摘要：

The treatment of cancer has been revolutionised by the introduction of targeted agents in the last two decades. A targeted agent aims at a particular target on the cancer cells and interferes with the growth and progression of cancer. Broadly, these agents can be of two types: inhibitors of small molecules involved in cancer growth (kinases) or monoclonal antibodies which target a specific antigen in the cancer cells. These agents have a well established role in the management of various solid organ cancers as well as lymphomas and leukemias. The unique mode of action allows them to express a different profile of toxicities which are comparatively better tolerated than chemotherapy and hence provide a better quality of life (QOL). Since the introduction of Rituximab in 1997 for the treatment of non-Hodgkin's lymphoma and Trastuzumab in 1998 for breast cancer, a large number of these agents have been added to the armamentarium [1, 2]. The evolving era of targeted agents supplanted the traditional cytotoxic agents clearly in terms of overall survival as in the case of trastuzumab for breast cancer and imatinib and other tyrosine kinase inhibitors for chronic myeloid leukemia (CML) [3, 4]. Another advantage over the conventional chemotherapy was demonstrated in the form of rapidity of response to treatment and improved QOL. Improved QOL was the result of oral administration of many of these agents thus avoiding frequent hospitalisation and better tolerated toxicity profile. The classical example is of erlotinib in adenocarcinoma lung and imatinib in CML. Hypersensitivity reactions though uncommon, were characteristics adverse events associated with monoclonal antibodies. However, recently developed agents contain an increased proportion of human components thus minimising these events. As more agents are in pipeline, it will not be a surprise when a targeted agent for every cancer will be available. High cost of treatment, cost-effectiveness and marginal benefits at the cost of added toxicity are two main issues which need to be addressed comprehensively. Targeted therapy is much costlier as compared to conventional chemotherapy. In an economically backward country like India, very few cancer patients are actually able to bear the burden of targeted therapy. A robust health reform is required in order to provide the benefit of targeted therapy to poor patients without crippling the health care system simultaneously. Targeted agents must be used judiciously: only when the target is available. A survival benefit of a few days to weeks carries no meaning when cost is a big concern. Similarly, a marginal survival benefit with the added toxicity of targeted agents must be taken care of. Patients with poor performance status and a very short life expectancy (extreme old age) should be given best supportive care [5, 6]. References 1. Press OW, Appelbaum F, Ledbetter JA, Martin PJ, Zarling J, Kidd P et al. Monoclonal antibody 1F5 (anti-CD20) serotherapy of human B cell lymphomas. Blood. 1987, 69:584-591 2. Hudziak RM, Lewis GD, Winget M, Fendly BM, Shepard HM, Ullrich A. p185HER2 monoclonal antibody has antiproliferative effects in vitro and sensitizes human breast tumor cells to tumor necrosis factor.

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