Increased H2O2 level in exhaled breath condensate in primary breast cancer patients

This study was designed to assess exhaled hydrogen peroxide (H2O2), blood serum antioxidant capacity, and tumor necrosis factor-alpha (TNF alpha) in primary breast cancer (PBC). The study included 34 consecutive, non-smoking PBC patients (aged 62.5 +/- A 13.5 at surgery) prior to the treatments, qualified for modified radical mastectomy and not undergoing any adjuvant systemic therapy, and 33 healthy controls. The post surgery pathological assessment included tissue expression of estrogen (ER) and progesterone (PR) receptors, and epidermal growth factor receptor type 2 (HER-2/neu). Exhaled H2O2 was determined fluorometrically in the exhaled breath condensate (EBC). Blood serum antioxidant capacity and TNF alpha levels were assessed with ferric reducing ability of plasma (FRAP) and ELISA immunoassay, respectively. In PBC patients, 10 ER, 11 PR, and 9 HER-2/neu positive tumors were identified and HER-2/neu score was 2+ in 20% of all tumors. Median (Me) H2O2 was increased up to 0.44 mu M (interquartile range IR: 0.20-1.25 mu M) compared with healthy control of 0.36 mu M (IR: 0.12-0.48 mu M; p < 0.05). The H2O2 concentration in EBC was significantly correlated (tau = 0.27; p = 0.03) and increased in cases with nodal metastases (n = 12; p = 0.04). Serum TNF alpha was increased up to 51.7 +/- A 21.0 pg/ml compared with controls 17.2 +/- A 3.65 pg/ml (p < 0.05). FRAP was increased to 1.41 +/- A 0.37 mM Fe2+ compared with control 1.19 +/- A 0.17 mM Fe2+; (p = 0.006). This is the first study to demonstrate increased H2O2 in exhaled breath condensate in patients with localized breast malignancy and its relation with clinical severity.