Having more than one urinary tract infection (UTI) within six months could dramatically raise the risk of deadly bladder cancer in older adults, a major study warns.
Researchers found that the danger rises sharply the more infections people have in a short space of time.
Adults aged between 67 and 81 who suffered three UTIs within six months were more than five times more likely to develop bladder cancer.
Those who had five or more infections in that period faced a risk over 13 times higher than normal.
The findings come from a large UK study published in The Lancet Primary Care.
There was, however, one piece of reassuring news. Women taking hormone replacement therapy (HRT) were around 23 per cent less likely to develop bladder cancer.
Bladder cancer often hides behind common urinary symptoms. Around four in ten patients experience a UTI in the year before they are diagnosed.
Experts believe repeated infections trigger long-lasting inflammation in the bladder. As the body constantly repairs the damaged lining, new cells are produced – increasing the chance that dangerous mutations will form.
Having more than one urinary tract infection (UTI) within six months could dramatically raise the risk of deadly bladder cancer in older adults, a major study warns
UTIs are extremely common. More than half of women will have one at some point in their lives, compared with around one in eight men. Symptoms include lower abdominal pain, exhaustion, and pain or burning when passing urine.
They are the most common bacterial infection in women in the UK. While many clear up quickly, antibiotic-resistant bacteria are making infections harder to treat.
For around 1.7 million UK women, UTIs are a recurring problem, striking several times a year.
Bladder cancer is one of the ten most common cancers in the UK, with around 18,000 new cases and 6,000 deaths every year. When caught early, it can often be treated successfully. When caught late, it is far more dangerous.
The researchers analysed the medical records of nearly 54,000 British patients. Just over a third had bladder cancer and had suffered at least one UTI before diagnosis. The rest were used for comparison.
Timing proved crucial. People who had three UTIs spread over a year were three times more likely to be diagnosed with bladder cancer within two years.
But those who had the same number of infections within just six months were almost five times more likely to develop the disease.
The link was strongest in women, which researchers say is likely because they are far more prone to repeated UTIs.
Experts now say anyone who develops multiple UTIs within six months should be checked for bladder cancer.
Current NHS guidance from the National Institute for Health and Care Excellence (NICE) says patients aged 60 or over with recurrent UTIs should be referred to a specialist to rule out cancer.
But the study found this only happens for around one in four eligible patients.
As a result, bladder cancer – especially in women – is often diagnosed later, after symptoms have been repeatedly dismissed as simple infections. This leads to poorer experiences, more advanced disease and lower survival rates.
HRT appeared to reduce cancer risk, possibly because some post-menopausal UTIs are caused by hormonal changes rather than hidden cancer.
The need for better prevention is clear.
The NHS advises drinking plenty of water to help flush bacteria from the urinary tract. Women are also advised to clean the genital area with water before and after sex, and to urinate afterwards.
Avoiding fizzy drinks, alcohol and coffee may help reduce flare-ups. These drinks do not cause UTIs, but they can irritate the bladder and weaken its defences.
Some experts also recommend the supplement D-mannose, which may help wash harmful bacteria out of the urinary system before they can take hold.
Bladder cancer affects more than 150,000 people in England today – and this study suggests that for many, the warning signs may appear months or even years earlier than doctors currently act on.
