SAN ANTONIO, Tex.—Oncology nurses can play a pivotal role in diagnosis and management of the rare neuroendocrine tumors pheochromocytomas and paragangliomas, according to an oral presentation at the ONS 41st Annual Congress.1
“These tumors are widely distributed, which makes them biologically and clinically different,” said Bonita Bennett, BSN, RN, a nurse coordinator at the University of Pennsylvania in Philadelphia.
Although pheochromocytomas and paragangliomas only occur in 2 to 8 per 1 million people, more than one-third are reportedly associated with an underlying genetic etiology, which is more common than any other cancer type. Pheochromocytomas develop from chromaffin tissue in the adrenal medulla while paragangliomas form in the extra-adrenal ganglia.
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“Pheochromocytomas from in the adrenal gland, while paragangliomas grow in the peripheral nervous system,” Bennett explained. “Tumors that secrete catecholamines are called functional tumors.”
These tumors are typically benign, with only 25% of cases being malignant; however, they are often associated with high morbidity and mortality due to hypersecretion of catecholamines, leading to hypertension, stroke, and death.
“Multiple inheritable genes have been implicated in the predisposition of pheochromocytomas and paragangliomas,” Bennett said.
More than 10 susceptibility genes have been identified that increase the risk for developing pheochromocytomas and paragangliomas: von Hippel-Lindau disease (VHL), Multiple Endocrine Neoplasia type 2 (MEN 2), Neurofibromatosis type 1 (NF1), succinate dehydrogenase A (SDHA), SDHB, SDHC, SDHD, SDHAF2, TMEM127, and MAX. Various somatic mutations that confer an increased risk have also been identified, including HIF2-alpha, ATRX, KIF1Bb, and PHF2.
Because positive genetic testing results have potential prognostic implications for patients with pheochromocytomas and paragangliomas and familial implications, oncology nurses should encourage genetic testing be performed in all patients.
“Awareness of genetic predisposition to developing these tumors guides care,” Bennett noted.
Knowledge of genetic predisposition to developing these tumors impacts medical managements, allowing for proper surveillance of recurrent or metastatic disease, development of additional primary tumors, other potential associated malignancies. For patients who test positive, family members should be referred for genetic screening as well, resulting in better clinical outcomes.
Oncology nurses can also play a substantial role in narrowing the differential diagnosis of pheochromocytomas and paragangliomas. Presenting signs and symptoms associated with these tumors can often be confused other medical conditions, thus resulting in being undiagnosed for many years. Being knowledgeable of potential signs and symptoms is particularly significant if classical symptoms are absent.
“Clinical presentations vary from case to case, but the classic triad is headache, palpitations, and sweating,” Bennett noted. “Each patient is unique.”
In terms of management, surgery is the definitive treatment, but limited control of metastatic disease can follow with treatments, such as chemotherapy.
REFERENCE
1. Bennett B. Neuroendocrine tumors and inherited cancer syndromes: Pheochromocytomas and paragangliomas-rare but risky. Oral presentation at: 2016 Oncology Nursing Society Annual Congress; April 28-May 1, 2016; San Antonio, TX.
