Abstract

e12588 Background: Adenocarcinoma with apocrine metaplasia (AAM) is an invasive form of carcinoma distinguishable by the conversion of malignant glandular cells to apocrine sweat cells with abundant granular eosinophilia. Although AAM has a favorable prognosis, early treatment, including surgical intervention or radiation therapy, is still required to decrease metastasis or resurgence. Due to the rarity of this disease, the impact of demographic factors has not yet been explored and could be essential to understand its epidemiology. Demographic trends of patients were analyzed within the National Cancer Database (NCDB). Methods: Within this retrospective cohort analysis, 155 patients were identified from the 2004–2020 NCDB with a confirmed AAM diagnosis using code 8573 from the International Classification of Diseases for Oncology (ICD-8573-3). Their demographic factors including sex, age, race, Hispanic status, Charleson-Deyo score, distance to facility, educational attainment, and household income were analyzed using incidence trends and descriptive statistics via regression analysis. Results: The average age at diagnosis was 62.7 years (SD = 14.3, range = 18 - 90 years) with a 58% ten-year survival rate. The incidence steadily decreased from 2004–2020 (R 2 = 0.3051). The majority of patients (85%) had no comorbidities (Charleson-Deyo = 0). Surgical treatment (73%) as a primary procedure was common and was combined with chemotherapy (57%) or radiation therapy (38%). The primary sites included the upper-outer quadrant (28%) and overlapping lesions of the breast (25%). The average tumor size at surgery was 30.7 mm (SD = 17.9 mm, range = 1.00–64.0 mm). The majority of patients were female (96%), White (72%), and non-Hispanic (88%). Patients tended to have household income greater than $57,857 (55%) and hailed from a metropolitan area with a population greater than 1 million (55%). The Western Central (53%) and Atlantic (24%) regions of the USA comprised most diagnoses. Patients traveled an average of 81.5 mi (SD = 184, range = 0.20–1110 mi) to receive care from an academic or research program (61%) or a comprehensive community cancer program (23%). Conclusions: The findings of this research support previous studies demonstrating that most patients tend to be over 60 years old and White. We reported an average tumor size of 30.7 mm, usually found in the upper-outer quadrant or overlapping regions in the breast. Patients typically underwent chemotherapy after surgical treatment at an academic hospital. Most patients lived in densely populated areas within the Western Central and Atlantic regions, which may suggest an ease of access to treatment. This is the first NCDB analysis of AAM, and thus fills an important gap in cancer research. Future work should identify the influence of demographic and socioeconomic factors on the diagnostic factors, cancer prognosis, treatment regimen, and overall survival rates of patients.