title: Smoking is associated with lower age, higher grade, higher stage, and larger size of malignant bladder tumors at diagnosis.
abstract: Smoking is a strong risk factor of bladder cancer (BC), but it is currently unclear whether smoking is also associated with severity of BC at diagnosis. We performed a large hospital-based case-comparison study, examining the relation between smoking and clinical characteristics of BC at diagnosis. A total of 1,544 cases from participating hospitals in the West Midlands were recruited between 19 December 2005 and 21 April 2011. Eligible cases were adult BC patients without a previous history of this disease. At time of diagnosis, semi-structured face-to-face interviews were conducted by trained research nurses to collect smoking information. Clinical characteristics were obtained from medical records. Linear mixed models were performed to calculate predicted means in clinical outcomes for a variety of smoking behaviors. A p < 0.05 was considered statistically significant. After adjustment for age and gender, current smokers were on average 4.0 years younger at diagnosis (95% CI: -5.9 to -2.0), had larger tumors (mean difference: 0.48 cm, 95% CI: 0.04-0.91), a higher T stage (mean difference: 0.25, 95% CI: 0.08-0.41), and a borderline significantly higher grade than never smokers (mean difference: 0.15, 95% CI: 0.00-0.30). Our results suggest that smoking could be associated with a more malignant phenotype of BC at diagnosis. More research is needed on the relation between smoking and prognosis, but our results could strengthen the message about the potential risks of smoking to these patients.
authors.affiliation: Department of Public Health, Epidemiology and Biostatistics, School of Health and Population Sciences, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Eline H
authors.initials: EH
authors.lastname: van Roekel
authors.forename: Kar K
authors.initials: KK
authors.lastname: Cheng
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: James
authors.forename: D Michael A
authors.initials: DM
authors.lastname: Wallace
authors.forename: Lucinda J
authors.initials: LJ
authors.lastname: Billingham
authors.forename: Paul G
authors.initials: PG
authors.lastname: Murray
authors.forename: Richard T
authors.initials: RT
authors.lastname: Bryan
authors.forename: Maurice P
authors.initials: MP
authors.lastname: Zeegers
mesh_terms: D017668:Age of Onset; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D010641:Phenotype; D011379:Prognosis; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D006113:United Kingdom / Q000453:epidemiology; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*