To explore the clinical characteristics and related background diseases of type 1 gastric neuroendocrine tumor (g-NET) and to provide reference information for clinical diagnosis and treatment.

From January 2011 to February 2019, at the First Affiliated Hospital of Sun Yat-sen University and China-Japan Friendship Hospital, the clinical features and related background diseases of type 1 g-NET patients (41 cases and 93 cases respectively)were retrospectively analyzed. The clinical symptoms, serological indicators, gastroscopic and pathological features, tumor location, metastasis and treatment, and concomitant diseases were statistically described.

Among 134 patients with type 1 g-NET, there were 53 males (39.6%) and 81 females(60.4%); and the mean diagnosed age was (51±11) years (21 to 76 years). Main clinical manifestations were non-specific gastrointestinal symptoms. The mean level of serum chromogranin A was (237.7±176.8) μg/L. The endoscopic findings of 97.8% (131/134) of the patients were polypoid or protuberant lesions at gastric fundus or gastric body. And 75.0%(96/128) of the patients had multiple tumors.65.7%(88/134) of the patients had the tumors with the maximum diameter less than 1 cm (77.2%, 88/114) and the lesions mainly located in mucosa (59.8%, 52/87) and submucosa (40.2%, 35/87). The pathological classification of 79.3%(96/121) of the tumors was G1 grade and 20.7%(25/121) were G2 grade.The rate of local lymph node metastasis was 1.4%(1/73) and no distant metastasis was found. About 70.9% (95/134) of the patients received endoscopic treatment. Among the patients, 93.6%(103/110) of the patients had chronic atrophic gastritis confirmed by endoscopy or pathology, 45.6%(47/103) were confirmed by both endoscopy and pathology. Among the patients with chronic atrophy gastritis, serum gastrin levels of 93.2%(96/103)patients were twice higher than the upper limit of the normal value. The positive rates of anti-parietal cells antibody (PCA) and intrinsic factor (IFA) were 78.5%(73/93) and 51.9%(14/27), respectively.The incidence of Helicobacter pylori (H.pylori) infection was 28.1%(16/57). The incidence of autoimmune atrophy gastritis was 80.6%(75/93). The percentage of patients with deficiency of serum vitamin B12 and ferritin was 70.8%(63/89) and 30.7%(27/88), respectively. Patients with anemia accounted for 27.8%(25/90). The patients with microcytic anemia, normocyticanemia and macrocytic anemia were 28.0%(7/25), 56.0%(14/25) and 16.0%(4/25), respectively. 46.9%(45/96) of the patients had increased thyroid autoantibodies and 17.9%(17/95) patients had changes of thyroid hormone level.

Type 1 g-NET is more common in women and mainly caused by autoimmune atrophic gastritis. The level of serum PCA and IFA increase in more than half of the patients. And it is often accompanied by vitamin B12 deficiency and autoimmune thyroid disease.

Type 1 gastric neuroendocrine tumor; Gastritis, atrophic; Autoantibodies; Clinical manifestations; Endoscopic characteristics