Frequency and characteristics of synchronous gastric cancers: Need for improved awareness and better detection

The pathway of gastric cancer involves progression from atrophic gastritis to intestinal metaplasia to dysplasia and then cancer. The background mucosa in patients with gastric cancer is likely to have areas of atrophy and metaplasia, and hence, coexisting gastric cancer may be present. In this paper, we have reviewed the prevalence, characteristics, and predictors of synchronous neoplasm in patients with gastric cancer. Data on synchronous gastric neoplasms (SGNs) are mainly available from two types of studies, those detected on surgically resected specimens and those detected endoscopically. The prevalence of SGN cancer generally ranges between 5%-12% although the number may vary. Most of the synchronous lesions are noted in the distal stomach and are well differentiated on histology. Increasing age, male gender, well-differentiated histology of primary cancer, early stage of the primary cancer, and presence of atrophy and intestinal metaplasia in the background gastric mucosa increase the risk of synchronous neoplasm. SGN cancers may be missed in about one-third of cases during initial endoscopy. Overall, there is an urgent need to improve awareness of SGN cancer and improve its detection by using appropriate endoscopic evaluation. This would lead to a greater chance of curative treatment and better patient outcomes.