Abstract OT1-06-05: Atomic force microscopy (AFM) - a novel nanotool for cancer diagnostics: A prospective, blinded study of nanomechanical profiling of human breast tissue as a potential biomarker for stratifying low- and high-risk breast cancer subtypes

Background

The crucial point in making treatment decisions for breast cancer patients is the assessment of tumour aggressiveness. The established prognostic markers may be insufficient to stratify cancer patients into treatment relevant risk groups. Emerging evidence indicates that mechanical properties of cancer cells and their microenvironment that occur on a nanometre scale play a critical role in cancer invasion and metastases. Therefore, detecting these nanomechanical changes could serve as biomarker of cancer aggressiveness.

Trial design

We conduct a prospective, blinded study in a routine clinical setting. Using minimal invasive breast biopsies we measure the nanomechanical (stiffness) properties of human breast tissue with our atomic force microscope (AFM) based method known as ARTIDIS (Automated and Reliable Tissue Diagnostics). These properties can only be measured using fresh (non-fixed) tissue under physiological conditions (Custodiol transplant buffer). This novel method is based on the use of a micro-fabricated 20nm-sharp tip that indents several thousand individual locations across tissue specimens within 60-180 minutes. Each indentation effectively measures the stiffness of local structures (e.g. cancer cells, extracellular matrix) located under the tip. Thus we obtain a quantitative, biopsy-wide, nanomechanical profile. Post-AFM the same biopsy is used for routine histopathological diagnosis, the current diagnostic gold standard to which the nanomechanical profile is then correlated.

Eligibility criteria

All women undergoing a minimal invasive breast biopsy (core needle or vacuum assisted biopsy) at the breast centre of the University of Basel.

Exclusion criteria: age younger than 18years, necrotic/disintegrated biopsy, and technical limitations

Specific aims

Our primary endpoint is to differentiate benign from cancerous breast lesions based on their nanomechanical properties. Our secondary endpoint is to subclassify biopsies with cancerous lesions into the current four main breast cancer subgroups (Luminal A, Luminal B, HER2+ and basal-like).

Statistical analysis

The full dataset will include all patients with valid AFM measurements. Primary analysis: the proportion of true positive results divided by the total number of patients with malignant tumour (sensitivity) will be estimated and presented together with its 95% confidence interval. The histological diagnosis of the same biopsy as analysed by AFM will serve as gold standard.

Present accrual and target accrual

Present accrual as of June 12, 2017: 200 breast tissue biopsies.

Target accrual is 508 biopsies. This will allow for a power of 0.8 and a sensitivity of 90%.

Contact information: Rosemarie.Burian@usb.ch

Citation Format: Burian R, Appenzeller T, Oertle P, Raez C, Lim R, Forte S, Dellas S, Münst S, Obermann E, Plodinec M. Atomic force microscopy (AFM) - a novel nanotool for cancer diagnostics: A prospective, blinded study of nanomechanical profiling of human breast tissue as a potential biomarker for stratifying low- and high-risk breast cancer subtypes [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT1-06-05.

Multimodal ultrasound tomography for breast imaging: a prospective study of clinical feasibility

Background

To describe the clinical set-up and evaluate the feasibility of multimodal ultrasound tomography (MUT) for breast imaging.

Methods

Thirty-two consecutive patients referred for breast imaging and 24 healthy volunteers underwent MUT. In the 32 patients, the examination discomfort was compared to that of mammography (n = 31), handheld ultrasound (HUS) (n = 27) and magnetic resonance imaging (MRI) (n = 4) on a scale from 1 (lowest discomfort) to 10 (highest discomfort). MUT investigation time was recorded. Findings automatically detected by MUT were correlated with conventional imaging and biopsy results.

Results

Breast MUT was well tolerated by all 56 participants; 55 bilateral exams were uneventful. During one exam, the digitalisation card failed and the exam was successfully repeated within three days. Mean examination discomfort was 1.6 (range = 1-5) for MUT, 1.5 (range = 1-5) for HUS, 5.3 (range = 3-7) for MRI, and 6.3 (range = 1-10) for mammography. MUT examination time was 38 ± 6 min (mean ± standard deviation). In the patients referred for breast imaging, MUT detected four lesions and indicated malignancy in three of these cases. These findings were confirmed by additional imaging and biopsy.

Conclusion

MUT is feasible in a clinical context considering examination time and patient acceptance. These interesting initial diagnostic findings warrant further studies.

Prediction of long-term disability in multiple sclerosis

BACKGROUND

Little is known about the predictive value of neurophysiological measures for the long-term course of multiple sclerosis (MS).

OBJECTIVE

To prospectively investigate whether combined visual (VEP) and motor evoked potentials (MEP) allow prediction of disability over 14 years.

METHODS

A total of 30 patients with relapsing-remitting and secondary progressive MS were prospectively investigated with VEPs, MEPs and the Expanded Disability Status Scale (EDSS) at entry (T0) and after 6, 12 and 24 months, and with cranial MRI scans at entry (T2-weighted and gadolinium-enhanced T1-weighted images). EDSS was again assessed at year 14 (T4). The association between evoked potential (EP), magnetic resonance (MR) data and EDSS was measured using Spearman's rank correlation. Multivariable linear regression was performed to predict EDSS(T4) as a function of z-transformed EP-latencies(T0). The model was validated using a jack-knife procedure and the potential for improving it by inclusion of additional baseline variables was examined.

RESULTS

EDSS values(T4) correlated with the sum of z-transformed EP-latencies(T0) (rho = 0.68, p < 0.0001), but not with MR-parameters(T0). EDSS(T4) as predicted by the formula EDSS(T4) = 4.194 + 0.088 * z-score P100(T0) + 0.071 * z-score CMCT(UE, T0) correlated with the observed values (rho = 0.69, p < 0.0001).

CONCLUSION

Combined EPs allow prediction of long-term disability in small groups of patients with MS. This may have implications for the choice of monitoring methods in clinical trials and for daily practice decisions.

[Controversies on screening mammography]

Brustkrebs ist die häufigste Krebserkrankung und Krebstodesursache der Frau in den industrialisierten Ländern. Bislang gibt es weder sinnvolle Präventionsmassnahmen, noch Vorsorgeuntersuchungen. Die Mammographie stellt zur Zeit die einzige akzeptable diagnostische Modalität zur Früherkennung und -therapie dar. Sie ist mit einer in Gross-Studien belegten Reduktion der Mortalitätsrate von 30% als Screeningverfahren geeignet und empfohlen und wird in den meisten europäischen Ländern schon durchgeführt.

Unenhanced helical computed tomography vs intravenous urography in patients with acute flank pain: accuracy and economic impact in a randomized prospective trial

Unenhanced helical computed tomography (UHCT) has evolved into a well-accepted alternative to intravenous urography (IVU) in patients with acute flank pain and suspected ureterolithiasis. The purpose of our randomized prospective study was to analyse the diagnostic accuracy of UHCT vs IVU in the normal clinical setting with special interest on economic impact, applied radiation dose and time savings in patient management. A total of 122 consecutive patients with acute flank pain suggestive of urolithiasis were randomized for UHCT ( n=59) or IVU ( n=63). Patient management (time, contrast media), costs and radiation dose were analysed. The films were independently interpreted by four radiologists, unaware of previous findings, clinical history and clinical outcome. Alternative diagnoses if present were assessed. Direct costs of UHCT and IVU are nearly identical (310/309 Euro). Indirect costs are much lower for UHCT because it saves examination time and when performed immediately initial abdominal plain film (KUB) and sonography are not necessary. Time delay between access to the emergency room and start of the imaging procedure was 32 h 7 min for UHCT and 36 h 55 min for IVU. The UHCT took an average in-room time of 23 min vs 1 h 21 min for IVU. Mild to moderate adverse reactions for contrast material were seen in 3 (5%) patients. The UHCT was safe, as no contrast material was needed. The mean applied radiation dose was 3.3 mSv for IVU and 6.5 mSv for UHCT. Alternative diagnoses were identified in 4 (7%) UHCT patients and 3 (5%) IVU patients. Sensitivity and specificity of UHCT and IVU was 94.1 and 94.2%, and 85.2 and 90.4%, respectively. In patients with suspected renal colic KUB and US may be the least expensive and most easily accessable modalities; however, if needed and available, UHCT can be considered a better alternative than IVU because it has a higher diagnostic accuracy and a better economic impact since it is more effective, faster, less expensive and less risky than IVU. In addition, it also has the capability of detecting various additional renal and extrarenal pathologies.

Assignment of glial brain tumors in humans by in vivo 1H-magnetic resonance spectroscopy and multidimensional metabolic classification

This study presents a simple approach for the noninvasive assignment of glial brain tumors according to malignancy by single-voxel proton magnetic resonance spectroscopy at short echo times (TE < or = 50 milliseconds). Based on peak area ratios, a five-dimensional data set was obtained for each investigated subject. This vector was then projected along metabolic coordinates in a two-dimensional metabolic space. These coordinates had been determined in a previous study (Hagberg G et al., 1995, Magn Reson Med 34: 242-252). Tumor assignment was done without any knowledge of histology by comparing the location of the new cases to the features of the previous study. All 11 investigated glioblastomas multiforme, as well as 4 of 5 astrocytomas grade II, could easily be assigned to the groups of high- and low-grade tumors, respectively. Classification was more difficult in the case of a cystic astrocytoma grade II and one astrocytoma grade III. Two spectra measured in normal-appearing matter of glioblastoma patients were not classified as healthy. Using single-voxel proton magnetic resonance spectroscopy at short echo times with the knowledge of a base study, a straightforward, fast, and noninvasive differential diagnosis of glial brain tumors is possible.

Reduced glucose metabolism in the frontal cortex and basal ganglia of multiple sclerosis patients with fatigue: a 18F-fluorodeoxyglucose positron emission tomography study

To investigate the pathophysiology of fatigue in MS, we assessed cerebral glucose metabolism (CMR-Glu) in 47 MS patients using PET and 18F-fluorodeoxyglucose. Applying the Fatigue Severity Scale (FSS), we first compared MS patients with severe fatigue (MS-FAT, n = 19, FSS > 4.9) and MS patients without fatigue (MS-NOF, n = 16, FSS < 3.7) on a pixel-by-pixel basis using Statistical Parametric Mapping (SPM95). Second, we compared FSS values of all 47 patients covering the whole range of this scale with CMRGlu using an analysis of covariance (SPM95). In addition, we determined global CMRGlu by region-of-interest analysis. Sixteen healthy subjects served as control subjects (CON). Global CMRGlu was significantly lower in both MS groups compared with CON (CON 43.3 +/- 6.9 mumol/100 mL/min, MS-FAT 34.7 +/- 4.4, MS-NOF 35.4 +/- 4.5) but was not related to fatigue severity. Comparing the two MS groups, SPM95 analysis revealed predominant CMRGlu reductions bilaterally in a prefrontal area involving the lateral and medial prefrontal cortex and adjacent white matter, in the premotor cortex, putamen, and in the right supplementary motor area of MS-FAT. In addition, there were CMRGlu reductions in the white matter extending from the rostral putamen toward the lateral head of the caudate nucleus. FSS values were inversely related to CMRGlu in the right prefrontal cortex. CMRGlu in the cerebellar vermis and anterior cingulate was relatively higher in MS-FAT than in MS-NOF patients. CMRGlu of both regions showed positive correlations with FSS values. Our data suggest that fatigue in MS is associated with frontal cortex and basal ganglia dysfunction that could result from demyelination of the frontal white matter.

A patient with cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) confirmed by sural nerve biopsy

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