Measurement of interferon sensitivity in tumour cells from fine-needle aspirations

Previous studies have shown significant correlations between interferon (IFN) induced enhancement of the enzyme 2',5'-oligoadenylate (2',5'-A) synthetase in vitro and response to IFN therapy. A limitation of this and other predictive tests is the availability of malignant cells for culture. Malignant cells can be obtained from most palpable solid tumours by fine-needle aspiration. We investigated whether malignant cells from such aspirations can be used in a 2',5'-A synthetase assay. In 23/27 (85%) of the cases sufficient amounts of viable cells were obtained, containing a high proportion (greater than or equal to 90%) of tumour cells. In 13/23 tumour samples (57%) IFN-alpha significantly enhanced the 2',5'-A synthetase levels. The use of cells from the fine-needle aspirations for prediction of IFN sensitivity, makes the 2',5'-A synthetase test applicable in a wide range of tumours at a variety of disease stages.