No abstract

The purpose of this study was to define the indications and limitations of endoscopic resection (ER) of early gastric carcinoma (EGC). Over the 15 year period from 1978 to 1992, 308 early cancers were resected endoscopically either through a single operative intervention or in stages. Of 266 lesions resected in a single step, 222 (85%) entered remission. Forty-four cases had either residual or recurrent lesions. The size, histology and location affected the curability; 89% of Type IIa lesions less than 2 cm were resected curatively, while only 50% of those larger than 2 cm were resected completely. In Type IIc, 83% of lesions less than 1 cm and 57% of those greater than 1 cm were excised completely by ER. In Type IIc, curative ER was possible in 85% of differentiated carcinomas and 43% of undifferentiated carcinomas. The rate of incomplete resection was higher for lesions of the anterior or posterior wall, than for those of the lesser curvature. Semiserial sections of the resected specimens made at 2 mm intervals, indicated that, if the positive margin was confined to one section, cure may be possible by the burning effect. Follow-up showed that there was no single case undergoing endoscopic resection which subsequently died of gastric carcinoma. The lesions that are suitable for ER comprise Type IIa EGC of less than 2 cm in diameter, and Type IIc differentiated adenocarcinoma of less than 1 cm. Lesions in which the entire margin is difficult to observe by front-view endoscopy should be smaller than defined by the above criteria.

We should pay particular attention to unrecognizable intramucosal spread, especially in markedly atrophied mucosa, when treating small diffuse-type mucosal gastric cancer by local resections such as endoscopic mucosal resection. In addition, because of unrecognizable intramucosal spread, a surgical incision margin of at least 10 mm from the macroscopic margin is indicated.

No abstract

To investigate whether gonadal hormones are involved in the tumorigenesis of dimethylhydrazine (DMH)-induced colonic neoplasms, the authors measured steroid receptors in the neoplasms. 30- or 60-day-old BD-IX rats were injected with 20 mg of 1,2-DMH per kg of body weight once a week for 20 weeks. Fifty-seven rats were sacrificed at 40 to 45 weeks after the initial injection. Androgen receptor (AR), estrogen receptor (ER), and progesterone receptor (PR) were measured in colonic neoplasms. The total number of colonic neoplasms was 274 among 57 rats, 65.8% in male rats and 34.2% in female rats. The mean number of colonic neoplasms per rat was higher in male rats, i.e., 5.6, compared with 3.5 in female rats. A slightly higher number of colonic neoplasms per rat was seen in the rats that had the initial injection at 30 days of age. The number of large colonic neoplasms with a diameter of more than 1 cm was 77 (28.1%), 74% of which were seen in male rats. Thus, a higher incidence of tumors that were also larger were seen in male rats. Histologic findings showed that 53.6% of the neoplasms were carcinomas. The highest incidence of colonic neoplasms was in the distal colon in both sexes. Most of the well-differentiated adenocarcinoma were seen in the distal colon (82.2%), whereas mucinous carcinoma and undifferentiated adenocarcinoma were prominent in the proximal colon or cecum (56.1%). In rats with a normal colon, low levels of AR and PR were determined; but ER was not found in any regions of the colon. In DMH-induced colonic cancer, the incidence as well as the concentration was higher in male rats (60.6%, 16.9 +/- 3.6 fm/mg protein), compared with female rats (40.0%, 4.6 +/- 0.8 fm/mg protein). Similar incidences and levels of ER and PR were seen in both sexes. There was no relationship between steroid receptors and histologic findings in colonic neoplasms. These results suggest that the gonadal hormones, especially androgens, appear to be involved in DMH-induced colon tumorigenesis in male rats.