Background: Colorectal cancer (CRC) is the most frequently diagnosed cancer in Spain in both sexes with 41,441 new cases in 2015. There is little evidence regarding the pattern and impact of comorbidities on time from cancer diagnosis to surgical treatment and short-term mortality among CRC patients in Spain.
Objective: To describe the pattern of comorbidities and to investigate the extent to which comorbidities influence time-to-cancer treatment and one-year survival in Spain.
Methods: We developed a population-based high-resolution cohort study, including all CRC cases in Granada and Girona diagnosed in 2011. Data were drawn from two cancer registries and hospital digital medical records. We describe the frequency and distribution of comorbidities by patient, tumor and healthcare factors using radar-plots and heatmaps. Then, we used nonparametric methods to study the impact of comorbidities on time to surgical treatment and short-term mortality. Finally, we developed a web app: watzilei.com/shiny/CoMCoR/
Results: The most common comorbidities were diabetes (23.6%), COPD (17.2%) and congestive heart failure (14.5%). Dementia was the most common comorbidity among older patients (75+ years) showing a higher proportion (30%) of late cancer diagnosis (stage IV). The median time from diagnosis to surgical treatment was 35 days. Overall, patients with 2+ comorbidities had an increased time to surgery of 17 days (95%CI: 12 to 34). However, patients aged 75+ years having 2+ comorbidities showed a higher prevalence of emergency hospital admission followed by surgery the same day or the day after admission (37%). Overall, the presence of 2+ comorbidities increased two-times the risk of short-term mortality one-year after diagnosis.
Conclusions: Results from our study allow identifying patterns in the frequency and distribution of comorbidities among CRC patients and their impact on time from diagnosis to surgical treatment. Thus, this web application is meant to serve as a scientific tool supporting evidence-based policymaking to improve CRC patients' outcomes.