Experiencing menopause before the age of 45 is associated with a higher risk of bladder cancer particularly among smokers, says a new study.

Women who entered menopause before the age of 45 were 45 per cent more likely to have bladder cancer than those who had menopause after 50. However, if these women had smoked, the risk of bladder cancer was 53 per cent greater than women who had menopause later, the researchers said. "We found that smoking women who experienced menopause before they were 45 years old had a greater risk of bladder cancer. Smoking remains the most important risk factor for bladder cancer," said lead researcher Mohammad Abufaraj at the University of Vienna.

The study will be presented at the European Association of Urology congress in Barcelona. Besides smoking as the underlying reason for the increased incidence of bladder cancer, other factors such as hormonal changes also leads to an earlier menopause, said Arnulf Stenzl, Chairman at the EAU Scientific Congress Committee.

In general, around three times more men than women get bladder cancer, but the mortality rate in women is around 40 per cent higher. Delay in diagnosis, genetic or epigenetic factors and hormonal factors could be some of the reasons for these differences. However, the study "revealed that it is unlikely that factors such as age when periods begin, number of pregnancies, oral contraceptive use or the use of hormone replacement therapy are associated with bladder cancer risk", Abufaraj added. For the study, the team examined health outcomes of more than 220,000 nurses.