Flexible care in breast cancer

Treatment of patients with cancer in hospitals or clinics is resource-intensive and imposes a burden on patients. 'Flexible care' is a term that can be used to describe treatment administered outside the oncology ward, oncological outpatient clinic or office-based oncologist setting. Programmes that reduce travel burden by bringing cancer treatment to the patient's home, workplace or closer to the patient's home, in the form of satellite clinics or mobile cancer units, expand treatment capacity and are well received. Clinical trial data show that, compared with intravenous administration, subcutaneous (s.c.) administration of trastuzumab is preferred by patients with breast cancer (BC), saves healthcare professionals' (HCPs) time, reduces drug preparation and administration time and reduces direct and indirect costs. As such, s.c. trastuzumab is well suited to flexible care. The results of a Belgian study (BELIS) show that home administration of s.c. trastuzumab is feasible and preferred by patients with BC. Numerous programmes and pilot studies in Europe show that s.c. trastuzumab can be administered effectively in the patient's home, in primary care settings or local hospitals. Such programmes require planning, training, careful patient selection and technology to link patients, caregivers and specialists in oncology clinics. Once these elements are in place, flexible care offers patients with BC a choice of how treatment may be delivered and lead to improved quality of life, while reducing pressure on HCPs and hospitals. The concept of flexible care is particularly relevant amid the COVID-19 pandemic where guidelines have been developed encouraging remote care.

WE-G-217BCD-11: A New Phantom to Study Combined Effects of In-Plane (x,y) and Z Axis Resolution for 3-D Imaging

PURPOSE

The aim of this work is to develop phantoms that can be used to sample the radial and 3D properties of a CT image, including in-plane (x,y) and z-axis information. The Phantom is amenable to mathematical analysis of the x, y, and z axis resolution properties separately and combined.

METHODS

A periodic pattern of a pair of opposed (30°) angled ramps is configured to produce a waveform profile across the CT image. A perfect CT image (with no loss of resolution) of the test object would produce a consistent geometric pattern of the intersection of a line with the pair of angled ramps. However, due to the finite resolution (x, y and z), the CT waveform profile will not yield the perfect profile; rather it will be influenced by slice thickness, and in-plane resolution (PSF, MTF), as well as noise limitations, and other sources of non-uniformity such as beam hardening etc. Various characteristics of the waveform profile including, amplitude, frequency, and slope (rate of climb) of the peaks, can be studied using mathematical analysis such as the Fourier transform. It will be shown how these performance characteristics are encoded in the wave pattern.

RESULTS

The waveform profiles are visually examined and mathematically analyzed, to demonstrate the effect of Slice Thickness (z axis) and changes of In-Plane (x,y) Resolution and non-uniformity across the image field; moreover, the harmonic analysis of the waveform is used to predict, either the in-plane resolution (MTF), or the z-axis MTF when one of the two is already known.

CONCLUSIONS

The Wave pattern phantom offers a way to consider 3-D imaging characteristics of a CT scanner by scanning a single repetitive test object that encodes both in-plane resolution and z-axis resolution and also offers a way to study non-uniformity effects throughout the CT plane (volume). DJG is a consultant to The Phantom Laboratory and Image OWL, Salem, NY. Funding of other authors is supplied by Image OWL Salem, NY.

SU-E-I-38: Optimizing CT Slice Width Measurements

PURPOSE

For almost four decades bead and wire ramps have been used in the evaluation of slice width as part of QA testing for CT scanners. While each of these approaches have been recognized and accepted as reliable, in this paper we investigate the differences, advantages and limitations of these tools. Moreover, we study the effect of varying the field of view (FOV) and focal spot size.

METHODS

The Catphan® 700 phantom includes two pairs of bead ramps (coarse and fine) and a pair of wire ramps in the same module providing an ideal setting for comparing bead ramps and wire ramps. The phantom was scanned using three devices from two different manufacturers. The data set consisted of 428 slices of 0.5,1,2,4,8 and 10 mm thickness. For the study of FOV and focal spot, 512 slices from the Catphan® 600 were acquired. All images were analyzed using Image Owl Catphan® QA software.

RESULTS

For 0.5mm slices, bead ramps gave more accurate and precise (lower variance) estimation of the thickness than wire ramps. For 2-4 mm slices, the two approaches performed on equal terms while for the thickest slices (8 and 10mm), the wires gave more precise results. For thin slices, a small FOV (100mm) gave better results and lower spread than a large FOV (240mm). Finally, a small focal spot gave significantly better results than a large one using wire ramps for 0.5 and 1mm slices.

CONCLUSIONS

For measuring thin slices, the use of bead ramps, with adequately small FOV and a small focal spot should be advised. For measuring thick slices, wire ramps will give less variability although bead ramps give equally accurate results on average. Funding provided by The Phantom Laboratory, Incorporated and Image Owl, Incorporated.

A polymorphism in the adiponectin gene influences adiponectin expression levels in visceral fat in obese subjects

OBJECTIVE

Reduced serum adiponectin levels have been found in obesity and type 2 diabetes and variations in the adiponectin gene (APM1) have been associated with type 2 diabetes and features of the metabolic syndrome in different populations.

STUDY DESIGN

Here, we investigated the expression of APM1 in adipose tissue and studied the relationship between variation in APM1 expression, the APM1 G276T polymorphism, the common PPARG Pro12Ala polymorphism and clinical features of 36 morbidly obese (body mass index (BMI) 41.5 +/- 4.9 kg/m2) nondiabetic subjects.

RESULTS

APM1 mRNA expression in visceral fat was correlated with serum adiponectin levels (r = 0.54, P = 0.012). In visceral, but not in subcutaneous, adipose tissue APM1 mRNA level was 38% higher among carriers of the APM1 G276T T allele (G/T and T/T) than among carriers of the G/G genotype (0.91 +/- 0.06 for G/T and T/T carriers vs 0.66 +/- 0.09 for G/G carriers, P = 0.013). Carriers of the T allele also had significantly higher body fat percent compared to G/G carriers (65 +/- 6 vs 56 +/- 10%, P = 0.011).

CONCLUSION

Our results indicate that genetic variation in APM1 influences the expression of the gene in visceral adipose tissue and suggest a potential role for such variation in regulation of body fat accumulation in obese subjects.

Women and men have similar amounts of liver and intra-abdominal fat, despite more subcutaneous fat in women: implications for sex differences in markers of cardiovascular risk

AIMS/HYPOTHESIS

Fat accumulation in the liver has been shown to be closely correlated with hepatic insulin resistance and features of insulin resistance, also independently of body weight. It remains to be established how fat in the liver correlates with that in other depots, and whether any association differs between men and women.

METHODS

Liver fat (assessed using proton spectroscopy), intra-abdominal and subcutaneous fat (measured using magnetic resonance imaging) and markers of insulin resistance, including serum adiponectin, were determined in 132 non-diabetic subjects: 66 men (age 41+/-1 years) and 66 women (age 42+/-1 years).

RESULTS

Although the women had almost twice as much subcutaneous fat as the men (5045+/-207 vs 2610+/-144 cm3, p<0.0001), amounts of intra-abdominal fat (1305+/-80 vs 1552+/-111 cm3, NS) and liver fat (6.7+/-0.8 vs 8.9+/-1.2%, NS) were similar. In this study, no sex differences were observed with respect to serum insulin, adiponectin, triglyceride and HDL cholesterol concentrations. Of all measures of body composition, liver fat was best correlated with serum insulin (r=0.58, p<0.001), with no difference observed between men and women. Serum adiponectin was inversely correlated with liver fat content (r=-0.21, p<0.05). Multiple linear regression analysis revealed that intra-abdominal fat was significantly associated with liver fat, independently of serum adiponectin and subcutaneous fat. Liver fat, but not intra-abdominal fat, significantly explained the variation in serum insulin concentrations.

CONCLUSIONS/INTERPRETATION

Intra-abdominal fat is independently associated with liver fat, whereas subcutaneous fat is not. Liver fat, but not intra-abdominal fat, is independently associated with serum insulin. Men and women with similar amounts of intra-abdominal and liver fat do not exhibit sex differences in markers of insulin resistance (serum insulin, triglycerides, HDL cholesterol and adiponectin).

Parallel manifestation of insulin resistance and beta cell decompensation is compatible with a common defect in Type 2 diabetes

AIMS/HYPOTHESIS

The aim of the study was to evaluate the relationship between insulin sensitivity, beta cell function and glucose tolerance, and its dependence on variants in the newly identified Type 2 diabetes susceptibility gene, calpain-10 ( CAPN10).

METHODS

We studied 203 men of the same age but with varying degrees of glucose tolerance. These men participated in (i) an oral glucose tolerance test, (ii) a euglycaemic clamp combined with indirect calorimetry and infusion of [3-(3)H]-glucose and (iii) a stepwise assessment of acute insulin response to arginine (AIR) at three different glucose concentrations (fasting, 14 and 28 mmol/l).

RESULTS

There was a linear increase in NEFA levels ( p<0.0005) and WHR ( p<0.0005) and decrease in glucose uptake due to a reduction in glucose storage over the entire range of glucose tolerance ( r=-0.404; p<0.005). No increase in endogenous glucose production (EGP) was seen until patients had manifest diabetes. However, when EGP was expressed relative to fasting insulin concentrations, there was a linear deterioration of basal hepatic insulin sensitivity ( r=-0.514; p<0.005). The AIR followed a bell-shaped curve with an initial rise and subsequent decrease. However, AIR adjusted for insulin sensitivity (disposition index) showed a linear decrease with increasing glucose concentrations ( r=-0.563; p<0.001) starting already in subjects with normal glucose tolerance. There was an inverse correlation between increase in WHR and NEFA and peripheral as well as hepatic insulin sensitivity. Subjects with the genotype combination of CAPN10 consisting of SNP44 TT and SNP43 GG genotypes had significantly lower insulin-stimulated glucose uptake than carriers of the other genotype combinations (5.3+/-0.4 vs 7.2+/-0.4 mg.ffm kg(-1).min(-1).mU.l(-1); p<0.005).

CONCLUSIONS/INTERPRETATION

We conclude that the pre-diabetic state is characterised by a similar linear deterioration of peripheral and hepatic insulin sensitivity as beta cell function and that variants in the CAPN10 gene modify this relationship. These findings are compatible with a common defect in muscle, liver and beta cells in the pathogenesis of Type 2 diabetes.

Characterization of the human skeletal muscle glycogen synthase gene (GYS1) promoter

BACKGROUND

Impaired activation of the human skeletal muscle glycogen synthase by insulin is typical for type 2 diabetic patients. Regulation of glycogen synthase occurs mainly by phosphorylation/dephoshorylation but little is known whether there also is transcriptional regulation. Therefore we studied transcriptional regulation of the human skeletal muscle glycogen synthase gene (GYS1) and evaluated the effects of insulin and forskolin on the promoter activity.

METHODS

Seven promoter fragments were expressed in C2C12 myoblasts and myotubes and in HEK293 cells, and the luciferase assay was used to determine transcriptional activity.

RESULTS

The highest luciferase activity, 350-fold of the promoterless vector, was obtained with nucleotides -692 to +59 in myotubes (P < 0.001), while the nucleotides -250 to +59 provided the highest, 45-fold, activity in the HEK293 cells (P < 0.001). Longer promoter constructs (nucleotides -971, -1707 and -2158 to +59, respectively) had low promoter activity in both cell types. Forskolin treatment for 24 h resulted in approximately 30% decreased promoter activity in myotubes (P < 0.05). Insulin treatment for 0.5-3 h did not increase GYS1 promoter activity; instead the activity was slightly but significantly decreased after 24 h in myotubes (P < 0.005).

CONCLUSIONS

From our results we conclude that basal GYS1 promoter activity is obtained from the first 250 nucleotides of the promoter, while the nucleotides -692 to -544 seem to be responsible for muscle-specific expression, and nucleotides -971 to -692 for negative regulation. In myotubes, the GYS1 promoter was sensitive to negative regulation by forskolin, whereas insulin did not increase GYS1 transcription.

Vaccinations May Induce Diabetes-Related Autoantibodies in One-Year-Old Children

Vaccinations have been discussed as one among many environmental candidates contributing to the immune process that later may lead to type 1 diabetes. ABIS (All Babies in Southeast Sweden) is a prospective cohort study following a nonselected birth cohort of general population. In a randomly selected sample collection from 4400 children, GADA and IA-2A have been determined at the age of 1 year. The information on vaccinations was collected from questionnaires answered by the parents and was related to beta cell autoantibodies. When studying the induction of autoantibodies using the autoantibody level of 90th percentile as cutoff level, hemophilus influenza B (HIB) vaccination appeared to be a risk factor for IA-2A [OR 5.9 (CI 1.4-24.4; p = 0.01)] and for GADA [OR 3.4 (CI 1.1-10.8; p = 0.04)] in logistic regression analyses. Furthermore, the titers of IA-2A were significantly higher (p < 0.01 in Mann-Whitney test) in those children who had got HIB vaccination. When 99th percentile was used as cutoff to identify the children at risk of type 1 diabetes, BCG vaccination was associated with increased prevalence of IA-2A (p < 0.01). We conclude that HIB vaccination may have an unspecific stimulatory polyclonal effect increasing the production of GADA and IA-2A. This might be of importance under circumstances when the beta cell-related immune response is activated by other mechanisms.