Influence of interferon on the growth of primary ovarian carcinoma cells in a semi-solid agar system: comparison with clinical effects of interferon therapy.

The sensitivity of primary human ovarian cancer cells to interferon (IFN) was studied in vitro by the use of a tumor cloning system in semi-solid agar. Tumor colonies were found in 37% (34/93) of the experiments with tumor cells from ascites and in 35% (6/17) of the experiments with solid tumors. The relative colony-forming ability could not be correlated to prior treatment. In 15 out of 18 patients the ascitic tumor cells were sensitive to IFN-alpha. Sensitivity was found in one test out of three with solid tumors. The sensitivity was dependent on the dose of IFN but could vary for the natural IFNs alpha and gamma. In seven patients the relation between in vitro and in vivo sensitivity of the tumor cells to IFN could be studied. Any correlation between in vitro and in vivo sensitivity could not be revealed in this small group of patients.