Laboratory Tests to Ascertain Tumor Resistance to Drugs Are Available
Individualized treatment, which is promoted as the optimum treatment modality nowadays, makes it desirable for the diagnosis of a neoplasm to be able to confirm not only the malignancy of the tumor tissue but also its growth characteristics and responsiveness to therapy.
New morphological and molecular diagnostic procedures for lung cancer enable differentiation between main types and subtypes. However clinically relevant characteristics of these groups can be defined only to a limited extent, which means that the number of patients benefiting from this approach is currently still small.
Drug treatment of lung cancers is difficult owing to the high rate of intrinsic tumor resistance. This is induced by the body’s own resistance to toxic substances—for example, toxins contained in cigarette smoke (1). The detoxification mechanisms thus induced consequently also inactivate toxic chemotherapeutic drugs. A laboratory finding of tumor resistance to drugs is possible by using morphological and molecular diagnostic methods. Tumor resistance to drugs can be diagnosed by means of immunohistochemical tests of tumor resistance factors—for example, overexpressed substances of the group of ABC transport proteins (2). Methods that can test the non-response to anticancer drugs in living biopsy specimens have also been available for some time (3). For the patient, the diagnosis means that he or she is spared ineffective pharmacotherapies. However, more research is needed to optimize the methods for routine tests.
In recent years, drug resistance testing has met with increased interest and has been used in many cases. The National Comprehensive Cancer Network (NCCN) reported a while ago that in treating ovarian cancer, resistance tests were used in selecting the drugs for treatment (3). In the diagnostic evaluation of tumors, testing drug resistance provides pathologists with an opportunity to also act as pilots in identifying a suitable therapeutic regimen.
Prof. Dr. med. Theodor H. Lippert
Medical Faculty, University of Tübingen, Germany
Conflict of interest statement
The author declares that no conflict of interest exists according to the guidelines of the International Committee of Medical Journal Editors.
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|3.||Lippert TH, et al.: Current status of methods to assess cancer drug resistance. Int J Med Sci 2011; 8: 245–53 CrossRef MEDLINE PubMed Central|
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