Pre-radiotherapy plasma carotenoids and markers of oxidative stress are associated with survival in head and neck squamous cell carcinoma patients: a prospective study
The purpose of this study was to compare plasma levels of antioxidants and oxidative stress biomarkers in head and neck squamous cell carcinoma (HNSCC) patients with healthy controls. Furthermore, the effect of radiotherapy on these biomarkers and their association with survival in HNSCC patients were investigated.
Methods: Seventy-eight HNSCC patients and 100 healthy controls were included in this study.
Follow-up samples at the end of radiotherapy were obtained in 60 patients. Fifteen antioxidant biomarkers (6 carotenoids, 4 tocopherols, ascorbic acid, total antioxidant capacity, glutathione redox potential, total glutathione and total cysteine) and four oxidative stress biomarkers (total hydroperoxides, gamma-glutamyl transpeptidase, 8-isoprostagladin F2alpha and ratio of oxidized/total ascorbic acid) were measured in plasma samples.
Analysis of Covariance was used to compare biomarkers between patients and healthy controls. Kaplan-Meier plots and Cox'proportional hazards models were used to study survival among patients.
Results: Dietary antioxidants (carotenoids, tocopherols and ascorbic acid), ferric reducing antioxidant power (FRAP) and modified FRAP were lower in HNSCC patients compared to controls and dietary antioxidants decreased during radiotherapy.
Total hydroperoxides (d-ROMs), a marker for oxidative stress, were higher in HNSCC patients compared to controls and increased during radiotherapy. Among the biomarkers analyzed, high levels of plasma carotenoids before radiotherapy are associated with a prolonged progression-free survival (hazard rate ratio: 0.42, 95 % CI: 0.20-0.91, p = 0.03).
Additionally, high relative increase in plasma levels of d-ROMs (hazard rate ratio: 0.31, 95 % CI: 0.13-0.76, p = 0.01) and high relative decrease in FRAP (hazard rate ratio: 0.42, 95 % CI: 0.17-0.998, p = 0.05) during radiotherapy are also positively associated with survival.
Conclusions: Biomarkers of antioxidants and oxidative stress are unfavourable in HNSCC patients compared to healthy controls, and radiotherapy affects many of these biomarkers. Increasing levels of antioxidant biomarkers before radiotherapy and increasing oxidative stress during radiotherapy may improve survival indicating that different factors/mechanisms may be important for survival before and during radiotherapy in HNSCC patients.
Thus, the therapeutic potential of optimizing antioxidant status and oxidative stress should be explored further in these patients.
Author: Amrit SakhiKjell RussnesMagne ThoresenNasser BastaniAnette KarlsenSigbjorn SmelandRune Blomhoff
Credits/Source: BMC Cancer 2009, 9:458
Published on: 2009-12-21
Copyright by the authors listed above - made available via BioMedCentral (Open Access). Please
make sure to read our disclaimer prior to contacting 7thSpace Interactive. To contact our editors, visit our online helpdesk. If you wish submit your own press release, click here.
Social Bookmarking
RETWEET This! | Digg this! | Post to del.icio.us | Post to Furl | Add to Netscape | Add to Yahoo! | Rojo
|
|
