The effect of iron deficiency on experimental oral carcinogenesis in the rat

The effect of iron deficiency on oral carcinogenesis was investigated in 30 young adult male Charles River white rats. In 15 animals, prior to the start of carcinogen treatment, iron deficiency anaemia was produced and subsequently maintained by a combination of low iron diet (12 mg Fe2+ kg-1 diet) and repeated venesection. Fifteen control animals were fed the same diet supplemented with iron to approximately 140 mg FE2+ kg-1 diet. All animals were treated with the carcinogen 0.5% 4-Nitroquinoline-N-oxide in propylene glycol which was painted on the palate 3 times weekly. Animals were killed when tumours were grossly evident. The mean haemoglobin levels at the start of carcinogen applications were 10.1 g dl-1 in the anaemic group and 14.1 g dl-1 in the control group, and at the time of killing were 8.2 g dl-1 in anaemic animals and 13.8 g dl-1 in controls. The incidence of animals developing squamous cell carcinomas was similar in both groups, but tumour development was significantly earlier in iron-deficient animals (mean 183 days) compared to controls (mean 229 days). Iron-deficient animals showed a significantly greater incidence of tongue tumours and control animals showed a significantly greater incidence of palatal tumours.