Relation of erythrocyte and iron indices to oral cancer growth.

BACKGROUND AND PURPOSE: Anaemia is known to influence prognosis of head and neck cancer patients, but how anaemia and tumour growth influences each other is not clear. The present study investigates the relation of erythrocyte and iron indices of oral cancer patients to primary tumour size (Tsize), invasiveness and lymph node involvement.

MATERIALS AND METHODS: The haemoglobin (Hb), erythrocyte count (RBC), packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), Serum iron (SFe), transferrin iron-binding capacity (TIBC) and transferrin saturation (%Fe) were evaluated in 217 untreated patients with epidermoid cancer of the bucco-gingivo-palatine area. The association of erythrocyte and iron indices with sex, tumour size groups, invasion of adjacent structures and lymph node involvement, as well as the relation of SFe to Hb were analyzed.

RESULTS: Most of the patients were anaemic in terms of Hb (63%), RBC (43%) and PCV (48.4%) but almost all had normal or higher MCH (97.3%) and MCV (93.3%) though MCHC was less than normal in 70.7%. Normal or higher SFe was seen in nearly 70% and TIBC in 45% of patients. Hb, RBC and PCV were significantly lower in women, but there was no difference between men and women in the case of MCV, MCH and MCHC. Primary tumour size showed negative association with Hb, RBC and PCV but positive association with MCH (< 2 cm: 29.7 pg; 2-4 cm: 31.4 pg; > 4 cm: 31. 7 pg; P = 0.04) and MCHC (< 2 cm: 29.9; 2-4 cm: 31.5; > 4 cm: 32.1; P = 0.006). MCV, SFe, TIBC and %Fe did not show any relation to primary tumour size. None of the indices had any relation to invasion of adjacent structures or lymph node involvement. MCH, MCHC and MCV were not different in men and women but women had significantly lower Hb, RBC and PCV. The SFe showed poor correlation with Hb.

CONCLUSIONS: The negative association of Hb, RBC and PCV with tumour size is most likely due to chronic RBC destruction, probably tumour induced, with the products of haemolysis such as polyamines, glutathione, iron, etc., promoting tumour growth, and the positive association with MCH and MCHC reflects compensatory regeneration attempts by bone marrow. Lack of relation between the iron indices and tumour parameters and the poor correlation between SFe and Hb is probably due to utilization of iron by both bone marrow and tumours. Lack of difference in MCH and MCHC between men and women obviates the need of using separate cut-off values for the two sexes, unlike Hb, RBC and PCV. The study suggests that anaemia in oral cancer patients represents a tumour-host interaction and that evaluation of all erythrocyte indices should be part of research on cancer related anaemia.