Epidemiology of Bladder Cancer in Individuals with Spinal Injury

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Epidemiology of Bladder Cancer in Individuals
with Spinal Injury

• Suzanne L. Groah, MD, MSPH

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Part 1 Bladder Cancer Incidence
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Bladder Cancer Epidemiology

• 5th most common cancer
• 12th leading cause of cancer mortality
• Adjusted yearly incidence 17.0 per 100,000
• 54,400 new cases per year
• Males at greater risk
• Majority are transitional cell carcinoma

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Risk Factors for Bladder Cancer

• Smoking
• Male gender
• Aromatic amines
• Schistosomiasis
• UTI

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Hypotheses

• Incidence of bladder cancer is higher in SCI than
  in the general population
• Indwelling catheter use is associated with
  bladder cancer in SCI
• 3 There is an increasing risk of bladder cancer
  with longer duration of IDC use

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Part 1 Design Retrospective Cohort
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Methods - Stratification According to Bladder
Management
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Methods - Analyses

• Chi-square
• Survival analysis
• Kaplan-Meier
• Regression model
• Cox proportional hazards
• Statistical significance
• p lt 0.05
• 95 confidence intervals

• Relative risk
• Adjustment
• SMR
• Attributable risk

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Results
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Demographics
data presented in years
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Demographics
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Comparison to General PopulationSMRMales
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Risk of Bladder Cancer

• Age-adjusted rate of bladder cancer (per 100,000)
• IDC - 77.0
• Multi - 56.1
• NIDC - 25.1
• Age-adjusted RR 4.9 (95 CI, 1.3 13.8)
• Attributable risk percent due to IDC 64.8
• Attributable risk percent in all SCI 55.8

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Cumulative Incidence of Bladder Cancer
Wilcoxan lt 0.05
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Cumulative Incidence of Bladder Cancer
Wilcoxan lt 0.05
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Attributable Risk due to Bladder Cancer
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Uncontrolled Confounders?
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Summary of Smoking Status
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Indirect Adjustment for Smoking
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Part 1 Conclusions

• Incidence of bladder cancer is higher in SCI than
  in the general population
• Indwelling catheter use is associated with
  bladder cancer in SCI
• The risk of bladder cancer increases with
  increasing duration of indwelling catheter use

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Evidence for Causality

• Strength of association
• Biologic plausibility
• Consistency with other knowledge

• Temporal relationship
• Dose-response association
• Alternate explanations
• Cessation of exposure
• Replication of findings
• Specificity of association

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Part 2 Bladder Cancer Mortality
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Epidemiology of Bladder Cancer Mortality

• Adjusted risk 3.2 per 100,000
• Associated with age
• gt50 deaths occur in 70 year olds
• Mortality related to stage at diagnosis
• Superficial 5-yr survival 90
• Invasive 5-yr survival lt50

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Hypotheses

• Bladder cancer mortality is heightened in SCI
  compared with the general population
• 2 Compared with other bladder management methods,
  IDC use is associated with heightened BC
  mortality
• 3 The risk of BC mortality increases with
  increasing duration of IDC use

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Part 2 Retrospective Cohort
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Bladder Cancer Mortality
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Risks

• IDC age-adjusted BC mortality 51.2/100,000 p-y
• Multi age-adjusted BC mortality 31.5/100,000 p-y
• SMR SCI vs. SEER 70.9 95 CI 36.4-124.0
• SMR IDC vs. SEER 127.9 95 CI 61.2-235.2

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Bladder Cancer Mortality by Age
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Proportional Mortality Due to Bladder Cancer
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Survival After Bladder Cancer Diagnosis

• Of those dying due to BC, majority of death
  occurred in lt1 year
• Survival range .4 3.3 years

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Part 2 Conclusions

• Bladder cancer mortality is heightened in SCI
  compared with the general population
• Compared with other bladder management methods,
  IDC use is associated with heightened BC
  mortality

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Part 3 Risk Factors, Diagnosis, and Surveillance
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Purpose

• To evaluate factors influencing survival after
  bladder cancer in individuals with SCI
• To examine bladder cancer surveillance

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Hypotheses

• Bladder cancer survivors have fewer genitourinary
  risk factors than those dying due to bladder
  cancer
• 2 Bladder cancer survivors have undergone more
  intense genitourinary surveillance

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Part 3 Design Case-control
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Methods

• Design case-control
• 8 BC survivors
• 12 BC controls who died
• Outcome measures
• Demographics
• Frequency of surveillance
• Risk factors
• Analyses
• Students t test
• Fishers exact test

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Demographics
data presented as proportion
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Demographics
data presented in years
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Bladder Management Method
data presented in years
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Presentation
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Diagnosis
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Bladder Cancer Histology
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Potential Associated Risk Factors
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Risk Factors
RF IDC use, tobacco use, calculi, or
pyelonephritis
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Bladder Cancer Surveillance
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Biopsy Results
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Conclusions

• Bladder cancer survivors have fewer genitourinary
  risk factors than those dying due to bladder
  cancer
• While IDC use is related to BC incidence,
  concurrent multiple risk factor status may be
  related to mortality
• Bladder cancer survivors have undergone more
  intense genitourinary surveillance

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Discussion of Cases