Stemming the tide

摘要

Cancer cells are distinguished by the fact that they multiply rapidly and in an uncontrolled manner. Hence, scientists and drug companies have developed drugs that kill cells which divide quickly, while sparing slow-growing-and thus presumably healthy-cells. The catch is that while such therapies often shrink tumours, they rarely cure the underlying disease. Patients often relapse years after an apparently successful treatment. At the annual meeting of the American Association for Cancer Research, which took place in Orlando, Florida, in the last few days of March, Michael Clarke, of the University of Michigan, in Ann Arbor, discussed why such relapses might occur. Dr Clarke believes that a small population of slow-growing cells in tumours-cancerous stem cells-may be responsible not only for the recurrence of tumours, but for the original cancers as well.