Esophageal Cancer in Golestan Province, Iran: A Review of Genetic Susceptibility and Environmental Risk Factors

Abstract

Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor that is typically diagnosed only when the tumor has gained remarkable size, extended to peripheral tissues, and led to dysphagia. Five-year survival of advanced cancer is still very poor (19%), even with improved surgical techniques and adjuvant chemoradiation therapy. Therefore, early detection and prevention are the most important strategies to reduce the burden of ESCC. Our review will focus on the studies conducted in Golestan province, an area with a high prevalence of ESCC in northern Iran. We review three aspects of the research literature on ESCC: epidemiological features, environmental factors (including substance abuse, environmental contaminants, dietary factors, and human papillomavirus [HPV]), and molecular factors (including oncogenes, tumor suppressor genes, cell cycle regulatory proteins, and other relevant biomarkers). Epidemiological and experimental data suggest that some chemicals and lifestyle factors, including polycyclic aromatic hydrocarbons (PAHs), cigarette smoking, opium use, and hot tea drinking are associated with the development of ESCC in Golestan. HPV infects the esophageal epithelium, but so far, no firm evidence of its involvement in esophageal carcinogenesis has been provided. Some of these factors, notably hot tea drinking, may render the esophageal mucosa more susceptible to injury by other carcinogens. There are few studies at molecular level on ESCC in Golestan. Increasing awareness about the known risk factors of ESCC could potentially reduce the burden of ESCC in the region. Further studies on risk factors, identifying high risk populations, and early detection are needed.

Effects of exposure to polycyclic aromatic hydrocarbons combined with high‐risk human papillomavirus infection on cervical intraepithelial neoplasia: A population study in Shanxi Province, China

“…Extensive investigations suggested that PAHs exposure should be correlated with a variety of cancers, such as lung cancer, larynx cancer, breast cancer and esophageal cancer . However, the study on the association between PAHs exposure and cervical cancer is rare.…”

“…17 Extensive investigations suggested that PAHs exposure should be correlated with a variety of cancers, such as lung cancer, 18 larynx cancer, 19 breast cancer 20 and esophageal cancer. 21,22 However, the study on the association between PAHs exposure and cervical cancer is rare. Cytological studies showed that B[a]P might enhance the persistent infection of HPV, resulting in an increase of HPV16 viral titers, 23 and thus leading to cancerization.…”

The Incidence of Esophageal Cancer in Iran: A Systematic Review and Meta-analysis

“…Iran is one of the countries with very high incidence of EC [8,26]. Some parts of Iran, which have common borders with Turkmenistan and Afghanistan countries, experience much higher incidence rates of this cancer.…”

“…Based on studies, risk factors such as drinking hot tea, burned opium consumption, gastric Helicobacter pylori infection, family history of esophageal cancer, drinking contaminated water, inappropriate diet, low physical activity, and smoking are associated with EC incidence [19,55]. The genetic role is also a major contributor to the high incidence of EC in Golestan province, having one of the highest worldwide rates of this type of cancer incidence [56][57][58].…”

Evaluation of Haptoglobin Genotype and Some Risk Factors of Cancer in Patients with Early Stage Esophageal Cancer

“…After cancer of the stomach, it is the most common cancer in the Iranian population. Golestan province, one of the northern provinces of Iran, is considered as one of the high-risk areas for esophageal cancer, with an esophageal cancer incidence rate of 100 people per 100,000 people (Gholipour et al, 2016). Esophageal cancer has a complex and diverse etiology, and many genetic and nutritional factors are involved in its etiology.…”