How Does Japan Differentiate Hyperplasia from Neoplasia?

Abstract

A Japanese pathologist's contribution to the discussion of the problem on differentiation of hyperplasia from neoplasia is to introduce his experience and knowledge in human and experimental pathology of gastric, hepatic, and uterine cervical cancers, all of which are prevalent in Japan. Canine and rodent gastric cancers induced experimentally by N-ethyl-N'-nitro-N-nitrosoguanidine or N-methyl-N'-nitro-N-nitrosoguanidine, respectively, show different histologic types which are similar to human gastric cancer when examined routinely by endoscopic method. Dogs show more similarities to human gastric cancer than rats in the morphologic features and responses to chemotherapy. Serial liver biopsies performed on patients with liver diseases revealed the final stages of liver cell carcinoma in some of them. They all progressed to liver cirrhosis before terminating in carcinoma. However, this does not mean that the hyperplastic nodule is an obligatory precursor of carcinoma in human. Among experimental models of liver cancer produced by a large number of agents, only carbon tetrachloride and luteoskyrin seem to induce liver cell carcinoma combined with cirrhotic lesions in rodents. The mode of manifestation of atypical changes in the proliferating cells as preneoplastic or neoplastic lesions seems to differ according to tissue. The cellular pathology of cervicovaginal smears is a reliable index for detection of carcinoma in the cervix, where the appearance of atypical cells represents a landmark between benign and malignant tumors.

Contribution of toxicologic pathologists for the safety of human health in biomedical research—past, present, and future of the JSTP

“…Histopathological changes in rodents associated with progression from acute to chronic hepatic damage including cirrhosis and liver cancer induced by carbon tetrachloride and luteoskyrin were compared with biopsy or autopsy specimens from human liver cancer patients ( Fig. 1B and 1C ) 2 .…”

“…Histological specimens of stomach cancer induced by derivatives of nitrosoguanidine in rats or dogs were compared with those of human endoscopic biopsy specimens (Figure 1A). Histopathological changes in rodents associated with progression from acute to chronic hepatic damage including cirrhosis and liver cancer induced by carbon tetrachloride and luteoskyrin were compared with biopsy or autopsy specimens from human liver cancer patients (Figure 1B and 1C) 2 .…”

Risk of human health by particulate matter as a source of air pollution -Comparison with tobacco smoking-

“…Evaluation of human liver biopsy specimens were conducted for over 30 years with a special attention given to the possibly of exposure to numerous agents, such as hormones. Results have revealed practically no evidence that pesticides-or food-additives induced hepatic cancers (Sugimoto et al,1982;Enomoto, 1985;Enomoto, 2000).…”

Correspondance: Waddell WJ, Thresholds in Chemical Carcinogenesis: What are Animal Experiments Telling Us?

“…Clinical experts on liver diseases in Japan consider the hepatitis virus to be the major cause for liver cancer in humans (8). The remainder, less than 10% of all liver cancers, arise from the consumption of alcoholic beverages.…”

“…Comparison of the threshold doses in animals together with epidemiological studies in humans at similar exposure levels plus historical analyses of the occurrence of human cancers for the past century must give a clue to causative agents. Clinical experts on liver diseases in Japan consider the hepatitis virus to be the major cause for liver cancer in humans (8). The remainder, less than 10% of all liver cancers, arise from the consumption of alcoholic beverages.…”