Gemcitabine in cisplatin-resistant ovarian cancer

Many new drugs have been tested in phase II studies in recent years. With a number of drugs the results vary because of differences in the patients recruited to these studies. A number of factors impact the response to second-line therapy, including the treatment-free interval between the end of previous therapy and the entry into phase II study, the bulk and stage of disease, the histology of the tumor, and hemoglobin level. The activity of the new drug tested is also important. It may be difficult to compare the results of different studies, as not all reports contain the same information. A report of a phase II study should contain information on all previous treatment, time since diagnosis, time since last treatment, tumor size at entry, hemoglobin values, performance status, histology, frequency of tests performed to evaluate toxicity, and clear definitions of response. Of the new drugs recently tested, the taxane paclitaxel has shown promising activity even in platinum-resistant patients. Gemcitabine, the novel nucleoside analog, also has shown activity in platinum-resistant patients in a phase II study. The response rate in this study was 19% (95% confidence limits, 9% to 34%). More importantly the responses were observed in a poor prognostic group of patients, characterized by primary platinum resistance, International Federation of Gynecology and Obstetrics stage IV, a treatment-free interval < or = 6 months, large bulky disease, and poorly differentiated/undifferentiated tumors. Both hematologic and nonhematologic toxicities were modest. The data suggest that gemcitabine, like paclitaxel, is non-cross-resistant to platinum.