Association of Anger Expression-Out with NK Cell Counts in Colorectal Cancer Patients.

Abstract

There is growing evidence describing the relation between psychological factors and the progression of colorectalcancer. Several mechanisms have been proposed but the one showing more promising evidence relies on the modulation of the antitumoralimmune response by psychological factors, particularly through natural killer cells. We aimed to study the relation betweennatural killer cell count and anxiety, depression and anger state, trait and expression in 54 pre-surgical colorectal cancer patients. We measured peripheral blood natural killer cell count and applied the State-Trait Anger Expression Inventoryand the Hospital Anxiety and Depression Scale to 54 pre-surgical colorectal cancer patients. We used the Mann-Whitney U test and theKruskal-Wallis test when appropriate to compare independent groups. Patients with higher Anger Expression-Out had lower natural killer cell numbers than patients with lower Anger Expression-Out (p value = 0.008). No relation was found between natural killer cell levels and Anger State, Anger Trait, or Anger Expression-In. Nodifference in natural killer cell count was found between patients with and without clinical anxiety or depression. These results suggest that, in colorectal cancer patients, natural killer cell counts are influenced by Anger Expression-Out, but not by clinical anxiety or depression. The unregulated emotional expression might be a conditioning factor of innate immunity. Additional studies are neededto further investigate this relation and to ascertain the clinical impact of therapeutic interventions regarding emotional regulation on theanti-tumoral immune response.