We investigated the relationship of oestrogen receptor (ER) status to the severity of depressive symptoms and quality of life (QOL) impairment in breast cancer patients.

Seventy-seven breast cancer patients with comorbid depression were evaluated with the Hamilton Depression Rating Scale (HAMD), the Clinical Global Impression-Severity of Illness (CGI-S) for depression, and the Functional Assessment of Cancer Therapy-Breast (FACT-B). ER status was determined using immunohistochemical analysis.

The ER-positive group (n = 31) showed significantly higher scores compared with the ER-negative group (n = 46) on HAMD total (p = 0.04) and somatic anxiety factor (p = 0.004) scores as well as CGI-S score (p = 0.03). As for QOL measured with the FACT-B, a significantly higher score was found on the Functional Well-Being (FWB) subscale in the ER-positive group (p = 0.001). The relationships were further analysed using generalised linear models (GLM), after controlling for the influence of the current anti-oestrogen treatment. The analysis revealed that ER status was still significantly related to the FWB subscale score of the FACT-B (p = 0.04). However, the HAMD and CGI-S scores were no longer significantly related to ER status after the influence of anti-oestrogen treatment was controlled for.

These results suggest that ER status, which is a well-known biological prognostic factor in breast cancer, may be related to the severity of certain aspects of depressive symptoms or QOL impairment, implying a role of the ER in affective and behavioural regulation. However, anti-oestrogen treatments significantly influence these relationships.