A study published this week in the journal Sleep shows that chemotherapy for Breast Cancer, a disease with which approximately 210,000 women are diagnosed each year, impairs sleep-wake cycles in patients. Sleep disturbances can negatively affect treatment and increase risks for other health and mental problems.
Results indicate that chemotherapy patients switched from low to high activity about 30 minutes later in the day and decreased their level of activity about 50 minutes earlier at night during their first round of chemotherapy, suggesting that their days were shorter.
The study involved 95 women with an average age of 51 years, who were scheduled to receive chemotherapy for stage I-III Breast Cancer. Of the participants, 75 percent were Caucasian, 69 percent were married, 77 percent had at least some college education, and 73 percent reported an annual income of more than $30,000.
“Our biological clock, or (24-hour cycles) help keep our bodies in sync with the environment. During chemotherapy, our biological clock, or circadian rhythm gets out of sync, especially after the first cycle of treatment. The clock seems to regulate itself after only one cycle, but with repeated administration of chemotherapy, it becomes more difficult for the biological clock to readjust,” study author Dr. Sonia Ancoli-Israel told the AASM.
Sleep disturbances are common in cancer patients, with 30 percent to 50 percent reporting symptoms of insomnia. The authors state that it is important to screen more routinely for sleep disruptions in Breast Cancer patients undergoing chemotherapy and to offer treatment, such as cognitive behavioral therapy or bright light therapy, to prevent sleep disturbances from becoming chronic.
According to the AASM, studies show that cognitive behavioral therapy helps both women with breast cancer and breast-cancer survivors. It helps patients develop habits that promote healthy sleep patterns by changing actions and thoughts that hurt their ability to sleep well.