転移性大腸癌の臨床病理

Clinicopathological Study on Metastatic Colo-rectal Cancer

要旨　転移性大腸癌93例の内訳は原発癌手術例66例（71％）で，そのうち転移性大腸癌手術例はわずか17例（26％）であった．その17例中，大腸転移部を再切除できたものは5例（29％）であった．すなわち転移性大腸癌の転移部再切除率は5.4％（5/93）であった．胃癌からの大腸転移が一番多く，61例であり，次いで婦人科領域の癌であった．最も多かった転移部位は横行結腸で，次いでS状結腸，直腸の順であり，この3区域で80％を占めていた．原発性大腸癌のほとんどは限局型でpapillaryな形態であるが，転移性大腸癌は粘膜下に浸潤波及する浸潤型を示し，その約30％は多発していた．再発転移を早期と晩期に分けて検討したが，早期転移再発は若年者に多く，大腸転移以外の転移因子も加わり，再手術率が低かった．晩期転移再発例は，癌の遺残が少ないこと，癌の進行発育が遅いこと，などが考えられ，再手術される率も高かった．胃癌漿膜面露出例の治療方法と手術後の制癌剤投与の改善が，大腸転移の予防と予後の向上につながるものと思われる．

　A clinicopathological study was conducted on 93 cases of metastatic colo-rectal cancer diagnosed by x-ray examination over a five-year period ending in 1985. Primary carcinomas detected included gastric carcinoma in 61 cases, uterine or ovarian carcinoma in 13, colorectal cancer in 6, lung carcinoma in 4, as well as gallbladder carcinoma, choledochal carcinoma, and others. The primary carcinoma was surgically treated in 66 cases. In only 17 of these 66 cases was the matastatic colo-rectal cancer surgically treated after the primary lesion was resected. Recurrent metastatic colo-rectal carcinoma was re-excised in 5 of the 17 cases (the rate of re-excision was 5.4% (5/93) ). The recurrence of metastatic colo-rectal cancer occurred most frequently in the transverse colon, which was followed by sigmoid colon and rectum in decreasing order of frequency.

　Gastric carcinoma was the leading cause of metastatic colo-rectal cancer, with the following clinicopathological characteristics : the gastric serosa being extensively infiltrated, high frequency of linitis plastica type (represented by Borrmann's type 4), and high frequency of adenocarcinoma (signet-ring cell carcinoma and poorly differentiated adenocarcinoma) which produces mucus with scant glandular lumina.

　Most of the primary colo-rectal cancers were of the localized type. Almost all of these were papillary or tubular adenocarcinomas. On the other hand, metastatic colo-rectal cancer was of the invasive type involving extensively submucosal layer. Most of these were poorly differentiated adenocarcinomas or signet-ring cell carcinomas. Furthermore, metastases were multiple in approximately 30% of the cases of metastatic colorectal cancer.