Gastric cancer mortality in a high-incidence area (Ardabil Province, Northwest Iran): What risk factors are causative?

(RET)/papillary thyroid carcinoma (PTC) rearrangements in radiation-induced thyroid cancer was mainly identified from post-Chernobyl tumors, which resulted from extremely high dose radiation exposure (Nikiforova et al., 2004). Chernobyl-related radiation-induced RET/ PTC rearrangements were also associated with more aggressive tumor behavior (Rabes et al., 2000). However, no clear evidence has shown that low-dose radiation exposure through medical practice induces RET/PTC rearrangements. Although Seaberg et al. (2009) found that ionizing radiation exposure resulting from various sources was associated with more aggressive tumor pathology, this relationship is still inconclusive (Furlan and Rosen, 2004; Seaberg et al., 2009). Our study did not find diagnostic radiography to be associated with multifocal disease and lymph node involvement.