This paper presents a systematic overview or meta-analysis of 54 randomized clinical trials testing a variety of chemotherapeutic approaches in advanced ovarian carcinoma. Prolonged follow-up data are available for most patients and individual patient data were made available for all patients; analysis was made on the basis of "intention to treat." Our report concentrates on two comparisons: (1) platinum alone versus platinum in combination, which appears to show a long-term survival advantage for the combination (however, the platinum dose in the single-agent arm was relatively low); and (2) carboplatin versus cisplatin, which shows no obvious survival differences. It is striking that no single study to date has been large enough to detect the modest survival differences expected from current therapy. Consequently, a series of international studies have been initiated. The International Collaborative Ovarian Neoplasm (ICON) group will examine the role of adjuvant chemotherapy in early ovarian cancer (ICON 1) and will compare carboplatin with cisplatin, doxorubicin, and cyclophosphamide in more advanced disease (ICON 2).