Background: Gastric 'indefinite for neoplasm/dysplasia' (IFND) is a borderline lesion that is difficult to diagnose as either regenerative or neoplastic. There is a need for guidance in the identification of a subset of patients, who have an IFND lesion with a higher risk of malignant potential, to enable risk stratification and optimal management.
Aim: To determine the clinical and pathologic factors for the accurate diagnosis of gastric IFND lesions.
Methods: In total, 461 gastric lesions diagnosed via biopsy as IFND lesions were retrospectively evaluated. Endoscopic resection (n = 134), surgery (n = 22), and follow-up endoscopic biopsy (n = 305) were performed to confirm the diagnosis. The time interval from initial biopsy to cancer diagnosis was measured, and diagnostic delays were categorized as > 2 wk, > 2 mo, > 6 mo, and > 1 year. The IFND lesions presenting as regenerating atypia (60%) or atypical epithelia (40%) at initial biopsy were adenocarcinomas in 22.6%, adenomas in 8.9%, and gastritis in 68.5% of the cases.
Results: Four clinical factors [age ≥ 60 years (2.445, 95%CI: 1.305-4.580, P = 0.005), endoscopic size ≥ 10 mm (3.519, 95%CI: 1.891-6.548, P < 0.001), single lesion (5.702, 95%CI: 2.212-14.696, P < 0.001), and spontaneous bleeding (4.056, 95%CI: 1.792-9.180, P = 0.001)], and two pathologic factors [atypical epithelium (25.575, 95%CI: 11.537-56.695, P < 0.001], and repeated IFND diagnosis [6.022, 95%CI: 1.822-19.909, P = 0.003)] were independent risk factors for gastric cancer. With two or more clinical factors, the sensitivity and specificity for carcinoma were 91.3% and 54.9%, respectively. Ten undifferentiated carcinomas were initially diagnosed as IFND. In the subgroup analysis, fold change (5.594, 95%CI: 1.458-21.462, P = 0.012) predicted undifferentiated or invasive carcinoma in the submucosal layers or deeper. Diagnostic delays shorter than 1 year were not associated with worse prognoses. Extremely well-differentiated adenocarcinomas accounted for half of the repeated IFND cases and resulted in low diagnostic accuracy even on retrospective blinded review.
Conclusion: More than two clinical and pathologic factors each had significant cut-off values for gastric carcinoma diagnosis; in such cases, endoscopic resection should be considered.
Keywords: Biopsy; Diagnostic delay; Endoscopic surgical procedure; Gastric cancer; Prognosis.