title: Peritoneal dissemination in early gastric cancer: importance of the lymphatic route.
abstract: The current paradigm concerning the mechanism of peritoneal dissemination of gastric cancer is that it occurs through an invasive process in which cancer cells directly penetrate the gastric wall and exfoliate into the peritoneal cavity. However, some experimental studies suggest the lymphatic route as an alternative. We present five early gastric cancer cases, which support this alternative pathway of peritoneal dissemination without direct invasion in the serosa. We investigated all patients with early gastric cancer who underwent curative gastrectomy between September 2002 and February 2015 at the Shizuoka Cancer Center, Japan. We examined them by intraoperative peritoneal lavage cytology and frozen section diagnosis of peritoneal nodules during laparotomy. Peritoneal dissemination was defined as peritoneal metastasis by positive cytology or histological diagnosis. Among 1509 early gastric cancers, five cases (0.3 %, 95 % CI 0.1-0.8 %) presented peritoneal dissemination detected by lavage cytology and frozen section diagnosis of peritoneal nodules. Histological examination revealed that the primary tumors invaded the submucosal layer using the lymphatic route, through which they metastasized to regional lymph nodes. Our data indicate that gastric cancer may give rise to peritoneal dissemination even at an early stage, probably through the lymphatic route without direct invasion into the serosa.
authors.affiliation: Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan. ma.yoshida@scchr.jp.|Division of Endoscopy, Shizuoka Cancer Center, 1007 Shimonagakubo, Nagaizumi, Sunto-gun, Shizuoka, 411-8777, Japan. ma.yoshida@scchr.jp.
authors.forename: Masao
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Sugino
authors.affiliation: Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Kimihide
authors.initials: K
authors.lastname: Kusafuka
authors.affiliation: Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakajima
authors.affiliation: Division of Gastric Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Makuuchi
authors.affiliation: Division of Gastric Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Tokunaga
authors.affiliation: Division of Gastric Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tanizawa
authors.affiliation: Division of Gastric Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Etsuro
authors.initials: E
authors.lastname: Bando
authors.affiliation: Division of Gastric Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Taiichi
authors.initials: T
authors.lastname: Kawamura
authors.affiliation: Division of Gastric Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Terashima
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, 1007 Shimonagakubo, Nagaizumi, Sunto-gun, Shizuoka, 411-8777, Japan.
authors.forename: Noboru
authors.initials: N
authors.lastname: Kawata
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, 1007 Shimonagakubo, Nagaizumi, Sunto-gun, Shizuoka, 411-8777, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Tanaka
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, 1007 Shimonagakubo, Nagaizumi, Sunto-gun, Shizuoka, 411-8777, Japan.
authors.forename: Naomi
authors.initials: N
authors.lastname: Kakushima
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, 1007 Shimonagakubo, Nagaizumi, Sunto-gun, Shizuoka, 411-8777, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Takizawa
authors.affiliation: Division of Endoscopy, Shizuoka Cancer Center, 1007 Shimonagakubo, Nagaizumi, Sunto-gun, Shizuoka, 411-8777, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ono
mesh_terms: D000328:Adult; D000368:Aged; D003581:Cytodiagnosis / Q000379:methods; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000175:diagnosis; D042601:Lymphatic Vessels / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010533:Peritoneal Lavage / Q000379:methods; D010534:Peritoneal Neoplasms / Q000175:diagnosis / Q000473:pathology*; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*
keywords: Gastric cancer; Lymphatic metastasis; Lymphatic vessels; Neoplasm seeding; Neoplastic processes