Quality of life in women with breast cancer receiving chemotherapy and the moderating role of cortisol

Background: Quality of life (QoL) is severely affected by breast cancer (BC) and its
treatment, particularly chemotherapy treatment. Psychological morbidity, illness
perceptions, and self-efficacy for coping are important variables that impact QoL during
the treatment of BC. The impact of cortisol on QoL has been poorly studied.
Objective: The aim of this study was to identify the contributing variables to QoL in
women with BC receiving adjuvant chemotherapy, as well as the moderating role of
cortisol in the relationship between treatment adverse effects and QoL. Methods: This
cross-sectional study included 112 women with BC undergoing chemotherapy who
answered the European Organization for Research and Treatment of Cancer Core
Quality of Life Questionnaire, the Supplementary Questionnaire Breast Cancer Module,
the Illness Perception Questionnaire, the Cancer Behavior Inventory—Brief Version, and
the Hospital Anxiety and Depression Scale. In addition, salivary cortisol concentrations
were also assessed. Results: The strongest contributor to lower QoL was treatment
adverse effects. The illness perception and the cancer stage also contributed to a lower
QoL. Nadir cortisol moderated the relationship between adverse effects and QoL.
Conclusion: Breast cancer chemotherapy and illness perceptions, even at the
beginning of treatment, showed a great impact on QoL. Implications for Practice: It
is important during chemotherapy to assess women’s illness perceptions, as well as their
stress levels to help women cope with the stress associated with treatment adverse effects.
Monitoring cortisol is important as cortisol moderated the relationship between adverse
effects and QoL. For those women struggling with stress, a reference to a mental health
provider is warranted.