Intensive chemotherapy for solid tumours--current clinical applications.

The treatment of solid tumours with high-dose chemotherapy using alkylating agents either as single agents or in combination schedules has received increasing attention from clinical investigators in recent years. This has frequently been given in association with autologous bone marrow support, a technique which appears to ameliorate myelosuppression that might otherwise be dose-limiting, and which thus may allow dose escalation into a range previously not reached. Despite this ability, and in spite of much experimental evidence from drug-sensitive animal tumours that increasing doses result in increased response rates, no major impact has yet been made in the therapy of solid tumours using this form of therapy. In addition, the use of high-dose schedules has seen the emergence of extramedullary manifestations of drug toxicity which were not encountered at conventional doses. Nevertheless, there are some encouraging data from reports in certain tumours, including small cell lung cancer, testicular cancer, ovarian cancer, and lymphoma, and further studies are clearly indicated. These should probably be restricted to certain drug-sensitive tumours, and should include an examination of the role of high-dose chemotherapy as consolidation treatment, following conventional induction therapy for selected tumour types. This form of treatment may yet provide an important contribution to the control of human solid tumours, but much further work, probably with combination drug schedules, is required.