Cancer chemotherapy: a critical analysis of its 60 years of history.

Chemotherapy has already proven widely effective in the treatment of cancer, occupying a prominent place in the current therapeutic arsenal. However, in recent years, there has been a plateau in the evolution of the clinical results obtained with this modality treatment. In some cases, the limitations of chemotherapy observed during the early days still apply. These facts forced us to do a thorough analysis of what happened in the past 60years. We have observed that each major advance obtained in this field was based on empirical clinical observations. We thus believe that the current results of old or new agents can only be improved by understanding the natural history of each specific cancer subtype at the clinical level and by overcoming the physiological barriers involved in chemotherapy failure. This strategy will surely allow us to enlarge the list of curable cancers by chemotherapy.