Blood and tissue nitric oxide and malondialdehyde are prognostic indicators of localized prostate cancer

Our objective was to examine blood and tissue levels of nitric oxide (NO) and malondialdehyde (MDA), and their correlations with well-known prognostic indicators [total prostate-specific antigen (tPSA), %free/total PSA (%f/t PSA), pathological stage (pT), and Gleason sum] in patients who had radical retropubic prostatectomy (RRP) for localized prostate cancer (PCa) without metastasis.

Preoperatively 31 patients' bloods were obtained for determination of NO, MDA, fPSA, tPSA, and %f/tPSA ratios. Tissues were obtained from RRP specimens for determination of NO and MDA. Gleason sum was assigned for each patient, and pT was determined according to 2002 TNM staging system. pTs were as follows: 10 pT2a, 7 pT2b, 8 pT2c, 4 pT3a, and 2 pT3b. Gleason sum of the PCa in the RRP specimens was as follows: 5 in 1, 6 in 14, 7 in 14, and 9 in 2 patients.

There were strong correlations between blood and tissue levels of NO (r=0.83, p<0.001) and MDA (r=0.63, p<0.001), between serum NO and plasma MDA (r=0.88, p<0.001), and finally between tissue NO and tissue MDA (r=0.83, p<0.001). There was also a significant (p<0.05) relationship between all well-known prognostic indicators of PCa (tPSA, %f/tPSA, Gleason sum, and pT) and blood and tissue NO and MDA levels, with single exception of correlation between tissue MDA and Gleason sum (p=0.073).

Clinically appropriate correlations shown in this study indicates that NO and MDA may be used for prognostic assessment of localized PCa, especially if supported with other well-designed studies including higher number of patients through multi-institutional collaboration.