A 64-year-old man presented to my office with a history of a 0.4 mm thickness melanoma having been excised from his back in 2014. He subsequently saw his primary care provider, who decided to order a PET scan just to be sure that âeverything was OK.â $7,500 later, the patient was relieved to be told that the scan was completely normal.
What is wrong with this scenario? The patient is relieved to find that his melanoma has not disseminated. The ordering physician is happy to give him the good news and is assured in his own mind that he has done everything possible to manage the disease.
Furthermore, if the patient should develop late metastases, the physician has built a firewall around himself against possible malpractice litigation. In fact, there is recent published data to support the notion that more laboratory testing does lead to fewer malpractice claims.1 The authors report that practitioners in acute care hospitals in Florida who used more resources in patient management had fewer malpractice claims filed against them.
I suspect that most dermatologists in this country would not order a routine PET scan for this patient in spite of the positive feedback they might get from doing so, simply because there is no data to support the survival benefit of PET scans in those with a thin melanoma, and ordering such a scan fails the âreasonableness testâ of cost-to-benefit analysis.
Organized medicine is beginning to take an active role in assisting physicians in deciding the value of certain laboratory examinations. A good example of this is the PSA test for prostate cancer, which is no longer being recommended routinely based on extensive clinical data that shows the test has poor predictive value. An interesting recent study in the allergy literature2 concludes that no diagnostic testing may be necessary or useful in patients with chronic urticaria after a medical history and physical examination fail to direct one to an underlying cause of the eruption.
We utilize numerous medications in dermatology where potentially severe side effects can occur and can be detected by laboratory analysis. No one would argue against a person about to be placed on methotrexate having a baseline complete blood count, liver and renal function testing and screening for active hepatitis infection, with routine follow-up testing for the duration of the treatment period. We know that tuberculosis screening is important in those about to be started on biologic agents. Patients in my part of the country also need tests for coccidioidomycosis because it is endemic and can be a severe problem in immunocompromised individuals. Those on cyclosporine require frequent monitoring of blood pressure and renal function and occasional testing for low magnesium. However, many commonly prescribed drugs rarely cause problems but have acquired the reputation of potentially toxic agents, which require close laboratory monitoring.