Comorbidity in HPV+ and HPV- oropharyngeal cancer patients: A population-based, case-control study

OBJECTIVES: Comorbid conditions impact outcome for patients treated for oropharyngeal squamous cell carcinoma (OPSCC) and serve as competing risk factors for death. The purpose of this study was to examine differences in comorbidities in patients with OPSCC and known HPV-DNA.

MATERIAL AND METHODS: We included patients diagnosed with OPSCC in Eastern Denmark in 2000-2014. Patients were linked to the Danish National Patient Register to identify comorbidities based on the Charlson Comorbidity Index (CCI) at time of diagnosis and following cancer treatment. Patients were age-and sex-matched in a 1:10 ratio with a reference group and stratified according to HPV-status.

RESULTS: In total 1,499 patients (55.0% HPV+) and 14,990 controls were included. Significantly more HPV+ patients had no comorbidities compared to HPV- patients at time of diagnosis (RR: 1.5 (1.3;1.6), n = HPV+: 522, HPV-: 302) and following treatment (RR 1.5 (1.4;1.6), n = HPV+: 342, HPV-: 142). Most prevalent comorbidity was malignancy not including OPSCCs. HPV+ patients had an increased risk of having AIDS before their OPSCC diagnosis compared to the reference population (OR: 4.8 (1.8;12.9)). HPV- patients had increased risk of multiple comorbidities including cerebrovascular disease (OR: 1.9 (1.4;2.5)), peripheral vascular disease (OR: 1.7 (1.9;3.7)), dementia (OR: 2.9 (1.4;5.8)), ulcer disease (OR: 2.6 (1.9;3.5)), liver disease, mild (OR: 9.5 (7.0;13.0)) and severe (OR: 13.9 (5.8;22.8)).

CONCLUSION: This study showed that HPV- patients had more comorbidities than HPV+ patients at the diagnosis time and following treatment. Irrespective of HPV-status, OPSCC patients had a significant increased risk of (secondary) malignancy compared to the reference population.