In response to new treatments, cancer came back stronger and more resistant than ever. Medicine’s counterattack will be more effective with a clear target.
How do you solve a problem like drug resistance in cancer research? There’s no clear-cut answer yet, not least because the disease can vary so widely. But there has been some exciting research working around drug resistance e.g. lung cancer therapies.
As an example, EGFR is overexpressed in a number of cancers, including squamous cell lung cancer. The first generation of drugs, tyrosine kinase inhibitors (TKI’s), worked by checking its up-regulation. However, tumors quickly developed resistance to these treatments, presenting a new challenge to medical researchers.
It was discovered that a mutation, T790M, is present in over 50% of TKI-resistant tumors: consequently, it became the target of second- and third-generation lung cancer therapies. But this leaves almost half of drug-resistant lung cancers without explanation or a target, so there is a nearly 50% chance that the second line of treatment will be ineffective.
A biopsy of the tumor is usually the primary means of analysis,