Emotional control and breast cancer : implications for coping, immunocompetence, and the experience of chemotherapy side effects

Abstract

Emotional control (EC) has been associated with cancer onset and progression. The aims of the present studies were to examine whether this personality characteristic can be altered by a psychosocial intervention aimed at improving emotional expression; how this intervention influences immune function for women with high and low EC tendencies; and how EC can influence the experience of chemotherapy symptoms. The Common Sense Model of selfregulation was used as the theoretical framework for explaining these processes. Study I examined the effectiveness of a 12-week structured, group intervention (GI) on immune function in newly diagnosed breast cancer patients, and whether the effects were moderated by EC. Women were recruited 2-8 weeks post-surgery (baseline), and undertook either standard care (SC; N = 44), or the GI (N = 53). A third condition, Study Only (SO; N = 57), included women who chose not to participate in the GI, but who received SC and completed the study. The intervention emphasised emotional expression strategies. Participants completed assessments of EC (at baseline, 6- and 12 months), immune function (at baseline and at 6 months), and symptomatic side effects (at 4-months). Repeated measures analyses revealed a trend towards a decrease in EC for GI women at 12- months. Regression analyses revealed that EC moderated the effects of the GI on six immune and blood parameters: natural killer cells (NK-cells), basophils, CD4/8 ratios, mean cell haemoglobin, helper-T cells (CD4s), and eosinophils. The findings regarding NK-cells and CD4s are particularly important given that they can kill cells altered by cancer, and augment immunocompetence, respectively. EC also predicted mood, weight gain, vomiting, and weakness in women undergoing chemotherapy. Study II examined whether EC predicted side effects of a specific chemotherapy treatment (AC) in newly diagnosed breast cancer patients (N = 30). Participants reported their mood, coping and physical side effects on a daily basis for the duration of treatment (84 days). EC predicted reports of mood, coping, and 15 physical symptoms. This research has significant implications for understanding the role of EC in psychoneuroimmunology, the treatment experience, and psychological adjustment in breast cancer patients.