Overall survival in 92,991 colorectal cancer patients in Germany: differences according to type of comorbidity

Abstract

Background Poorer survival in cancer patients with vs. without comorbidity has been reported for various cancer sites. For patients with colorectal cancer (CRC), limited data are available so far. Methods Patients with CRC diagnosed between 2010 and 2018 were identified in a health claims database covering 20% of the German population. We assessed the prevalence of comorbidities at cancer diagnosis and categorized the patients into the groups: ‘none’, ‘somatic only’, ‘mental only’ or ‘both’ types of comorbidities. Hazard ratios (HR, with 95% confidence intervals) for five-year overall survival were estimated by Cox proportional hazard models, adjusted for age, sex and stage at diagnosis (advanced vs. non-advanced). Results We included 92,991 patients (females: 49.1%, median age: 72 years) with a median follow-up of 30 months. The proportions assigned to the groups ‘none’, ‘somatic only’, ‘mental only’ or ‘both’ were 24.7%, 65.5%, 1.4% and 8.4%. Overall, 32.8% of the patients died during follow-up. Compared to patients without comorbidities (‘none’), the adjusted HR regarding death from any cause was 1.11 (95% CI: 1.07–1.14) in the group ‘somatic only’, 1.74 (95% CI: 1.58–1.92) in the group ‘mental only’ and 1.92 (95% CI: 1.84–2.00) in the group ‘both’. For patients with ‘mental only’ comorbidities, the adjusted HR was higher in males than in females (HR = 2.19, 95% CI: 1.88–2.55 vs. HR = 1.55, 95% CI: 1.37–1.75). Conclusions Our results suggest that patients with CRC and with mental comorbidities, particularly males, have a markedly lower overall survival compared to those without any or only somatic comorbidities.