胃sm癌の深達度と粘液形質および癌関連遺伝子産物の発現

A Correlation of Intramural Tumor Invasion with Mucin Histochemistry, and Immunohistochemical Expressions of Oncogene-related Proteins in Early Gastric Carcinomas

要旨　胃sm癌を腫瘍先進部のレベルでsm₁からsm₃に分類し，リンパ節転移との関連を検討した．リンパ節転移率はsm₁で8.1％，sm₂で17.0％，sm₃で30.4％と壁浸潤とともに増加し，m癌（2.2％）と有意差がみられた．リンパ節転移例は非転移例よりも病変部面積とsm/m比が有意に大であり，リンパ管侵襲率が高かった．リンパ節転移群はm癌の時点から胃型粘液を優位に認めたが，非転移例は壁浸潤に並行して胃型形質の発現例が増加し，粘液形質と生物学的悪性度との関連が示唆された．p53蛋白およびc-erbB-2蛋白の過剰発現とリンパ節転移との関連はなかった．sm₁癌のリンパ節転移例は，全例潰瘍や潰瘍瘢痕を認める陥凹型腫瘍で，組織学的には低分化腺癌領域を少なくとも一部に認め，リンパ管侵襲が4例（67％）にみられた．

　We categorized gastric carcinomas invading the submucosa as tumors restricted to the superficial submucosa (sm₁), tumors invading the deep portion of the submucosa (sm₃), and others (sm₂), along with lymph node involvement (NI).

　The frequency of NI was 8.1％, 17.0％ and 30.4％ among the cases with sm₁, sm₂ and sm₃, respectively, which percentage increased with an intramural tumor invasion and was significantly higher than that (2.2％) of intramucosal carcinoma cases.

　Areas of both mucosal and submucosal lesions and the ratio of sm to m in tumoral areas in cases with NI were significantly larger than those in cases without NI. Lymphatic permeation was more frequently observed in cases with NI than in cases without NI.

　In mucin histochemistry, gastric-type mucin was frequently observed even in intramucosal carcinoma cases with NI, whereas the mucin was gradually expressed in non-metastasizing carcinoma cases as intramural tumor invasion. It was suggested that expressed mucin may be related with biological aggressiveness of the tumor. Overexpression of p53 and c-erbB-2 proteins were not correlated with NI.

　All six cases of sm₁ with NI showed macroscopically depressed lesions with ulcers or ulcer scars and poorly-differentiated adenocarcinomatous components. Lymphatic permeation was also detected in four (67％) of the cases.