Australian scientists have helped unlock the secret of how a deadly lung cancer manages to regenerate despite being blasted with chemotherapy.
Researchers from Monash University in Melbourne teamed up with colleagues in the United States to make the discovery, which they believe could have major implications for the future treatment of millions of cancer patients.
The researchers focused on the fast-spreading small cell lung cancer, which has a five-year survival rate of just five per cent.
Patients with the disease usually respond well to chemotherapy and go into remission.
However, in most cases the cancer grows back and quickly takes the life of the patient.
The phenomenon has puzzled scientists for years, particularly because scans taken after chemotherapy often cannot detect any trace of cancerous cells.
But the researchers discovered in a series of laboratory experiments that they could stop the cells regenerating by using a drug to block a type of protein, known as a hedgehog, which is responsible for growth in cells.