Short-term moderate exercise programs reduce oxidative DNA damage as determined by high-performance liquid chromatography-electrospray ionization-mass spectrometry in patients with colorectal carcinoma following primary treatment

Scand J Gastroenterol. 2008 Aug;43(8):971-8. doi: 10.1080/00365520701766111.


Objective: Oxidative DNA damage is believed to be involved in tumor formation and may be an important biomarker for malignant transition or relapse. A decrease of such damage has been observed in human and animal studies following dietary intervention and/or changes in lifestyle such as physical exercise at different levels of intensity. The purpose of this study was to carry out a clinical trial comparing the effects of a short-term (2 weeks) exercise program of moderate intensity (0.3-0.4 x maximal exercise capacity) (MI) versus high intensity (0.5-0.6 x maximal exercise capacity) (HI) on individual urinary excretion of 8-oxo-dG before and after completion of the exercise programs.

Material and methods: In this short-term, prospective and randomized trial, 19 patients with colorectal cancer were allocated to the MI group following primary therapy and 29 to the HI group. Urinary 8-oxo-dG excretion concentration was determined by a highly sensitive detection method using high-performance liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC-ESI-MS). Concentrations were determined immediately before and after completion of the exercise programs.

Results: Using HPLC-ESI-MS, it was shown that MI exercise significantly reduced urinary 8-oxo-dG excretion levels from 8.47 +/- 1.99 to 5.81 +/- 1.45 (ng/mg creatinine, mean +/- SE, p = 0.02), whereas HI exercise resulted in a non-significant increase from 5.00 +/- 1.31 to 7.11 +/- 1.63 (ng/mg creatinine, p = 0.18). Clinical characteristics (gender, age, body mass index (BMI), diet, chemotherapy/irradiation) were not associated/correlated with urinary 8-oxo-dG levels.

Conclusions: By using HPLC-ESI-MS it was shown that short-term MI exercise after primary therapy in patients with colorectal cancer was associated with lower levels of urinary 8-oxo-dG, suggesting decreased oxidative DNA damage. In contrast, HI exercise tended to increase DNA damage. A prospective trial is now warranted to prove that reduced oxidative DNA damage lowers the risk of relapse of colorectal cancer in treated patients.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • 8-Hydroxy-2'-Deoxyguanosine
  • Biomarkers, Tumor / urine
  • Carcinoma / genetics
  • Carcinoma / therapy*
  • Carcinoma / urine
  • Chromatography, High Pressure Liquid / methods
  • Colorectal Neoplasms / genetics
  • Colorectal Neoplasms / therapy*
  • Colorectal Neoplasms / urine
  • Combined Modality Therapy / methods
  • DNA Damage / genetics*
  • Deoxyguanosine / analogs & derivatives*
  • Deoxyguanosine / urine
  • Exercise Therapy / methods*
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Oxidative Stress / genetics*
  • Prospective Studies
  • Reproducibility of Results
  • Spectrometry, Mass, Electrospray Ionization / methods
  • Time Factors
  • Treatment Outcome


  • Biomarkers, Tumor
  • 8-Hydroxy-2'-Deoxyguanosine
  • Deoxyguanosine