Haematological profile in cancer patients: analysis of circadian pattern

This study was intended to evaluate whether unusual circadian patterns in blood cells exist in cancer patients. Ten patients (five men and five women) suffering from advanced malignancy were compared with a control group of apparently healthy volunteers, of comparable age and sex. After synchronization of daily activities, meals and rest of the two groups, blood samples were taken four times (at 8.00 a.m., 12.00 a.m., 4.00 p.m. and 8.00 p.m.) in a single day. The total red and white cell counts, haemoglobin, platelet count, and neutrophil, lymphocyte, eosinophil, monocyte and basophil differential white cell counts were analysed by both conventional (Student's t-test; multifactorial analysis of variance) and inferential statistics (single and mean cosinor). The average values for platelets (P = 0.04), white blood cells (P = 0.004) and lymphocytes (P << 0.001) showed significant changes with time, independently of disease state. Cosinor analysis indicated a circadian rhythmicity for haemoglobin (P = 0.02), eosinophils (P = 0.014), and lymphocytes (P = 0.001) in healthy subjects, and for eosinophils only (P = 0.024) in cancer patients.