"The research, published in the journal Oncotarget, explored tumour heterogeneity – where different cells have different appearances or their own DNA signatures within the same cancer. Such differences could make it difficult to design effective, targeted treatment strategies.
"Firstly they confirmed the mutual exclusivity between the EGFR mutation and either the KRAS or BRAF mutation. Secondly, they found that lung cancers driven by the EGFR gene mutation have that specific mutation present uniformly throughout the tumour, regardless of microscopic appearance. In stark contrast, they discovered that some tumours, with either KRAS or BRAF gene mutations, do not have the mutation present in all parts of the tumour. "
Editor's note: In recent years, lung cancer treatment has focused on the use of targeted therapy drugs. These drugs kill tumor cells that have certain cancer-causing genetic mutations, while generally leaving healthy cells unharmed. Oncologists use genetic testing to see if a patient's tumor has any specific genetic mutations that can be targeted by a specific drug. According to the research described here, different parts of a tumor may have different mutations that can be targeted by different drugs. This makes treatment more complicated, but continued research could lead to more effective treatments.