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.

Keywords:

• Colorectal cancer
• survival
• mental health
• comorbidity
• risk factors

Acknowledgement

The authors would like to thank all statutory health insurance providers which provided data for this study, namely AOK Bremen/Bremerhaven, DAK-Gesundheit, Techniker Krankenkasse (TK), and hkk Krankenkasse.

Authors contributions

OR wrote the first draft of the manuscript and conceptualized the statistical analyses. JV conducted the statistical analyses including sensitivity analyses and reviewed the draft of the manuscript. UH reviewed the draft of the manuscript and provided a critique.

Disclosure statement

All authors of this study are working at an independent, non-profit research institute, the Leibniz Institute for Prevention Research and Epidemiology – BIPS. Unrelated to this study, BIPS occasionally conducts studies financed by the pharmaceutical industry. Almost exclusively, these are post-authorization safety studies (PASS) requested by health authorities. The design and conduct of these studies as well as the interpretation and publication are not influenced by the pharmaceutical industry. The study presented was not funded by the pharmaceutical industry and was performed in line with the ENCePP Code of Conduct. The authors declare no conflict of interest

Additional information

Funding

This study was not supported by funding.