New research suggests that small cell lung cancers exist as unique, non-uniform tumours in need of both genetic testing and targeted combination treatment.
The study, by scientists at Huntsman Cancer Institue (HCI) at the University of Utah, discovered a number of sub-type tumours in small cell lung cancer samples that were behaviourally distinct from each other.
Using mouse models, the team created a replica of a small cell lung tumour sub-type called C-MYC – a type of tumour thought to makeup around one fifth of all small cell lung cancers.
After a while, researchers began to notice a distinct set of behavioural patterns unique to the sub-type.
“The C-MYC tumours physically look different under the microscope,” says Oliver. “They’re much more aggressive. They grow faster and they spread faster. And most importantly, they respond differently to therapy.”
Once the team had discovered the C-MYC tumour behavioural traits, they then collaborated with Martin Sos at the University of Cologne to investigate which drugs could effectively treat this particular tumour sub-type.
The results from the study indicated a type of drug called an Aurora kinase inhibitor as the most effective for treating C-MYC tumours when combined with chemotherapy.
“The mice survive about twice as long,” said Oliver. “We have some mice that really had extended survival. If these observations could be translated to people, this could be a significant breakthrough for patients with small cell lung cancer.”
Current treatment for small cell lung cancer is chemotherapy which, at first, can prove effective. However, around 80% of these tumours quickly develop resistance.
The new findings indicate a need for genetic testing on small cell lung cancer tumours as a greater understanding of their genetic makeup could improve the effectiveness of the treatment patients are getting.
“Currently when small cell lung cancer patients come in, there is no genetic testing for them. They’re just diagnosed with small cell and they are all treated basically the same way,” explained Oliver. “But our research showed small cell tumours do not all act alike. That becomes very important in how a patient is treated.
“Historically when you would test a drug in small cell lung cancer, almost everything failed. You’d maybe have 10 or 20 percent of people respond — and you didn’t know why those did. Now that we have a new appreciation for the different molecular types of tumours, we might realise, ‘Oh, 100 percent of this tumour subgroup actually responded – it just happened to be only 20 percent of the whole.'”