Jane Mattei

Marine-derived anticancer agents in clinical trials

Anticancer agents may be derived either from the isolation of an active lead compound occurring spontaneously in nature or by novel chemical synthesis in the laboratory. There are examples of successful drugs being derived from both sources, which have had a profound impact on the natural history of various types of cancer. The treatment of lymphomas and acute leukaemias with the use of combination chemotherapy, including anthracyclines and vinca alkaloids, are examples of the contribution of nature. In contrast, agents such as 5-fluorouracil, methotrexate and more recently, the humanised anti-CD20 antibody rituximab and the tyrosine kinase inhibitor imatinib are examples of synthetic compounds, which were designed with a clear rationale, that are routinely used in patients with solid tumours and haematological malignancies. Until recently, the tradition in natural product-derived anticancer drug development was to rely almost exclusively on the screening of terrestrial sources (plant extracts and fermentation products) for their cytotoxic properties. Although C-nucleosides obtained from Caribbean sponge were the initial inspiration for the synthesis of antiviral substituted nucleosides and the successful anticancer agent citarabine, active against leukaemias and lymphomas, the contribution of marine compounds as a source of anticancer agents was modest. In recent years, the improvements in the technology of deep-sea collection and aquaculture added to the growing recognition of the tremendous biodiversity present in the marine world, and has contributed to the growing interest of exploring the oceans as a potential source of new anticancer candidates. This is reflected in the number of marine-derived compounds undergoing preclinical and early clinical development. In this paper, the authors discuss the available literature on anticancer agents that have reached clinical trials, such as didemnin B, aplidine, dolastatin-10, bryostatin-1 and ecteinascidin-743 (ET-743, trabectedin), as well as other promising compounds still undergoing tests in the laboratory.

Clinical features in osteosarcoma and prognostic implications

OBJECTIVE To identify the clinical features in osteosarcoma and to investigate their influence on the prognosis of children and adolescents presenting this disease. MATERIAL AND METHODS The records of children and adolescents with osteosarcoma treated by the Bone Tumors Group of the state of Rio Grande do Sul, Brazil, between January 1992 and December 2001 were reviewed. RESULTS Fifty consecutive patients were included in this study. Mean age at diagnosis was 13 years (3-22); 68% of the patients were males. The primary site of disease was the femur in 50% of the patients, tibia in 30%, pelvis in 4%, humerus in 10%, fibula in 2% and other sites in 4%. Nineteen patients presented metastases at diagnosis (38%). All patients received chemotherapy and were treated with three different schemes. As for surgical treatment, 26 patients (52%) had an amputation and 17 (34%) received conservative surgery. Serum lactic dehydrogenase > 1,000 UI/ml (p = 0.0159, log rank), tumor necrosis < 90% and presence of metastases had a negative influence on prognosis. The overall 5-year survival was of 33.2+/-7.2% with mean follow-up of 36 months (6-126). Event-free survival was 29.7+/-7%. The 5-year event-free survival in non-metastatic patients was 45+/-10.7%, and zero in metastatic patients (follow-up of 78.4 and 18.7 months, respectively). Only two out of 19 metastatic patients are alive and free of disease at 18 and 30 months respectively. CONCLUSION Metastatic disease at diagnosis, serum levels of serum lactic dehydrogenase > 1,000 UI/ml and tumor necrosis < 90% are predictors of unfavorable prognosis. The excessively high incidence of metastatic patients may suggest the presence of an aggressive pattern of disease in our population, or may indicate late diagnosis.

Gastrin-releasing peptide receptor expression in lung cancer.

CONTEXT Gastrin-releasing peptide receptors (GRPRs) activate mitogen-activated protein kinase signaling pathway primarily through epidermal growth factor receptor activation and are under investigation as a molecular target because they are overexpressed in several solid tumors. OBJECTIVE To determine GRPR expression in both non-small cell lung carcinoma and small cell lung carcinoma, comparing results with clinical stages and demographic data. DESIGN We analyzed the immunohistochemical expression of GRPR in 200 non-small cell lung carcinoma and 38 small cell lung carcinoma archival cases from 2004 to 2008. RESULTS Non-small cell lung carcinoma cases tended to be higher GRPR expressers at a rate of 62.5% (weak, moderate, and strong expression in 41.5%, 13.5%, and 7.5%, respectively), compared with 52.62% in small cell lung carcinoma cases (weak, moderate, and strong expression in 34.21%, 15.78%, and 2.63%, respectively; P = .30). In non-small cell lung carcinoma there was a trend for higher percentages of strong expression in adenocarcinoma cases (10%; P = .67), and in patients with advanced stages (III and IV; 9.43% and 6.9%; P = .01). CONCLUSIONS To the best of our knowledge, this is the first study to demonstrate GRPR tissue expression in a large population of patients with lung cancer. Although GRPR expression was similar in small cell and non-small cell carcinoma, the expression was more pronounced in an advanced-stage lung cancer, particularly in adenocarcinoma cases, and may represent a potential target for the development of new treatment approaches in this population.