Cancer stem cells help maintain the malignant tissue in the tumour by regenerating the tumour after attack from chemotherapy drugs. This indicates that the stem cells themselves should be the specific target of chemotherapy drugs, said Dr: Rodriguez. Rather than the broad brush approach, in which cells are killed indiscriminately, targeting the stem cells may be more effective and also prevent some of the unpleasant side effects associated with conventional chemotherapy treatment.
Scientists believe that cancer stem cells come into being through damage to their own DNA, which affects the regulation of their self-renewal. Other cells divide into two daughter cells, but a stem cell can divide into a new stem cell and a progenitor cell. The progenitor cell loses the power of self-renewal, but can still change into the cell type of the tissue served by the stem cell. The stem cell population then continues to renew itself as it generates new cells for the tissue. This means that, unlike other cells, the stem cell has lost control over its own population size, said Dr. Rodriguez.
Lapatinib has few side effects, and those that exist are minimal, including diarrhoea and acne. But it is expensive. In the US it costs between $2000 and $3000 a month, he said.
This is an exciting finding, and we will be starting further studies on stem cells in order to confirm it. We will also look into its applicability in testing novel agents targeting tumour-initiating cells. This finding should also apply to other types of cancers and research of tumour-initiating stem cells in other cancers is ongoing, said Dr. Rodriguez.
International studies are currently underway looking at the effect of lapatinib in lung, colon, head and neck, gastric, oesophageal, and bladder cancer and lymphoma, among others, he said.
|Contact: Mary Rice|
ECCO-the European CanCer Organisation