Changes in CoQ(10)/Lipids Ratio, Oxidative Stress, and Coenzyme Q(10) during First-Line Cisplatin-Based Chemotherapy in Patients with Metastatic Urothelial Carcinoma (mUC)

Oxidative stress plays an important role in cancer pathogenesis, and thiobarbituric acid-reactive substance level (TBARS)—a parameter of lipid peroxidation—has prognostic significance in chemotherapy-naive patients with metastatic urothelial carcinoma (mUC). However, the effect of cisplatin (CDDP)-based chemotherapy on oxidative stress, coenzyme Q(10), and antioxidants remains unknown. The objective of this prospective study was to determine possible changes in the CoQ(10) (coenzyme Q(10))/lipids ratio, antioxidants (α-tocopherol, γ-tocopherol, β-carotene, CoQ(10)), total antioxidant status (TAS), and TBARS in plasma at baseline and during first-line chemotherapy based on CDDP in mUC subjects. In this prospective study, 63 consecutive patients were enrolled. The median age was 66 years (range 39–84), performance status according to the Eastern Cooperative Oncology Group (ECOG) was 2 in 7 subjects (11.1%), and visceral metastases were present in 31 (49.2%) patients. Plasma antioxidants were determined by HPLC and TAS and TBARS spectrophotometrically. After two courses of chemotherapy, we recorded significant enhancements compared to baseline for total cholesterol (p < 0.0216), very low-density lipoprotein (VLDL) cholesterol (p < 0.002), triacylglycerols (p < 0.0083), α-tocopherol (p < 0.0044), and coenzyme Q(10-TOTAL) (p < 0.0001). Ratios of CoQ(10)/total cholesterol, CoQ(10)/HDL-cholesterol, and CoQ(10)/LDL-cholesterol increased during chemotherapy vs. baseline (p < 0.0048, p < 0.0101, p < 0.0032, respectively), while plasma TBARS declined (p < 0.0004). The stimulation of antioxidants could be part of the defense mechanism during CDDP treatment. The increased index of CoQ(10-TOTAL)/lipids could reflect the effect of CDDP protecting lipoproteins from peroxidation.