The Risk Factors for Metastasis in Non-Ampullary Duodenal Neuroendocrine Tumors Measuring 20 mm or Less in Diameter.
OBJECTIVE
The treatment strategy for non-ampullary duodenal neuroendocrine tumors (NAD-NETs) ≤20 mm in diameter has not been established. In this study, we aimed to evaluate the detailed characteristics of NAD-NETs ≤20 mm in diameter to clarify the risk factors of subsequent metastasis.


METHODS
The patients with NAD-NETs ≤20 mm in diameter who had been treated at 12 institutions between 1992 and 2013 were enrolled. Clinical records were retrieved, and histopathological findings of all cases were centrally reviewed by 2 pathologists.


RESULTS
We studied 49 patients with a mean follow-up period of 66.5 months. Thirty-five patients were initially treated with endoscopic resection (ER), and 14 with surgery. A univariate analysis revealed the ORs and 95% CIs of the risk factors for metastasis were lymphovascular invasion (12.5 [2.01-77.9]), multiple tumors (9.75 [1.46-65.4]), a tumor size of 11-20 mm (6.67 [1.21-36.6]), and World Health Organization grade G2 (7.13 [1.16-43.9]). Five-year overall and disease-specific survival rates were 86.1 and 97.2%, respectively.


CONCLUSIONS
This is the first study to demonstrate the risk factors of metastasis in NAD-NETs ≤20 mm in diameter. These findings may be helpful for determining the appropriate therapeutic approach and the clinical strategy of treatment following ER.
Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Waku
W
Hatta
Tomoyuki
T
Koike
Katsunori
K
Iijima
Kiyotaka
K
Asanuma
Naoki
N
Asano
Hiroaki
H
Musha
Yoshifumi
Y
Inomata
Toshikazu
T
Sano
Hiroyuki
H
Endo
Atsushi
A
Ikehata
Toru
T
Horii
Motoki
M
Ohyauchi
Satoshi
S
Yokosawa
Atsuko
A
Kasajima
Fumiyoshi
F
Fujishima
Hironobu
H
Sasano
Naoki
N
Nakaya
Tomohiro
T
Nakamura
Tooru
T
Shimosegawa
D000368:Aged; D004379:Duodenal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D004384:Duodenoscopy; D004386:Duodenum / Q000473:pathology / Q000601:surgery; D000069916:Endoscopic Mucosal Resection; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology / Q000601:surgery; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D018358:Neuroendocrine Tumors / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D047368:Tumor Burden
Duodenum; Metastasis; Neuroendocrine tumor