Sleep, which is quintessential for the healthy functioning of our mind and body, has a direct impact on our response to various chronic illnesses, including diabetes, heart ailments, hypertension, etc. But, did you know that sleep deprivation is also linked to your risk of developing cancer and its aggressiveness? We reached out to experts who delved deeper into this relationship. “During the various sleep cycles, individuals shift between REM (rapid eye movement) and non-REM sleep stages. It’s essential to note that memory consolidation occurs during the REM stage, and biochemical renewal occurs during the NREM stage, notably throughout a phase known as ‘slow wave sleep’, which impacts how our body functions. Some risk factors for the disease, including the effects of sleep on hormones, metabolism, and inflammation, may influence the aggressiveness of cancer,” explained Dr Sibasish Dey, Head of Medical Affairs, South Asia, ResMed. Agreeing, Dr Pooja Babbar, Consultant, Medical Oncology, CK Birla Hospital, Gurugram said that lack of sleep has an “indirect relationship” with cancer. “People with cancer usually find it difficult to sleep; it is one of the symptoms of cancer. First of all, lack of sleep depresses the immune system and this has long-term effects on the human body. There is a shift in cytokine and inflammatory marker production in the body because of which the risk of cancer increases. Secondly, due to less sleep, the melatonin level is less. Melatonin is helpful in suppressing cancer cells inside the body. So it suppresses the initial phase of tumour formation and it inhibits the proliferation of human cancer cells. Hence, if there is a problem in the sleep duration, this particular substance reduces in the body,” she elaborated. Additionally, sleep deprivation is linked to chronic stress which, in turn, can impact cancer incidence as depression is “one of the most common risk factors for cancer progression”. “Sleep deprivation also alters your appetite-stimulating hormones. It also leads to increased appetite and obesity and obesity has a direct link with cancer. There is a certain rhythm of sleep, so when that rhythm is disturbed, that also promotes mitosis and tumour proliferation,” Dr Babbar added. As such, considering the results of several population and laboratory-based studies, the World Health Organization has designated circadian disruption as a likely carcinogen, Dr Meenu Walia, Senior Director, Medical Oncology, Max Institute of Cancer Care, Vaishali told indianexpress.com. Further, International Agency for Research on Cancer (IARC) has also classified “shift-work that involves circadian disruption” as potentially “carcinogenic to humans (Group 2A)” in 2007 and again in 2019. Sleep deprivation in a patient may hamper their treatment and recovery journey “Several epidemiologic studies have reiterated the fact that sleep-wake cycle disruptions are associated with increased risk of cancers of the prostate, breast, colon, liver, pancreas, ovary, and lung,” Dr Walia highlighted. Apart from cancer itself, experts stress that cancer treatment may also affect a patient’s sleep cycle. According to National Cancer Institute, cancer patients may have changes in their sleep habits or have trouble falling asleep. “The possible reasons for sleep disturbances in cancer patients, include pain or discomfort brought on by treatment, gastrointestinal or urinary issues brought on by cancer or its treatment. Also, stress, anxiety or depression that cancer patients may experience, drug side effects, such as those associated with painkillers, might make patients sleepy, but also interfere with obtaining a restful night of sleep,” Dr Dey said, adding that the sleep-related issues can differ for every person based on the type of cancer, treatment, and general health, including any comorbid diseases. Agreeing, Dr Walia said that as many as half of patients with cancer have trouble sleeping. “It has also been seen that almost 19 per cent to 20 per cent of childhood cancer survivors in John Hopkins studies have sleep-disordered breathing, which is five times higher than the rate in healthy children,” Dr Babbar added. Conversely, sleep deprivation in a patient may hamper their treatment and recovery journey. “Loss of circadian control can affect the efficacy of anticancer treatment and might lead to early mortality amongst patients with cancer. A disrupted cycle can also increase the risk of recurrence among cancer patients,” Dr Walia said. Also in the series |Why you may be waking up with a body ache every morning Adding, Dr Dey shared that cancer medications frequently target distinct proteins, enzymes, or receptors on the cell surface, most of which is impacted by circadian timing. A new study shows sleeping less than six hours per night may increase your risk to develop a key sign of early colon cancer by about 50 percent. Patients who reported short sleep durations are far more likely to be diagnosed with colorectal adenomas, a precursor to cancer tumors. The study involved 1,240 patients scheduled for colonoscopies. The screening results found about 350 of the patients had colorectal adenomas. Prior to the screening, each patient answered questions about sleep habits from the Pittsburg Sleep Quality Index. Patients reported their overall sleep quality during the past month, frequency of insomnia and other details related to sleep. Study results show colorectal adenomas appeared more frequently among patients who said they slept fewer than six hours each night. The findings were adjusted for other risk factors for colon cancer, such as family history, smoking and obesity. It’s still not known why short sleep duration may increase the risk for colon cancer. The lead author of the study speculates it may be because of the decrease in melatonin production or the increase in insulin resistance from sleep deprivation. Colon cancer isn’t the only serious health risk related to sleeplessness. Short sleepers have a higher risk of obesity, diabetes and heart disease. Last year a study found men with chronic insomnia have four times the risk of death compared to men who slept more than six hours per night. The latest findings clearly demonstrate the importance of sleep to your overall health. Do your body a favor and make sleep a health priority, along with diet and exercise. So, what can cancer patients do? Doctors advised cancer patients to consult sleep and oncology specialists in case they have trouble sleeping to discuss their symptoms, the root of the problem, and possible treatments. Here are some tips! *Tell your doctor about problems that interfere with sleep and get treated for them. *Cognitive behavioural therapy (CBT) and relaxation therapy may help. *Set good bedtime habits. Go to bed only when sleepy, in a quiet and dark room, and in a comfortable bed. *Stop watching television or using other electrical devices a couple of hours before going to bed. *Don’t drink or eat a lot before bedtime. *Your doctor may prescribe sleep medicine, for a short period, if other strategies don’t work.