Possible Japanese Racial Predisposition for Particular Tumors in Edwards Syndrome

Abstract

Japan, the frequency of HB cases in Japan is too high to be explained only by publication bias. There may besome racial differences that promote HB and suppress WT in Japanese T18 cases. INTRODUCTIONCongenital chromosomal disorders are sometimes accompanied by malignant diseases. For example, it is well known that persons with Down syndrome have an increased risk of leukemia. Employing articles and abstracts, we reported a tumor profile in those with Edwards syndrome, or trisomy 18 (T18), and they are at high risk for several malignant tumors such as hepatoblastoma (HB) or Wilms tumor (WT), etc [1] . At the same time, however, it was noted that there were regional differences (Japan vs the USA) in the frequency of developing them.The mortalities of adulthood malignancies (gastric cancer, breast cancer, etc.) are different between Japan and the USA [2] . These differences seem to be dependent mainly on the differences in lifestyle, but part of them might be attributable to racial factors. In this report, based on these articles and abstracts, the frequencies of HB in Japan and the USA are compared. NUMBER OF CASES REPORTEDIn this article, the same references employed in our previous article [1] are used. Using the key words "trisomy 18", "malignancy", "hepatoblastoma", "Wilms tumor", "leukemia", "neuroblastoma", and so on, articles and abstracts reporting patients with trisomy 18 and malignant neoplasms were gathered from "Pubmed" and ABSTRACTIt is known that a case with trisomy 18 (T18) develops hepatoblastoma (HB) or Wilms tumor (WT). But are there any differences among districts in the frequency of developing them? In this report, based on articles and abstracts, frequency of HB is compared between Japan and the USA. Using key words of "T18", "HB", "WT", "leukemia", etc., articles and abstracts reporting cases with T18 and malignant neoplasms were gathered from the Pubmed as well as the Igaku Chuo Zassi (Japanese Central Journal of Medicine), which is a searching tool for medical articles written in Japanese and English. In Japan, a total of 21 cases with HB and only 1 case with WT were reported. In the USA, however, 5 cases with HB and 8 cases with WT in T18 cases were reported. Long survival periods lead to increased chances to develop HB. Infant mortality of Japan is the lowest in the world, being less than half of that of the USA. Several authors reported survival rates of T18 cases in general. Survival rates of Japanese cases were longer than those in western countries. The general incidence of WT in Japan is about half of that in the USA. These facts might partially explain why HB cases are frequent and WT ones are less frequent in T18 cases in Japan. Considering the number of live births of the USA and that of