John A. Schmidt, MD 

Precision Medicine

As described in the June 4 issue of the New England Journal of Medicine, precision medicine is once again gaining traction.  A related concept is number needed to treat (NNT). For example, the NNT for insulin in a type 1 diabetic is one, meaning that every insulin deficient patient treated with insulin benefits. Similarly, every hypothyroid patient treated with levothyroxine benefits. The same can be said for essentially any medicine used to treat a deficiency syndrome (e.g. iron in iron deficiency anemia). Unfortunately, this is not the case for most medications. Consider the results with flibanserin described above. Only about 10 percent of women responded. Thus, a physician needs to prescribe the medication to 10 patients to obtain one responder. The cost/benefit ratio of the medicine is therefore increased by a factor of 10. But what if one could identify the responders in advance and prescribe the medication only to those who would benefit? Because we usually lack the tools to identify responders in advance, physicians often resort to "therapeutic trials" which is a fancy way of saying "try it and see." In the case of new medicines, this can be a very expensive and, for patients, a very frustrating approach.

Nowhere is this concept more important than in cancer chemotherapy. Patients with cancer don't have time to experiment. Nevertheless, the NNT for many new and expensive cancer therapies is often high. To address this problem, the National Cancer Institute (NCI) announced a new precision medicine trial at the American Society of Clinical Oncology (ASCO) meeting held in Chicago on June 1. Patients with tumors bearing a mutation known to be a drug target will be treated with that drug regardless of the cancer type (lung, pancreas, etc.).

A dramatic and close-to-home example of precision medicine was reported on the cover of Time magazine on March 30. The cover shows two women, both with glioblastoma, the brain tumor that killed Senator Edward (Ted) Kennedy. One of these women happens to be a Monmouth County resident and the wife of a patient in my practice. Because her brain tumor contained a certain mutation, she was given a medicine usually reserved for patients with malignant melanoma. Her brain tumor shrank and she continues to do well. The other woman's tumor had no such mutation and she has unfortunately died. It is anecdotes like these that are behind the NCI's precision medicine initiative.   

Clot Retrievers Revolutionizing the Treatment of Stroke

Stroke results when a clot blocks blood flow to the brain and is the second leading cause of death in the United States and a common cause of serious disability. As reported in the June 11 issue of the New England Journal of Medicine, a device known as a clot retriever has now been shown in five controlled randomized trials to help preserve brain tissue and neurological function in some stroke victims. The clot retriever is located on the tip of a catheter and snags the clot. The entire device including the snagged clot is then removed through a small puncture in the groin. The device is used in combination with the clot buster known as tissue plasminogen activator (TPA). According to the editorial in the same issue, the NNT (number needed to treat to help one patient) is between three and seven. This development makes it more important than ever that patients suspecting a stroke call 911 immediately and go to a Comprehensive Stroke Center. Jersey Shore University Medical Center in Neptune is the only comprehensive stroke center in all of Monmouth and Ocean counties.  

Institute of Medicine Issues New Diagnostic Criteria for Chronic Fatigue Syndrome

Fatigue is probably the most common complaint in my practice and some wonder if they have Chronic Fatigue Syndrome (CFS). In February, the Institute of Medicine, a blue ribbon panel of experts, proposed three diagnostic criteria:

1) A profound reduction in the ability to engage in usual activities for more than six months not alleviated by rest. Patients with CFS typically have a long list of things they would like to do if only their body would cooperate; and

2) The worsening of symptoms after any type of exertion (physical, emotional, or cognitive). This "post exertional malaise" or feeling "wiped out" typically lasts at least 24-hours; and

3) Unrefreshing sleep. Patients with CFS typically can't remember feeling rested no matter how much time they spend in bed.

And at least one of these:

1) Cognitive impairment (some call this "fog"); or

2) The inability to remain upright and no improvement after lying down.

There is no blood test for CFS and no approved medication. However, because treatable diseases often masquerade as CFS, it is important to be evaluated. Let me know if I can help.