Time Trend Analysis of Stomach Cancer Incidence in the West of Iran

Stomach cancer is the fourth most prevalent cancer in the world. Although many studies have been carried out on the incidence of this type of cancer in the world, information about changes in its incidence rate in Iran during the recent years is not sufficient. The aim of this study is to assess the incidence and trend of this cancer in the west of Iran, during the recent years. In this study the data of the Iranian National Cancer Registry from 2000 to 2005 was used. The standardized incidence rates were calculated with the direct method and according to the standard population provided by the World Health Organization (WHO). Poisson regression was applied for the evaluation of the trend of cancer incidence during the years under study. during the studied years, 1758 cases of stomach cancer were identified in this region and the cases increased from 224 in the year 2000 to 444 in 2005. The male to female ratio was 2.7. The age standardized incidence rate from 6.1 cases per 100000 in the year 2000 reached 10.1 cases in 2005 (slope = 0.16, p = 0.06). A significantly increasing trend was seen in Kermanshah, Ilam and Kurdistan provinces, but this increase was not significant in Hamadan. The trend of stomach cancer is increasing in the west of Iran. Although, some of this increase can be due to improvement in cancer registrations, there is a possibility that increase in stomach cancer incidence is due to increase in its risk factors.