Endocrine Abstracts

Introduction: Sporadic neuroendocrine neoplasms (NEN) occur rarely in young-adult (YA) patients, with an estimated incidence is about 2.8 cases per million, and data specific to their epidemiology are limited. The aim of our study was to better characterize the natural history, prognosis and management of NEN in YA patients (≤ 35 years old) compared to adult-elderly (AE; >35 years old).

Methods: A retrospective observational study including 204 patients, of which 24 (11.8%) YA and 180 (88.2%) AE, with confirmed diagnosis of sporadic NEN and referred to ENETS Centre of Excellence of Naples – Federico II University between 2010 and 2019 was conducted. Clinical and pathological data, type of treatment, disease-specific survival (DSS) and recurrence-free survival (RFS) were evaluated.

Results: Median age at diagnosis was 25 (16–35) years in YA and 59 (36–84) years in AE patients (P < 0.001). Female gender was slightly more frequent in YA [M:F = 9:15; odds ratio (OR) 1.3, 95% CI 0.9–1.8]. Primary tumor site significantly differed between YA and AE patients (χ² = 68.5, P < 0.001), being appendix the most common site of origin (41.7% vs 1.1%, respectively), followed by pancreas (33.3% vs 26.7%), lung (16.7% vs 20%) and midgut 4.2% vs 12.2%). Other tumor sites were more frequent in AE compared to YA patients (40.0% vs 4.2%). YA had a significantly higher frequency of low-grade well differentiate (G1) tumors in comparison to AE (78.3% vs 41.3%, OR 1.9, 95% CI 1.4–2.5, P = 0.001). Functioning tumors were also more frequent in YA patients compared to AE (OR 2.2, 95% CI 0.8-5.4, P = 0.09), and this was statistically significant considering only the pancreatic NEN (62.5% vs 20.8% in YA and AE, respectively; OR 3.0, 95% CI 1.4-6.5, P = 0.01). Treatment strategy also differed, being YA treated with fewer regimes (OR 0.4, 95% CI 0.2-0.9, P = 0.007), including surgery (91.7% vs 70.6%, χ² = 4.8, P = 0.03) and SSA (25% vs 53.9%, χ² = 7.1, P = 0.008). Targeted- and chemotherapy were equally used. No differences in DSS and RFS were observed, although YA patients had a trend to a better RFS (median 180 vs 93 months, HR 0.45, P = 0.07). Among the YA group, age <19 years and G1 tumors were associated with better RFS (P = 0.04 and P = 0.03, respectively), although they were not confirmed as prognostic factors at multivariate analysis.

Conclusion: Clinical presentation of NEN significantly differed between YA and AE patients. Due to the lack of prognostic markers, awareness of these rare neoplasms results crucial for a better management.