Determinants of quality of life in patients with breast cancer undergoing external beam radiotherapy.

Quality of life (QoL) of patients with breast cancer is not dependent only on the presence of the disease, as there is such a multitude of social and clinical factors [1, 2]. However, data on the determinants of QoL in Polish breast cancer patients during the course of radiotherapy are scarce and based on custom-made questionnaires [3], rather than the EORTC QLQ-C30 or QLQ-BR23, which are the tools of choice for such patients [4, 5]. We evaluated breast cancer patients undergoing radiotherapy for treatment-related determinants of QoL and compared them with the intensity of depressive symptoms.

A total of 98 women with breast cancer during the standard course of external beam radiotherapy agreed to complete the validated Polish versions 3.0 of EORTC QLQ-C30, QLQ-BR23 (all global, functional and symptom scales) and – at the same time point – the Beck Depression Inventory (BDI) to evaluate the intensity of depressive symptoms. A control group of 127 healthy women referred to the mammography department for screening purposes was evaluated using the BDI.

Median age of the study group was 54 (25–75%: 46.7–60.5) years. Breast conserving therapy (BCT) had been performed in 50% of patients. In the breast cancer group, 65% of subjects had undergone some form of chemotherapy and 51% were undergoing hormone therapy. Cronbach's α values for QLQ-C30, QLQ-BR23 and BDI were 0.91, 0.81 and 0.83 respectively, confirming adequate test performance.

Median total radiation dose given to the patients was 34 Gy (25–75%: 18–42 Gy), and only affected intensity of nausea/vomiting and constipation subscales (R = 0.25, p = 0.04; R = 0.27, p = 0.03 respectively) of the QLQ-C30 functional scales. No statistically significant correlations were found between the total dose and QLQ-BR23 scales, but the early reactions (RTOG staged ≥ 2 [6]) significantly worsened arm symptom subscale score assessment in QLQ-BR23.

Hormonal therapy was not significantly correlated with any of those three questionnaires’ subscores. Previously received chemotherapy impacted neither QLQ-C30 nor BDI results, but it was associated with body image (BRBI) and systemic therapy side effect scores (BRST) (p = 0.02 and p = 0.005). Type of surgical intervention before radiotherapy impacted the field of global health status, resulting in better overall QoL in patients who had undergone BCT (58% (25–75%: 50–67) vs. 50% (25–75%: 42–58); p = 0.0405). BCT was also associated with lower reported intensity of breast symptoms (p = 0.0338) and better perception of future perspectives (BRFU; p = 0.0328). The level of depressive symptoms measured in controls was significantly lower than in cancer patients (median 5 (25–75%: 1–10) vs. 12 (25–75%: 6–17) points; p < 0.0001). BDI scores were correlated negatively and significantly with all functional scales of QLQ-C30 (Spearman's correlation coefficients ranging from –0.36 to –0.46, all p < 0.05) and QLQ-BR23 subscales: BRBI and BRFU (R = –0.47 and –0.51; p < 0.05).

In conclusion, radiotherapy itself has a minor influence on QoL of breast cancer patients, although organ-specific complications may significantly impair physical functioning. Other forms of oncological treatment, such as the type of surgical procedure performed, have a much more profound impact on all fields of QoL. Intensity of depressive symptoms is an important determinant of QoL in cancer patients which mandates routine psychological evaluation.