Table 5.

Association between leukoplakia diagnosis before OCC diagnosis and mortality after cancer diagnosis

DeathsMortality rate, per 100 person-yearsUnadjusted HR (95% CI)Adjusted 1a HR (95% CI)Adjusted 2b HR (95% CI)
All-cause mortality
No leukoplakia4,20722.6ReferenceReferenceReference
Leukoplakia25617.40.76 (0.67–0.87)0.74 (0.65–0.84)0.88 (0.78–1.00)
 ≤3 months before cancer8316.40.75 (0.60–0.92)0.73 (0.59–0.90)0.86 (0.69–1.06)
 >3 months before cancer17318.00.77 (0.66–0.90)0.75 (0.64–0.87)0.90 (0.77–1.05)
Cancer-specific mortalityc
No Leukoplakia2,98016.0ReferenceReferenceReference
Leukoplakia16911.50.71 (0.60–0.82)0.69 (0.60–0.81)0.88 (0.75–1.03)
 ≤3 months before cancer489.490.62 (0.47–0.81)0.61 (0.46–0.81)0.76 (0.58–1.00)
 >3 months before cancer12112.60.75 (0.63–0.90)0.74 (0.61–0.89)0.94 (0.78–1.13)
Non-cancer mortalityd
No leukoplakia1,1706.29ReferenceReferenceReference
Leukoplakia825.600.89 (0.71–1.11)0.83 (0.67–1.04)0.88 (0.70–1.10)
 ≤3 months before cancer336.521.02 (0.73–1.43)0.94 (0.67–1.33)0.98 (0.70–1.38)
 >3 months before cancer495.110.82 (0.62–1.09)0.77 (0.58–1.03)0.82 (0.61–1.09)
  • Abbreviations: OCC, oral cavity cancer; HR, hazard ratio; CI, confidence interval.

    aAdjusted for sex, race, age at cancer diagnosis, and calendar year at cancer diagnosis.

  • bAdjusted for sex, race, age at cancer diagnosis, calendar year at cancer diagnosis, and cancer stage.

  • cCancer-specific mortality was defined as codes C00.0–C97.0 for causes of death coded with ICD-10.

  • dNon-cancer mortality was defined as deaths that were not coded as C00.0–C97.0 with ICD-10 and were not categorized as unknown causes of death. Sixty-two deaths were attributable to unknown causes (57 among oral cancer cases with no prior leukoplakia, and 5 among oral cancer cases with prior leukoplakia).