Management trends and outcomes of appendiceal cancers: A National Cancer Database study.

810 Background: Appendiceal tumors encompass a variety of histological types that exhibit different behaviors. The current study aimed to investigate and compare overall survival, predictive factors for overall survival, and management of histological variations of appendiceal tumors. Methods: The National Cancer Data Bank (NCDB) database (2004–2020) was evaluated to include patients with appendiceal tumors histologies including goblet cell adenocarcinoma (GCA), neuroendocrine neoplasm (NEN), non-mucinous adenocarcinoma (NMA), and mucinous adenocarcinoma (MA). Univariate and multivariable analyses were conducted. Results: The GCA, MA, NEN, and NMA groups consist of 6,111, 16,471, 19,199, and 11,065 patients, respectively. The NMA and NEN groups had significantly lowest and higher overall survival compared to other types (p<0.001 for both) (GCC: 143.27 (140.23-146.30), MA: 111.91 (109.996-113.832), NEN: 170.88 (168.56-173.20), and NMA: 101.399 (99.132-103.666) months). The independent predicting factors of worse overall survival were age (HR: 1.03 (1.03-1.04)), black race (HR: 1.24 (1.08-1.43), ref: white race), fourth median income (HR: 0.84 (0.74-0.96), ref: first median), Charleson index comorbidity score (HR: 1.3 (1.22-1.38)), lymphovascular invasion (HR: 1.28 (1.15-1.42)), pathologic stage 2 (HR: 1.32 (1.12-1.57)), stage 3 (HR: 1.99 (1.66-2.40)), stage 4 (HR: 4.20 (3.47-5.07)), ref: stage 1, intraoperative systemic therapy (HR: 0.52 (0.39-0.70)), positive surgical margin (1.55 (1.39-1.73)), number of positive lymph nodes (HR:1.06 (1.05-1.07)), moderately differentiated tumors (HR:1.43 (1.25-1.63)), poorly differentiated (HR: 1.94 (1.69-2.24)), undifferentiated (HR: 1.48 (1.14-1.91)), ref: well differentiated, and NMA type (HR:1.30 (1.10-1.55)). Furthermore, in terms of type of surgery, significantly higher patients of GCA (54.6%) and NMA (55.2%) groups underwent subtotal colectomy compared to other groups. Regarding systemic therapy, significantly higher patients of MA group received intraoperative, and both neoadjuvant and adjuvant therapy compared to other groups. Also, NEN group had significantly higher patients who underwent surgery with laparoscopic approach compared to others. Conclusions: This study reveals that different types of appendiceal tumors have distinct characteristics in regard to overall survival outcomes and treatment approaches. NENs showed the highest survival rates, while NMAs had the lowest. These results underscore the need for personalized treatment strategies for each tumor type to improve patient outcomes.