Atsushi Nakayama, Kurato Miyazaki, Kentaro Iwata, Yoko Kubosawa, Teppei Masunaga, Yukie Hayashi, Mari Mizutani, Yoshiyuki Kiguchi, Koshiro Tsutsumi, Teppei Akimoto, Yusaku Takatori, Noriko Matsuura, Makoto Mutaguchi, Tomohisa Sujino, Kaoru Takabayashi, Yasutoshi Ochiai, Tadateru Maehata, Akiko Matsubara, Ryoji Kushima, Naohisa Yahagi, Motohiko Kato
The gastric phenotype is strongly associated with increased histological malignancy in SNADETs. Specific endoscopic features can predict G-type SNADETs, suggesting that mucin phenotype-oriented endoscopic diagnosis may provide useful information for pretreatment risk stratification and treatment planning.
BACKGROUND: Superficial non-ampullary duodenal epithelial tumors (SNADETs) are being increasingly detected during routine endoscopy. However, biological malignancy and optimal risk stratification remain poorly defined. We aimed to clarify the association between mucin phenotypes and histological malignancies in SNADETs using a prospective study design.
METHODS: In this prospective observational study, patients with suspected SNADETs underwent a standardized magnified endoscopic examination with image-enhanced endoscopy (IEE-ME), followed by endoscopic resection. All specimens were centrally reviewed by expert gastrointestinal pathologists. Mucin phenotypes were classified as G type (gastric, predominantly gastric, or mixed) or I type (intestinal or predominantly intestinal). Histological malignancy was assessed using the Vienna classification (VCL). Clinicopathological and endoscopic factors associated with mucin phenotype and malignancy were systematically analyzed.
RESULTS: Among the 401 SNADETs, adenomas were predominant (72.1%), whereas submucosal invasive cancers were rare (2.5%). G-type SNADETs comprised 15.5% of lesions but demonstrated a markedly higher frequency beyond VCL category 4.1 compared to I-type SNADETs (P < 0.0001). The risk of histological malignancy increased stepwise with the proportion of gastric phenotypic components. Most invasive submucosal cancers exhibit a gastric phenotype. Multivariate analysis of the endoscopic findings identified a closed-loop structure, the absence of a white opaque substance on IEE-ME, and protruding morphology as independent predictors of G-type SNADETs.
CONCLUSION: The gastric phenotype is strongly associated with increased histological malignancy in SNADETs. Specific endoscopic features can predict G-type SNADETs, suggesting that mucin phenotype-oriented endoscopic diagnosis may provide useful information for pretreatment risk stratification and treatment planning.