Cancer as a risk factor for urinary tract calculi: a retrospective cohort study using 'The Health Improvement Network' : Cancer and urinary tract calculi.

PURPOSE Urolithiasis is a common condition that poses significant morbidity to patients. There are similarities in the development of certain cancers and urinary tract calculi (UTC), however, little is known about their temporal relationship. This study aims to identify if cancer is a risk factor for the development of UTC. METHODS A population-based retrospective cohort study was conducted for the period 1st January 1990 to 1st May 2016. 124,901 exposed patients identified using clinical codes with newly diagnosed cancer were matched to 476,203 unexposed controls by age, gender, BMI, and general practice. The main outcome measure was the risk of developing UTC described by hazard ratios. RESULTS There were 512 incident UTC events in the cancer group compared to 1787 in the unexposed controls. This translated to an adjusted hazard ratio of 1.26 (95% CI 1.14-1.39; p < 0.001). A sub-analysis assessing cancer-specific effects demonstrated increased risks for 10 out of 12 common cancers, most significantly in bladder, colorectal and prostate cancer. CONCLUSION This study demonstrated a 26% increased risk of UTC in cancer patients suggesting wider recognition of this risk amongst clinicians could improve diagnosis and prevention of UTC, as well as encourage further research exploring this association