Serum total thiol levels and the risk of lung, colorectal, breast and prostate cancer: A prospective case–cohort study

• Published in: International journal of cancer 2020-03, Vol.146 (5), p.1261-1267
• Main Authors: Gào, Xīn, Wilsgaard, Tom, Jansen, Eugène H. J. M., Xuan, Yang, Anusruti, Ankita, Brenner, Hermann, Schöttker, Ben
• Format: Article
• Language: English
• Subjects: Adult; Aged; Breast cancer; Breast Neoplasms - blood; Breast Neoplasms - epidemiology; Cancer; Cohort analysis; Cohort Studies; cohort study; Colorectal cancer; Colorectal Neoplasms - blood; Colorectal Neoplasms - epidemiology; Female; Free radicals; Health risk assessment; Health risks; Humans; Lung cancer; Lung Neoplasms - blood; Lung Neoplasms - epidemiology; Male; Medical research; Middle Aged; Neoplasms - blood; Neoplasms - epidemiology; Norway - epidemiology; Oxidative stress; Population studies; Proportional Hazards Models; Prospective Studies; Prostate cancer; Prostatic Neoplasms - blood; Prostatic Neoplasms - epidemiology; Risk; Statistical analysis; Sulfhydryl Compounds - blood; Thiols; total thiol levels; Young Adult
• ISSN: 0020-7136; 1097-0215
• DOI: 10.1002/ijc.32428

Free thiol groups of intra and extracellular molecules are considered to be antioxidative and to protect cells from damage caused by free radicals. However, the associations of serum total thiol levels (TTL) with the incidences of the four most frequent cancer sites have not yet been investigated in a large population‐based, prospective study. TTL was measured in case–cohort design in a sample from the population‐based, Norwegian Tromsø 3 study (cancer cases: n = 941; random subcohort: n = 1,000) and was repeatedly measured at Tromsø 5. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated by weighted multivariable‐adjusted Cox regression with time‐dependent modeling of TTL for incident lung, colorectal, breast and prostate cancer. High serum TTL were associated with a reduced risk of all four major cancers. The associations with lung (top vs. bottom tertile: HR, 0.64; 95% CI, 0.41, 0.99) and breast cancer (top vs. bottom tertile: HR, 0.64; 95% CI, 0.42, 0.96) were statistically significant, whereas associations with colorectal (top vs. bottom tertile: HR, 0.79; 95% CI, 0.54, 1.16) and prostate cancer (top vs. bottom tertile: HR, 0.79; 95% CI, 0.53, 1.17) were not statistically significant but pointed in the same protective direction. These findings from a large, prospective Norwegian cohort study suggest a preventive role of thiols against the development of the four most frequent cancers. Whereas associations with breast and lung cancer could be shown with statistical significance, larger studies are needed to corroborate potential associations of TTL with colorectal and prostate cancer. What's new? Circulating free radicals can damage DNA, cause havoc in cells, and induce cancer. Thiols are part of the body's system to clean up those harmful molecules, and serum total thiol levels (TTL) can serve as a reflection of the body's antioxidant capacity. Here, the authors assessed the relationship between thiol levels and risk of four common cancers. Using data from a large Norwegian cohort study, the authors found a statistically significant association between high TTL and reduced risk of breast cancer or lung cancer, and a weaker association with colorectal and prostate cancer.