Scientists have identified a protein that could help doctors decide which patients with bladder cancer would benefit from a treatment that makes radiotherapy more effective, according to a new study.
The research team found that patients whose bladder tumor had high levels of the protein HIF-1α were more likely to benefit from receiving carbogen (oxygen mixed with carbon dioxide gas) and nicotinamide tablets at the same time as their radiotherapy. The treatment, called CON, makes radiotherapy more effective.
By comparing levels of HIF-1α in tissue samples from 137 patients who received radiotherapy on its own or with CON, the researchers found the protein predicted which patients benefited from the CON treatment. High levels of the protein were linked to better survival from the disease when patients had radiotherapy and CON. Patients with low protein levels did not benefit from receiving CON with their radiotherapy. The study was published in the British Journal of Cancer (2014; doi:10.1038/bjc.2014.315).
The HIF-1α protein indicates low oxygen levels in tumor cells, which is a state known as hypoxia. The CON treatment works by adding oxygen to the oxygen-deprived tumor cells making them more sensitive to the radiotherapy.
“Although we have another biomarker that can predict responsiveness to CON and radiotherapy in bladder cancer patients, our findings tell us a bit more about the characteristics of bladder cancer tumours and how they may respond to this treatment,” said study author Catharine West, PhD, a Cancer Research UK scientist at The University of Manchester in the United Kingdom. She continued, “But we desperately need to do more work to find ways to treat those patients who won’t see as much benefit from this.”