Time from first symptoms to diagnosis in GEP-NET patients: Results from a large German tertiary referral center.

Abstract

610 Background: Patients with neuroendocrine tumors (NET) often go through a long phase between onset of symptoms and initial diagnosis. Methods: Retrospective analysis of 486 patients with GEP-NET (488 tumors) at tertiary referral center from 1984-2019; inclusion criteria: Patients > 18 years, diagnosis of GEP-NET; descriptive analysis using SPSS; Cox regression, Log rank test. Results: Demographics: Male 54% / 52.9% (all/GEP-NET), median age at first diagnosis 63y/58y (all /GEP-NET). Localizations: small intestine 145/488 (29.7%), pancreas 143/488 (29.3%), CUP 53/488 (10.9%), colon 49/488 (10%), stomach 45/488 (9.2%), rectum 27/488 (5.5%), other digestive organs 11/488 (2.3%), esophagus 5/488 (1%), other 10/488 (2%). Ki67 in 330/488 (67.6%) evaluable patients: < 3%: 155/330; 46.9%; ≥ 3%: 111/330; 33.6%; > 20%: 64/330;19.3%. 128/488 (26.2%) of patients had NET specific symptoms (abdominal pain 77/128; 60.2%, diarrhea 51/128; 39.8%, flush 19/128; 14.8%, carcinoid syndrome 8/128; 6.3% tachycardia 6/128; 4.7%). 122/488 (25%) patients showed other tumor-specific symptoms (weight loss 48/122; 39.3%, stool irregularity 21/122; 17.2%, hypoglycemia 10/122; 8.2%, painless jaundice 8/122; 6.6%). 154/ 488 (32%) of NET were incidental findings (imaging 39.6%, endoscopy 23.4%, surgery for other causes 18.8%, appendectomy 15.6%). 221/279 (initial diagnosis/any time; 79.2%) patients had distant metastases at initial diagnosis (187/221 liver metastases). Time from tumor manifestation to initial diagnosis: pNET 360 ± 116 days, siNET 309 ± 87 days, gastric NET 66 ± 47 days, colonic NET 98 ± 67 days. Time from onset of symptoms to diagnosis in symptomatic patients was significantly longer than in asymptomatic patients (388 ± 86 days vs. 174 ± 58 days, p = 0.001). No significant difference in patients with or without distant metastases (223 ± 78 days vs. 259 ± 57 days, p = 0.355). Conclusions: A large proportion of NET are incidental findings and only about half of all patients are symptomatic at the time of diagnosis. Diagnosis for symptomatic patients takes significantly longer than for asymptomatic, which might be due to mainly unspecific symptoms. Presence of metastases has no influence on time to diagnosis.