Characteristics and prognosis of mucinous gastric carcinoma

Mucinous gastric carcinoma (MGC) is a rare histological subtype of undifferentiated gastric carcinoma, accounting for ~2.6-6.6% of all gastric cancer cases. The clinicopathological characteristics and prognosis of MGC are controversial. The present study aimed to determine the clinicopathological characteristics and prognosis of patients with MGC. We retrospectively compared the characteristics and postoperative survival of 70 patients with MGC and 2,492 non-MGC (NMGC) cases who underwent surgical resection between 1990 and 2010. MGC was characterised by larger tumor size, macroscopic Borrmann type 2 and 3, T4 invasion of the gastric wall, positive N2 and N3 lymph node metastasis, positive lymphatic vessel invasion, positive venous invasion, peritoneal metastasis and advanced tumor stage III and IV. The prognosis of MGC patients was worse compared to that of NMGC patients, as the former group consisted of more advanced-stage cases. When patients with similar disease stages were compared, the incidence of peritoneal metastasis was significantly higher among MGC patients. However, hepatic metastasis was found significantly more often in NMGC patients. Otherwise, the prognosis of MGC and NMGC patients with similar disease stages was not significantly different. Therefore, our findings indicated that, although MGC is more rare and mostly detected at an advanced stage, the diagnosis of the mucinous histological subtype was not an independent prognostic factor.