Increased singlet oxygen-induced secondary ROS production in the serum of cancer patients

• Published in: Journal of photochemistry and photobiology. B, Biology Vol. 107; pp. 14 - 19
• Main Authors: Bigot, Edith, Bataille, Regis, Patrice, Thierry
• Format: Journal Article
• Language: English
• Published: Switzerland Elsevier B.V 06.02.2012
• Subjects: Adult; Aged; Aged, 80 and over; Anti-oxidant status; Area Under Curve; blood serum; Cancer; Case-Control Studies; Disease Progression; Female; Humans; Male; men; Middle Aged; neoplasms; Neoplasms - blood; Neoplasms - drug therapy; Neoplasms - metabolism; oxidants; Oxidative stress; patients; peroxides; photobiology; photochemistry; Photochemotherapy; Photodynamic therapy; prognosis; reactive oxygen species; Reactive Oxygen Species (ROS); Singlet oxygen; Singlet Oxygen - blood; Singlet Oxygen - metabolism; surgery; Treatment Outcome; women; Young Adult; Oxidative stress; Singlet oxygen; Reactive Oxygen Species (ROS); Photodynamic therapy; Anti-oxidant status; Cancer
• ISSN: 1011-1344; 1873-2682; 1873-2682
• DOI: 10.1016/j.jphotobiol.2011.11.003

► More secondary ROS are produced in sera of patients with cancers after a standardized production of 1O 2. ► Secondary ROS production is associated with a worse prognosis. ► Secondary ROS production is independent of gender but correlates with cancer severity. Photodynamic therapy (PDT) generates singlet oxygen ( 1O 2) and Reactive Oxygen Species (ROS) that are counteracted by patient’s defenses. As cancer treatments are among the most important PDT applications the aim of this pilot study was to determine whether the serum of cancer patients produces more or less secondary ROS or peroxides after a photoreaction as compared to healthy persons. Fifty-three volunteers and 105 cancer patients were recruited. The capacity of 1O 2 or secondary oxidant production was found to be increased in 6 healthy donors and 36 cancer patients (23/69 women and 13/31 men p < 0.007 and p < 0.04) with a mean value of 1.52 as compared to 1.29 in the healthy subjects ( p < 0.05) when considering values higher than the normal range (norm = 1 ± 10%) or 1.1 vs. 0.85 ( p < 0.01) in the whole cohort. This increase correlated with a poor prognosis, TNM and SBR classification. Serum 1O 2 deactivation capacity was impaired and secondary ROS were more produced during cancer progression. Although it is currently unclear whether this is the cause or effect of cancer, this finding may hold interest as a potential marker of cancer severity. It would also support the interest of PDT as an adjuvant for cancer treatment, even for aggressive tumors particularly when associated to surgery for bulk removal.