Natalie Sun, MD1, Isa Jacoba, MD1, Sofia D. Shaikh, MD1, Enoch Chung, BS2, Howard Cabral, PhD3, Grace Zhao, MD, PhD1, Horst C. Weber, MD4 1Boston Medical Center, Boston, MA; 2Boston University Chobanian & Avedisian School of Medicine, Boston, MA; 3Boston University School of Public Health, Boston, MA; 4VA Boston Healthcare System, Boston, MA
Introduction: Gastrointestinal neuroendocrine tumors (GI-NETs) are rare, heterogenous tumors that have increased in incidence over the past three decades. Rectal NETs (rNETs) are the second most common GI-NET. While the biology of long-term outcomes remains uncertain, limited data has suggested that tumor size, stage and grade, and surgical approach are important prognostic factors. In particular, the impact of race and ethnicity on survival is poorly characterized.
Methods: The pathology database was searched for unique patients with biopsy-proven rNETs at Boston Medical Center between 2002 and 2022. Clinical-pathologic characteristics were collected by chart review. Data were compared across all races and ethnicities using t-test, chi-square, and Fisher’s exact tests. Overall survival (OS) was analyzed using the Kaplan Meier method.
Results: A total of 299 GI-NETs were identified, 56 of which were rNETs (18.7%). Black patients (N=26) represented the largest group of our sample, followed by White (N=14), Hispanic (N=6), and Asian patients (N=5) with 8 uncategorized. No differences of any clinical or tumor characteristics were present comparing Black and non-Black patients (see Table). None of the rNETs were functional, nor were any associated with Multiple Endocrine Neoplasia. Most tumors were local at time of diagnosis (79%) and less than 1cm in size (73%). Most patients were asymptomatic undergoing screening colonoscopy (70%). The most common treatment modality was endoscopic polypectomy (91%). 6-year OS was 91% (95% CI: 77%, 96%) with no difference between Black and non-Black patients (p=0.7; see Figure) and analysis of only non-Hispanic patients did not change this.
Discussion: Our study showed rNETs to comprise about 20% of the total GI-NET sample, similar to other studies. Unlike other reports, we did not identify any significant differences in clinical-pathologic features of rNETs across ethnicities or races. The prognosis of rNETs is excellent with no differences in OS between Black and non-Black patients in this sample, even when stratified by non-Hispanic ethnicity. Larger studies are warranted to confirm our results regarding the role of race and ethnicity in rNET presentation and survival.
Figure: For the entire cohort of rNET patients (N=56), the median follow up time among survivors was 6 years (range 0, 19 yr). 6-year overall survival (Panel A, left) is 91% (95% CI: 77%, 96%). There is no difference in OS between Blacks and Non-Blacks (p=0.7 from log-rank test). When only Non-Hispanic Black and non-Black patients were considered (Panel B, right), similar results were obtained (p=0.8).
Table: Table 1. Demographic and Clinical Characteristics of Patients with Rectal Neuroendocrine Tumors: Unique patients with biopsy-proven rNETs (N=56) were identified in the CoPath database (Boston Medical Center, Department of Pathology and Laboratory Medicine) over a 20-year span (1/1/2002 to 12/31/2021). Percent numbers may not add up to 100 because of rounding or if values were unknown. Immunohistochemistry of slides for synaptophysin and chromogranin A was available in 45 and 40 subjects, respectively. *Numbers do not add up to 56 as some patients presented with >1 symptom. No findings comparing Black and non-Black subjects met statistical significance (p < 0.05) and are therefore indicated as NS= not significant.
Disclosures:
Natalie Sun indicated no relevant financial relationships.
Isa Jacoba indicated no relevant financial relationships.
Sofia Shaikh indicated no relevant financial relationships.
Enoch Chung indicated no relevant financial relationships.
Howard Cabral indicated no relevant financial relationships.
Grace Zhao indicated no relevant financial relationships.
Horst Weber indicated no relevant financial relationships.
Natalie Sun, MD1, Isa Jacoba, MD1, Sofia D. Shaikh, MD1, Enoch Chung, BS2, Howard Cabral, PhD3, Grace Zhao, MD, PhD1, Horst C. Weber, MD4, 14, Overall Survival and Clinical-pathological Features of Rectal Neuroendocrine Tumors at a Large Safety-Net Hospital, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.
