Steroid inhalers to prevent asthma attacks may potentially raise the risk of developing prostate cancer in men, a new study has found.

Scientists in Melbourne, Australia, studied 1,179 men who had been diagnosed with prostate cancer and analyzed how many had a history of asthma. They have found men who regularly take inhaled steroids to keep their asthma under control are almost 40 per cent more likely than men without asthma to develop a tumor.

While the risk for developing prostate cancer was 36 percent in men who regularly used another type of inhaler, the highest risk of around 70 percent persisted among men with severe asthma who frequently need treatment with steroid tablets or injections.

Even though asthma itself appears to play a role in increasing the risk of prostate cancer by around 25 per cent, the study noted that the chances of a tumor remained significantly higher in men taking the medication.

But it was 'difficult to disentangle' the effects of asthma drugs from the result of just having the condition itself, the authors admitted while publishing the results in the journal Cancer Epidemiology, Biomarkers and Prevention.

Asthma inhalers are generally of two types: ones that provides instant relief from symptoms and another to use once or twice day to prevent them developing in the first place.