Comparison of surgical strategies in the treatment of low-risk differentiated thyroid cancer

CONTEXT

Increasing diagnostic sensitivity in the detection of thyroid cancer has led to uncertainties in the optimal surgical approach of the smaller, low risk tumors. Current ATA guidelines consider lobectomy safe between 1 and 4 cm, while ETA advocates for primary total thyroidectomy to avoid reoperation, as final risk stratification is based on the histological results.

OBJECTIVE

Our aim was to compare the differences in outcomes that are potentially achievable with adherence to the different guidelines, and also to examine the predictive value of clinical parameters on the incidence of postoperative risk factors.

METHODS

We performed a retrospective cohort database analysis to identify the different surgical outcomes (based on postoperative risk factors) using ATA and ETA guidelines; the hypothetical rate of completion thyroidectomy when ATA or ETA recommends lobectomy; the accuracy of our preoperative evaluation; the utility of preoperative findings in predicting the optimal surgical strategy using binary logistic regression.

RESULTS

Out of 248 patients, 152 (ATA) and 23 (ETA) cases would have been recommended for initial lobectomy. Following the guidelines, a postoperative risk factor would have been present in 61.8, and 65.2% of the cases, respectively. Except for angioinvasion, tumor size was not a significant predictor for the presence of postoperative risk factors.

CONCLUSION

Current pre-operative criteria are inadequate to accurately determine the extent of initial surgery and our postoperative findings verify the frequent need for completion thyroidectomy using both guidelines. As a consequence, in the absence of effective pre-operative set of criteria, we advocate primary total thyroidectomy in most cases.

Genetic variants of VDR and CYP2R1 affect BMI independently of serum vitamin D concentrations

BACKGROUND

Vitamin D metabolism and obesity have been linked by several studies, however the reason for this association is unclear. Our objective was to investigate potential correlations between genetic variants in key enzymes of vitamin D metabolism and the body mass index on a representative and random sample of Hungarian adults.

METHODS

Altogether 462 severely vitamin D deficient individuals were studied at the end of winter in order to decrease environmental and maximize any relevant genetic effect. Furthermore, participants with lifestyle factors known to affect vitamin D homeostasis were also excluded. We selected 23 target SNPs in five genes that encode key proteins of vitamin D metabolism (NADSYN1, GC, CYP24A1, CYP2R1, VDR).

RESULTS

Variants in 2 genetic polymorphisms; rs2853564 (VDR) and rs11023374 (CYP2R1) showed a significant association with participants' BMI. These associations survived further adjustment for total-, free-, or bioactive-25(OH) vitamin D levels, although the variance explained by these 2 SNPS in BMI heterogeneity was only 3.2%.

CONCLUSION

Our results show two novel examples of the relationship between genetics of vitamin D and BMI, highlighting the potential role of vitamin D hormone in the physiology of obesity.

Impact of genetic influence on serum total- and free 25-hydroxyvitamin-D in humans

Serum 25-hydroxyvitamin D /25OHD/ levels in humans are determined primarily by environmental factors such as UV-B radiation and diet, including vitamin D intake. Although some genetic determinants of 25OHD levels have been shown, the magnitude of this association has not yet been clarified. The present study evaluates the genetic contribution to total- /t-25OHD/ and free-25OHD /f-25OHD/ in a representative sample of the Hungarian population (n = 462). The study was performed at the end of winter to minimize the effect of sunlight, which is a major determinant of serum vitamin D levels. Single nucleotide polymorphisms (SNPs) of five genes playing major roles in vitamin D metabolism were investigated (NADSYN1, DHCR7, GC, CYP2R1 and CYP24A1). The selected SNPs account for 13.1% of the variance of t-25OHD levels. More than half of the genetic effect on t-25OHD levels was explained by two polymorphisms (rs7935125 in NADSYN1 and rs2762941 in CYP24A1), which had not previously been investigated with respect to vitamin D metabolism. No SNPs exhibited association with f-25OHD levels. Unexpectedly, SNPs that showed univariate associations with vitamin D binding protein (DBP) levels were not associated with f-25OHD levels questioning the biological significance of these polymorphisms. The present study shows that t-25OHD levels are significantly influenced by genetic factors, however, the clinical significance of this observation remains to be defined, as variation in f-25OHD levels are marginally explained by genetic effects.

[Novelties and experience with tyrosine kinase inhibitor therapy in chronic myeloid leukemia]

The introduction of tyrosine kinase inhibitor (TKI) treatment has resulted in dramatically improved survival in chronic myeloid leukemia (CML). With the new generation of TKIs the majority of patients reach optimal molecular response. Due to the improving survival and the need for lifelong treatment, the safety profile of the various TKIs and the comorbidities of patients have to be considered. More than half of our CML patients had comorbidities that could have influenced the choice of therapy. Because of the high prevalence of cardiovascular comorbidities, cardiovascular risk assessment plays an important role in the care of CML patients. The aim of this article is to summarize the current national and international guidelines of the treatment in CML and to show the importance of comorbidities and cardiovascular risk assessment in our CML patients.

The role of serum total and free 25-hydroxyvitamin D and PTH values in defining vitamin D status at the end of winter: a representative survey

We sought the lowest serum total 25-hydroxyvitamin D (t-25OHD) values in geographic areas with four seasons and investigated whether the calculation of serum free 25-hydroxyvitamin D (f-25OHD) could provide additional information on vitamin D status. This is a representative, cross-sectional study restricted to a sampling period at the end of winter, using a non-probability, stratified sample of the adult community-dwelling Hungarian population (n = 882). We measured t-25OHD, vitamin D binding protein (DBP), parathyroid hormone (PTH), and albumin levels. f-25OHD concentrations were calculated. We assessed environmental factors that could affect vitamin D levels and diseases possibly related to vitamin D deficiency. Mean t-25OHD values of the total population were 41.3 ± 20.6 nmol/L. t-25OHD levels were below 75, 50, and 30 nmol/L in 97, 77, and 34 % of participants not receiving vitamin D supplementation, respectively. t-25OHD values weakly positively correlated with DBP (r = 0.174; p = 0.000), strongly with f-25OHD (r = 0.70; p = 0.000). The association between t-25OHD and f-25OHD and between t-25OHD and PTH were non-linear (p _{squared term} = 0.0004 and 0.004, respectively). t-25OHD levels were not affected by gender, age, place of residence; however, they were related to body mass index, sunbed sessions, and tropical travel. In contrast, f-25OHD levels were different in males and females but were not related to obesity. t- and f-25OHD were lower among people with cardiovascular diseases (p = 0.012). Nearly the entire Hungarian population is vitamin D insufficient at the end of winter. The use of t-25OHD could show a spurious association with obesity; however, it does not reflect the obvious sex difference.

Rapid height growth after liver transplantation in adulthood

Glycogen storage disease Ib is a rare, inherited metabolic disorder caused by glucose-6-phosphatase translocase deficiency. Its main symptoms are hypoglycemia, hyperlipidemia, neutropenia, hepatomegaly, liver adenomas and short stature. The exact mechanism of short stature in this disease is unclear, the most feasible possibility is that it is caused by impairment of growth-hormone and insulin-like growth factor I axis. Here we report the case of a patient who showed typical symptoms of glycogen storage disease Ib since his infancy, his height being under 1 percentile since then. Later-developed hypothyroidism and hypogonadism have also contributed to his short stature. Hypothyroidism was treated but sexual steroid substitution was not started because of an increased risk of hepatic adenomas. Because he developed hepatic adenoma at the age of 23, he had to undergo orthotopic liver transplantation. At the time of the transplantation his height was 128cm. The transplantation was followed by rapid height growth; our patient's height reached 160.3cm 62months after transplantation. We observed that while his IGF-I level increased, his GH level remained unchanged. During the post-transplantation period we ensured adequate calcium and vitamin D supplementation, leaving hormonal substitution unchanged. According to our knowledge, this is the first report of a rapid height growth as big as 32cm, of an individual over the age of 20, not related to endocrine treatment but liver transplantation.

Strong effect of SNP rs4988300 of the LRP5 gene on bone phenotype of Caucasian postmenopausal women

The purpose of this study was to identify relationships between single nucleotide polymorphisms (SNPs) in the genes of the Wnt pathway and bone mineral density (BMD) of postmenopausal women. We chose this pathway due to its importance in bone metabolism that was underlined in several studies. DNA samples of 932 Hungarian postmenopausal women were studied. First, their BMD values at different sites (spine, total hip) were measured, using a Lunar Prodigy DXA scanner. Thereafter, T-score values and the patients' body mass indices (BMIs) were calculated, while information about the fracture history of the sample population was also collected. We genotyped nine SNPs of the following three genes: LRP5, GPR177, and SP7, using a Sequenom MassARRAY Analyzer 4 instrument. The genomic DNA samples used for genotyping were extracted from the buccal mucosa of the subjects. Statistical analyses were carried out using the SPSS 21 and R package. The results of this analysis showed a significant association between SNP rs4988300 of the LRP5 gene and total hip BMD values. We could not reveal any associations between the markers of GPR177, SP7, and bone phenotypes. We found no effect of these genotypes on fracture risk. We could demonstrate a significant gene-gene interaction between two SNPs of LRP5 (rs4988300 and rs634008, p = 0.009) which was lost after Bonferroni correction. We could firmly demonstrate a significant association between rs4988300 of the LRP5 gene and bone density of the hip on the largest homogeneous postmenopausal study group analyzed to date. Our finding corroborates the relationship between LRP5 genotype and bone phenotype in postmenopausal women, however, the complete mechanism of this relationship requires further investigations.

Vitamin D-neutralizing CYP24A1 expression, oncogenic mutation states and histological findings of human papillary thyroid cancer

OBJECTIVE

The aims of the present study were to examine gene and protein expression of the vitamin D-inactivating 24-hyroxylase (CYP24A1) and the activating 1-alpha-hydroxylase (CYP27B1) enzyme in human papillary thyroid cancer (PTC), furthermore, to investigate the association between CYP24A1 expression and numerous clinical, histological parameters and somatic oncogene mutation status of thyroid tumor tissues.

MATERIALS AND METHODS

Gene expression analysis was carried out in 100 Hungarian thyroid samples, both normal and papillary tumor tissue sections of the same patient. The specific mRNA to the selected genes was analyzed by TaqMan probe-based quantitative real-time RT-PCR. The somatic oncogene mutation states of BRAF, NRAS, HRAS and KRAS were also tested.

RESULTS

CYP24A1 mRNA expression was markedly increased in 52 cases (52%) of the examined papillary cancers compared with that of normal thyroid tissue. There was a tendency toward difference in the distribution of high-level CYP24A1 in the PTC accompanied with somatic oncogene mutation. Positive correlation was seen between increased CYP24A1 expression rate and a group of variables reflecting tumor malignity (mainly vascular invasion, lymph node metastasis, tumor size, hypothyreosis) by principal components analysis. No significant alteration was seen in CYP27B1 gene expression between neoplastic and normal tissues.

CONCLUSIONS

A definite alteration was seen in vitamin D3-inactivating CYP24A1 gene activity in PTC compared to their normal tissues on a relatively large patient population. Our findings raise the possibility that CYP24A1 may also directly be involved in thyroid carcinogenesis.

Exercise increases exhaled breath condensate cysteinyl leukotriene concentration in asthmatic patients

BACKGROUND

Although the importance of cysteinyl leukotrienes (Cys-LTs) in exercise-induced bronchoconstriction (EIB) is supported by various sources of evidence, how the concentration of these mediators change during the development of EIB has not been investigated.

OBJECTIVES

Our goal was to determine the effect of exercise on the concentration of airway Cys-LT in asthmatic patients by measuring Cys-LT in exhaled breath condensate (EBC).

METHODS

Seventeen atopic asthmatic patients with a previous history of EIB and six healthy volunteers were studied. Before and two times within 10 minutes after exercise challenge, FEV₁ was measured and EBC was collected for Cys-LT measurement. Exhaled nitric oxide level, a marker of airway inflammation, was also determined at baseline.

RESULTS

Baseline Cys-LT level was higher in the asthmatic group versus healthy subjects (168 pg/mL /112-223/ vs. 77 pg/mL /36-119/, p = .03). EBC Cys-LT concentration increased in all asthmatic patients post-exercise (n = 17, p = .03), with the increase significantly greater in patients developing exercise-induced bronchospasm (n = 7, p = .03), whereas no change was observed in healthy controls (p = .59). The exercise-induced fall in FEV(1) in asthmatics was related to the increase in EBC Cys-LT concentration (r = -0.40, p = .03).

CONCLUSIONS

Our study shows that Cys-LT concentration of EBC is elevated minutes after physical exercise in asthmatic patients and strongly supports the concept that the release of this mediator is involved in the development of EIB.

[The pH of the exhaled breath condensate: new method for investigation of inflammatory airway diseases]

Collecting exhaled breath condensate (EBC) has become a frequently used method in respiratory researches to date. Through this method we can sample airway surface liquid non-invasively by streaming the exhaled breath through a cooled chamber and after we examine the fluid deposited on the wall of the condenser. The sample contains several mediators, biomarkers. The pH of the condensate is one of the most important markers measured in the EBC. Measuring the pH is easy, cheap and it is in the optimal range, there is no problem with the detection limit. The uncertainty of the pH assays is derived from the instability of the EBC pH which results from the altering carbon-dioxide concentration. Many articles have been published on EBC pH in different airway diseases. Acidification of the condensates has been described in bronchial asthma (especially in acute exacerbations), chronic obstructive lung disease (COPD). Due to the steroid treatment the pH has increased in both cases. In patients with bronchiectasis, cystic fibrosis and in chronic cough (bronchial asthma, gastro-esophageal reflux, postnasal drip, and unknown origin) the pH of EBC was also lower. Acidification of the airways in different diseases can play a role in the pathomechanism, and its indicator, the EBC pH might help managing patients with airway diseases.

Exhaled breath condensate pH standardised for CO2 partial pressure

Exhaled breath condensate (EBC) pH is considered to reflect the acid-base balance of the airways. Current pH measurements do not take into account the effect of CO2. The aim of the present study was to determine the effect of condensate CO2 partial pressure on pH and to provide a more precise mode of EBC pH determination. Condensate pH and CO2 partial pressure were measured in parallel from 12 healthy volunteers and 12 asthmatics using a blood gas analyser in neat, argon de-aerated and CO2-loaded samples. The regression analysis was used to test the relationship between pH and CO2, and to calculate the pH at a CO2 level of 5.33 kPa (physiological alveolar CO2 partial pressure). Reproducibility of different pH readings was compared using the Bland-Altman test. Condensate CO2 concentration was variable both in neat and argon de-aerated samples. There was a close negative logarithmic relationship between CO2 and pH. Calculation of pH at a CO2 level of 5.33 kPa provided reproducibility approximately six times as good as that of the currently used measurements. Condensate CO2 partial pressure influences pH measurements. Determination of pH at a standard CO2 level provides the most reproducible condensate pH values to date.