two years ago in this blog, I described a young man with an aggressive non-small cell lung cancer. Following his diagnosis he was screened for EGFR mutation (the target of Erlotinib [Tarceva]) and ALK gene rearrangement (the target of Crizotinib [Xalkori]). Found negative for both, his options were limited to chemotherapy.

When I met the patient, a PleurX catheter had already been inserted to remove fluid that was rapidly re-accumulating in his right chest. This provided access to cancer-laden fluid and offered an excellent opportunity for EVA-PCD® laboratory analysis.

The results showed the expected resistance to Erlotinib (for which no mutation was found) but very high activity for Crizotinib. When he returned for follow-up we repeated a second analysis. The results were identical. One possibility was that the patient carried a second mutation sensitive to this class of drugs, like ROS-1 or MET, both targets of Crizotinib. However, at the time, MET and ROS-1 gene testing was not readily available. I referred the patient to a colleague who was conducting Crizotinib trials. Fluid was re-aspirated and submitted to a different reference lab for genomic analysis. The finding: The original laboratory test had been erroneous. The patient was indeed, ALK gene rearranged.

After a course of chemotherapy, he qualified for and responded beautifully to single-agent Crizotinib. In my blog, I examined how our functional profile more closely approximated the patient’s biology (phenotype) over the genomic profile (genotype). However appealing these genomic tests may be, they can only identify potential targets for therapy that may or may not be relevant to a patient’s ultimate clinical response.

A year later, a female patient with a mucinous adenocarcinoma presented with brain metastases. An EVA-PCD analysis revealed relative chemotherapy resistance and no activity for Erlotinib (Tarceva). She was found EGFR non-mutated. Unfortunately, there was insufficient tissue for the EVA-PCD to test Crizotinib.

During subsequent Cyber-Knife treatment for her brain metastases, a specimen of tumor showed the ALK gene rearrangement and the patient started Crizotinib. She responded promptly.

At the one-year point, signs of progression appeared in the opposite lung, but while she continued to experience good response in the original sites, a repeat biopsy was performed. This time the EVA-PCD functional profile revealed no activity for Crizotinib, but identified activity for the combination of Platinum and Vinorelbine. We combined these two drugs with the Crizotinib and she remained in remission for an additional year. Low blood counts forced us to withhold chemotherapy and her disease progressed. She was referred to a clinical trial with a second-generation ALK inhibitor. By the second month, her disease had progressed rapidly.

Cancerous cells from a bronchoscopic biopsy were submitted for analysis. The finding: No ALK gene mutation. Instead her tumor carried a MET mutation. The patient now rapidly progressing will require immediate therapy, but what?  Fortunately, a small sample of fluid aspirated from the lung provided adequate cells for analysis. The results are striking since they confirm persistent activity for Crizotinib. The patient has now been re-challenged with Crizotinib and we await clinical follow-up.

Taken together, these cases offer interesting insights. The first reflects the medical community’s preternatural faith in genomics. We, as a society, have so completely accepted the accuracy and predictive validity of genetic tests, that no one seems willing to scrutinize the data for its ultimate accuracy. This may not be serving our patients well, as both these cases exemplify. An error that missed the ALK gene re-arrangement in the first patient almost cost this young man his life, despite our protestations. Then, an error in this woman’s analysis serendipitously led to her response to the right drug for the wrong reason, her gene results notwithstanding

We forget at our peril, that all tests are fallible. Clinicians must recognize that highly sophisticated analyses using the most advanced technologies still function within the infinitely complex confines of human biology. The crosstalk, redundancy and promiscuity of human cellular circuitry remain demonstrably more complex than our best artificial neural networks. Genomic analyses and companion diagnostics now dictate who can and who cannot receive drugs, but as can be seen here, these wonders of modern science are not perfect predictors. They have the potential to deprive patients of life-saving treatment while subjecting others to drugs with little chance of benefit. Physicians must remember to be artful as we apply the science of our trade.

Organic Whole Milk – The Whole Story

An article in PLOS | One (Organic Production Enhances Milk Nutritional Quality by Shifting Fatty Acid Composition, a United States-wide 18 month study) reports the benefits of organic milk.

Investigators from Washington State University found that organic milk contains 25 percent less Omega-6 and 62 percent more Omega-3 over that produced conventionally. Alpha linolenic acid, the most important vegetable source of Omega-3 constituted 60 percent of the total fat content. Comparing organic milk to conventional milk using the ratio of Omega-6 to Omega-3 the researchers found a value of 2.28 for the organic and 5.77 for conventional milk, a 2.5 fold difference favoring organic milk.

cow grazingOrganic milk production entails grazing cows that consume grass while conventional milk is produced using corn feed with the cows often being barn-raised or confined. We now know that it is the grass consumption that provides the Omega-3 and the higher fat content in whole milk over skim provides the highest quantity of omega-3 of all.

Over recent decades the consumption of milk has fallen in the U.S.  This has been driven in part by pediatricians’ recommendations that children be converted to nonfat milk, as they grow older. Concerns regarding dietary fat intake and obesity led many to eschew whole milk in favor of low or non-fat alternatives, yet the data supporting these restrictions is far from established. Indeed one study in the Archives of Disease in Childhood, 2013, found that children ages 2 to 4 who consumed 1 percent milk actually gained more weight not less.

Many readers are familiar with omega-3 fatty acids as constituents of fish. Salmon_FishThe fattiest fish, salmon and sardines, have the highest omega-3 content. The term omega-3 refers to three types of fats commonly found in the diet among them ALA (alpha linolenic acid), EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).

While EPA and DHA are found mostly in fish, ALA is the principal vegetable source of Omega-3. These are all distinct from the omega-6 fatty acids such as linoleic acid and arachidonic acid. As arachidonic acid is a precursor to prostaglandin synthesis, there has long been concern that Omega-6 consumption might contribute to inflammation but even this has not been fully borne out in the literature.

As with nut consumption, the subject of an earlier blog, we may need to re-evaluate many long held beliefs regarding dietary health and well-being. Mankind evolved in an environment devoid of foodstuffs that today we take for granted, among them ready sources of grains and many fruits. Our bodies are designed to consume and metabolize lipids.
ALA, EPA and DHA are essential fatty acids that must be consumed in the diet. Have we deprived ourselves of the health benefits of these foodstuffs ill advisedly? Whole milk consumption is now rising faster than other dairy product. Perhaps the public at large have decided that the “bloom is off the rose” for low fat goods.

Gastric Cancer: A Call for Patient Selection

Gastric cancer is the fourth most common cancer worldwide with more than 930,000 diagnoses and 800,000 deaths attributed to this disease each year. Although relatively uncommon in the U.S., constituting only 2 percent of new cancers, in countries like Korea it makes up 20 percent of all new malignancies.

Among the causes are Helicobacter pylori infection, diets rich in smoked food, a high intake of nitrates and nitrites and cigarette smoking. A rare but aggressive form of the disease is associated with a gene mutation known as CDH1. The high frequency of metastatic disease at the time of initial diagnosis often precludes surgery, leaving systemic chemotherapy as the principal treatment option.

Annals of Oncology coverA recent report in The Annals of Oncology (No improvement in median survival for patients with metastatic gastric cancer despite increased use of chemotherapy: Bernards N. et al, Annals of Oncology. November, 2013) describes a retrospective analysis by Dutch investigators who examined the use of chemotherapy in patients with inoperable gastric cancer.

In total, 4,797 cases were examined from 1990 to 2011. Over this time, the proportion of patients presenting with metastatic disease increased from 24 percent in 1990 to 44 percent in 2011. At the same time, palliative chemotherapy use increased from 5 percent to 36 percent. Younger patients and those of higher socioeconomic status had the largest increase in chemotherapy use, while older patients, those with linitis plastica and those with multiple metastases had lower chemotherapy use. Despite the significant increase in the use of chemotherapy, the median survival for patients was unchanged at 15 weeks in 1990 and 17 weeks in 2011 (P = 0.1).

Over this period, early treatment regimens like 5-fluorouracil (5FU) and FAM were largely replaced by combinations like Docetaxel/Cisplatin/5-FU (DCF), Cisplatin/Irinotecan, Epirubicin/Oxaliplatin/Capecitabine (EOX) and Carboplatin/Taxol. While response rates and palliative benefits have continued to improve, this has not translated into improved overall survival. This reflects a dilemma that has confronted medical oncologists for decades.

For many years, clinical trialists have held that one cannot assess the benefit of a treatment by comparing responders to non-responders. That is, time to progression and survival must compare all patients on a given treatment arm to those on the control arm. Their rationale was that “one must treat all patients to obtain the benefit seen in some.”  Put differently you cannot “cherry pick” your winners and losers. It was said that this proscription was needed to avoid selection bias. But as any medical or nonmedical person would recognize, people who respond to treatment do better than those who do not. Lacking the ability to identify responders upfront, these trialists have insisted upon a one-size-fits-all approach to the detriment of clinical therapeutics and drug development.

With the dawn of the molecular era we see chinks in the armor of these trial designs as investigators now question why everyone should receive a treatment if only a small percentage will benefit. In gastric cancer, HER2 over-expression, found in 20-25 percent of patients, is now routinely used to identify patients who will respond to trastuzumab. But what of the other 75-80 percent of patients who do not carry HER2 and for whom there are no widely used determinants of clinical response? Do the results of Bernard article suggest that these patients should not receive therapy?

The Bernard article offers an interesting insight into what may be the future of medical oncology. As cancer therapy is increasingly scrutinized, not only for response or palliation but also for overall survival, patients may soon be denied treatments unless the results of the therapy rise to this, the highest level of evidence, for the entire population of treated patients.

Would it not be preferable to use laboratory analyses, like the EVA-PCD®, to select among treatment candidates before subjecting all patients to the risk and expense of toxic chemotherapy? In this regard, the author’s comments are poignant: “Identification of the subgroup of patients which benefit from palliative chemotherapy is of the utmost importance to avoid unnecessary treatment.” As a laboratory investigator engaged in the field of drug selection science (functional profiling), I couldn’t agree more.