Cancer in persons diagnosed with facial nerve paresis: A hospital-based cohort study in Denmark

Neoplasms can compress or infiltrate the facial nerve, leading to facial nerve paresis or palsy (FNP). As evidence regarding cancers outside the head, neck, and nervous system in persons initially diagnosed with FNP remains limited, we examined the overall and site-specific cancer rates among all patients diagnosed with FNP in Denmark over a 29-year study period.

We conducted a hospital-based cohort study in Denmark, 1994-2022, identifying FNP from inpatient, outpatient, or emergency room visits. We computed absolute risks (AR), and age- and sex-standardized incidence ratios (SIR) with corresponding 95 % confidence intervals (CIs) for all cancers, cancer groups, and site-specific cancers diagnosed <1 year and ≥1 after FNP diagnosis.

There were 27,147 recorded diagnoses of FNP. For cancers diagnosed <1 year after FNP, the AR was 1.67 % (95 %CI: 1.53,1.83) and the SIR was 2.62 (95 %CI: 2.38,2.87) with strong associations for cancers of the nervous system (SIR=14.7, 95 %CI: 12.1,17.7) and head and neck (SIR = 8.37, 95 %CI: 6.41,10.7). For cancers diagnosed ≥1 year after FNP, the AR was 20.2 % (95 %CI: 18.0,22.6) and the SIR was 1.08 (95 %CI: 1.04,1.13) with persistent associations for cancers of the salivary gland (SIR=2.43, 95 %CI: 1.11,4.62), brain (SIR = 1.48, 95 %CI: 1.16,1.86), spinal cord, cranial nerves, and other parts of the central nervous system (SIR = 1.83, 95 %CI: 1.22,2.62), liver (SIR = 2.02, 95 %CI: 1.50,2.65), and anus (SIR = 1.94, 95 %CI: 1.09,3.20).

Rates of local cancers remained persistently elevated among persons diagnosed with FNP as compared with the Danish general population, as did rates of distant cancers implying a key role for metastatic disease as an underlying cause of FNP. Research that explores these associations by cancer stage may yield additional insight into these observed associations.