Gastric Cardiac Carcinoma: Recent Progress in Clinicopathology, Prognosis, and Early Diagnosis

Gastric cardiac carcinoma (GCC), also known as gastroesophageal junction (GEJ) carcinoma, is a slow-growing fatal cancer that arises in gastric cardiac mucosa in a region of about 2 cm above and 3 cm below the GEJ line. This carcinoma shows clinicopathologic and genomic features similar, but not identical, to gastric noncardiac carcinoma (GNCC). In contrast, GCC is much more complicated than esophageal adenocarcinoma (EA) in clinicopathology, genomics, and prognosis. GCC is heterogeneous geographically, accounting for 20%-50% of all gastric carcinomas in endemic regions in China. Compared with EA, GCC shows a much broader histopathologic spectrum and worse prognosis. Although detailed mechanisms of GCC pathogenesis remain elusive, advanced age, Helicobacter pylori infection, and gastroesophageal reflux disease are key risk factors. Intriguingly, goblet cell intestinal metaplasia may not be an essential initial step toward carcinogenesis in all GCC cases. At present, an accurate diagnosis of early GCC with prompt curative resection is the only realistic hope for dramatically improving patient outcomes. The recently developed liquid biopsy technology for serum cell-free DNA is a promising tool for the detection of early GCC, though many challenges remain and an in-depth investigation is required. Given the recent rapid advances in artificial intelligence, endoscopic technology, and a better understanding of endoscopists for subtle mucosal/vascular changes in early GCC, accurate detection of early GCC in a high proportion of cases would be possible.