A cost-effectiveness analysis of adrenalectomy for nonfunctional adrenal incidentalomas: is there a size threshold for resection?

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare, but aggressive, malignancy. Current American Association of Clinical Endocrinologists (AACE)/American Association of Endocrine Surgeons (AAES) guidelines recommend resection of nonfunctional adrenal neoplasms ≥ 4 cm. This study evaluates the cost-effectiveness of this approach.

METHODS

A decision tree was constructed for patients with a nonfunctional, 4-cm adrenal incidentaloma with no radiographic suspicion for ACC. Patients were randomized to adrenalectomy, surveillance per AACE/AAES guidelines, or no follow-up ("sign-off"). Incremental cost-effectiveness ratio (ICER) includes health care costs, including missed ACC. ICER (dollar/life-year-saved [LYS]) was determined from the societal perspective. Sensitivity analyses were performed.

RESULTS

In the base-case analysis, assuming a 2.0% probability of ACC for a 4-cm tumor, surgery was more cost-effective than surveillance (ICER $25,843/LYS). Both surgery and surveillance were incrementally more cost-effective than sign-off ($35/LYS and $8/LYS, respectively). Sensitivity analysis demonstrated that the model was sensitive to patient age, tumor size, probability of ACC, mortality of ACC, and cost of hospitalization. The results of the model were stable across different cost and complications related to adrenalectomy, regardless of operative approach.

CONCLUSION

In our model, adrenalectomy was cost-effective for neoplasms >4 cm and in patients <65 years, primarily owing to the aggressiveness of ACC. Current AACE/AAES guideline recommendations for the resection of adrenal incidentalomas ≥ 4 cm seem to be cost-effective.