Urinary tract stone raises subsequent risk for urinary tract cancer: a population-based cohort study.
OBJECTIVE
To evaluate the association between urinary tract stone (UTS) and urinary tract cancer (UTC) in Taiwanese patients, as the results of epidemiological studies about the relationship between UTS and the development of UTC remain inconclusive.


METHODS
We conducted a population-based cohort study using data from the Taiwanese National Health Insurance system. The UTS cohort included 21 862 patients, and each patient was randomly frequency-matched for age, sex, and index year with two insured members of the general population who did not have UTS. Cox proportional hazard regression analysis was performed to estimate the effect of UTS on the risk of UTC.


RESULTS
Patients with UTS were at a significantly higher risk of developing UTC compared with the comparison group (adjusted hazard ratio 4.66; 95% confidence interval 2.97-7.30). Women were at higher risk than men. Further analyses showed that the level of UTC was associated with that of UTS, and that the risk for UTC became more divergent for the two groups over time.


CONCLUSIONS
Taiwanese patients with UTS, particularly women, had a higher risk for developing UTC than patients without UTS. The risk became more marked over time for this group.
Department of Radiation Oncology, Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan.
Li-Min
LM
Sun
Cheng-Li
CL
Lin
Yen-Jung
YJ
Chang
Ji-An
JA
Liang
Shu-Hui
SH
Liu
Fung-Chang
FC
Sung
Chia-Hung
CH
Kao
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D017678:Sex Distribution; D013624:Taiwan / Q000453:epidemiology; D014545:Urinary Calculi / Q000150:complications* / Q000453:epidemiology / Q000276:immunology; D014552:Urinary Tract Infections / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology; D014571:Urologic Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000276:immunology
population-based study; urinary tract cancer; urinary tract stone