The new research comes from the Brussels' Central Hospital, University of Charleroi, and the Hospital Vesale Experimental Medicine Laboratory at Free University of Brussels. The researchers tested 36 patients with head and neck squamous cell carcinomas – one of the most lethal forms of skin cancer. The researchers collected the tumor tissues of the 36 patients along with close-by tissue without tumors.
The researchers then conducted an in-depth analysis of the tissues and tested them using capillary electrophoresis – testing that separates and breaks down tissues into their smaller components. The researchers also conducted oxidation testing and specifically determined the ratios between oxidized glutathione and reduced glutathione.
The ratio of oxidized glutathione to reduced glutathione in the tissues relates directly to the amount of oxidative stress in the tissues, as well as indicates the level of antioxidant activity. This is because glutathione is the leading scavenger of oxidation within the body.
The researchers found that the tumor tissues showed significantly higher variation in the glutathione GSH part of the ratio. This indicates that the free scavenging abilities of glutathione are reduced within skin cancer tissue.
Nine out of ten cancers on the head and neck are squamous cell carcinomas. About half of those with this cancer will die within five years. The Brussels research confirms findings from the University of Oslo in Norway. In this study, the researchers compared 78 patients with head and neck squamous cell carcinoma together with 100 healthy people.
This time the researchers tested the tissues and blood of all the participants for levels of oxidative stress related to not only glutathione, but also hydroperoxides, gamma-glutamyl transpeptidase, prostagladin and oxidized/total ascorbic acid levels.
The researchers also tested for levels of antioxidants present in all the subjects – including total antioxidant capacity, glutathione redox potential, total glutathione levels and total cysteine levels. They also tested all the subjects for dietary antioxidant levels - including six different carotenoids (carrots and tomatoes are high in carotenoids), four tocopherols (seeds, grains and oils are high in tocopherols, and ascorbic acid (fruits are high in ascorbic acid).
The study found that the patients with squamous cell carcinoma all had higher levels of oxidative stress biomarkers in their blood and tissues. The levels of total hydroperoxides were significantly higher in the skin cancer patients - indicating specifically that their bodies were under oxidative stress.