Tatsuhisa Morodomi

An index for estimating the probability of lymph node metastasis in rectal cancers. Lymph node metastasis and the histopathology of actively invasive regions of cancer

We examined resected specimens from 40 cases of advanced rectal cancer to determine the extent of microtubular cancer nests and undifferentiated cancer cells (budding). We investigated the relationship between this budding and lymphatic invasion (ly), venous invasion (v), and lymph node metastasis (n), respectively. Moreover, we examined the relationship between ly, budding, and n in the preoperative biopsy specimens of 112 patients, including those of the 40 cases mentioned above. The degree of budding, which was abundant in the actively in asive region, showed a strong correlation with the degree of ly and the existence of n in the resected specimens. Also, budding was recognized in a relatively large portion of the biopsy specimens (52 of 112 [46.4%]) and lymph node metastasis was found in 41 of 52 specimens (78.8%). In 57 specimens, neither ly nor budding was found, and 16 of these specimens (28.1%) had positive lymph nodes. These results implied that the degree of budding in the actively invasive region can be a great help in predicting the presence of n. The presence or absence of budding in preoperative biopsy specimens also can be an important factor (along with the degree of differentiation and ly) in estimating the probability of n.

Carcinomatous lymphatic permeation. Prognostic significance in patients with rectal carcinoma—A long term prospective study

Background. The question of whether lymphatic permeation in rectal carcinoma is an index of prognosis remains controversial.

Primary linitis plastica carcinoma of the colon and rectum

Background. Linitis plastica carcinoma (LPC) usually shows a scirrhous growth pattern with a severe stromal desmoplastic reaction. Another growth pattern showing lymphangiosis carcinomatosa rather than scirrhous growth pattern, however, was noted. This study was designed to clarify the clinical and pathologic characteristics of colorectal LPC.

Small-cell carcinoma of the rectum

Three cases of small-cell carcinoma of the rectum are presented. Our conclusions are as follows: 1) small-cell carcinoma and carcinoid tumor of the rectum might have a common origin; 2) indications for surgical intervention for small-cell carcinoma of the rectum should be considered seriously; 3) small-cell carcinoma of the rectum should be classified as an aggressive type of rectal tumor that metastasizes easily to distant organs.

Clinicopathologic characteristics of large bowel cancer developing after radiotherapy for uterine cervical cancer

PURPOSE: This study was designed to clarify the characteristics of large bowel cancer developing after radiotherapy for uterine cervical cancer. METHODS: A retrospective chart review was performed. RESULTS: The latent period was a mean of 20.5 years. The most common site was in the rectum (16/32). Mucin-producing carcinoma was observed in 53.1 percent, with an especially high rate of 75 percent in the rectum. Histologic radiation damage was also demonstrated at a high rate of 64.3 percent. CONCLUSIONS: It was difficult to judge from clinicopathologic findings whether large bowel cancer developed with relation to radiation effect. We emphasize, however, that the characteristics are different from ordinary large bowel cancer. Particular consideration should be given to the high incidence of mucin-producing carcinoma.

Effect of OK-432 on large-bowel carcinogenesis in rats.

To examine the carcinogenetic and growth inhibitory effects of OK-432, large-bowel carcinoma was induced experimentally in rats by intrarectal injection of N-methyl-N-nitrosourea (MNU), and OK-432 was administered intradermally. Rats were sacrificed after six months and the large intestine was cut into serial sections. Histopathologic examination and analysis of the infiltrating menonuclear cells, using monoclonal antibodies, were performed. The average rate of carcinogenesis per rat was 15.7±8.5 in the MNU alone group (n=10) and 8.3±3.5 in the MNU and OK-432 group (n=6). The invasion was deeper than the muscularis propria in 16 out of 157 lesions (10.2 percent) in the MNU alone group and in one out of 50 lesions in the MNU+OK-432 group (2.0 percent) (P<0.05). When time of appearance of atypical glands or carcinomas were compared in the MNU alone and MNU+OK-432 group. In the investigation of infiltrating mononuclear cells using monoclonal antibodies, there were increases in helper T cells in both the MNU alone and MNU+OK-432 groups, but there was little difference between the two groups. The results of this study suggest that the suppression of experimental carcinogenesis in the large bowel by the concomitant administration of OK-432 with MNU, may be due to the enhanced activation or prolonged activated state of immunocompetent cells, which appear via antigen recognition, by OK-432.

The Expression of Neural Cell Adhesion Molecule in Advanced Rectal Cancer

The expression of neural cell adhesion molecule (NCAM) was studied immunohistochemicaly in 164 cases of advanced rectal cancer (StageII and StageIII). Fourteen cases (8.5%) were positive for NCAM, and NCAM positive cases had a high incidence of perineural invasion of cancer and poor prognosis compared with NCAM negative cases. These results suggest that NCAM plays an important role in perinural invasion of tumor and survival rates for rectal cancer.

Evaluation of hepatectomy for hepatic metastasis of colorectal cancer.

大腸癌肝転移に対する肝切除の評価を臨床病理学的立場から検討し, 以下の結果を得た.(1) 肝切除例では化学療法例に比べ長期生存例が存在した.(2) 肝切除例における肝切除後の生存期間は, リンパ節転移や組織所見 (分化度, リンパ管侵襲) などの原発巣側の因子によって有意差が認められた.(3) 肝切除の術式, 肝転移の時期, 程度, 個数などの転移巣側の因子については, 生存期間に有意差は認められなかった.(4) 肝切除後の再発は残肝, 肺が高頻度であった.以上のことより (1) 肝切除は化学療法よりも有効性があるが, 原発巣の組織学的特徴を考慮した合理的肝切除を施行すべきである.(2) 肝切除後の再発をいかに予防するかが今後の課題であると考えている.