***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background The brain is a critical target organ for thyroid hormone , but it is unclear whether variations in thyroid function within and near the reference range affect quality of life , mood , or cognition . Methods A total of 138 subjects with levothyroxine (L-T4)-treated hypothyroidism and normal thyrotropin ( TSH ) levels underwent measures of quality of life ( 36-Item Short Form Health Survey , Underactive Thyroid-Dependent Quality of Life Question naire ) , mood ( Profile of Mood States , Affective Lability Scale ) , and cognition ( executive function , memory ) . They were then r and omly assigned to receive an unchanged , higher , or lower L-T4 dose in double-blind fashion , targeting one of three TSH ranges ( 0.34 to 2.50 , 2.51 to 5.60 , or 5.61 to 12.0 mU/L ) . Doses were adjusted every 6 weeks based on TSH levels . Baseline measures were reassessed at 6 months . Results At the end of the study , by intention to treat , mean L-T4  doses were 1.50 ± 0.07 , 1.32 ± 0.07 , and 0.78 ± 0.08 μg/kg ( P < 0.001 ) , and mean TSH levels were 1.85 ± 0.25 , 3.93 ± 0.38 , and 9.49 ± 0.80 mU/L ( P < 0.001 ) , respectively , in the three arms . There were minor differences in a few outcomes between the three arms , which were no longer significant after correction for multiple comparisons . Subjects could not ascertain how their  L-T4 doses had been adjusted ( P = 0.55 ) but preferred L-T4 doses they perceived to be higher ( P < 0.001 ) . Conclusions Altering L-T4 doses in hypothyroid subjects to vary TSH levels in and near the reference range does not affect quality of life , mood , or cognition .  L-T4-treated subjects prefer perceived higher L-T4 doses despite a lack of objective benefit . Adjusting L-T4 doses in hypothyroid patients based on symptoms in these areas may not result in significant clinical improvement PURPOSE The effect of and rogen deprivation therapy ( ADT ) on cognitive performance ( CP ) in prostate cancer ( PCa ) patients is not well understood . We evaluated changes in CP after 6 months of medical castration with luteinizing hormone-releasing hormone ( LHRH ) analogues . METHODS AND MATERIAL S We performed a prospect i ve , observational , multicenter , open-label study of PCa patients scheduled to receive LHRH analogues for ≥6 months . We assessed 4 domains of CP at baseline and after 6 months of ADT : ( 1 ) working memory , assessed with the Wechsler Adult Intelligence Scale III ( WAIS III ) Digit Span subtest ; ( 2 ) visual memory , assessed with an ad hoc visual memory test ; ( 3 ) visuospatial ability , assessed with the Judgment of Line Orientation test and Mental Rotation of Three-Dimensional Objects test ; and ( 4 ) nonverbal analytical reasoning , assessed with the WAIS III Matrix Reasoning test . Changes outside the baseline 95 % confidence intervals were considered significant . RESULTS A total of 308 patients completed the study . Of these , 245 ( 79.6 % ) experienced no statistically significant changes on any test whereas 63 ( 20.4 % ) experienced significant changes on ≥1 test . Most of these patients showed a change on only 1 test , distributed evenly between improvement ( 58 patients , 18.8 % ) and worsening ( 56 patients , 18.2 % ) . For individual tests , most patients ( 87.8%-91.8 % ) had no change from baseline ; however , the significant changes ( improvement vs deterioration ) were as follows : WAIS III Digit Span subtest ( 6.3 % vs 5.9 % ) , visual memory ( 5.3 % vs 5.7 % ) , Judgment of Line Orientation test ( 5.3 % vs 4.5 % ) , Mental Rotation of Three-Dimensional Objects test ( 4.1 % vs 4.1 % ) , and WAIS III Matrix Reasoning test ( 4.8 % vs 5.8 % ) . CONCLUSIONS CP in patients with PCa does not appear to be adversely affected by 6 months of LHRH analogue administration Importance Neurocognitive deficits ( NCD ) have been observed in non central nervous system cancers , yet short- and long-term neurocognitive data on patients treated for head and neck cancer ( HNC ) are lacking . Objective To assess objective neurocognitive function before and after definitive radiation therapy for HNC . Design , Setting , and Participants In a prospect i ve , longitudinal study , neurocognitive function and self-reported symptoms were assessed in 80 patients with histologically proven HNC requiring definitive chemoradiotherapy or radiotherapy and in 40 healthy controls 4 times ( baseline , 6 , 12 , and 24 months after baseline ) prior to commencing treatment at Princess Margaret Cancer Centre , Toronto , Canada . Main Outcomes and Measures Neurocognitive test scores were converted to age-corrected z scores ( mean , 0 ; st and ard deviation , 1 ) and reported as mean scores , st and ardized regression-based scores , and frequencies of impairments in intellectual capacity , concentration , memory , executive function , processing speed , and motor dexterity . Multivariable analysis was used to identify factors associated with NCD 2 years after treatment . Results Eighty patients and 40 healthy controls enrolled . Analyses revealed significant differences between patient and control mean performance in some domains , with patient deficits increasing over time : intellectual capacity ( Cohen d , effect sizes [ 95 % CIs ] of −0.46 [ −0.64 to 0.30 ] , −0.51 [ −0.72 to −0.30 ] , and −0.70 [ −0.92 to −0.49 ] for time points 6 , 12 , and 24 months , respectively ) ; concentration/short-term attention span ( −0.19 [ −0.37 to 0.00 ] , −0.38 [ −0.55 to −0.21 ] , −0.54 [ −0.71 to −0.37 ] ) ; verbal memory ( −0.16 [ −0.33 to 0.02 ] , −0.38 [ −0.64 to −0.12 ] , −0.53 [ −0.74 to −0.32 ] ) ; executive function ( −0.14 [ −0.27 to 0.00 ] , −0.34 [ −0.52 to −0.16 ] , −0.43 [ −0.64 to −0.22 ] ) , and global cognitive function composite ( −0.38 [ −0.55 to −0.22 ] , −0.75 [ −0.92 to −0.58 ] , −1.06 [ −1.26 to −0.86 ] ) . There was an increased rate of impaired global neurocognitive functioning among patients ( 38 % ) at 24 months compared with controls ( 0 % ) . Neurocognitive deficits were not associated with baseline cytokines . Conclusions and Relevance Head and neck cancer survivors have neurocognitive sequelae up to 2 years after definitive chemoradiotherapy or radiation treatment . Patients and health care teams should know about such potential risks . Further research is warranted in search of strategies to avoid , reduce , and compensate for declines BACKGROUND The purpose of this study was to enhance the current underst and ing and interpretation of longitudinal change on tests of neurocognitive function in individuals with cancer . Scores on st and ard neuropsychological instruments may be impacted by practice effects and other r and om forms of error . METHODS The current study assessed the test-retest reliability of several tests and overarching cognitive domains comprising a neurocognitive battery typical of those used for research and clinical evaluation using relevant time frames . Practice effect-adjusted reliable change confidence intervals for test-retest difference scores based on a sample of patient-matched healthy controls are provided . RESULTS By applying reliable change confidence intervals to scores from two sample s of breast cancer patients at post-treatment follow-up assessment , meaningful levels of detectable change in cognitive functioning in breast cancer survivors were ascertained and indicate that st and ardized neuropsychological instruments may be subject to limitations in detection of subtle cognitive dysfunction over clinical ly relevant intervals , especially in patient sample s with average to above average range baseline functioning . CONCLUSIONS These results are discussed in relation to reported prevalence of cognitive change in breast cancer patients along with recommendations for study design s that enhance detection of treatment effects After total thyroidectomy all thyroid cancer patients require lifelong treatment with thyroid hormones ; the treatment of choice is synthetic levothyroxine ( LT4 ) . The question of whether these patients might benefit from the combined LT4 and liothyronine ( LT3 ) treatment has been addressed with conflicting conclusions . The aim of the present study was to compare the effects of combined low LT4/LT3 molar ratio therapy versus LT4 monotherapy on various target organs and tissues in patients thyroidectomized for thyroid cancer . Urine collection ( 24 hour ) , a fasting blood sample for laboratory examinations , thyroid function clinical score , and cardiovascular , neurological , and neuropsychological evaluations were obtained . Clinical parameters and peripheral markers of thyroid function were measured during the two different treatment regimens in 20 patients .  Mean serum aspartate aminotransferase , alanine aminotransferase , sex hormone binding globulin , and osteocalcin values were significantly higher during the combined treatment . No significant differences in the clinical score , the systolic and diastolic performance , and the neurological and neuropsychological evaluations were observed between the two treatment regimens . Moreover , no alteration due to sub clinical hyperthyroidism or to the fluctuations in serum T3 concentrations during the combined therapy was observed . In conclusion , we found no evidence that combined therapy with a low LT4/LT3 molar ratio result ed in improved well-being and cognitive function or in increased thyroid hormone action on peripheral tissues in respect to LT4 monotherapy . Until future large , blind , r and omized , and controlled trials prove otherwise , LT4 should remain the st and ard treatment for thyroid cancer patients Importance A growing body of evidence supports a link between and rogen deprivation therapy ( ADT ) and cognitive dysfunction , including Alzheimer disease . However , it is currently unknown whether ADT may contribute to the risk of dementia more broadly . Objective To use an informatics approach to examine the association of ADT as a treatment for prostate cancer with the subsequent development of dementia ( eg , senile dementia , vascular dementia , frontotemporal dementia , and Alzheimer dementia ) . Design , Setting , and Participants In this cohort study , a text-processing method was used to analyze electronic medical record data from an academic medical center from 1994 to 2013 , with a median follow-up of 3.4 years ( interquartile range , 1.0 - 7.2 years ) . We identified 9455 individuals with prostate cancer who were 18 years or older at diagnosis with data recorded in the electronic health record and follow-up after diagnosis . We excluded 183 patients with a previous diagnosis of dementia . Our final cohort comprised 9272 individuals with prostate cancer , including 1826 men ( 19.7 % ) who received ADT . Main Outcomes and Measures We tested the effect of ADT on the risk of dementia using propensity score – matched Cox proportional hazards regression models and Kaplan-Meier survival analysis . Results Among 9272 men with prostate cancer ( mean [ SD ] age , 66.9 [ 10.9 ] years ; 5450 [ 58.8 % ] white ) , there was a statistically significant association between use of ADT and risk of dementia ( hazard ratio , 2.17 ; 95 % CI , 1.58 - 2.99 ; P < .001 ) . In sensitivity analyses , results were similar when excluding patients with Alzheimer disease ( hazard ratio , 2.32 ; 95 % CI , 1.73 - 3.12 ; P < .001 ) . The absolute increased risk of developing dementia among those who received ADT was 4.4 % at 5 years ( 7.9 % among those who received ADT vs 3.5 % in those who did not receive ADT ) . Analyses stratified by duration of ADT found that individuals with at least 12 months of ADT use had the greatest absolute increased risk of dementia ( hazard ratio , 2.36 ; 95 % CI , 1.64 - 3.38 ; P < .001 ) . Kaplan-Meier analysis demonstrated that ADT users 70 years or older had the lowest cumulative probability of remaining dementia free ( log-rank P < .001 ) . Conclusions and Relevance And rogen deprivation therapy in the treatment of prostate cancer may be associated with an increased risk of dementia . This finding should be further evaluated in prospect i ve studies CONTEXT TSH-suppressive doses of levothyroxine ( L-T4 ) have adverse effects on bone and cardiac function , but it is unclear whether central nervous system function is also affected . OBJECTIVE The aim of the study was to determine whether women receiving TSH-suppressive L-T4 doses have decrements in health status , mood , or cognitive function . DESIGN AND SETTING A cross-sectional comparison was made among three groups of women in an academic medical center research clinic . PATI 
    Output:
    
Conclusions Cognitive function was worse in TC survivors in multiple domains .