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

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. 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. 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. 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.