The clinical utility of the test refers to the likelihood that the test will, by prompting an intervention, result in an improved health outcome. The clinical utility of a genetic test is based on the health benefits related to the interventions offered to people with positive test results. Theoretically, there are at least five strategies that might improve the health outcome of people with a genetic susceptibility to cancer:
Correction of the underlying genetic defect (not currently available)...
The age-adjusted incidence rate for gastric cancer in the United States for the years 2004 to 2008 was 7.7 persons per 100,000 population. Incidence among men is twice as high as among women. Mortality rates for gastric cancer have been declining worldwide in recent decades, most prominently in the United States.[2,3] Mortality rates for white males in the United States were approximately 40 deaths per 100,000 population in 1930, compared with 4.6 deaths per 100,000 population for the years 2003 to 2007. The death rate from gastric cancer for black males was 2.3 times higher than for whites for the years 2003 to 2007. The annual number of new cases seems to be steady in recent years; in 2013, it is estimated 21,600 Americans will be diagnosed with gastric cancer and 10,990 persons will die of it. Gastric cancer is the fourth most common cancer in the world.[6,7] Worldwide, the estimated number of cases per year in 2008 was 988,000, and the estimated number of deaths was 736,000. Age-standardized annual incidence rates vary widely across the world: from 3.9 to 42.4 cases per 100,000 in men, and from 2.2 to 18.3 cases per 100,000 in women. More than 70% of cases occur in developing countries, and 50% of the cases occur in Eastern Asia.
Most cancers in the United States are advanced at diagnosis, which is reflected in an overall 5-year survival rate of 27.1% from 2001 to 2007. Carcinomas localized to the mucosa or submucosa ("early" cancers) have a much better prognosis; the 5-year survival rate is more than 95% in Japan and more than 65% in the United States. In high-risk populations, secondary prevention measures linked to screening programs have been instituted. In Japan, endoscopic resection techniques have been refined and could possibly be responsible for drastic reductions in mortality rates in the presence of steady incidence rates. This hypothesis, however, has not been tested in clinical trials. (Refer to the PDQ summary on Stomach (Gastric) Cancer Screening for more information.)