Systemic therapy of cancer: facts and expectations

Abstract

Background: Systemic therapy of cancer had its first major expansion in the second half of the 20th century with the development of chemotherapy and hormonal therapy. Some cancers, like leukemias, lymphomas, osteosarcoma and testicular cancer became highly curable irrespective of anatomic size – stage of the disease. Other more common cancers, such as breast cancer, colon cancer, ovarian cancer, lung cancer and prostate cancer became on a larger scale curable in the early stages of the disease while in the advanced stages of the disease long term remissions could be achieved by chemotherapy and/or hormonal therapy.

Conclusions: Cancer patients nowadays live longer and with a better quality of life. With mapping of the human genom, possibilities for determining and identifying the cancer genom became available at the turn of the last century. The era of molecular oncology which enables personalized treatment tailored to each patient and his tumor is now upon us. Molecular oncology makes it possible to identify the molecular targets and to develop therapy which targets them. In addition it gives us more knowledge about the prognostic as well as predictive markers. Good examples of effective targeted cancer therapy are treatment of GIST with imatinib and treatment of HER2+ breast cancer with trastuzumab. In both cases the target as well as the patients were precisely selected. Experience from various trastuzumab trials teach us that targeted therapy will also be the most effective in the early stages of cancer, when the burden of the disease is quite limited. Treatment of advanced cancer with targeted treatment so far mostly results in remissions but not cure. Numerous additional new targeted therapies are currently under development and by no doubt they will very soon allow us to facilitate the selection of proper treatment at proper time for proper patients. In contrast to empirical treatment approaches, a personalized one enables the best possible treatment for each individual patient and also decreases the cost of treatment in a society. This kind of an approach requires a much closer collaboration between clinician and other members of the multidisciplinary team, especially with a molecular oncologist/pathologist, availability of drugs and a large ammount of knowledge and experience by the leading molecular oncologist and medical oncologist.