Nail Molybdenum and Zinc Contents in Populations with Low and Moderate Incidence of Esophageal Cancer

Background: The objective of our study was to compare the zinc and molybdenum contents of nails in two populations at high and low risk for esophageal cancer in northern Iran. Methods: Four groups were studied including a control group in Tehran—a low-risk area (n=20); a group of patients with esophageal cancer from Sari—a moderate- risk region in northern Iran (n=20); a group of patients’ family members (n=20); and a control group in Sari (n=40). Molybdenum and zinc levels were measured in their nail samples using flame atomic absorption spectrometry. Results: Both molybdenum and Zinc were significantly (P<0.01) lower in the Sari control group (molybdenum: 0.472 ppm, zinc: 173.0 ppm) compared with the Tehran control group (molybdenum: 0.740 ppm, zinc: 251.5 ppm). These elements were lower in content in patients with esophageal cancer (molybdenum: 0.283 ppm, zinc: 126.5 ppm) compared with the Sari control group (P<0.05 for molybdenum and P<0.001 for zinc). Only zinc was significantly (P<0.001) lower in patients compared with their family members (molybdenum: 0.456 ppm, zinc: 175.5 ppm). No differences were found between the Sari control group and the patients’ family members in any of the two elements. Conclusion: Zinc and molybdenum levels are much lower in north of Iran—a moderate- risk area for esophageal cancer—compared with Tehran—a low-risk area. Based on these results, more investigations on the relations of trace elements with esophageal cancer in high-risk areas in northern Iran are warranted.