Carcinoid crisis: History, dogmas, and data

Patients with neuroendocrine tumors are at risk for carcinoid crises, which have no strict definition, but are generally described as sudden events of hemodynamic instability in patients typically undergoing invasive procedures. Many dogmas exist about crises: crises are due to massive release of hormones in patients with functional tumors, crises can be prevented and treated with octreotide, and avoid the use of catecholamines in patients with neuroendocrine tumors as they can precipitate crises. Given the sudden and life-threatening nature of carcinoid crises, only a handful of studies have been conducted so the data to support these dogmas are sparse and include only retrospective reviews and a single prospective study. A systematic dismantling of these dogmas has begun to form from recent study: crisis can occur in patients without carcinoid syndrome, it is not necessarily associated with a massive release of hormones, octreotide neither prevents nor treats carcinoid crisis, and the use of beta-adrenergic agonists does not precipitate crises. The data for supporting and leading to questioning these dogmas on carcinoid crisis will be discussed in this chapter, as well as future directions for related research.