Sleep and endocrine therapy in breast cancer

Sleep oscillations related to memory consolidation during aromatases inhibitors for breast cancer

Aromatase inhibitors (AIs) are associated with sleep difficulties in breast cancer (BC) patients. Sleep is known to favor memory consolidation through the occurrence of specific oscillations, i.e., slow waves (SW) and sleep spindles, allowing a dialogue between prefrontal cortex and the hippocampus. Interestingly, neuroimaging studies in BC patients have consistently shown structural and functional modifications in these two brain regions. With the aim to evaluate sleep oscillations related to memory consolidation during AIs, we collected polysomnography data in BC patients treated (AI+, n = 17) or not (AI-, n = 17) with AIs compared to healthy controls (HC, n = 21). None of the patients had received chemotherapy and radiotherapy was finished since at least 6 months, that limit the confounding effects of other treatments than AIs. Fast and slow spindles were detected during sleep stage 2 at centro-parietal and frontal electrodes respectively. SW were detected at frontal electrodes during stage 3. Here, we show lower frontal SW densities in AI + patients compared to HC. These results concord with previous reports about frontal cortical alterations in cancer following AIs administration. Moreover, AI + patients tended to have lower spindle density at C4 electrode. Regression analyses showed that, in both patient groups, spindle density at C4 electrode explained a large variance of memory performances. Slow spindle characteristics did not differ between groups and sleep oscillations characteristics of AI- patients did not differ significantly from those of both AI + patients and HC. Overall, our results add to the compelling evidence of the systemic effects of AIs previously reported in animals, with deleterious effects on cortical activity during sleep and associated memory consolidation in the current study. There is thus a need to further investigate sleep modifications during AIs administration. Longitudinal studies are needed to confirm these findings and investigation in other cancers on this topic should be conducted.

Comparing the sensitivity of fatigue and sleep disturbance assessment tools in women with advanced cancer undergoing chemotherapy

Objective

This study aims to investigate the variations in fatigue and sleep disturbances among female patients with advanced lung cancer (ALC) and advanced breast cancer (ABC) during chemotherapy.

Methods

A total of 36 female patients with ALC and 36 with ABC, all of whom had completed their first cycle of chemotherapy, were included. Fatigue was assessed using the General Fatigue Scale (GFS), and sleep disturbances were evaluated using the Pittsburgh Sleep Quality Index (PSQI) at designated time points throughout the chemotherapy process.

Results

Linear regression analysis indicated that variables such as age, education level, employment status, cancer type, clinical stage, and symptom distress had no significant correlation with either fatigue or sleep disturbances. The GFS significantly discriminated fatigue among the ALC, ABC, and combined groups, while the PSQI demonstrated a significant distinction in sleep disturbance only within the ALC and combined groups.

Conclusions

In summary, when considering the findings of both assessments in this study, the GFS score exhibited greater sensitivity in detecting fatigue than the PSQI score did for identifying sleep disturbances in advanced cancer patients undergoing chemotherapy.

Prolonged endocrine therapy in the management of hormone receptor-positive early-stage breast cancer: What is the appropriate duration?

AIM

The clinical benefits associated with 5 years of endocrine therapy in the treatment of hormone receptor-positive, early-stage breast cancer (ESBC) have been well-substantiated. However, numerous studies have reported on the results of extended (i.e., >5 years) endocrine therapy to further effectuate a clinical benefit, with varying outcomes. Hence, the purpose of this study is to review these prolonged investigations and endeavor to clarify their corresponding treatment implications.

METHODS

We reviewed the study findings from several randomized controlled trials and meta-analyses, which incorporated clinical outcomes from pre-and postmenopausal, hormone receptor-positive, ESBC patients.

RESULTS

Hormone receptor-positive, ESBC patients treated with 5 years of endocrine therapy, who are node-negative with tumors <2 cm, will unlikely benefit from five additional years of treatment. Conversely, in women with larger tumors and node-positive disease, 7-8 total years of endocrine therapy may be indicated. Ultimately, clinicians should also consider the attendant side effects from endocrine therapy, namely bone fractures, namely cardiovascular symptoms, and vasomotor symptoms, when considering the appropriate treatment regimen.

CONCLUSIONS

While increased duration of endocrine therapy may selectively accord significant clinical benefits, prior to determining the patient's treatment interval, physicians should also assess the cumulative side effects from endocrine therapy when endeavoring to maintain treatment compliance and bolster quality of life.

Longitudinal Changes in Circulating Metabolites and Lipoproteins After Breast Cancer Treatment

The multimodal treatment of breast cancer may induce long term effects on the metabolic profile and increase the risk of future cardiovascular disease. In this study, we characterized longitudinal changes in serum lipoprotein subfractions and metabolites after breast cancer treatment, aiming to determine the long-term effect of different treatment modalities. Further, we investigated the prognostic value of treatment-induced changes in breast cancer-specific and overall 10-year survival. In this study, serum samples from breast cancer patients (n = 250) were collected repeatedly before and after radiotherapy, and serum metabolites and lipoprotein subfractions were quantified by NMR spectroscopy. Longitudinal changes were assessed by univariate and multivariate data analysis methods applicable for repeated measures. Distinct changes were detectable in levels of lipoprotein subfractions and circulating metabolites during the first year, with similar changes despite large differences in treatment regimens. We detect increased free cholesterol and decreased esterified cholesterol levels of HDL subfractions, a switch towards larger LDL particles and higher total LDL-cholesterol, in addition to a switch in the glutamine-glutamate ratio. Non-survivors had different lipid profiles from survivors already at baseline. To conclude, our results show development towards an atherogenic lipid profile in breast cancer patients with different treatment regimens.

Rest activity rhythms characteristics of breast cancer women following endocrine therapy

Rest-activity rhythm (RAR) disruptions are frequently associated with chemotherapy in breast cancer (BC), but they are less known in BC with endocrine therapy. The aim of this ancillary study was to characterize the RAR and estimated sleep characteristics from actigraphy in BC patients either treated (ET+) or untreated with endocrine therapy (ET-), compared to healthy controls (HC) and using a cross-sectional design. Eighteen ET+, 18 ET- and 16 HC completed questionnaires and wore wrist actigraphs at home for 2 weeks. Parametric and non-parametric RAR, sleep parameters, and quality of life were compared between groups (p<0.05). BC groups presented lower daytime activity than HC according to RAR analysis (mesor and M10 parameters). Compared to HC, ET- had lower inter-daily stability and ET+ had greater sleep complaints. Compared to ET-, ET+ had lower sleep efficiency, more time awake and higher activity levels at night, as assessed with actigraphy. Our results suggest an effect of cancer independent of treatment on RAR in BC, highlighting the need for further investigation of this topic. In contrast, sleep as assessed with actigraphy seems modified only during ET which matches with patients' sleep complaints. Further longitudinal studies would aid in confirming the latter hypothesis.