Background: Besides tumor characteristics, colorectal cancer (CRC) outcomes are also determined by host factors, in particular the systemic inflammatory response. The basis of this relationship with survival is not known; however, systemic inflammation may reflect comorbidity. The present study examines relationships between host factors (including age, comorbidity, deprivation, and systemic inflammation) and survival in CRC.
Methods: A total of 302 patients underwent curative elective CRC resection between 1997 and 2005. Data was collected on patient comorbidity (Charlson Comorbidity Index [CCI], Lee Cardiac Risk Index [LCRI], National Institute on Aging and National Cancer Institute Comorbidity Index [NIA/NCI], and Adult Comorbidity Evaluation-27 [ACE-27]), systemic inflammatory response (Glasgow Prognostic Score [mGPS]), deprivation [Carstairs Deprivation Index], body mass index, and smoking status.
Results: For cancer-specific survival, age (P = 0.047), tumor, node, metastasis system stage (P < 0.001), high-risk Petersen Index (P < 0.001), LCRI (P = 0.021), and mGPS (P < 0.001) were independent factors by multivariate analysis. For overall survival, age (P < 0.001), tumor, node, metastasis system stage (P = 0.001), high-risk Petersen Index (P = 0.002), postoperative infective complications (P = 0.002), ACE-27 (P = 0.008), and mGPS (P < 0.001) were independent factors. Older age related to increasing comorbidity (ACE-27, CCI, LCRI [P < 0.005]) and increased mGPS (P < 0.005). Smoking and deprivation related to increasing comorbidity (P < 0.05). The mGPS was associated with high comorbidity burden assessed with ACE-27 (P = 0.065), CCI (P = 0.016), LCRI (P = 0.095), and NIA/NCI (P = 0.084).
Conclusions: Comorbidity does not fully explain the relationship between the mGPS and cancer-specific survival in CRC patients. Furthermore, comorbidity, in particular that measured by the LCRI, is an important independent indicator of cancer survival.