Staging Studies for Cutaneous Melanoma in the United States: A Population-Based Analysis

Background: Routine cross-sectional imaging for staging of early-stage cutaneous melanoma is not recommended. This study sought to investigate the use of imaging for staging of cutaneous melanoma in the United States.

Methods: Patients with nonmetastatic cutaneous melanoma newly diagnosed between 2000 and 2007 were identified from the Surveillance Epidemiology End Results-Medicare registry. Any imaging study performed within 90 days after diagnosis was considered a staging study.

Results: The study identified 25,643 patients, 3,116 (12.2 %) of whom underwent cross-sectional imaging: positron emission tomography (PET) (7.2 %), computed tomography (CT) (5.9 %), and magnetic resonance imaging (MRI) (0.6 %). From 2000 to 2007, the use of cross-sectional imaging increased from 8.7 to 16.1 % (p < 0.001), driven predominantly by increased usage of PET (4.2–12.1 %). Stratification by T and N classification showed that cross-sectional imaging was used for 8.6 % of T1, 14.3 % of T2, 18.6 % of T3, and 26.7 % of T4 tumors (p < 0.001) and for 33.3 % of node-positive patients versus 11.1 % of node-negative patients (p < 0.001). Factors predictive of cross-sectional imaging included T classification [odds ratio (OR) for T4 vs T1, 2.66; 95 % confidence interval (CI) 2.33–3.03], node positivity (OR 2.70; 95 % CI 2.36–3.10), more recent year of diagnosis (OR 2.05 for 2007 vs 2000; 95 % CI 1.74–2.42), atypical histology, and non-Caucasian race (OR 1.32; 95 % CI 1.02–1.73).

Conclusions: The use of cross-sectional imaging for staging of early-stage cutaneous melanoma is increasing in the Medicare population. Better dissemination of guidelines and judicious use of imaging should be encouraged.