Partial Adrenalectomy Increases Risk for Pheochromocytoma Recurrence

Patients with bilateral pheochromocytoma who undergo a partial adrenalectomy are at a greater risk for recurrence compared with patients undergoing a full adrenalectomy, according to study findings in the Frontiers of Endocrinology.

A partial adrenalectomy may preserve adrenal function in patients with bilateral pheochromocytoma. However, there are concerns for potential relapse with this procedure. Researchers conducted a systematic review to assess the different outcomes for partial and total adrenalectomy in patients with bilateral pheochromocytoma. Electronic databases and clinical trial registries were used to search for trials comparing total and partial adrenalectomies. Studies with single interventions, without sufficient primary data, or with only patients with metastatic tumors, were excluded. The researchers considered a procedure as a partial adrenalectomy if there was complete removal of one adrenal gland combined with partial removal of the other adrenal gland or bilateral partial removal. 

A total of 1169 records were identified, with 905 studies and 264 registers. There were 26 studies remaining after exclusion and 1444 patients in total with either bilateral total adrenalectomy (n=826) or partial adrenalectomy (n=618). The primary outcomes were pheochromocytoma recurrence risk and steroid dependence, defined by lifelong glucocorticoid substitution. Time to recurrence following surgery, development of metastatic disease, incidence of adrenal crisis, morbidity, and overall or pheochromocytoma-specific mortality were all considered secondary outcomes.

The researchers reported the risk of recurrence in 20 studies which included 985 patients. Of these studies, 14 showed that partial adrenalectomy was associated with an increased risk of recurrence when compared with total adrenalectomy (odds ratio [OR], 3.72; 95% CI, 1.54-8.96; P =.003; I², 28%). In the other 6 studies, there were no pheochromocytoma recurrences noted for total and partial adrenalectomy. 

In 22 studies with 1404 patients, all patients who underwent bilateral adrenalectomy were steroid dependent. Over 60% of patients who underwent partial adrenalectomy did not require supplementation (risk ratio [RR], 0.32; 95% CI, 0.26-0.38; P <.00001; I², 21%).

A total of 10 studies reported patients undergoing partial adrenalectomy had a lower risk of developing acute adrenal insufficiency when compared to patients undergoing total adrenalectomy (OR, 0.3; 95% CI, 0.1-0.91; P =.03; I², 0%). 

The researchers investigated the secondary outcome, the presence of metastatic pheochromocytoma in patients, in 5 studies and no difference was observed in patients between partial and total adrenalectomy after the procedure. Additionally, the researchers reported no differences for overall mortality rate and time to recurrence between the groups.

Study limitations include the use of only observational studies, lack of assessment of confounding factors, and the inability to assess co-interventions across all groups. 

The researchers concluded, “The development of new imaging techniques and training of adrenal surgeons should be pursued to facilitate accurate differentiation of cortical from medullary adrenal tissue and thereby contribute to a lower recurrence rate and reduced steroid dependency rate after partial adrenalectomy.”