The Endocrine Society Guideline on pheo

The Endocrine Society, the world's largest scholarly society on endocrine diseases, just released its clinical practice guideline on pheo and para (http://www.endocrine.org/education-and-practice-management/clinical-practice-guidelines). The writing committee includes leading international experts on pheo and para.

Before the publication of this guideline, the North American Neuroendocrine Tumor Society (NANETS) published a guideline in 2010, and the First International Symposium on pheo published another guideline in 2007. The authors of the 3 guidelines overlap significantly. I am very familiar with the two previous guidelines.

I have read the new guideline in detail and am pleased to find that some of my own work is cited. Overall, the Guideline is thoughtful, up-to-date, succinct, and clear. I congratulate the writing committee on its completing such a wonderful piece. It has 6 parts: biochemical testing, imaging, genetic testing, perioperative management, surgery, and personalized approach. The Guideline is a great resource for physicians and patients. If the Guideline is followed, the majority of clinical scenarios will be covered very well and the clinical decisions will be correct most of the times. For non-specialists, the Guideline is a great resource for decision making regarding pheo.

I like the Guideline so much that I cannot think of almost anything that I have to change if I had been involved in the writing. As a pheo specialist, I do find a few places in the Guideline where some discussions are worthwhile. You can call me nitpicker but you will see why the following issues can actually matter in clinical practice.

Table 1. I would add heart problems without clear causes as another indication for testing. Over 10% of patients with pheo present with cardiovascular complications. Most patients with heart disease, indeed, do not have pheo, but those without clear common causes should be tested for pheo. For example, most patients with heart failure do not have pheo and pheo testing is not needed if a clear cause such as severe coronary heart disease is present. A young patient with heart failure of unknown (“idiopathic”) causes, however, should be tested for pheo. Pheo-induced cardiomyopathy is reversible upon pheo removal so that it is worthwhile to test for pheo in patients with heart problems without clear causes.

1.4. “All positive results require follow-up.” This recommendation is not incorrect but deserves some comments. In real world, most positive results are false alarms. In my experience, more than 50% of patients with positive results can be safely reassured that they don’t have pheo and further testing is not needed. A common example is an elderly patient with hard-to-control hypertension who has a slight elevation of pheo test results. I would be very comfortable in telling the patient that further testing for pheo is not needed. The Guideline goes on to say that the ways of follow-up should be determined by the pre-test probability and by clinical judgment, and that clinical follow-up (i.e. without further testing or imaging) is appropriate in select cases.

4.2. “We recommend preoperative medical treatment for 7 to 14 days to allow adequate time to normalize blood pressure and heart rate.” This recommendation is the only one that I have serious issues with. 1) This recommendation assumes that all pheos are the same and gives a general recommendation without considering the individual perioperative risks of each pheo. An incidentally found 1-cm pheo and a 7-cm pheo causing cardiac arrest are certainly different and should be prepared differently. 2) It perpetuates a long-held but likely incorrect notion that the goal of preoperative preparation is to normalize blood pressure and heart rate. Not uncommonly, patients with very active pheos have normal blood pressure and heart rate. An un-experienced doctor may feel that preoperative preparation is not needed because those patients already “achieve” the goals of preoperative preparation. Normal blood pressure and heart rate are important before operation but they should not be the goals of preoperative preparation. The real goal should be to revert or prevent pheo-induced cardiomyopathy.

A major challenge in writing clinical guidelines is to make balanced recommendations covering both common and uncommon clinical situations. A guideline will become too long and cumbersome if it tries to cover all situations. The Endocrine Society Guideline on pheo did a great job in balancing the common and uncommon situations. When we read guidelines, we should bear in mind that they are intended as “guidelines” and it is up to us to apply the guidelines to each unique patient. In other words, the physicians and patients should make the final clinical decisions, using the guidelines as a reference but not the only reference. Clinical experience and literature review are perhaps more important than following guidelines. As the Endocrine Society Guideline on pheo emphasizes, a multi-disciplinary team on pheo is the key to optimal pheo diagnosis and management.

Dr. Pheo