Psychosocial predictors of outcome IV: patients with early-stage breast cancer

Abstract

SUMMARY Research interest in psychosocial predictors of the onset and course of cancer has been active since the 1950s. However, results have been contradictory and the literature is noted for methodological weaknesses. In this prospective study we aimed to systematically obtain data on psychosocial factors thought to be associated with cancer outcome in early-stage breast cancer. Consecutive patients with early-stage breast cancer seen for the first time for ongoing treatment at a major teaching hospital in Sydney participated in the study. Exclusion criteria included inability to speak English and co-existing psychiatric illness. Participants completed a series of questionnaires every 3 months for up to 2 years following their diagnosis. Domains measured included cognitive appraisal of threat, coping, psychological adjustment, social support, quality of life and perceived aim of treatment. Disease and demographic data were obtained from medical records, including age, marital status, education and occupational status, treatment received, menopausal status, tumour size and grade. 233 patients agreed to participate in the study and 211 (88%) had sufficient data for analysis. Patients were a mean age of 51 years; 84% of the sample were Australian-born; 25% of the sample had a University education and 39% were in managerial or professional occupations. 59% had chemotherapy following surgery and 54% were taking tamoxifen. Women entered the study a median of 91 days since diagnosis. 30 (14%) of the 211 women died within the study period and 36 (17%) relapsed. Multivariate analysis of baseline measures only, used the Cox proportional hazards model. Two psychosocial factors independently predicted both survival and time to relapse. Apart from disease variables, three non-medical factors remained in both of the final models: appetite, concern about dependence and concern about the disease. Patients who had high levels of concern about the disease and low levels of concern about dependence survived for a significantly shorter time (Hazard Ratio (HR) = 1.04, 95% CI = 1.01–1.06; HR = 0.96, 95% CI = 0.94–0.99) and relapsed quicker (HR = 1.03, 95% CI = 1.01–1.06; HR = 0.96, 95% CI = 0.93–0.98). Concern about the disease was also predictive of outcome in primary melanoma patients, but the directional effect was opposite; that is, patients with a higher concern about their disease did better. Perhaps patients with early melanoma are mobilized by their concern to take active self-protective measures which can have a real impact on their disease (such as staying out of the sun), whereas similar self-protective strategies are not available to patients with early breast cancer. Alternatively, concern about the disease may reflect medical factors in breast cancer which we did not record. Interestingly, the coping response of minimization, which was significantly predictive of outcome in our metastatic breast cancer sample, was not significant in this population. It is likely that different coping styles are salient and predictive of outcome at different stages of disease. There is still much to learn about the potential relationships between psychological wellbeing, human behaviours and cancer outcome. Research in this area needs to clarify the psychological processes themselves as well as understand the biological and/or behavioural mechanisms that may link them to outcome.