Advanced cancer patients receiving chemotherapy or radiation treatments often report suffering from insomnia, daytime sleepiness, fatigue, and depression. In fact, experts estimate that as many as 50% of patients dealing with lung and other cancers experience fatigue syndrome (a combination of physical exhaustion, mental weariness, and reduced emotional stamina.) Many factors in cancer and treatment contribute to these symptoms, but a key issue is disruption in patients’ circadian rhythms, or daily patterns of sleeping, waking, eating and other activities.
Cancer patients may have irregular schedules in which they take long naps during the day – meaning, longer than 30 minutes which can interfere with a solid deep sleep vs. taking a 20-30-minute power naps – and thus have difficulty getting to sleep, staying asleep, falling back to sleep after awakening in the middle of the night.
Circadian rhythms are governed in large part by melatonin, our “sleep hormone,” often found to be low in many cancer patients. With recent studies demonstrating that cancer patients who have irregular or disrupted circadian rhythms have shorter survival than those with normal daily rhythms, it’s not surprising that circadian rhythms have become a key target for interventional therapy among cancer patients.
The Block Center recently conducted a randomized study with 30 of our chemotherapy patients to investigate whether a simple intervention could help raise melatonin levels naturally and, as a result, improve sleep, quality of life, objective measures of circadian rhythm, and reduce fatigue. The intervention was blue-blocking eyeglasses (often sold as “blue-blockers”), which can be worn in the evening to stop blue light from entering the eyes. Because blue light suppresses melatonin levels, these glasses are expected to raise melatonin levels, potentially improving sleep and circadian rhythmicity and, thus, providing several health benefits.
Much to our surprise, the blue-blocking glasses produced absolutely no add-on benefits for our patients’ circadian rhythms, sleep, fatigue, or quality of life. Initially, we were baffled as to why, wondering: “Did this mean that either blue-blockers or melatonin have no effect in chemotherapy patients?” We re-examined our data to find out.
It turned out that our data held another surprise for us. As mentioned, most advanced cancer patients have disrupted circadian rhythms, with irregular sleep and diminished daytime activity. However, the Block Center’s patients – of whom 86.7% had Stage IV disease – had circadian rhythms that more closely matched those of a normal, cancer-free population!
More surprises came when we looked at other important findings on our patients. We compared their quality of life, fatigue scores and sleep to normal populations and other groups of advanced cancer patients on whom data has been published. The good news: In measurements on sleep and fatigue, as well as the data on two different quality of life factors, the Block Center patients matched or were very close to normal populations, and were notably better in those two factors when compared to other groups with advanced cancers. This means that the blue-blocker glasses showed “no effect” on our patients because the circadian rhythms and related aspects of quality of life of Block Center patients were already normal, so it was impossible for the glasses to improve them! (In other words, “You can’t fix what doesn’t need fixing.”). Rather remarkable.
Why would our patients’ circadian rhythms be normal, and what does this mean about their treatment tolerance and the outlook for their diseases? While it’s possible that the Block Center just happens to attract patients who already have good sleep habits, advanced stage IV cancer patients are well known to suffer from either sleep-onset insomnia or sleep-maintenance insomnia, or both. But on the off-chance that our Center seems to attract advanced patients with good sleep habits, just taking chemotherapy often disrupts sleep and circadian rhythms. So how is it that our patients’ circadian rhythms are normal?
We believe that the individualized recommendations we provide to patients within our comprehensive, integrative treatment program reinforces and encourages good sleep habits. We specifically train and guide our patients on ways to maintain healthy circadian rhythms. One factor — we recommend daily exercise, thus enhancing the body’s production of adenosine which the brain uses to induce deep sleep, and we provide patients with strategies to calm concern/anxiety, essential for making sleep easier. We also administer patients’ drugs based on time sensitivity. Wherever possible, we give patients their chemotherapy and other treatments at times of day or night that are best adapted to circadian rhythms – an approach called chronotherapy. Chronotherapy may cause less disruption to circadian rhythms than typical patterns of drug administration.
When combined, these may help our patients experience a better quality of life during chemotherapy. What’s even more encouraging is that several published studies have shown that advanced cancer patients who have normal circadian rhythms tend to survive longer than those who have disrupted rhythms. While we don’t yet completely understand all the mechanisms behind these results, we expect that the findings should apply to our patients as much as they did to patients in the other published studies.
We are very excited to see the study results, since they reassure us that our patients are tolerating their chemotherapy treatments without disruption of important aspects of their quality of life, and especially because of the implications that their normal circadian rhythms have on their long-term survival.
The scientific paper describing our study has recently been published in the journal SAGE Open Medicine. The paper is free to download and read.
Link to article: https://journals.sagepub.com/doi/10.1177/20503121221100137?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed