Relationship Between the Histological Type of Initial Lesions and the Risk for the Development of Remnant Gastric Cancers After Gastrectomy for Synchronous Multiple Gastric Cancers

Clinicopathological features of remnant gastric cancers after gastrectomy for synchronous multiple gastric cancers have not been fully addressed. In this study we evaluated the potential risk factors attributable to the development of remnant gastric cancers after initial gastrectomy for multiple gastric cancers. We retrospectively analyzed 3042 patients diagnosed with gastric cancers who underwent a gastrectomy. Of these, 922 total gastrectomy cases were excluded and the remaining 2120 cases were clinicopathologically investigated. Among the 2120 patients, 1967 patients were histopathologically diagnosed with a solitary lesion and 153 patients with multiple lesions. The incidence of remnant gastric cancers was higher in patients with multiple lesions at initial surgery than in those with a solitary lesion (7/153 [4.5%] vs. 9/1967 [0.45%], p < 0.05). Among the patients with remnant gastric cancer, the percentages of cases with a combination of undifferentiated-type carcinoma (Type C), differentiated-type carcinoma (Type A), and differentiated- and undifferentiated-type carcinoma (Type B) as initial lesions were 15.0, 3.3, and 2.7%, respectively. Compared with those with no remnant gastric cancer, the incidence of the combination of undifferentiated-type carcinoma (Type C) as an initial lesion was significantly associated with a higher (p < 0.05) incidence of remnant gastric cancer. As initial lesions, a combination of undifferentiated-type carcinoma was a potential risk factor for the development of remnant gastric cancers after initial gastrectomy.