Smoking status, usual adult occupation, and risk of recurrent urothelial bladder carcinoma: data from The Cancer Genome Atlas (TCGA) Project.
OBJECTIVE
Tobacco smoking and occupational exposures are the leading risk factors for developing urothelial bladder carcinoma (UBC), yet little is known about the contribution of these two factors to risk of UBC recurrence. We evaluated whether smoking status and usual adult occupation are associated with time to UBC recurrence for 406 patients with muscle-invasive bladder cancer submitted to The Cancer Genome Atlas (TCGA) project.


METHODS
Kaplan-Meier and Cox proportional hazard methods were used to assess the association between smoking status, employment in a high-risk occupation for bladder cancer, occupational diesel exhaust exposure, and 2010 Standard Occupational Classification group and time to UBC recurrence.


RESULTS
Data on time to recurrence were available for 358 patients over a median follow-up time of 15 months. Of these, 133 (37.2%) experienced a recurrence. Current smokers who smoked for more than 40 pack-years had an increased risk of recurrence compared to never smokers (HR 2.1, 95% CI 1.1, 4.1). Additionally, employment in a high-risk occupation was associated with a shorter time to recurrence (log-rank p = 0.005). We found an increased risk of recurrence for those employed in occupations with probable diesel exhaust exposure (HR 1.8, 95% CI 1.1, 3.0) and for those employed in production occupations (HR 2.0, 95% CI 1.1, 3.6).


CONCLUSIONS
These findings suggest smoking status impacts risk of UBC recurrence, although several previous studies provided equivocal evidence regarding this association. In addition to the known causal relationship between occupational exposure and bladder cancer risk, our study suggests that occupation may also be related to increased risk of recurrence.
Division of Cancer Epidemiology and Genetics, Department of Health and Human Services, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Rockville, MD, USA.
Amber N
AN
Wilcox
Division of Cancer Epidemiology and Genetics, Department of Health and Human Services, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Rockville, MD, USA.
Debra T
DT
Silverman
Division of Cancer Epidemiology and Genetics, Department of Health and Human Services, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Rockville, MD, USA.
Melissa C
MC
Friesen
Division of Cancer Epidemiology and Genetics, Department of Health and Human Services, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Rockville, MD, USA.
Sarah J
SJ
Locke
Division of Computational Bioscience, Department of Health and Human Services, Center for Information Technology, National Institutes of Health, Bethesda, MD, USA.
Daniel E
DE
Russ
Division of Cancer Epidemiology and Genetics, Department of Health and Human Services, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Rockville, MD, USA.
Noorie
N
Hyun
Division of Cancer Epidemiology and Genetics, Department of Health and Human Services, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Rockville, MD, USA.
Joanne S
JS
Colt
Usher Institute of Population Health Sciences and Informatics, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK.
Jonine D
JD
Figueroa
Division of Cancer Epidemiology and Genetics, Department of Health and Human Services, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Rockville, MD, USA.
Nathaniel
N
Rothman
Division of Cancer Epidemiology and Genetics, Department of Health and Human Services, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Rockville, MD, USA.
Lee E
LE
Moore
Division of Cancer Epidemiology and Genetics, Department of Health and Human Services, National Cancer Institute, National Institutes of Health, 9609 Medical Center Drive, Rockville, MD, USA. koutross@mail.nih.gov.
Stella
S
Koutros
D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology; D016273:Occupational Exposure / Q000706:statistics & numerical data*; D009790:Occupations / Q000706:statistics & numerical data*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology; D014481:United States / Q000453:epidemiology; D001749:Urinary Bladder Neoplasms / Q000453:epidemiology* / Q000235:genetics / Q000473:pathology
Bladder cancer; Diesel exhaust; Occupation; Recurrence; Smoking status