Relationships among sleep, adverse drug reaction, and quality of life in non-metastatic breast cancer patients receiving postoperative adjuvant chemotherapy

Abstract

Many patients with cancer experience a range of side effects while receiving chemotherapy. Among them, chemotherapy-induced nausea and vomiting are a significant burden. Cancer patients are known to experience psychological difficulties such as sleep and mood from cancer diagnosis itself.

We collected data from 198 patients who received highly emetogenic chemotherapy after surgery for breast cancer. We used questionnaires to measure morningness, sleep quality, insomnia, daytime sleepiness, anxiety, depression, cancer-related symptoms, and quality of life prior to the administration of chemotherapy, after the first cycle of chemotherapy, and one year later. Significant nausea and vomiting were defined according to a numeric rating scale (0 to 10) as follows: ≥3, nausea; ≥1, vomiting. To evaluate the adverse effects of chemotherapy, we compared the severity of cancer-related symptoms after the first cycle to that at the baseline. We evaluated the changes in quality of life to assess the long-term quality of life. We performed paired t-tests for the changes in time, logistic regression analysis for the risk factors of chemotherapy-induced nausea and vomiting, and multiple linear regression for the predictive factors related to the quality of life.

The symptoms showing the greatest change following initiation of chemotherapy were nausea and vomiting. The occurrence of chemotherapy-induced nausea was associated with poor sleep quality (odds ratio [OR] = 2.48, 95% confidence interval [CI] 1.13–5.46; P = 0.024) and pre-treatment nausea (OR = 4.81, 95 % CI 1.84–12.62; P = 0.015). Likewise, chemotherapy-induced vomiting was associated with poor sleep quality and pre-treatment nausea. The menopausal transition was found to be a risk factor in the secondary analysis based on hormonal change. After the initiation of chemotherapy, insomnia exacerbated significantly and maintained through one year. Insomnia and daytime sleepiness were significant predictors of the quality of life after one year of treatment.

Poor sleep quality before the initiation of chemotherapy was found to be associated with chemotherapy-induced nausea and vomiting. Menopausal transition, which is related to the change in sleep and mood, was also found to be a risk factor. Insomnia and sleepiness found in the post 1-year period of chemotherapy were significant predictors of quality of life.