DNA-repair Enzyme Linked with Likelihood of Head and Neck Cancer
According to the results of a study published in Cancer Research, individuals with low levels of a protein involved in DNA repair have an increased risk of developing head and neck cancer; smokers with low levels of this protein were at particularly high risk.
Head and neck cancers originate in the throat, larynx (voice box), pharynx, salivary glands, or oral cavity (lip, mouth, tongue). Most head and neck cancers involve squamous cells, which are cells that line the mouth, throat, or other structures.
Head and neck cancers, like other cancers, arise when genetic alterations in cells lead to uncontrolled cell growth. These alterations can be caused by cancer-causing agents such as tobacco, as well by a failure of normal DNA-repair processes.
To explore the relationship between levels of a protein involved in DNA repair-the enzyme 8-oxoguanine DNA glycosylase 1 (OGG1)-and risk of developing head and neck cancer, researchers in Israel conducted a study among 37 patients with head and neck cancer and 93 individuals without head and neck cancer.
- Head and neck cancer patients had lower OGG1 levels than the comparison subjects.
- Study participants with the lowest OGG1 levels were seven times more likely to have head and neck cancer than study participants with the highest OGG1 levels.
- Smokers with low OGG1 levels were the most likely to have head and neck cancer. Compared to non-smokers with normal OGG1 levels, smokers with the lowest OGG1 levels were almost 70 times more likely to have head and neck cancer.
The researchers conclude that if these results are confirmed, testing for this protein may identify smokers who are at particularly high risk of developing head and neck cancer. These results could provide motivation to stop smoking or may help identify individuals who require particularly close surveillance for cancer.
Reference: Paz-Elizur T, Ben-Yosef R, Elinger D et al. Reduced repair of the oxidative 8-oxoguanine DNA damage and risk of head and neck cancer. Cancer Research. 2006;66:11683-9.