Relationships between Altitude and Distance from a Volcano with Stomach Cancer Incidence Using a GIS

According to the estimations of the International Agency for Research on Cancer (IARC) in 2012, gastric cancer is the fifth most common cancer in the world (Kavousi et al., 2014), with a wide variation in incidence rates across different geographical areas. In Iran gastric cancer is the most common cancer in male and it is reported to be the third cancer after Breast and Colorectal cancers in female (Babaei et al., 2010). According to GLOBOCAN, gastric cancer in Iran accounted for 11.4% of all cases of cancer occurrence and the second most prevalent cancer and also most deadly cancer with 15.5 percent of all mortalities caused by cancers (Ferley et al., 2012). Ardabil is still one of the areas in the world that has the highest incidence of gastric cancer (Babaei et al., 2010; Sadjadi et al., 2003). Recently, the incidence and mortality rate of gastric cancer has dramatically fallen worldwide. In line with global reduction, the incidence rate of cancer has decreased in Asia as well. However, the incidence of gastric cancer in Iran remains very high at approximately 26.1 per 100, 000 (Rahman et al., 2014). In most countries there is a steady decline in the incidence and mortality from gastric cancer. However in the United States, like