The impact of comorbidities on the management and prognosis of oropharyngeal and hypopharyngeal cancer patients in Taiwan

Background: Comorbidity is often associated with negative outcome of prognosis. The aim of this study was to investigate the prevalence and impact of comorbidities in a retrospective nationwide population-based study of patients with oropharyngeal and hypopharyngeal cancers in Taiwan. Materials and Methods: A total of 4733 oropharyngeal and hypopharyngeal cancer patients diagnosed in the period 2007–2010 were identified through the Taiwan Cancer Registry (TCR) database. By linking this data set to the National Health Insurance Research Database (NHIRD) and the Death Registry (DR), information on comorbidity and cause of death was obtained and adapted to the Charlson’s comorbidity index (CCI). The influence of comorbidity on overall survival and cancer-related death was evaluated by Kaplan–Meier estimates and Cox regressions. Results: There were 23.5% of patients with comorbidities during the year before cancer diagnosis. Patients with comorbidities are associated with lower survival rates for stage 3 and for oropharynx. Although there was a tendency that patients with comorbidities received less curative treatment within the same cancer stage, the statistical significance was not reached. The data suggest having a co-morbidity condition had a significant effect on all-cause death (age and gender adjusted hazard ratios = 0.68-0.40) but no significance in cancer-related deaths. Conclusion: The cancer management was not significantly different between patients’ comorbidity conditions. However, the larger differences between all-cause and cancer-specific survival rates in certain treatment groups emphasize the importance of managing other medical conditions in cancer patients.