Reactive oxygen species in patients with ovarian adenocarcinoma treated with platinum based chemotherapy.

Abstract

e17047 Background: Ovarian adenocarcinoma (OA) is the most lethal of gynecologic tumors because women generally present with advanced stage disease. Platinum-based chemotherapy plays a pivotal role in OA treatment. The aim of the study was to assess the role of oxygen species in patients with OA and the effects of platinum based chemotherapy on blood redox status. Methods: Twenty three patients with advanced stage IIIC or IV OA who underwent platinum salts chemotherapy were included. Blood sample were collected before treatment, at 21 days (second cycle of chemotherapy) and at 42 days (3rd cycle) and at 63 day (4th cycle) with a platinum salt (cisplatin or carboplatin). Biochemical determination of oxidative stress was made by mesuring lipid peroxidation index (LPI), the enzymatic activity of ceruloplasmin and the thiol albumin groups. Results: Median age at diagnosis was 52 years, and 47.8% of patients presented with stage IIIC and 52.2% with stage IV. Nine patients received for the first time platinum based chemotherapy and 14 received multiple lines of chemotherapy. Response rate after 4 cycles were partial in 30%, stable disease in 57%, and progression disease in 13%. Mean value (± SD) of lipid peroxides was 6.81±1.μmol/100 ml (normal value 0-4), and of ceruloplasmin 156 ± 66 UI (normal value 80-120) which showed an increase of the final products of lipid peroxidation. Thiol mean value was 296±124 μmol/l (normal value 370- 450). The evolution of these reactive oxygen species were monitored during chemotherapy cycles. Decrease of the lipid peroxidation after 1st cycle was noticed, (7, 6.89, 5.87, 6.61), because platinum salt can bind peroxyde and this can be considered a marker of effectiveness of treatment.The thiol levels increased from one cycle to other (233, 311, 384, 393) showing that the cell is trying to contracarete the oxidative stress. Conclusions: Tumors produces reactive oxygen species in excess in patients with advanced OA. Platinum based chemotherapy in patients with OA induces radical formation and the dynamic of these markers may be used to monitor response to treatment.