A Phase II Study of S-1 Monotherapy as a First-line Combination Therapy of S-1 Plus Cisplatin as a Second-line Therapy, and Weekly Paclitaxel Monotherapy as a Third-line Therapy in Patients with Advanced Gastric Carcinoma: A Second Report

Phase II study on the combination of irinotecan plus cisplatin as a second-line therapy in patients with advanced or recurrent gastric cancer

A pilot phase II study was conducted to evaluate the efficacy and safety of the combined administration of irinotecan (CPT-11) plus cisplatin (CDDP) as a second-line therapy for advanced or recurrent gastric cancer. Between November, 2006 and May, 2009, 18 patients were enrolled in this study. The patients were required to have received prior chemotherapy with S-1 (n=17), an orally administered 5-fluorouracil (5-FU) prodrug, or S-1 plus CDDP (n=1). CPT-11 and CDDP were administered at a dose of 60 and 30 mg/m², respectively, on days 1 and 15 of a 4-week treatment cycle. The regimen was repeated until the occurrence of unacceptable toxicity, disease progression, or patient refusal. The primary endpoint of this study was the response rate (RR). In the second-line setting, 2 cases of complete response (CR), 1 of partial response (PR) and 7 of stable disease (SD) were identified. The RR was 16.7% and the disease control rate (DCR) was 55.6%. The median survival time (MST) and progression-free survival (PFS) was 282 and 111 days, respectively. As regards hematological toxicity, the major adverse effect during the second-line of chemotherapy was grade 3-4 leukopenia (22.2%). In addition, with regard to non-hematological toxicities, the major adverse effect during the second-line chemotherapy was grade 3-4 loss of appetite (11.1%). There was no mortality attributable to the adverse effects of the drugs. Findings of the present study suggested that CPT-11 and CDDP combination therapy in a second-line setting is an effective regimen in the treatment of advanced gastric cancer.

Mechanisms of Cisplatin-Induced Apoptosis and of Cisplatin Sensitivity: Potential of BIN1 to Act as a Potent Predictor of Cisplatin Sensitivity in Gastric Cancer Treatment

Cisplatin is the most important and efficacious chemotherapeutic agent for the treatment of advanced gastric cancer. Cisplatin forms inter- and intrastrand crosslinked DNA adducts and its cytotoxicity is mediated by propagation of DNA damage recognition signals to downstream pathways involving ATR, p53, p73, and mitogen-activated protein kinases, ultimately resulting in apoptosis. Cisplatin resistance arises through a multifactorial mechanism involving reduced drug uptake, increased drug inactivation, increased DNA damage repair, and inhibition of transmission of DNA damage recognition signals to the apoptotic pathway. In addition, a new mechanism has recently been revealed, in which the oncoprotein c-Myc suppresses bridging integrator 1 (BIN1), thereby releasing poly(ADP-ribose)polymerase 1, which results in increased DNA repair activity and allows cancer cells to acquire cisplatin resistance. The present paper focuses on the molecular mechanisms of cisplatin-induced apoptosis and of cisplatin resistance, in particular on the involvement of BIN1 in the maintenance of cisplatin sensitivity.