Cancer, Chemo, and Insomnia: Why Can't I Sleep?

 

Sleep disturbances are common in people with cancer — especially those who are undergoing chemotherapy or other types of treatment, or survivors who've been treated in the past.

Difficulty with insomnia, the ability to fall and stay asleep, is reported in 30 to 50 percent of all cancer patients, according to a recent study. Other studies say the rate may actually be much higher — 75 percent of all cancer patients reporting long and short term insomnia.

One thing’s for sure — the lack of sleep can make a difficult situation even more challenging.

Insomnia not only affects your quality of life. It can negatively impact your treatment and increase risks for other physical and mental health problems.

For example, cancer-related fatigue, daytime sleepiness (hypersomnia), anxiety and depression are commonly reported in people who experience sleep disturbances.

Women who are treated for breast cancer may be most affected, and often list sleep disturbances among the most distressing symptoms experienced during chemotherapy.

A joint study by researchers at Laval University Cancer Research Center in Québec, Canada, and the University of California-San Diego found “little distinction between daytime and nighttime activity cycles” in cancer patients prior to and during treatment.

This pattern indicates a disruption in circadian rhythms.

The master internal biological clock located in the brain helps regulate our body’s normal rhythms during the 24-hour cycle, from temperature and hormone levels to the natural sleep-wake cycle. Circadian rhythm disruptions may even contribute to cancer itself.

During chemo, our biological clock gets out of sync, especially during the first round which is most disruptive, according to the study. However, the longer the treatment goes, the more difficult it is to regulate your biological clock.

The authors stated that patients may need cognitive behavioral therapy or bright light therapy to prevent sleep disturbances from becoming chronic. Both types of therapy have been found to be beneficial for breast cancer patients and survivors.

Cognitive behavioral therapy for insomnia helps you identify and replace thoughts or behaviors that can cause or worsen sleep habits.

“Unlike sleeping pills, cognitive behavioral therapy for insomnia helps you overcome the underlying causes of your sleep problems,” according to the Mayo Clinic.

Bright light therapy is used to reset the biological clock that is off, to help restore healthy sleep patterns. Bright light therapy uses artificial light to expose your eyes to intense, but safe, amounts of light for a specific and regular length of time.

The time of day when the light is used will depend upon the disorder it is meant to correct, according to the American Academy of Sleep Medicine.

In addition to helping resolve insomnia, bright light therapy is used to correct Seasonal Affective Disorder. SAD is a type of depression that occurs in some people during fall and winter where natural sunlight is not available, and in people who suffer from insomnia related to shift work.

ianursing, thank you for the most interesting question..I didn't know personally, however, while searching I came across this article.. I hope it helps and answers some of your question.... Teresa

The relationship between fatigue and light exposure during chemotherapy

Background

Fatigue is one of the most common and distressing complaints among cancer patients, not only during radiation and chemotherapy, but also for months to years after the completion of treatment. Fatigue interferes with patients’ daily lives, reduces their quality of life, and is often a significant reason why patients discontinue treatment. We hypothesized that some of the fatigue may be related to disrupted circadian rhythms and low light exposure. The main objective of this study therefore was to investigate the association between fatigue and light exposure among patients with breast cancer.

Methods

As part of a larger, ongoing prospective study on fatigue, sleep, and circadian rhythms in patients with breast cancer, an analysis of 63 women newly diagnosed with stage I–IIIA breast cancer and scheduled to receive four cycles of adjuvant or neoadjuvant anthracycline-based chemotherapy was conducted. Data were collected before and during weeks 1, 2, and 3 of cycle 1 and cycle 4. Fatigue was assessed using the Short Form of Multidimensional Fatigue Symptom Inventory. Light exposure was recorded with a wrist actigraph.

Results

There were significant correlations between fatigue levels and light exposure (r=−0.28 to −0.45) within both cycle 1 and cycle 4, such that higher levels of fatigue were associated with less light exposure. There were also significant correlations between changes in light exposure and changes in fatigue within the first 2 weeks of each cycle (r=−0.28 to −0.52).

Conclusions

Increased fatigue was significantly correlated with decreased light exposure among patients with breast cancer. Although the cause and effect of exacerbated fatigue and decreased light exposure cannot be confirmed by the current study, and lower light exposure may just in part be due to the fatigued patients spending less time outdoors in bright light, two hypotheses are proposed about the mechanisms by which light may alleviate the fatigue of patients with breast cancer. These results suggest the need for prospective intervention studies of light therapy for breast-cancer-related fatigue.

Procedure

The study was approved by the University of California Committee on Protection of Human Subjects and by the Protocol Review and Monitoring Committee of the UCSD Rebecca and John Moores Cancer Center. After consent forms were signed, medical records were abstracted for medical history and current medication use.

The eight time points of data collection were before the start of the first cycle of chemotherapy (cycle 1 week −1 or C1W−1), during the 3 weeks of cycle 1 [week 1 (C1W1)= chemotherapy administration; week 2 (C1W2)=point of nadir of blood count; week 3 (C1W3)=recovery], before the start of cycle 4 [cycle 4 week −1 (C4W−1); note: this is usually the third week of cycle 3], and during the 3 weeks of cycle 4 (C4W1, C4W2, and C4W3). Table 1 presents the number of days that data collection occurred pre- or postchemotherapy. In general, baseline data collection began the week before chemotherapy, followed by data collection on the morning after chemotherapy administration. Data collected in each subsequent week (weeks 2 and 3) were collected on the same day of the week as during week 1.

Mean number of days postchemotherapy of data collection

During each of eight points of data collection, the women wore the Actillume recorder for three consecutive 24-h periods (i.e., 72 h) and completed an accompanying sleep log on which bedtime, wake time, and any napping behavior were recorded. MFSI-SF was completed once during the 3 days of data collection at each of the same eight time points.

Data analysis

Light data were separated into two periods: out-of-bed time and in-bed time, with bedtime based on the time reported on sleep logs. Since average light exposure of in-bed time suggested women were appropriately in the dark during all eight data collection time points (mean 1.9 lux, SD=5.7 lux, range 0–71.4 lux), only out-of-bed light data were used for analyses.

Spearman rank correlations were computed to examine the associations between fatigue (MFSI-SF total and subscale scores) and duration of light exposure (minutes >1,000 lux/day) and intensity of light (mean lux levels). Spearman correlations were also performed between the changes in fatigue and changes in light exposure between week −1 and week 1, between week 1 and week 2, and between week 2 and week 3 within both cycle 1 and cycle 4.

For descriptive purposes and to examine changes in fatigue and changes in light over time, multivariate analysis of variance with weeks of chemotherapy (W−1, W1, W2, W3) as the within-subject factor was computed for each cycle for fatigue (total and subscale scores) and duration and intensity of light exposure (minutes >1,000 lux/day and mean lux), followed by preplanned contrasts between baseline and each week of C1 and C4 and between each of the treatment weeks within C1 and C4.

In order to examine the changes of fatigue and changes of light exposure from before the start of chemotherapy (C1W−1) to each week of C4, paired t tests were performed. To compare mean levels of fatigue between C1 and C4, paired t tests were also performed.

All analyses were performed using version 8.02 of SAS [25]. All statistical tests with p values <0.05 are reported as statistically significant.

Fatigue

The mean fatigue scores for each week of each cycle are shown in Table 2. In general, fatigue significantly increased from baseline (W−1) to each week of cycle 1 (p value range <0.0001–0.02), but remained constant from week 1 to week 3.

Fatigue measures (mean±SD) (n) by week for cycle 1 and cycle 4

Fatigue within each week of cycle 4 was significantly higher than during baseline (C1W−1) (p value range, 0.0005–0.045) and significantly higher than each week of cycle 1 (p value range, 0.0005–0.045) (see Fig. 1).

Mean total fatigue (MFSI-SF) by week of cycle 1 and cycle 4. Total fatigue was significant higher during cycle 4 compared with cycle 1 (p=0.0005)

There were no significant differences in fatigue between women with different stages of cancer or between those with different chemotherapy regimens in any of the analyses.

Discussion.

The results of this study suggested that increased fatigue was associated with decreased intensity and duration of bright light exposure. We found significant correlations between fatigue and light exposure during the chemotherapy administration weeks of both cycles, as well as during week 3 of cycle 4. We also explored the relationship between the changes in fatigue levels and changes in light exposure from one week to the next and found significant correlations in both cycles from the pretreatment period to week 1, as well as from week 1 to week 2, suggesting that as the amount of light exposure increased, the amount of fatigue decreased. By week 3 of each cycle, both light and fatigue were stable. This association between fatigue and light exposure may suggest an existence of a negative feedback loop, with side effects of chemotherapy causing more severe fatigue, more severe fatigue causing less outdoor activity, less time spent outdoors causing lower bright light exposure, and lower light exposure then further exacerbating the fatigue. On the contrary, increased light exposure may break this negative feedback loop and mitigate the fatigue. These results need to be replicated and the casual relationship between light and fatigue needs to be examined more thoroughly. However, the results are sufficiently suggestive to warrant clinical trials of light treatment to test this hypothesis.

The results of this study also suggested that fatigue was stable within the cycles, but was significantly higher than before the start of treatment. In addition, fatigue not only persisted but was exacerbated by the fourth cycle of chemotherapy. The pattern of fatigue getting worse during and after chemotherapy confirms reports of other studies [8, 26]. However, the current data show a different pattern of fatigue during the second week of each cycle than previously reported. The so-called “roller-coaster” pattern, with significantly lower fatigue at the midpoint of each cycle, reported by Berger [26] and by Schwartz [27], was not confirmed in this study. Instead, we found that fatigue essentially remained at the same level within cycle 1 and within cycle 4, but got worse from cycle 1 to cycle 4. To our knowledge, this is the first study to report systematically recorded fatigue during cycle 4 of chemotherapy in patients with breast cancer, and to report increased fatigue during the fourth cycle relative to the first cycle. One question that could arise is whether the amount of fatigue reported by the women in this study differed from reports in other studies. Although there are no data reported in the literature during cycle 4, the fatigue levels reported during cycle 1 by the women in this study did not differ from those reported by cancer patients used in the validation report of the MFSI-SF [21]. The different pattern of fatigue found in this study may therefore be a result of the longer period studied and the more extensive definition of fatigue employed. Our results may also be specific to anthracycline-based chemotherapy, as different types of chemotherapy were used in the studies by Berger [36% with cyclophosphamide, methotrexate, and fluorouracil (CMF); 28% with doxorubicin and cyclophosphamide (A/C); 39% with cyclophosphamide, doxorubucin, and fluorouracil (CAF)] [26] and Schwartz [70% with doxorubicin and cyclophosphamide (A/C), 23% with cyclophosphamide, methotrexate, and fluorouracil (CMF), and 3% with vinorelbine] [27].

This brings up the question of whether the type of chemotherapy or the stage of disease might influence the amount of fatigue. In our study, the women were at different stages of severity and received different chemotherapies. However, there were no significant differences in reports of fatigue when analyzed by stage of disease or by type of chemotherapy.

Although the cause and effect of exacerbated fatigue and decreased light exposure cannot be confirmed by the current study, and lower light exposure may just in part be due to the fatigued patients spending less time outdoors in bright light, two hypotheses can be proposed about the mechanisms by which light may alleviate the fatigue of patients with breast cancer.

The first hypothesis is that light may improve fatigue via the entrainment of circadian rhythms. Examples of circadian rhythms, i.e., 24-h rhythms, include changes or alternations of hormone secretion, body temperature, and sleep–wake cycles. The circadian rhythm in humans is approximately 24 h and is regulated by neural (e.g., superchiasmatic nuclei, SCN) and hormonal (e.g., melatonin) processes. The synchronization of this rhythm with the solar day and night is maintained mainly through entrainment by light [28]. Data suggest that fatigue among patients with breast cancer may be related to disrupted circadian rhythms [29, 30]. Studies have shown that light therapy is effective in the treatment of circadian-rhythm related disorders (e.g., seasonal affective disorder, delayed or advanced sleep phase syndrome, jet lag syndrome, and shift work syndrome) and in consolidating sleep and improving the strength of circadian rhythms [31, 32].

A second hypothesis by which light may alleviate breast cancer fatigue is by improving mood. Treatment of seasonal affect disorder (SAD) with bright light improves symptoms of depression [33]. Fatigue is an independent symptom of SAD that differs from depression [34], but that also diminishes when SAD is alleviated. In this study, Emotional fatigue, which was already worse in cancer than noncancer subjects before the start of treatment (S. Ancoli-Israel et al., unpublished data), remained consistent within both cycles and was even worse during cycle 4 than cycle 1, suggesting that the affective dimension of fatigue may play an important role in chronic cancer-related fatigue. Increasing light exposure might alleviate the mood and consequently the fatigue.

There were some limitations to this study. Although data were rarely collected on a weekend since data collection always began on the same day of the week as chemotherapy, some of the women worked outside the home and some did not, which may have effected how much time they were able to spend outdoors in bright light. In addition, only limited information was available on how much these women exercised and whether they exercised outdoors. Future studies may wish to control for occupations and exercise levels.

In summary, our results showed that in patients with breast cancer, increased fatigue was associated with decreased light exposure during the first 2 weeks of the first and fourth cycles of chemotherapy. Although the cause and effect of fatigue and light exposure have not yet been confirmed, increased bright light exposure has been shown to improve sleep and mood in other populations and may therefore decrease fatigue among patients with breast cancer. These results suggest that prospective studies to evaluate the usefulness of light therapy in mitigating fatigue in patients with breast cancer might be warranted.

 

ianursing, I'm glad you are interested in it.. I truly hope it helps you and other member here on NL..Teresa