New phenotypic aspects in a family with Lynch syndrome II

Helicobacter pylori eradication to prevent gastric cancer: Underlying molecular and cellular mechanisms

Numerous cellular and molecular events have been described in development of gastric cancer. In this article, we overviewed roles of Helicobacter pylori (H pylori) infection on some of the important events in gastric carcinogenesis and discussed whether these cellular and molecular events are reversible after cure of the infection. There are several bacterial components affecting gastric epithelial kinetics and promotion of gastric carcinogenesis. The bacterium also increases risks of genetic instability and mutations due to NO and other reactive oxygen species. Epigenetic silencing of tumor suppressor genes such as RUNX3 may alter the frequency of phenotype change of gastric glands to those with intestinal metaplasia. Host factors such as increased expression of growth factors, cytokines and COX-2 have been also reported in non-cancerous tissue in H pylori-positive subjects. It is noteworthy that most of the above phenomena are reversed after the cure of the infection. However, some of them including overexpression of COX-2 continue to exist and may increase risks for carcinogenesis in metaplastic or dysplastic mucosa even after successful H pylori eradication. Thus, H pylori eradication may not completely abolish the risk for gastric carcinogenesis. Efficiency of the cure of the infection in suppressing gastric cancer depends on the timing and the target population, and warrant further investigation.

Analysis for phenotype of HNPCC in China

AIM: The aims of this study were to identify the clinicopathological features of Chinese HNPCC families and to evaluate the value of criteria for suspected HNPCC (sHNPCC) in clinical diagnosis.

METHODS: According to the follow-up records, 54 HNPCC families (including 12 ICG-HNPCC families and 42 sHNPCC families) were screened out from patients with colorectal cancers (CRCs), operated upon in 2^nd Affiliated Hospital of Zhejiang University from 1984 to 2001. Clinical data of probands and tumor spectrum in these families were listed and analyzed.

RESULTS: (1) Mean age, proportion of colonic cancer, poorly differentiated cancer, multiple CRCs and Dukes’ A+B of the probands in ICG-HNPCC and sHNPCC kindred were 39 ys and 47.5 ys, 75% and 62%, 0 and 12.8%, 16.7% and 14.3%, 58.3% and 81%, respectively. Compared with sporadic colorectal cancers, probands from ICG-HNPCC and sHNPCC families were obviously different at age of onset (P = 0.025 and 0.031), tumor location (P = 0.001 and 0.000), differentiation (P = 0.002 and 0.011) and development of multiple tumors (P = 0.014 and 0.002). (2) A total of 178 malignant neoplasms were found in 54 HNPCC families, including 139 colorectal cancers. Besides of colorectal cancer, extracolonic tumors occurred in stomach, endometrium, hepatobiliary system, and so on (8 gastric cancers, 6 endometrial cancers, 6 hepatobiliary system cancers and 19 others) can also be seen in Chinese ICG-HNPCC and sHNPCC families.

CONCLUSION: (1) Chinese HNPCC families have specific clinicopathological features, such as early onset, predilection for the involvement of colon, tendency of multiple CRCs, development of extracolonic tumors and well differentiation. (2) The criteria for suspected HNPCC is useful in clinical diagnosis and management of HNPCC.