195 The Application of Radiomics in Laryngeal Cancer: The Forgotten Cohort

Background

Radiomics is a novel method of extracting data from medical images that is difficult to visualise through the naked eye. This technique transforms digital images that hold information on pathology into high-dimensional-data for analysis. Radiomics has the potential to enhance laryngeal cancer care and to date, has shown promise in various other specialties.

Aim

The aim of this review is to summarise the applications of this technique to laryngeal cancer and potential future benefits.

Method

A comprehensive systematic review-informed search of the MEDLINE and EMBASE online databases was undertaken. Keywords ‘laryngeal cancer’ OR ‘larynx’ OR ‘larynx cancer’ OR ‘head and neck cancer’ were combined with ‘radiomic’ OR ‘signature’ OR ‘machine learning’ OR ‘artificial intelligence’. Additional articles were obtained from bibliographies using the ‘snowball method’.

Results

Seventeen articles were identified that evaluated the role of radiomics in laryngeal cancer. Two studies affirmed the value of radiomics in improving the accuracy of staging, whilst fifteen studies highlighted the potential prognostic value of radiomics in laryngeal cancer. Twelve (of thirteen) studies incorporated an array of different head and neck cancers in the analysis and only one study assessed laryngeal cancer exclusively.

Conclusions

Literature to date has various limitations including, small and heterogeneous cohorts incorporating patients with head and neck cancers of distinct anatomical subsites and stages. The lack of uniform data on solely laryngeal cancer and radiomics means drawing conclusions is difficult, although these studies have affirmed its value. Further large prospective studies exclusively in laryngeal cancer are required to unlock its true potential.

Concurrent occurrence of a wandering spleen, organoaxial gastric volvulus, pancreatic volvulus, and cholestasis - A rare cause of an acute abdomen

The concurrence of wandering spleen, organoaxial gastric volvulus, and pancreatic volvulus is very rare. They have been associated with symptoms such as severe abdominal pain, abdominal distention, and vomiting. However, the diagnosis remains complicated and any delay can result in ischemia and necrosis of the organs involved. In this case presentation, we present a unique case involving a 14-year-old girl who presented initially with acute abdominal pain. Assessment with enhanced computed tomography scan led to the diagnosis of wandering spleen, organoaxial gastric volvulus, and pancreatic volvulus, in addition to cholestasis, making it the first study to report on the simultaneous occurrence of this triad and cholestasis.

Validity and test-retest reliability of an at-work production loss instrument

BACKGROUND

Besides causing ill health, a poor work environment may contribute to production loss. Production loss assessment instruments emphasize health-related consequences but there is no instrument to measure reduced work performance related to the work environment.

AIMS

To examine convergent validity and test-retest reliability of health-related production loss (HRPL) and work environment-related production loss (WRPL) against a valid comparable instrument, the Health and Work Performance Questionnaire (HPQ).

METHODS

Cross-sectional study of employees, not on sick leave, who were asked to self-rate their work performance and production losses. Using the Pearson correlation and Bland and Altman's Test of Agreement, convergent validity was examined. Subgroup analyses were performed for employees recording problem-specific reduced work performance. Consistency of pairs of HRPL and WRPL for samples responding to both assessments was expressed using Intraclass Correlation Coefficient (ICC) and tests of repeatability.

RESULTS

A total of 88 employees participated and 44 responded to both assessments. Test of agreement between measurements estimates a mean difference of 0.34 for HRPL and -0.03 for WRPL compared with work performance. This indicates that the production loss questions are valid and moderately associated with work performance for the total sample and subgroups. ICC for paired HRPL assessments was 0.90 and 0.91 for WRPL, i.e. the test-retest reliability was good and suggests stability in the instrument.

CONCLUSIONS

HRPL and WRPL can be used to measure production loss due to health-related and work environment-related problems. These results may have implications for advancing methods of assessing production loss, which represents an important cost to employers.

LARP1 post-transcriptionally regulates mTOR and contributes to cancer progression

RNA-binding proteins (RBPs) bind to and post-transcriptionally regulate the stability of mRNAs. La-related protein 1 (LARP1) is a conserved RBP that interacts with poly-A-binding protein and is known to regulate 5'-terminal oligopyrimidine tract (TOP) mRNA translation. Here, we show that LARP1 is complexed to 3000 mRNAs enriched for cancer pathways. A prominent member of the LARP1 interactome is mTOR whose mRNA transcript is stabilized by LARP1. At a functional level, we show that LARP1 promotes cell migration, invasion, anchorage-independent growth and in vivo tumorigenesis. Furthermore, we show that LARP1 expression is elevated in epithelial cancers such as cervical and non-small cell lung cancers, where its expression correlates with disease progression and adverse prognosis, respectively. We therefore conclude that, through the post-transcriptional regulation of genes such as mTOR within cancer pathways, LARP1 contributes to cancer progression.

Changes in [18F]Fluorothymidine Pharmacokinetics Following Capecitabine Treatment in Human Breast Cancer Detected by Positron Emission Tomography

Background: Pre-clinical models used by our group have demonstrated that thymidylate synthase (TS) inhibition leads to redistribution of the nucleoside transporter, ENT1, to the cell membrane and hence increases the tissue uptake of [18F]fluorothymidine (FLT).Methods: In this study we assessed, for the first time, the altered pharmacokinetics of FLT in patients following TS inhibition. We analyzed 10 lesions from 6 breast cancer patients by positron emission tomography (PET) before and after treatment with capecitabine.Results: Whereas drug treatment did not alter tumor delivery pharmacokinetic variables or blood flow, tumor FLT retention variables increased with drug treatment in all but one patient. The baseline average standardized uptake value (SUV) at 60 min, rate constant for the net irreversible transfer of radiotracer from plasma to tumor (Ki) and unit impulse response function (IRF) at 60 min were 11.11 x 10-5 m2/ml, 4.38 x 10-2 ml plasma/min/ml tissue and 4.93 x 10-2 /min, respectively. At 1 h after capecitabine, the SUV was 13.55 x 10-5 m2/ml (p=0.004), Ki 7.40 x 10-2 ml plasma/min/ml tissue (p=0.004) and IRF 7.40 x 10-2 /min (p= 0.002).Conclusion: FLT pharmacokinetics did not change in normal tissues suggesting that the effect was largely restricted to tumor (p=0.55). In summary, we have identified FLT-PET retention parameters that could be used in future early clinical studies to measure the pharmacodynamics of TS inhibitors, as well as for identifying patients who are unlikely to benefit from TS inhibition.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5003.

[11C]Choline-PET imaging of breast cancer

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Background: Molecular imaging techniques are increasingly being used in cancer diagnosis, staging, and assessment of response to treatment. This study sought to evaluate, for the first time, [11C]choline-PET in patients with breast cancer. The potential of [11C]choline-PET for differentiating tumours from normal tissue, correlation with molecular markers, determine its normal variability range, and finally the effect of trastuzumab on [11C]choline uptake in patients with breast cancer was investigated. Methods: 21 patients with newly diagnosed and recurrent breast cancer AJCC stage II-IV were enrolled in the study, all of whom had a baseline dynamic [11C]choline-PET scan with arterial sampling. 14 patients had 2 [11C]choline-PET scans to examine reproducibility, and 7 had a scan after trastuzumab. Analysis of [11C]choline uptake was measured using SUV, Ki (irreversible retention), and IRF@60min (retention using spectral analysis). Results: Breast tumour lesions were visualised by [11C]choline PET in all patients. The difference in tumour and non-tumour uptake were significant for SUV, Ki, and IRF@60 min (Wilcoxon p < 0.0001 for all parameters). [11C]choline uptake was reproducible in breast tumour lesions (r2 = 0.945 for SUV, 0.894 for Ki, and 0.799 for IRF60). The metabolism analysis of arterial plasma samples in 19 patients showed that [11C]choline decreased rapidly post-injection such that at 60 mins the mean radioactivity in arterial plasma due to choline was 15.15 ± 2.16%.Early responses to trastuzumab were determined to be significant in 5 lesions which corresponded with 3 clinical responses. Conclusions: [11C]choline-PET is a promising imaging modality in breast cancer, and could play an important role for determining response to novel treatment strategies in vivo.

No significant financial relationships to disclose.

Imaging of angiogenesis in metastatic breast cancer by positron emission tomography (PET) using [18F]AH11585, an [18F]- labeled alphaVbeta3 (αvβ3) peptide

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Background: In vivo imaging of avβ3 expression in tumors and tumor endothelial cells may be a useful biomarker of angiogenesis. [18F]AH11585 is a novel peptide containing an Arginine-Glycine-Aspartic Acid (RGD) motif that binds to avβ3 with high affinity designed for use in PET studies. Methods: 7 patients with metastatic breast cancer (aged 37–68 years) received intravenous injections of [18F]AH11585 and were scanned dynamically by PET over 61.5 mins. Radioactivity concentrations, derived from regions of interest placed on tumour and normal tissues, were analysed mathematically to determine the net irreversible uptake (Ki), fractional retention (FRT) and standardized uptake at 56.5min (SUV) of the radiotracer. Computed tomography (CT) was performed within 4 weeks of the scan. Results: Tumor lesions were clearly visible on PET images in 6/7 patients. In one patient with a palpable supraclavicular lymph node not visible on CT, we were unsure if a hyperintense region visible by PET was tumor. In total 18/19 tumor lesions were identified on both PET and corresponding CT images. Tumors in areas of low background were hyperintense (lung, bone, breast) whereas those in areas of high background were hypointense regions (liver). Tumors with central necrosis showed high uptake of [18F]AH11585 around the periphery only. Mathematical analysis demonstrated irreversible retention of [18F]AH11585 in tumors. [18F]AH11585-PET discriminated between non-liver lesions (n=10) and normal tissues: Ki (p=0.002), FRT (p=0.0039), SUV (p=0.002). Corresponding comparisons for liver lesions (n=8) were significant for FRT (p=0.0078) and SUV (p=0.0078) only. Conclusions: [18F]AH11585 PET is a promisng method for in vivo imaging of avβ3 integrin expression in metastatic breast cancer.

No significant financial relationships to disclose.

A feasibility study of [11C]choline for the molecular imaging of human breast cancer in vivo using positron emission tomography (PET)

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Background: [11C]Choline is a novel PET radiotracer. Preclinical studies suggest that it may be promising in breast cancer. [11C]Choline has been recently evaluated as a screening agent in prostate cancer, but no studies have yet investigated its potential in breast cancer. We report a pilot study evaluating the utility and reproducibility of [11C]Choline-PET in breast cancer. Methods: Dynamic imaging was performed on an ECAT962 HR+ PET scanner for 65 min after intravenous injection with 190–369 MBq [11C]choline. Patients with locally advanced and metastatic breast cancer were eligible. All histological subtypes were included (ductal, lobular, and inflammatory). Arterial blood samples were taken continuously for 10 min, with 8 discrete samples up to 60 min to measure [11C]choline and metabolites. Tissue uptake was determined by standardised uptake value at 60 min (SUV, dose and BSA corrected) and Ki (irreversible trapping) calculated using Patlak (corrected for [11C]choline metabolites in plasma) and modified Patlak analysis (corrected for plasma + tissue metabolites). Reproduciblilty scans were performed 2–17 days later in the absence of treatment. Results: Tumour [11C]choline uptake was observed in 10 out of 11 patients (12 out of 13 distinct lesions). There was a significant difference between tumour and normal tissue (breast/lung) in [11C]choline uptake for Ki (p<0.0001) and SUV (p<0.0001). Tissue uptake was of the order lung ≤ normal breast < tumour < liver ≤ spleen. [11C]choline was rapidly metabolised, at 60 min the mean ± S.E. plasma radioactivity due to [11C]choline was 16.4 ± 2.9%. [11C]Choline uptake was found to be reproducible for Ki (modified Patlak: r=0.93, p<0.0001, Patlak: r=0.85, p=0.002) and SUV (r=0.94, p<0.0001) - measured in 8 patients (median of 2 days after the 1st scan). Tumour Patlak Ki was 13.2% > Ki calculated using modified Patlak analysis. Conclusions: [11C]Choline-PET imaging of breast cancer is promising and warrants further evaluation. Tumour [11C]Choline uptake measured by Ki and SUV is reproducible. We plan to study the relationship between choline uptake measured by PET and immunoassays of tumour samples. Functional imaging could have a vital role to determine the efficacy of target-specific agents.

No significant financial relationships to disclose.

Inhibiting estrogen responses in breast cancer cells using a fusion protein encoding estrogen receptor-alpha and the transcriptional repressor PLZF

Estrogen receptor alpha (ERalpha) is a ligand-inducible transcription factor that acts to regulate gene expression by binding to palindromic DNA sequence, known as the estrogen response element, in promoters of estrogen-regulated genes. In breast cancer ERalpha plays a central role, where estrogen-regulated gene expression leads to tumor initiation, growth and survival. As an approach to silencing estrogen-regulated genes, we have studied the activities of a fusion protein between ERalpha and the promyelocytic leukemia zinc-finger (PLZF) protein, a transcriptional repressor that acts through chromatin remodeling. To do this, we have developed lines from the estrogen-responsive MCF-7 breast cancer cell line in which the expression of the fusion protein PLZF-ERalpha is conditionally regulated by tetracycline and shows that these feature long-term silencing of the expression of several well-characterized estrogen-regulated genes, namely pS2, cathepsin-D and the progesterone receptor. However, the estrogen-regulated growth of these cells is not inhibited unless PLZF-ERalpha expression is induced, an observation that we have confirmed both in vitro and in vivo. Taken together, these results show that PLZF-ERalpha is a potent repressor of estrogen-regulated gene expression and could be useful in distinguishing estrogen-regulated genes required for the growth of breast cancer cells.

The physiological environment in cancer vascularization, invasion and metastasis

One of the most lethal aspects of cancer arises from its ability to invade and metastasize. Determining the factors that promote cancer cell invasion and metastasis is therefore critically important in treating this disease. The tumour physiological environment is uniquely different from normal tissue, and exhibits hypoxia, acidic extracellular pH and high levels of lactate. This environment, dictated largely by abnormal tumour vasculature and metabolism, in turn also promotes angiogenesis. The physiological environment, tumour metabolism, angiogenesis and vascularization are therefore inextricably linked. We have developed and applied non-invasive magnetic resonance (MR) imaging (I) and spectroscopy (S) techniques to understand the role of vascular, physiological and metabolic properties in cancer invasion and metastasis. These MR studies are performed with human breast and prostate cancer cells maintained in culture or grown as solid tumours in immune-suppressed mice. We have detected significant differences in vascular, physiological and metabolic characteristics of metastatic and non-metastatic human breast and prostate cancer models with MRI and MRS. Using a combined MRI/MRS approach we are currently acquiring metabolic, extracellular pH and vascular images from the same localized regions within a solid tumour to further understand the dynamics between these parameters and their role in cancer invasion and metastasis.

Radiolabelled tracers and anticancer drugs for assessment of therapeutic efficacy using PET

Positron Emission Tomography (PET) has the potential to improve efficacy of established and novel cancer therapies and to assist more rapid and rational progression of promising novel therapies into the clinic. This is due to PET's unrivalled sensitivity and ability to monitor the pharmacokinetics and pharmacodynamics of drugs and biochemicals radiolabelled with short -lived positron emitting radioisotopes. PET is a multidisciplinary science which employs chemists, biologists, mathematical modellers, pharmacologists as well as clinicians. Clinical research questions in oncology determine the methodological challenges faced by these other disciplines. Within this context we focus on the developments of the radiolabelled compounds that have underpinned the clinical work in oncology for monitoring tumour and normal tissue pharmacokinetics, assessment of tumour response, cell proliferation, gene expression, hypoxia, multidrug resistance and status of receptors on tumours.

Real-time measurements of cellular oxygen consumption, pH, and energy metabolism using nuclear magnetic resonance spectroscopy

Changes in molecular expression or apoptotic behavior, induced by malignant transformation or anticancer treatment, are frequently reflected in cellular metabolism and oxygen consumption. A technique to monitor oxygen consumption, cell physiology, and metabolism noninvasively would provide a better understanding of interactions between molecular changes and metabolism in malignant transformation and following cancer treatment. Such a system was developed in this study by adapting multinuclear MRI and spectroscopic techniques to an isolated cell perfusion system. The system was evaluated by studying the effects of two agents, carbonyl cyanide m-chlorophenylhydrazone (CCCP) which is an uncoupler of oxidative phosphorylation, and antimycin, an inhibitor of oxidative phosphorylation, on the oxygen consumption and metabolism of MCF-7 and MatLyLu cancer cell lines.