Abstract
e21598 Background: Basosquamous carcinoma (BSC) is an aggressive form of basal cell carcinoma. Research on BSC is minimal because of its rare nature and the lack of clinical features that distinguish BSC from other forms of basal cell carcinoma, meaning that a diagnosis is only confirmed following biopsy. BSC is distinct because it has features of squamous cell carcinoma, making it more locally invasive, more likely to metastasize and has a recurrence rate of 12 - 51% following surgical excision. While BSC most frequently presents in the head and neck, it can also occur in gynecological cases and this subset of cases has not been studied in literature. In order to more thoroughly understand the distinguishing features and epidemiological trends of this rare cancer, the National Cancer Database (NCDB) was analyzed to determine demographic factors in patients diagnosed with cases of BSC in the breast, vagina and vulva. Methods: The National Cancer Database (NCDB) was utilized to complete a retrospective cohort analysis from 2004 – 2020 that included all patients with histologically-confirmed gynecological cases of BSC (N = 211). Descriptive statistics were analyzed for demographic factors including age, sex, race, income level, insurance status, and Charlson-Deyo score. Results: Between 2004 and 2020 there were 211 identified gynecological cases of BSC. The average age of diagnosis was 71.1 years (SD = 14.6, range = 22 – 90 years) with the majority being non-Hispanic (89.1%) and White (86.3%). The primary site in the vast majority of cases was the vulva (88.6%) and remaining cases originated in other female organs including the breast, vagina and cervix (11.4%). Despite the older age of diagnosis, the majority of individuals (72.0%) had Charlson-Deyo comorbidity scores of 0. The greatest proportion of patients (38.8%) were in the top quartile of household income ( > $74,063) with 15.7% in the lowest income quartile ( < $46,277). Additionally, most patients were insured by Medicare (64.9%) which aligns with the older age of diagnosis. Conclusions: Classifying and fully understanding BSC has proved difficult due to the challenge of differentiating it from other forms of basal cell carcinoma. To further the overall understanding of this aggressive cancer and those that it impacts, this study specifically focuses on a unique subset of BSC cases that have not been well studied. To the best of our knowledge, this is the first NCDB analysis on gynecological cases of BSC. The majority of BSC patients are non-Hispanic and White with an average age of over 70 years old which is supported by the finding that most patients rely on Medicare to fund their treatment. Additional research is needed to better understand the sociodemographic factors, treatments, and overall survival of patients with BSC in aberrant locations.