[Molecular etiology of colorectal carcinogenesis, clinical manifestations and therapy].

Mutations of tumor suppressor genes, of the mismatch DNA repair system, and of the TGF-beta-II-receptor are the main causes for a higher risk of colorectal cancer. Among mutations of the Ape gene, which characterize the clinical manifestation of the familial polyposis (FAP), point mutations are dominating which create new stop codons or arise from deletions or insertions of nucleotides causing frame shifts. Because the binding site of beta-catenin is localized in the C-terminus of the Ape protein, disturbances result in the cellular signal transfer from its loss.

Significance of apoptosis in the process of tumorigenesis in colorectal mucosa and adenomas in FAP patients.

The relation between proliferation and apoptosis was studied in colorectal mucosal biopsies (N = 41), tubular adenomas (TA) (N = 104) and tubulovillous adenomas (TVA) (N = 34) from 37 FAP patients. Proliferative activity was determined by cell cycle distribution analysis. In addition, transcriptional capacity was determined by chromatin in situ testing.

Familial adenomatous polyposis: mutation at codon 1309 and early onset of colon cancer.

The clinical course of familial adenomatous polyposis (FAP) varies considerably between patients. Prediction of the severity of the disease is important in the interest of effective cancer prevention. We examined whether age at diagnosis of FAP due to gastrointestinal symptoms and age at death due to colorectal cancer are related to the site of mutation in the responsible gene.

[Autoradiography of DNA synthesis in colonic mucosa of patients with familial adenomatosis coli].

In connection with routine endoscopic examinations of 31 patients with familial adenomatosis coli and 28 health kindreds of patients with familial adenomatosis coli we investigated by autoradiography the in vitro incorporation of 3H-thymidine into bioptic mucosal particles from colon and adenomas. Within the 5-year follow-up period there was found a significantly increased labelling index of polyps and the surrounding mucosa in patients with polyposis independing on the time elapsed after operation. In 12 of 28 kindreds the histological normal colonic mucosa showed an increased labelling index too.

[Cell proliferation of the intestinal mucosa in patients with familial adenomatosis coli. Autoradiography study].

In connection with routine endoscopic examinations of 31 patients with familial adenomatosis coli and 28 healthy kindreds of patients with familial adenomatosis coli we investigated by autoradiography the in vitro incorporation of 3H-thymidine into bioptic mucosal particles from colon and adenomas. Within the 5-year follow-up period there was found a significantly increased labelling index of polyps and the surrounding mucosa in patients with polyposis independing on the time elapsed after operation. In 12 of 28 kindreds the histological normal colonic mucosa showed an increased labelling index too.

[Early detection of colorectal cancers by detection of occult blood in feces using Krypto-Haem SSW].

Screening for cancer of the bowels with tests for occult blood in the stools obtained an increasing interest during the last 15 years. In the GDR Krypto-Haem SSW is at the disposal for this purpose. Up to now two larger investigations were performed with this preparation.

DNA ploidy and proliferation characteristics of bowel polyps analysed by flow cytometry compared with cytology and histology.

56 human adenomatous bowel polyps and 44 samples of macroscopically unchanged bowel mucosa taken at a distance of 2-10 cm from the polyp were investigated by histology, cytology, and flow cytometry in respect to their dysplasia grade and DNA distributions. 30 human adenomatous polyps of the same localization were investigated by histology and flow cytometry; in 14 cases in addition to the DNA-patterns per se their changes mediated by heparin, a polyanion, were recorded. Histological and cytological investigations revealed mild dysplasia in 25 cases, moderate dysplasia in 43 cases and severe dysplasia in 18 cases.

[Ultrasound-guided fine needle biopsy in tumor diagnosis].

Ultrasound guided fine needle biopsy led in 92 of 100 patients with suspected tumours to correct diagnostic results which determined the diagnostic and therapeutic management. Ultrasound-tomography may thus in connection with fine needle biopsy enlarge and simplify tumour diagnosis.

[Endoscopic and histologic findings in malignant non-Hodgkin lymphomas of the stomach].

The authors have carried out a retrospective analysis of primary malignant Non-Hodgkin-lymphomas of the stomach verified histologically by surgical specimens, with the patients being submitted preoperatively to a gastroscopy with biopsy. The endoscopic and histological findings are outlined. Endoscopically the diagnosis of a malignant lymphoma was established only once, while an ulcerated carcinoma was diagnosed in almost two-thirds of the cases.

Characterization of human adenomatous polyps of the colorectal bowel by means of DNA distribution patterns.

64 human adenomatous polyps of the colorectal bowel were investigated by histological examination and by flow cytometrical analysis providing DNA distribution patterns. The histological investigation yielded tubular adenomas (TA) in 41 and tubulo-villous adenomas (TVA) in 23 cases. Epithelial dysplasia or carcinomatous degeneration was found in 23 TA and in 11 TVA.

A comparative study of early gastric cancer.

Authors provided a comparative study of early gastric cancers (EGC) which were found in the Cancer Research Centre of the Academy of Medical Sciences of USSR (Group A) and in the Central Institute of Cancer Research of the Academy of Sciences of GDR (Group B). The most frequent EGC-type in group B was type II, while types I and III were more frequent in group A. The rate of lymph node metastases in group A was 4,54% versus 16,2% in group B.

[Colonic cancer screening with KRYPTO-HAEM SSW. The results in 3015 persons].

In a factory 3015 individuals have been tested for occult blood in stool using the KRYPTO-HAEM SSW. Test results were positive in 100 individuals (3.3%).

[Cancer and polyps of the large intestine].

Incidence and mortality of the carcinoma of the large intestine increase also in the GDR. Carcinomas mostly develop in adenomas of the large intestine in the course of several years. Nowadays the adenoma-carcinoma-sequence is regarded as ascertained.

[Screening for colorectal cancer with a test for occult blood in stool (author's transl)].

Results of an occult-blood-test in 1 072 persons are reported. The test, recently registered as KRYPTO-HAEM, was developed by the Central Institute of Molecular Biology of the Academy of Sciences of the GDR. 27 patients (2.

[Early detection of gastrointestinal tumors (author's transl)].

"Early cancers" of stomach and colon have a favourable prognosis, but mass screenings for these tumors with endoscopic or radiographic methods are ineffective and expensive. The simple nonspecific test for occult blood as a suitable method for early detection of stomach and colorectal cancer in high-risk patients seems to be more useful. Some suggestions are given to detect and to control risk groups.

[Therapeutic aspects of endoscopic polypectomy].

466 endoscopic polypectomies of the upper and lower gastrointestinal tract were analysed according to their curative value. In 254 removed polyps of the upper gastrointestinal tract the result of the histological examination was twice a proof of a carcinoma. One it had to be after-resected, once a carcinoid, five times bleeding polyps were removed.

[The CEA-concentration in plasma of patients with colorectal carcinoma and polyps has been determined by radioimmunoassay (RIA, Z-gel-method)].

82% of the cancer patients and 52% of the patients with polyps showed CEA levels above the upper normal limit of 2,5 microgram/1. CEA-values of more than 10 microgram/1 could only be detected in patients with carcinoma. Complete removal of the tumour by surgery has been followed by a marked decrease of prior increased plasma-CEA to values in the normal range, which could not be observed in the cases with tumour residues or metastases.

Confirmation of cancer diagnosis--methods and problems.

Histo- und cytopathological proof of the diagnosis of cancer is crucial for the choice of an appropriate treatment. In the last decade effective methods for obtaining material from various organs of the body within operation have been developed, especially by new procedures in endoscopy, radiology, sonography and fine needle biopsying allowing further progress in cancer management.

[Experiences with coloscopy].

The introduction of fully flexible coloscopes has considerably contributed to the improvement of the diagnostics of the large intestine. According to the hitherto got experiences is to be expected that this method will contribute to the possibility of diagnose malignant and benign colon processes earlier and more exactly. In the paper the methodology of the coloscopy is described and it is referred to its difficulties and complications.