What is targeted therapy?

Unlike chemotherapy, which kills cells, which are in a similar phase of cell division, good or bad, targeted therapy “targets” specific proteins that are associated with the cancer cell. Some of those targets are Growth receptors (Epidermal Growth Factor Receptors) or EGFR, which then cannot send the growth signal to the interior of the cell. Cancer Cells are dependent on these receptors and enzymes they stimulate, to keep their fires stoked.

These drugs don’t affect other normal organs that are commonly affected by chemotherapy, e.g. bone marrow cells producing normal blood cells, or hair cells, or trigger the nausea receptors. Therefore, these are much better tolerated, particularly, in the frail population.

They do have other side effects, which involve skin EGFRs, e.g. a skin rash, or diarrhoea related to effects on the lining of the intestines.

These drugs are still not first line treatment for most conditions. But they are a valuable addition to available tools.

E.g. Breast cancer in which the her-2-neu receptor is over expressed is known to be more aggressive than the her- 2- neu negative cell. However a drug called trastusumab  (Herceptin by brand name), in combination with chemotherapy, has improved survival in her-2-neu over expressing tumors.