Upper aerodigestive tract cancer in patients with chronic lymphocytic leukemia: incidence, stage, and outcome.

OBJECTIVE

To compare incidence, stage, and survival of upper aerodigestive tract (UADT) cancers in patients with and without chronic lymphocytic leukemia (CLL).

DESIGN

Inception cohort.

SETTING

National database.

PATIENTS

Individuals with CLL and UADT cancers included in the Surveillance, Epidemiology, and End Results (SEER) database.

MAIN OUTCOME MEASURES

Incidence was compared by computing standardized incidence ratio (SIR), the ratio of observed UADT cancers in patients with CLL, and the number of UADT cancers expected based on the characteristics of patients with CLL and population incidence of UADT cancers. The association between CLL and UADT cancer stage was measured using odds ratio (OR) calculations. Survival of patients with UADT cancer with and without CLL was compared.

RESULTS

For the SIR calculation, 36 985 patients with CLL contributed a mean 6.36 years of follow-up each, for a total of 235 314 person-years of follow-up. The SIR was 1.18 (95% CI, 0.97-1.41) for UADT cancers; 1.52 (95% CI, 1.18-1.93) for laryngeal cancer; and 1.92 (95% CI, 1.05-3.23) for cancers of the nasal cavity and paranasal sinuses. In the stage and survival analyses, 253 patients with CLL followed by a UADT cancer were compared with 133 840 patients with 1 UADT cancer only. Cancers of the UADT in patients with CLL were more likely localized (OR, 0.50; 95% CI, 0.37-0.68). Relative survival was worse in patients with CLL. In multivariate analysis, CLL was independently associated with poorer observed survival (hazard ratio, 1.45; 95% CI, 1.24-1.70).

CONCLUSIONS

Larynx and nasal cavity cancers were more common in patients with CLL. Overall incidence of UADT cancers was not significantly elevated. Cancers of the UADT in patients with CLL were more likely to be localized at diagnosis than those in patients without CLL. Finally, CLL was associated with poorer survival outcomes.