Background

The modified Glasgow Prognostic Score (mGPS), based on the composite of plasma C-reactive protein and albumin concentrations, has been validated as a host prognostic factor, independent of TNM stage, in patients with colorectal cancer.  Moreover, B vitamins have been implicated in the development and progression of cancers.  It is therefore of interest that plasma B6 falls as part of the SIR whereas red cell concentrations do not (1).  The aim was to examine the relationships between the SIR, plasma and red cell vitamin B, and survival in patients with colorectal cancer.

Method

Pre-operative venous blood of 108 surgical patients with colorectal cancer were analysed for CRP, albumin and plasma and red cell B2 and B6.

Results

The majority of patients were female (52%), >65 years (72%), had TNM stage I-III (87%) disease, had mGPS=0 (59%) and normal vitamin B (plasma B2 75%; red cell B2 100%; plasma B6 74%; red cell B6 85%).  The fall of plasma B6, but not red cell B6 (p=0.459), is associated with raised mGPS (p<0.0001).  26% of patients had plasma B6 below the laboratory reference interval.

The median follow-up was 47.1 (23.1-106.3) months.  39 patients (36%) died during follow-up, 30 (28%) from cancer.  The median survival was 37.2 (2.0-105.9) months.  Only tumour stage (p<0.0001; <0.0001), mGPS (p= 0.023; 0.037) and red cell B6 (p=0.023; 0.010) were associated with cancer-specific and overall survival.  On multivariate survival analysis, tumour stage (p<0.0001; <0.0001), the mGPS (p=0.007; p=0.016) and red cell B6 (p= 0.034; 0.024) were independently associated with cancer-specific and overall survival.

Conclusion

The systemic inflammatory response is associated with the perturbation of plasma B6 but not red cell B6.  Only the mGPS and red cell B6 are prognostic of colorectal cancer survival, independent of tumour stage.