The natural history of sporadic non‐ampullary duodenal epithelial tumors: Can we wait and see?

Initial Tumor Size and Narrow-Band Image Findings Estimate Growth Speed in Duodenal Tumors

INTRODUCTION

Recently, the detection of superficial non-ampullary duodenal epithelial tumors (SNADETs) including adenomas and superficial duodenal carcinomas has increased. Various endoscopic treatment methods have also been reported for SNADETs, but there are few reports on the natural history. The aim of this study was to analyze factors related to tumor growth and determine the characteristics of SNADETs which need early therapeutic intervention.

METHODS

A single-center, retrospective study was performed on the medical records of 309 patients with SNADETs who underwent endoscopic or surgical resection between January 2010 and May 2021. Of these, 41 patients who were followed up for more than 1 year by endoscopy were analyzed. The primary outcome was an analysis of the tumor growth speed. Secondary outcomes were the relationship between the tumor growth speed and mucin phenotype, tumor size and findings of magnifying endoscopy with narrow-band imaging (M-NBI).

RESULTS

The observation period was 24 months (13-182). Tumor growth speed was 1.1 mm/year (0-21.6). Tumor diameter ≥10 mm at first detection (p = 0.004; odds ratio 19.5 [2.03-186.96]) and mixed type by M-NBI (p = 0.036; odds ratio 9.69 [1.05-89.88]) were identified as risk factors of tumors growing at a rate of ≥3 mm/year. There was no statistically significant difference in the speed of tumor growth between the different mucin immunohistochemical phenotypes.

CONCLUSION

Initial tumor size and findings of M-NBI are useful to predict tumor growth and consider early intervention.

Non-Pure Intestinal Phenotype as an Indicator of Progression in Sporadic Nonampullary Duodenal Adenomas: A Multicenter Retrospective Cohort Study

INTRODUCTION

We aimed to evaluate the natural course of sporadic nonampullary duodenal adenomas (SNDAs) and determine the risk factors of progression.

METHODS

We retrospectively analyzed the follow-up outcomes of patients with biopsy-diagnosed SNDA between April 2010 and March 2016 at 13 institutions. All initial biopsy specimens were centrally evaluated. Only those diagnosed with adenomas were included. Mucinous phenotypes were classified into pure intestinal and non-pure intestinal phenotypes. Cumulative incidence rates of carcinoma and tumor enlargement were evaluated. Tumor enlargement was defined as a ≥25% or 5-mm increase in tumor size.

RESULTS

Overall, 121 lesions were analyzed. Within a median observation period of 32.7 months, 5 lesions were diagnosed as carcinomas; the cumulative 5-year incidence of carcinoma was 9.5%. Male sex ( P = 0.046), initial lesion size ≥10 mm ( P = 0.044), and non-pure intestinal phenotype ( P = 0.019) were significantly associated with progression to carcinoma. Tumor enlargement was observed in 22 lesions, with a cumulative 5-year incidence of 33.9%. Initial lesion size ≥10 mm ( P < 0.001), erythematous lesion ( P = 0.002), high-grade adenoma ( P = 0.002), Ki67 negative ( P = 0.007), and non-pure intestinal phenotype ( P = 0.001) were risk factors of tumor enlargement. In a multivariate analysis, an initial lesion size ≥10 mm ( P = 0.010) and non-pure intestinal phenotype ( P = 0.046) were independent and significant risk factors of tumor enlargement.

DISCUSSION

Lesion size ≥10 mm and non-pure intestinal phenotype on initial biopsy are risk factors of cancer progression and tumor enlargement in cases with SNDA. Thus, management effectiveness may be improved by focusing on lesion size and the mucinous phenotype.

Superficial non-ampullary duodenal epithelial tumors now: endoscopic diagnosis and therapy

With the recent increase in the frequency of duodenal tumor detection, significant progress has been made in endoscopic diagnosis and treatment. Although the first guidelines were issued in Japan, patient treatment varies widely among institutions. There is a need for improving the quality of endoscopic diagnosis and more curative and safer treatments. Biopsy is the standard diagnostic method; however, the diagnostic accuracy of endoscopic biopsy is not so high. Therefore, the differentiation of superficial non-ampullary duodenal epithelial tumors from non-neoplastic lesions is being developed. The incidence of lymph node and distant metastases of duodenal epithelial tumors is extremely rare in intramucosal carcinomas, and they are considered good candidates for endoscopic treatment if the technical difficulties can be resolved. Adverse events associated with endoscopic treatment are greatly reduced at advanced facilities through novel resection and closure methods, and further improvements are expected in the future. Clarifying the risk of metastatic recurrence may lead to the development of more appropriate treatments and curative resection criteria.

Current status and perspectives for endoscopic diagnosis of superficial nonampullary duodenal epithelial tumors

In recent years, there have been significant advances in the endoscopic resection (ER) procedures of superficial nonampullary duodenal epithelial tumors (SNADETs). A preoperative endoscopic diagnosis is thus deemed necessary in determining the indication for subsequent ER. For the histologic and endoscopic diagnosis of SNADETs, understanding the mucin phenotype is inevitable. Recently, two diagnostic algorithms for the differential diagnosis of SNADETs from nonneoplastic lesions under magnifying endoscopy with narrow-band imaging have been proposed. In addition, various endoscopic approaches have been proposed to differentiate low- and high-grade adenomas/carcinomas, including white light endoscopy, magnifying image-enhanced endoscopy, and endocytoscopy. These methods, however, have not been standardized with respect to the classification of their findings and the validation of their diagnostic accuracy. Moreover, there are still concerns with respect to the histologic criteria required to establish a SNADETs diagnosis. Standardization in the histologic and endoscopic diagnosis of SNADETs is needed.