Selected-Lesion Stereotactic Radiosurgery in Treatment of Patients with Multiple Brain Metastases: A Single Institution Retrospective Study

PURPOSE/OBJECTIVE(S)

Stereotactic Radiosurgery (SRS) has been increasingly used as first and subsequent-line treatments for brain metastases. While the appropriate cut-off number of lesions for SRS is still being debated nationally in patients with multiple brain metastases, some institutions use an alternate approach particularly for patients with >10-15 lesions. Selected-lesion SRS (SL-SRS) is where only a subset of lesions are chosen for initial SRS treatment leaving small and clinically inconsequential lesions for treatment using alternate or delayed treatments. This study aims to investigate the patient selection criteria, patient and tumor characteristics and analyze the outcomes in patients receiving SL-SRS for brain metastases at our institution.

MATERIALS/METHODS

Clinical data from patients treated using the SL-SRS approach from 2012-2022 at our institution were retrospectively reviewed. Patients were divided into cohorts based on overall survival from time of SL-SRS treatment and indications for using SL-SRS. We compared the patient characteristics (age, histology, KPS, dsGPA), tumor characteristics (cumulative tumor volumes, tumor dose, number of brain metastases found, number of metastases treated), treatment characteristics (chemotherapy, immunotherapy, previous SRS/ radiation, previous WBRT) and the reason for decision to recommend SL-SRS across these cohort.

RESULTS

A total of 102 patients were treated using the SL-SRS approach. Indications for using SL-SRS were immunotherapy trial (n = 40), CNS penetrating drug options available (n = 18), patient refusing WBRT (n = 6), palliative after prior WBRT/SRS (n = 28), WBRT planned to follow SRS (n = 9). 31 patients were alive at 12 months and 21 patients at 24 months. In patients surviving <12 months - the most common indications for SL-SRS were CNS palliation in the setting of progressive disease after prior WBRT or SRS. Patients in this group had median KPS< = 60 and had predominantly non-small cell carcinoma primary diagnosis. In those patients surviving >12 months - the most common indication for SL-SRS was participation in CNS-penetrant agent clinical trials without WBRT. Patients in this group were more likely to be female, had a median KPS of 90, had predominantly diagnoses of melanoma. Following the SL-SRS treatment, 14 patients required further SRS and 4 patients went on to WBRT in the >12-month survival group. No patients died of CNS progression alone. 10 patients survived 24 months without requiring further CNS radiation.

CONCLUSION

In our institution, SL-SRS has predominantly been used either as palliative treatment at time of disease progression or to facilitate entry onto clinical trial with immunotherapy or potentially CNS-penetrant agents. The latter indication resulted in 47.6% patients surviving >24 month without the need for additional radiation to the CNS and therefore SL-SRS should be considered a feasible, safe and effective alternative to either WBRT or SRS treatment of all radiographically visible brain metastases.

0105 Working Memory Impairment Due to Chronic Sleep Restriction, Dose Response to Recovery and Re-Exposure

Introduction

Chronic sleep restriction negatively effects working memory. Recovery sleep following sleep restriction partially restores working memory performance. This study examines the impact of chronic sleep restriction and subsequent recovery sleep dose on the N-Back Task (N-Back), a valid measure of working memory.

Methods

N=223 participants (29.9±6.9 years; 48.4% female), completed two baseline nights of 8h time in bed (TIB), followed by five nights of 4h TIB, and were then randomized to a sleep dose of 0, 2, 4, 6, 8, 10, or 12 h TIB. A subset of participants (n=73) were re-exposed to another five nights of 4h TIB. Participants completed the three versions of the N-Back (i.e. 1-Back, 2-Back, and B-back) every two hours during wakefulness and daily averages were computed. Mixed effects and linear regression models were used to assess the impact of sleep restriction and the sleep dose response on percent correct on the N-Back corrected for baseline.

Results

N=219 participants had valid working memory data. The 2-Back (β =-4.5%; P&lt;0.0001) and the 3-Back (β =-12.5%; P&lt;0.0001) were more difficult than the 1-Back. Working memory performance declined across days of sleep restriction for all N-Backs: 1-Back (β =-1.10%; P&lt;0.0001), 2-Back (β =-0.99%; P&lt;0.0001), and 3-Back (β =-1.10%; P&lt;0.0001). The sleep dose analysis revealed a positive association with N-Back performance for all N-Back versions, 1-Back (β =0.99%; P=0.0002), 2-Back (β =1.46%; P&lt;0.0001), and 3-Back (β =1.43%; P&lt;0.0001). Re-exposure to only one night of 4h TIB following recovery sleep resulted in performance decrements equal to performance prior to recovery sleep for all N-Back versions (Ps&gt;0.41).

Conclusion

These data indicate that working memory is adversely impacted by sleep restriction, and that sufficient recovery sleep, possibly across consecutive days, is necessary to maintain optimal working memory performance.

Support

Funded by National Institute of Health NIH R01NR004281 and National Space and Biomedical Research Institute NSRBI NCC 5–98

0291 Recovery Sleep Alleviates Mood Disturbance Following Chronic Sleep Restriction, Albeit Transiently and in a Dose-Dependent Manner

Introduction

Fatigue is one contributor to mood disturbance observed following sleep restriction; however, the contribution of other factors remains unclear. This study examined contributions to mood disturbance resulting from sleep restriction beyond that of fatigue, evaluated the benefit of recovery sleep, and assessed whether recovery sleep buffered the re-emergence of mood disturbance upon re-exposure to sleep restriction.

Methods

N=223 healthy participants (48% female; n=108) approximately 30-years-old (SD=6.89, range=22–45 years) completed two baseline nights of 8h time in bed (TIB), followed by five nights of 4h TIB, and were then then randomized to one of 7 sleep recovery opportunities (i.e., 0, 2, 4, 6, 8, 10, or 12 hours TIB). Following the sleep period, a subset of participants (n=72) were re-exposed to five consecutive nights of 4h TIB. The profile of mood states (POMS) was completed every 2h during wakefulness and daily averages were calculated. The POMS total mood disturbance (TMD) score without the fatigue subscale (i.e., mood disturbance = TMD - fatigue) was the primary outcome to isolate changes in mood disturbance beyond fatigue. Individual growth curve models were applied to the trajectory of mood disturbance. General linear models were used to evaluate the dose-response function of mood disturbance after recovery sleep.

Results

Mood disturbance (absent the POMS fatigue scale) increased with each day of sleep restriction (β=1.550 per day; P&lt;0.0001), and decreased with longer recovery sleep durations in a dose-dependent manner (β=-1.614 for every 2h increase; P&lt;0.0001). The benefits of recovery sleep were abated by the second night of 4h sleep during re-exposure, where mood disturbance was slightly higher than that observed before recovery, but this difference was not statistically significant (β=0.046; P=0.85).

Conclusion

The study findings suggest that fatigue is not the only contributor to mood disturbance following sleep restriction. Recovery sleep attenuates mood disturbance in a dose-dependent manner, albeit transiently. Candidate pathways linking sleep restriction and mood include the immune system and the dynamics of sleep physiology.

Support

This work was funded by National Institute of Health NIH R01NR004281 and National Space and Biomedical Research Institute NSRBI NCC 5–98.

0292 Baseline Pro-Inflammatory Cytokine and Cortisol Levels Differentially Predict Mood Disturbance and Working Memory Deficits Induced by Chronic Sleep Restriction

Introduction

Sleep restriction disturbs mood, impairs neurocognitive performance, and elevates proinflammatory cytokine levels. However, whether basal inflammation influences mood and neurocognitive performance across sleep restriction is unknown. This study examines whether baseline IL-6, cortisol, and TNF-α levels predict the deterioration of mood and working memory performance across sleep restriction.

Methods

N=124 healthy participants (52% female; n=64), 22–45 years of age, had valid protein, mood, and working memory data. The study included two baseline nights (8h time in bed [TIB]) followed by five nights of 4h TIB. Venous blood was collected on the second baseline day and IL-6, cortisol, and TNF-α levels were measured via commercially available ELISA assays. The profile of mood states (POMS) and the digit span test (DST) were completed every 2h during wakefulness and daily averages were computed. Mixed-effects multi-level models, adjusted for baseline, evaluated the main effect of IL-6, cortisol, and TNF-α levels on the POMS and DST independently and examined the trajectory of POMS and DST by the interaction of protein levels and day of sleep restriction.

Results

At baseline, IL-6, cortisol, and TNF-α levels were not associated with POMS or DST. There was a main effect of IL-6, but not cortisol or TNF-α, levels on mood disturbance (β=3.811; P=0.015); IL-6 levels did not predict the trajectory of mood across sleep restriction (β=0.187; P=0.57). Higher baseline cortisol levels predicted increasing mood disturbance across days (β=-1.329; P&lt;0.0001). Higher baseline TNF-α levels predicted degrading DST performance across days (β=-0.313; P=0.020). Higher IL-6 (β=-0.246; P=0.010) and lower cortisol (β=0.185; P=0.037) levels also predicted degrading DST performance across days.

Conclusion

The study findings suggest that basal inflammatory cytokine and cortisol levels are implicated in the individual risk of mood disturbance and working memory deficits resulting from chronic sleep restriction and highlight the need to consider biological processes and phenotypes together.

Support

This work was supported by National Institute of Health NIH R01NR004281 and National Space and Biomedical Research Institute NSRBI NCC 5–98.

Proteomic analysis of differently archived breast cancer tissues

Currently, the most common practice of human breast tissue preservation is formalin fixation which ensures good quality for histopathological analyses but damages DNA, RNA, and proteins, impairing their usefulness for molecular analysis and biomarker investigations. We investigated the potential value of a non-toxic fixative for sparing proteins preserved in paraffin-embedded breast biopsies. Specimens were fixed in formalin-free fixative prior to paraffin embedding, and then processed for quality and quantity of protein conservation. Similar protein patterns were observed in formalin-free fixative and frozen tissues using mono- and bi-dimensional electrophoresis, as well as western blotting. Protein patterns assessed by mass spectrometric analysis were found to be identical for frozen and formalin-free-fixed tissues. Immunohistochemistry using various antibodies showed comparable results for both tissue storage methods. In conclusion, we believe that formalin-free fixative represents an easy-to-use alternative to formalin for archived tissue and for biomarker investigations, since it simultaneously protects both the histomorphology and the integrity of macromolecules.

Autoantibody signatures: progress and perspectives for early cancer detection

Becoming invasive is a crucial step in cancer development, and the early spread of tumour cells is usually undetected by current imaging technologies. In patients with cancer and no signs of overt metastases, sensitive methods have been developed to identify circulating autoantibodies and their antigen counterparts in several cancers. These technologies are often based on proteomic approaches, and recent advances in protein and antibody microarrays have greatly facilitated the discovery of new antibody biomarkers in sera from cancer patients. Interestingly, in a clinical application setting, combinations of multiple autoantibody reactivities into panel assays have recently been proposed as relevant screening tests and validated in several independent trials. In addition, autoantibody signatures seem to be particularly relevant for early detection of cancer in high-risk cancer patients. In this review, we highlight the concept that immunogenic epitopes associated with the humoural response and key pathogenic pathways elicit serum autoantibodies that can be considered as relevant cancer biomarkers. We outline the proteomic strategies employed to identify and validate their use in clinical practice for cancer screening and diagnosis. We particularly emphasize the clinical utility of autoantibody signatures in several cancers. Finally, we discuss the challenges remaining for clinical validation.

A naturally occurring sequence variation that creates a YY1 element is associated with increased cystic fibrosis transmembrane conductance regulator gene expression

We have identified previously a novel complex mutant allele in the cystic fibrosis transmembrane conductance regulator (CFTR) gene in a patient affected with cystic fibrosis (CF). This allele contained a mutation in CFTR exon 11 known to cause CF (S549R(T>G)), associated with the first alteration described so far in the minimal CFTR promoter region (-102T>A). Studies on genotype-phenotype correlations revealed striking differences between patients carrying mutation (S549R(T>G)) alone, who had a severe disease, and patients carrying the complex allele (-102(T>A)+S549R(T>G)), who exhibited milder forms of CF. We thus postulated that the sequence change (-102T>A) may attenuate the effects of the severe (S549R(T>G)) mutation through regulation of CFTR expression. Analysis of transiently transfected cell lines with wild-type and -102A variant human CFTR-directed luciferase reporter genes demonstrates that constructs containing the -102A variant (which creates a Yin Yang 1 (YY1) core element) increases CFTR expression significantly. Electrophoretic mobility shift assays indicate that the -102 site is located in a region of multiple DNA-protein interactions and that the -102A allele recruits specifically an additional nuclear protein related to YY1. The finding that the YY1-binding allele causes a significant increase in CFTR expression in vitro may allow a better understanding of the milder phenotype observed in patients who carry a severe CF mutation within the same gene.