SP70 is a Potential Biomarker to Identify Gastric Fundic Gland Neoplasms

Abstract

Background Gastric neoplasms with fundic gland differentiation include oxyntic gland adenomas (OGAs) and gastric adenocarcinomas of fundic gland type (GA-FGs). Due to their extremely well differentiation and morphological similarity to normal fundic glands, it is usually challenging to identify these lesions in pathological diagnosis, especially in biopsy specimens. This study aims to explore and verify the potential role of a newly developed monoclonal antibody (McAb) NJ001 (SP70) in differentiating fundic neoplasms from non-neoplastic fundic gland lesions. Methods Twenty-three cases of histological confirmed gastric fundic gland neoplasms were obtained, including 12 cases of OGAs and 11 of GA-FGs. Fifty cases of fundic gland polyps (FGPs) were also obtained in the control group. Key clinicopathological information was collected. SP70 immunostaining was performed, the intensity, as well as the staining pattern was analyzed and compared. The para-tumor normal fundic glands were used as internal control.Results In normal gastric mucosa, SP70 was strongly and diffusely stained on the cytoplasm in fundic glands, but not in foveolar epithelium. Therefore, a zonal distribution of SP70 was observed in normal mucosa. FGPs (50/50, 100%) shared a similar expression pattern with normal fundic glands. In fundic gland neoplasms, a significant down-expression of SP70 was observed in both OGAs and GA-FGs. The positive rate of SP70 in fundic gland neoplasms (6/23, 26.1%) was significantly lower than that in FGPs (100%) (P＜0.0001). There was no difference of SP70 positivity between OGAs (3/12, 25.0%) and GA-FGs (3/11, 27.2%) group (P>0.05).Conclusion Down-expression of SP70 is a specific feature to fundic gland neoplasms including OGAs and GA-FGs. Therefore, SP70 can serve as a potential biomarker in the identification and differential diagnosis of fundic gland neoplasms.