Aggressive Digital Papillary Adenocarcinoma: Population-Based Analysis of Incidence, Demographics, Treatment, and Outcomes

BACKGROUND As a rare cutaneous malignancy, epidemiologic and outcomes data for aggressive digital papillary adenocarcinoma (ADPA) are limited and no treatment guidelines exist. OBJECTIVE To provide a population-based study of ADPA incidence and outcomes with a subgroup comparison of patients with localized versus regional disease. METHODS Data from 18 registries within the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program were examined for patients with ADPA (1995-2013) to provide demographic-and cancer-related information, and to calculate race-and age-specific rate ratios, incidence, and mortality. Patients were stratified by the stage for further comparison. RESULTS Ninety-four cases of ADPA were identified. Overall, ADPA incidence was 0.08 per 1,000,000 person-years, 4 times higher in males than in females (0.13 vs 0.03, p < .001), and most common in Caucasians. Regional disease spread occurred in 22.3% of patients and disease-specific mortality in 2.1% of patients. Patients with regional versus localized disease at diagnosis did not differ significantly in sex, age, race, primary site, tumor size, or mortality. CONCLUSION Aggressive digital papillary adenocarcinoma is a rare malignancy with increasing incidence. Regional disease spread is not infrequent, but mortality is rare. Identification of patients best suited for additional diagnostic procedures or more extensive surgical resection remains challenging. The authors have indicated no significant interest with commercial supporters.