Drug therapy of cancer.

Cancer chemotherapy was introduced at the same time as antibacterial chemotherapy but has not been nearly such a success. However, there is a growing optimism in oncology today due to the introduction of several more or less target-specific drugs as complements to the conventional cytotoxic drugs introduced half a century ago. The success in the treatment of chronic myelogenous leukemia by imatinib, inhibiting the bcr-abl-activated tyrosine kinase and thereby interrupting the signal transduction pathways that lead to leukemic transformation with impressive survival benefit, has paved the way for this new optimism. Another success story is the introduction of trastuzumab in breast cancers overexpressing the HER-2 receptor. In contrast, there has been little progress in other malignancies such as metastatic malignant melanoma, although very recently, clinical trials with new targeted drugs have shown increased survival. All major pharmaceutical companies now have ambitious development programs in the cancer area. However, the high costs of the novel drugs cause economic distress in the health care system in many countries leading to an intense debate on the cost-effectiveness of these drugs in relation to other health care activities.