Clinical profile and response to adjuvant treatments in patients with follicular dendritic cell sarcoma in the United States: Insights from SEER analysis.

person Nikhil Vojjala Trinity Health Oakland Hospital/Wayne State University School of Medicine, Pontiac, MI info_outline Nikhil Vojjala, Sumeet Kumar Yadav, Kim Abbegail Tan Aldecoa, Bolun Liu, Guleid Hussein, Ibrahim Azar, Sri Yadlapalli, Geetha Krishnamoorthy, Judie R. Goodman

Authors person Nikhil Vojjala Trinity Health Oakland Hospital/Wayne State University School of Medicine, Pontiac, MI info_outline Nikhil Vojjala, Sumeet Kumar Yadav, Kim Abbegail Tan Aldecoa, Bolun Liu, Guleid Hussein, Ibrahim Azar, Sri Yadlapalli, Geetha Krishnamoorthy, Judie R. Goodman Organizations Trinity Health Oakland Hospital/Wayne State University School of Medicine, Pontiac, MI, Mayo Clinic Health System, Mankato, MN, Trinity Health Oakland Hospital/Wayne State University, Pontiac, MI, Mayo Clinic Health Care, Mankato, MN, Trinity Health Oakland/Wayne State University School of Medicine, Pontiac, MI Abstract Disclosures Research Funding No funding sources reported Background: Follicular Dendritic Cell Sarcoma (FDCS) is a rare, indolent, low-grade sarcoma known for local recurrences managed primarily by surgery. The role for adjuvant therapy has not been established for either radiation or chemotherapy. We aimed to comprehensively analyze clinical and epidemiological profiles and responses to treatment in these patients. Methods: This is a retrospective study using the National Cancer Institute (NCI) Surveillance, Epidemiology, and End Result (SEER) database. Cases of FDCS between 2001 to 2022 were identified utilizing the International Classification of Diseases for Oncology edition 3 (ICD-O-3) code 9758/3. Only adults > 18 years of age and diagnosed by positive histology or cytology were included. Descriptive statistics were used to describe demographic and tumor characteristics. Logistic regression was used to identify the factors influencing survival. Kaplan-Meier method was used to plot survival based on different treatment regimens and stages. Results: A total of 168 patients with FDCS were identified, with more than 50% of the patients ≥ 50 years of age. The mean age at diagnosis was 52.6 years, 56% were female, and 74.4% were white. Most of the patients had localized disease (63.7%), 17.9% had distant disease, and the remaining had unknown stages. About 90% of the patients underwent surgery, with 41% receiving local tumor excision. In Univariate analysis, older age, and distant disease were found to have poor outcomes. Surgery, irrespective of stage, was found to improve overall Survival (Table 1). While chemotherapy and distant disease had poor outcomes in univariate analysis, they were not statistically significant in multivariate analysis. The majority of the patients who received chemotherapy alone without surgical intervention had distant disease, explaining the poor outcome seen in univariate analysis. Among 107 patients with localized disease, 41 patients (41.1%) underwent only surgery and 43 patients (40.1%) received adjuvant therapy (either chemotherapy or radiation vs both) along with surgery. 5-year overall survival was significantly lower in patients who received adjuvant therapy. (88.4% vs 68.4%, p = 0.001). Conclusions: In conclusion, FDCS has a fair overall 5-year survival with surgery alone. Patients with localized disease, who received adjuvant therapies had poor survival outcomes as compared to the surgery-only group owing to disease burden. Large prospective studies are required to properly evaluate the benefit of adding chemotherapy or radiotherapy in resectable disease.