It has long been known that the neutrophil to lymphocyte count ratio (NLR) is a marker of inflammation and that a higher ratio relates to poorer outcomes in some malignant tumours including some head and neck cancers. Neutrophilia (and therefore higher NLR) inhibits the immune system by suppressing the cytolytic activity of other immune cells. The team in Glasgow have looked at the NLR in relation to vestibular schwannomas (VS) and found that a higher ratio correlates with a growing VS. One hundred and sixty-one patients were looked at (79 growing VS and 82 non-growing) with a blood test within 12 months of VS diagnosis. Blood tests at times of illness and patients with chronic diseases and taking certain medications were excluded. Mean follow-up was for three years (one to seven years). The mean NLR for the group with growing VS was 3.34 and for the group with non-growing VS 2.31 (p=0.03) – statistically significant after data was adjusted for age, side, sex and size. The higher the NLR, the more likely the VS to grow but, interestingly, a low NLR value was not strongly predictive of non-growth (so we can’t rely on a low value to mean no growth). What does this mean in practice? Well, treating an NLR value (however high) without radiological evidence of growth risks over treating VS, but that risk reduces the higher the NLR value. It is more likely that in time skull base centres will use this as added information in which to weigh up the risk benefit ratio of treating a VS that has possibly grown on a surveillance scan. For example, to save hearing in a ‘small tumour ear’ with hearing preservation surgery. Further research with added parameters such as CRP measurement may improve the specificity and sensitivity of the NLR ratio.
