Purpose: Local hypoxia has been linked to a higher risk of metastasis in patients with cancer of the uterine cervix and a haemoglobin concentration of 7.45 mmol/l or less. It is unknown whether the same holds true for rectal cancer. We evaluated the independent impact of pre-operative anaemia on survival in patients with rectal cancer.
Patients and methods: A random set of 144 patients diagnosed with Dukes' A, B or C rectal cancer in the period 1995-1999 and registered in the database of the Eindhoven Cancer Registry was included in a survival analysis. Parameters tested were gender, age, pre-operative haemoglobin concentration, tumour stage and therapy. The ones that showed a relation with survival (log-rank test, p<0.1) were entered in a multivariate analysis.
Results: For patients without pre-operative anaemia, the hazard ratio of death was 0.35 (95% confidence interval 0.19-0.65, p=0.001), which indicates a three times higher mortality risk. For patients with a higher tumour stage (Dukes' B vs. Dukes' A or Dukes' C vs. Dukes' B) the hazard ratio of death was 1.52 (95% CI 1.04-2.23, p=0.03). For older patients (64-73 years vs. <64 years or >73 years vs. 64-73 years) the hazard ratio of death was 1.85 (95% CI 1.29-2.63, p=0.001).
Conclusion: Long-term survival was significantly affected in rectal cancer patients with pre-operative anaemia. Further study on the relation between anaemia, tumour oxygenation and prognosis is needed, as it may have implications for future therapy.