The Incidence of Hereditary Gastric Cancer in Korean

Kim, Soo Jin; Cho, Sam Je; Heo, Seung Chul; Yang, Han Kwang; Kim, Woo Ho; Park, Jae Gahb; Lee, Kuhn Uk; Choe, Kuk Jin; Kim, Jin Pok

Abstract

PURPOSE: We wanted to determine the incidence of HGC (hereditary gastric cancer) in Korean under the minimal criteria of ICG-HGC (International Collaborative Group on Hereditary Gastric Cancer).
MATERIALS AND METHODS
Tumor registry abstracts of 1752 patients who underwent operations for gastric cancer during the time period 1996 to 1998 in the Department of Surgery at Seoul National University College of Medicine were examined. Based on their family histories, candidate HGCs were identified. Their detailed family histories including diagnosis of cancer, age at diagnosis, and dates of birth and death were obtained from interviews by phone. Another study was performed on 195 patients with gastric cancer who admitted for operations in the same department during the time period April, 1999 to June, 1999. Their detailed family histories were also obtained from probands or nearest relatives during admission. Pedigree studies of documented families were conducted. Minimal Criteria of ICG-HGC we used for present study are as followings: At least three relatives with histologically verified gastric cancer; one of them should be a first-degree relative to the other two. At least two successive generations should be affected. In one of the relatives, gastric cancer should be diagnosed under 45 years of age. Suspected HGC fullfills only two of the above three criteria. HNPCC, FAP and Li-Fraumeni syndromes should be excluded.
RESULTS
A total of 12 HGCs were identified in this study. In recent 3 years, during the time period 1996 to 1998, the incidence of true and suspected HGC accounted for 6 (0.3%) and 44 probands (2.5%) among 1752 patients (in 1996, 0.4% and 3.2%; in 1997, 0.3% and 1.8%; in 1998, 0.3% and 2.8%) respectively. In contrast, during the time period April, 1999 to June, 1999, the incidence of true and suspected HGC increased up to 3.1% (6 probands) and 11.3% (22 probands), respectively, out of 195 patients (in April, 1999, 0% and 11.7%; in May, 1999, 4% and 14.7%; in June, 1999, 5% and 6.7%). There was no difference in terms of the incidence even if the third criterion of age at diagnosis among Minimal Criteria of ICG-HGC was modified from 'under 45 years of age' to 50. Mean ages of 12 probands (46.3 8.8) were statistically younger than those of control gastric cancer patients (54.2 11.5) retrieved from database of Department of Surgery at Seoul National University College of Medicine.
CONCLUSION
In the present study, the incidences of HGC were remarkably altered in accordance with study methods. Retrospective reviews of medical records revealed to be ineffective for this kind of study since their informations were often incomplete and some suspected patients were lost during follow-up. According to the Minimal Criteria of ICG-HGC, the incidence of true and suspected HGC was 3.1% (6 probands) and 11.3% (22 probands), respectively, out of 195 gastric cancer patients. We propose that families who meet the Minimal Criteria of ICG-HGC should be prospectively found in order to determine the exact incidence of HGC in Korean.