Pre-treatment MDCT-based texture analysis for therapy response prediction in gastric cancer: Comparison with tumour regression grade at final histology

PURPOSE

An accurate prediction of tumour response to therapy is fundamental in oncology, so as to prompt personalised treatment options if needed. The aim of this study was to investigate the ability of preoperative texture analysis from multi-detector computed tomography (MDCT) in the prediction of the response rate to neo-adjuvant therapy in patients with gastric cancer.

MATERIAL AND METHODS

Thirty-four patients with biopsy-proven gastric cancer were examined by MDCT before neo-adjuvant therapy, and treated with radical surgery after treatment completion. Tumour regression grade (TRG) at final histology was also assessed. Image features from texture analysis were quantified, with and without filters for fine to coarse textures. Patients with TRG 1-3 were considered responders while TRG 4-5 as non- responders. The response rate to neo-adjuvant therapy was assessed both at univariate and multivariate analysis.

RESULTS

Fourteen parameters were significantly different between the two subgroups at univariate analysis; in particular, entropy and compactness (higher in responders) and uniformity (lower in responders). According to our model, the following parameters could identify non-responders at multivariate analysis: entropy (≤6.86 with a logarithm of Odds Ratio - Log OR -: 4.11; p=0.003); range (>158.72; Log OR: 3.67; p=0.010) and root mean square (≤3.71; Log OR: 4.57; p=0.005). Entropy and three-dimensional volume were not significantly correlated (r=0.06; p=0.735).

CONCLUSION

Pre-treatment texture analysis can potentially provide important information regarding the response rate to neo-adjuvant therapy for gastric cancer, improving risk stratification.

Apparent diffusion coefficient by diffusion-weighted magnetic resonance imaging as a sole biomarker for staging and prognosis of gastric cancer

Objective

To investigate the role of apparent diffusion coefficient (ADC) from diffusion-weighted magnetic resonance imaging (DW-MRI) when applied to the 7th TNM classification in the staging and prognosis of gastric cancer (GC).

Methods

Between October 2009 and May 2014, a total of 89 patients with non-metastatic, biopsy proven GC underwent 1.5T DW-MRI, and then treated with radical surgery. Tumor ADC was measured retrospectively and compared with final histology following the 7th TNM staging (local invasion, nodal involvement and according to the different groups — stage I, II and III). Kaplan-Meier curves were also generated. The follow-up period is updated to May 2016.

Results

Median follow-up period was 33 months and 45/89 (51%) deaths from GC were observed. ADC was significantly different both for local invasion and nodal involvement (P<0.001). Considering final histology as the reference standard, a preoperative ADC cut-off of 1.80×10^–3 mm²/s could distinguish between stages I and II and an ADC value of ≤1.36×10^–3 mm²/s was associated with stage III (P<0.001). Kaplan-Meier curves demonstrated that the survival rates for the three prognostic groups were significantly different according to final histology and ADC cut-offs (P<0.001).

Conclusions

ADC is different according to local invasion, nodal involvement and the 7th TNM stage groups for GC, representing a potential, additional prognostic biomarker. The addition of DW-MRI could aid in the staging and risk stratification of GC.

Abstract A07: Identification of endocrine/metabolic biomarkers associated to early PDC in a transgenic mouse model

Background: Pancreatic ductal adenocarcinoma (PDC) is a deadly disease, even surgery contributes little to survival if PDC is not diagnosed at an initial stage. Glucose homeostasis alteration associated to PDC was described to identify an high risk population for screening. Moreover the weight loss often manifests several months before cachexia. The crosstalk between metabolism and cancer could be a key to early diagnosis. Our aim is to find endocrine/metabolic biomarkers of early PDC development in a gold standard murine model.

Materials and Methods: Candidate markers were investigated using LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre (KPC) mouse, a genetically-engineered model that develops PDC with 100% penetrance. KPC has been fed with standard diet (SD) or high fat diet (HFD) introducing a further risk factor for diabetes and metabolic alterations. To overcome the problem of asynchronous development of PDC in KPC, 7T-MRI was used to classify mice in actual pathological stage: normal (S1); cystic degeneration (S2); small tumor (S3) and advanced pancreatic cancer (S4). We performed metabolic test (OGTT) and serum endocrine/metabolic profile (xMAP technology and clinical biochemistry) in n=27 KPC (and control mice PDX-1 Cre) fed with HFD vs n=26 KPC (and control mice PDX-1 Cre) fed with SD. To prioritize markers we computed the ROC curve analysis.

Results: i) Glucose metabolism: KPC were normoglycemic regardless of the diet; the AUC in OGTT increases in KPC fed with HFD (HFD vs SD: S1 p&lt;0,001, S2 p&lt;0,001, S3 p=0,002, Cre p&lt;0,001) ii) Serum levels of 29 endocrine/metabolic biomarkers were assessed during disease progression. The more relevant results are: increase of PYY (p&lt;0,003) and decrease of leptin (p&lt;0,02), GIP (p&lt;0.005) albumin (p&lt;0.001) both in HFD and SD fed KPC (Cre vs S2); increase of amylase in stage 1 HFD-fed KPC (p=0,037). Moreover PYY was able to discriminate control from stage 2 KPC with an AUC=0,929 in the ROC curve analysis (p&lt;0,001).

Conclusions: Unlike human, in the mouse model the development of PDC is not associated with an hyperglycemic status, regardless of the diet. However KPC fed with HFD experience a mild impairment of glucose metabolism (as well as in control mice) and a mild pancreatic damage. Our results identify Leptin, PYY, GIP and albumin as markers of early stage PDC in a preclinical model with a diagnostic potential to be validated in human patients.

Citation Format: Valentina Pasquale, Erica Dugnani, Daniela Liberati, Paolo Marra, Tamara Canu, Antonio Esposito, Lorenzo Piemonti1.{Authors}. Identification of endocrine/metabolic biomarkers associated to early PDC in a transgenic mouse model. [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2016 May 12-15; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(24 Suppl):Abstract nr A07.

IFNα gene/cell therapy curbs colorectal cancer colonization of the liver by acting on the hepatic microenvironment

Colorectal cancer (CRC) metastatic dissemination to the liver is one of the most life‐threatening malignancies in humans and represents the leading cause of CRC‐related mortality. Herein, we adopted a gene transfer strategy into mouse hematopoietic stem/progenitor cells to generate immune‐competent mice in which TEMs—a subset of Tie2⁺ monocytes/macrophages found at peritumoral sites—express interferon‐alpha (IFNα), a pleiotropic cytokine with anti‐tumor effects. Utilizing this strategy in mouse models of CRC liver metastasis, we show that TEMs accumulate in the proximity of hepatic metastatic areas and that TEM‐mediated delivery of IFNα inhibits tumor growth when administered prior to metastasis challenge as well as on established hepatic lesions, improving overall survival. Further analyses unveiled that local delivery of IFNα does not inhibit homing but limits the early phases of hepatic CRC cell expansion by acting on the radio‐resistant hepatic microenvironment. TEM‐mediated IFNα expression was not associated with systemic side effects, hematopoietic toxicity, or inability to respond to a virus challenge. Along with the notion that TEMs were detected in the proximity of CRC metastases in human livers, these results raise the possibility to employ similar gene/cell therapies as tumor site‐specific drug‐delivery strategies in patients with CRC.

Breast conservation following neoadjuvant therapy for breast cancer in the modern era: Are we losing the opportunity?

The main rationale for neoadjuvant therapy for breast cancer is to provide effective systemic treatment while surgically down-staging the cancer. This down-staging was initially to convert inoperable patients to operable and later to increase rates of breast conservation in patients initially deemed mastectomy only candidates. Unexpectedly, in recent neoadjuvant trials lower rates of breast conservation have been observed than in past decades, despite remarkable advances in systemic therapies, which have increased pathologic complete response rates. These results point to factors aside from response and eligibility for breast conservation that may lead surgeons and/or patients to recommend and choose mastectomy. Here, we aim to examine the surgical benefits offered by the modern era neoadjuvant therapy and explore factors that have contributed to this decrease in breast conservation rates. If the main benefit of neoadjuvant therapy is to increase the opportunity for breast conservation, then our review suggests that to optimize less invasive surgical approaches, we will need to address both surgeon and patient-level variables and biases that may be limiting our ability to identify patients appropriate for less aggressive options. As an oncology community, we must be aware of the surgical overtreatment of breast cancer, especially in a time where systemic therapies have remarkably improved outcomes and responses.

Prospective comparison of MR with diffusion-weighted imaging, endoscopic ultrasound, MDCT and positron emission tomography-CT in the pre-operative staging of oesophageal cancer: results from a pilot study

OBJECTIVE

To compare the diagnostic performance of MR and diffusion-weighted imaging (DWI), multidetector CT, endoscopic ultrasonography (EUS) and ¹⁸F-FDG (fluorine-18 fludeoxyglucose) positron emission tomography CT (PET-CT) in the pre-operative locoregional staging of oesophageal cancer.

METHODS

18 patients with oesophageal or Siewert I tumour (9 directly treated with surgery and 9 addressed to chemo-/radiotherapy before) underwent 1.5-T MR and DWI, 64-channel multidetector CT, EUS and PET-CT before (n = 18) and also after neoadjuvant treatment (n = 9). All images were analysed and staged blindly by dedicated operators (seventh TNM edition). Two radiologists calculated independently the apparent diffusion coefficient from the first scan. Results were compared with histopathological findings. After the population had been divided according to local invasion (T1-T2 vs T3-T4) and nodal involvement (N0 vs N+), sensitivity, specificity, accuracy, positive- and negative-predictive values were calculated and compared. Quantitative measurements from DWI and PET-CT were also analysed.

RESULTS

For T staging, EUS showed the best sensitivity (100%), whereas MR showed the highest specificity (92%) and accuracy (83%). For N staging, MR and EUS showed the highest sensitivity (100%), but none of the techniques showed adequate results for specificity. Overall, MR showed the highest accuracy (66%) for N stage, although this was not significantly different to the other modalities. The apparent diffusion coefficient was different between surgery-only and chemo-/radiotherapy groups (1.90 vs 1.30 × 10^-3 mm² s^-1, respectively; p = 0.005)-optimal cut off for local invasion: 1.33 × 10^-3 mm² s^-1 (p = 0.05). Difference in standardized uptake value was also very close to conventional levels of statistical significance (8.81 vs 13.97 g cm^-3, respectively; p = 0.05)-optimal cut off: 7.97 g cm^-3 (p = 0.44).

CONCLUSION

In this pilot study, we have shown that MR with DWI could enrich the current pre-operative work-up for oesophageal cancer and could be used for T and N staging. However, larger studies will need to be carried out before introducing this technique in the standard diagnostic pathway, in order to understand if MR with DWI could change its management and replace more costly or invasive tests such as PET-CT or EUS. Advances in knowledge: This pilot study represents the first effort where the four techniques have been prospectively compared together for oesophageal cancer staging. The combination of MR and DWI could provide important, additional information for staging and initial treatment decision-making.

A SINGLE-EXPOSURE, MULTIDETECTOR NEUTRON SPECTROMETER FOR WORKPLACE MONITORING

This communication describes a recently developed single-exposure neutron spectrometer, based on multiple active thermal neutron detectors located within a moderating sphere, which have been developed jointly by CIEMAT (Spain), INFN (Italy) and Politecnico di Milano (Italy) in the framework of Italian and Spanish collaboration projects. The fabricated prototypes permit to achieve spectrometric resolution with nearly isotropic response for neutron with energies from thermal to 100-200 MeV, thus being able to characterise the complete neutron spectrum in only one exposure by unfolding the measured responses of the detectors. This makes it especially advantageous for characterising neutron fields and workplace monitoring purposes in neutron-producing facilities.

Gastric cancer: texture analysis from multidetector computed tomography as a potential preoperative prognostic biomarker

OBJECTIVES

To investigate the association between preoperative texture analysis from multidetector computed tomography (MDCT) and overall survival in patients with gastric cancer.

METHODS

Institutional review board approval and informed consent were obtained. Fifty-six patients with biopsy-proved gastric cancer were examined by MDCT and treated with surgery. Image features from texture analysis were quantified, with and without filters for fine to coarse textures. The association with survival time was assessed using Kaplan-Meier and Cox analysis.

RESULTS

The following parameters were significantly associated with a negative prognosis, according to different thresholds: energy [no filter] - Logarithm of relative risk (Log RR): 3.25; p = 0.046; entropy [no filter] (Log RR: 5.96; p = 0.002); entropy [filter 1.5] (Log RR: 3.54; p = 0.027); maximum Hounsfield unit value [filter 1.5] (Log RR: 3.44; p = 0.027); skewness [filter 2] (Log RR: 5.83; p = 0.004); root mean square [filter 1] (Log RR: - 2.66; p = 0.024) and mean absolute deviation [filter 2] (Log RR: - 4.22; p = 0.007).

CONCLUSIONS

Texture analysis could increase the performance of a multivariate prognostic model for risk stratification in gastric cancer. Further evaluations are warranted to clarify the clinical role of texture analysis from MDCT.

KEY POINTS

• Textural analysis from computed tomography can be applied in gastric cancer. • Preoperative non-invasive texture features are related to prognosis in gastric cancer. • Texture analysis could help to evaluate the aggressiveness of this tumour.

2-Deoxy-d-Glucose Ameliorates PKD Progression

Autosomal dominant polycystic kidney disease (ADPKD) is an important cause of ESRD for which there exists no approved therapy in the United States. Defective glucose metabolism has been identified as a feature of ADPKD, and inhibition of glycolysis using glucose analogs ameliorates aggressive PKD in preclinical models. Here, we investigated the effects of chronic treatment with low doses of the glucose analog 2-deoxy-d-glucose (2DG) on ADPKD progression in orthologous and slowly progressive murine models created by inducible inactivation of the Pkd1 gene postnatally. As previously reported, early inactivation (postnatal days 11 and 12) of Pkd1 resulted in PKD developing within weeks, whereas late inactivation (postnatal days 25-28) resulted in PKD developing in months. Irrespective of the timing of Pkd1 gene inactivation, cystic kidneys showed enhanced uptake of (13)C-glucose and conversion to (13)C-lactate. Administration of 2DG restored normal renal levels of the phosphorylated forms of AMP-activated protein kinase and its target acetyl-CoA carboxylase. Furthermore, 2DG greatly retarded disease progression in both model systems, reducing the increase in total kidney volume and cystic index and markedly reducing CD45-positive cell infiltration. Notably, chronic administration of low doses (100 mg/kg 5 days per week) of 2DG did not result in any obvious sign of toxicity as assessed by analysis of brain and heart histology as well as behavioral tests. Our data provide proof of principle support for the use of 2DG as a therapeutic strategy in ADPKD.

Single-centre experience of extending indications for percutaneous intraportal islet autotransplantation (PIPIAT) after pancreatic surgery to prevent diabetes: feasibility, radiological aspects, complications and clinical outcome

OBJECTIVE

Islet allotransplantation is a less invasive alternative to surgical pancreas transplantation for Type 1 diabetes, while percutaneous intraportal islet autotransplantation (PIPIAT) is usually performed after pancreatic surgery to prevent diabetes. Our aim was to assess the feasibility, radiological aspects, complications and clinical outcome of PIPIAT following pancreatic surgery for not only chronic pancreatitis but also benign and malignant nodules.

METHODS

From 2008 to 2012, 41 patients were enrolled for PIPIAT 12-48 h after pancreatic surgery (extended pancreatic surgery for chronic pancreatitis and benign/malignant neoplasms). PIPIAT was performed using a combined ultrasonography and fluoroscopy-guided technique (4-F catheter). PIPIAT feasibility, median follow-up and metabolic (insulin independence rate, graft function based on C-peptide levels) and oncologic outcomes were recorded.

RESULTS

PIPIAT was not performed in 7/41 patients (4 cases for an inadequate islet mass, 2 cases for haemodynamic instability and 1 case for islet culture contamination), while it was successfully performed in 34/34 patients. Procedure-related major complications occurred in four patients: two bleedings requiring transfusions, one patient with left portal vein thrombosis and one patient with sepsis. Median follow-up duration was 546 days. Insulin independence was achieved in 15/34 (44%) patients, partial graft function in 16/34 (47%) patients and no function in 3/34 (9%) patients. None of the 17 patients with malignant nodules developed liver metastases during follow-up.

CONCLUSION

PIPIAT, performed under ultrasound and fluoroscopy combined guidance and not requiring immunosuppression, is feasible, with a relatively low complication rate and a better metabolic outcome than allotransplantation.

ADVANCES IN KNOWLEDGE

PIPIAT can prevent pancreatogenic diabetes. Ultrasound is a useful tool for the guidance and monitoring of PIPIAT.

Does cyclic guanosine monophosphate induce autophagy in thyroid malignant carcinoma through down-regulation of cyclic guanosine monophosphate phosphodiesterase?

The aim of this study was to evaluate whether or not the expression of cGMP- phosphodiesterases (cGMP-PDE) varies in different thyroid pathologies and to elucidate the relationship between the expression of cGMP-PDE, cGMP, and autophagy. Fifty-four thyroid biopsy samples, excised to perform the biopsy, were split into two parts and randomly assigned: one part was microscopically examined and histological classified, and the other was frozen and analysed in order to evaluate the cGMP-PDE activity. Intracellular cGMP was also measured. A strong expression of intracellular cGMP and cGMP-PDE activity was observed in carcinoma in respect to controls and benign pathologies. The level of cGMP-PDE in papillary carcinoma without lymph node involvement (N-) was approximately four-fold higher compared to those with lymph node invasion (N±). On the contrary, the cGMP was one and a half times higher in N± than N-. Our results are promising, although further epigenetical studies are needed to confirm this association. A correlation between the cGMP-degrading activity and the severity of thyroid pathology has been shown. The decrease of cGMP-PDE and the increase of cGMP in N± papillar carcinoma could be an autophagic stimulus, a defence mechanism of the body, against the cancer that is expanding and invading other tissues and organs.

Leukocytes recruited by tumor-derived HMGB1 sustain peritoneal carcinomatosis

The factors that determine whether disseminated transformed cells in vivo yield neoplastic lesions have only been partially identified. We established an ad hoc model of peritoneal carcinomatosis by injecting colon carcinoma cells in mice. Tumor cells recruit inflammatory leukocytes, mostly macrophages, and generate neoplastic peritoneal lesions. Phagocyte depletion via clodronate treatment reduces neoplastic growth. Colon carcinoma cells release a prototypic damage-associated molecular pattern (DAMP)/alarmin, High Mobility Group Box1 (HMGB1), which attracts leukocytes. Exogenous HMGB1 accelerates leukocyte recruitment, macrophage infiltration, tumor growth and vascularization. Lentiviral-based HMGB1 knockdown or pharmacological interference with its extracellular impair macrophage recruitment and tumor growth. Our findings provide a preclinical proof of principle that strategies based on preventing HMGB1-driven recruitment of leukocytes could be used for treating peritoneal carcinomatosis.

Accelerated bone turnover identifies hemiplegic patients at higher risk of demineralization

Immobilization osteoporosis represents a severe complication in hemiplegic patients (HPs), causing fragility fractures, which may occur during rehabilitation reducing functional recovery and survival. The aim of the study was to investigate determinants of bone loss, independent from length of immobilization, which may be useful in early identification of HPs at higher risk of demineralization. Forty-eight HPs of both sexes underwent anthropometric measurements, evaluation of scores of spasticity and of lower limb motory capacity. Laboratory tests were performed. On serum: calcium; phosphorus; creatinine; ALP; iPTH; 25(OH) vitamin-D; sex hormones; Δ4-androstenedione; DHEA-S; insulin; IGF-1; FT3; FT4; TSH; c-AMP. On urine: c-AMP and calcium/creatinine ratio. Two bone turnover markers were measured: serum osteocalcin (BGP) and urinary deoxypyridinoline (DPD). Bone mineral density was determined at both femoral necks, defining a percentage difference in bone loss between paretic and non-paretic limb, thus controlling for the complex cofactors involved. Only bone turnover markers significantly and directly correlated with the entity of demineralization, controlling for age, sex and length of immobilization in the multivariate analysis (BGP coefficient estimate=0.008; SE=0.003; p=0.020; DPD coefficient estimate=0.005; SE=0.002; p=0.036). BGP and DPD are not dependent on anthropometric and endocrine-metabolic parameters, disability patterns and duration of immobilization, thus represent independent determinants of the degree of demineralization. A cutoff was defined for BGP and DPD above which subjects show significantly greater risk of demineralization. The immobilization event generates more severe bone loss when it occurs in subjects with higher bone turnover. BGP and DPD measurements may be of primary importance for early identification of HPs at risk, with relevant preventive implications.

Preoperative locoregional staging of gastric cancer: is there a place for magnetic resonance imaging? Prospective comparison with EUS and multidetector computed tomography

BACKGROUND

The aim of this study was to prospectively compare the diagnostic performance of magnetic resonance imaging (MRI), multidetector computed tomography (MDCT) and endoscopic ultrasonography (EUS) in the preoperative locoregional staging of gastric cancer.

METHODS

This study had Institutional Review Board approval, and informed consent was obtained from all patients. Fifty-two patients with biopsy-proven gastric cancer underwent preoperative 1.5-T MRI, 64-channel MDCT and EUS. All images were analysed blind, and the results were compared with histopathological findings according to the seventh edition of the TNM classification. After the population had been divided on the basis of the local invasion (T1-3 vs T4a-b) and nodal involvement (N0 vs N+), sensitivity, specificity, positive and negative predictive value, and accuracy were calculated and diagnostic performance measures were assessed using the McNemar test.

RESULTS

For T staging, EUS showed higher sensitivity (94%) than MDCT and MRI (65 and 76%; p = 0.02 and p = 0.08). MDCT and MRI had significantly higher specificity (91 and 89%) than EUS (60%) (p = 0.0009 and p = 0.003). Adding MRI to MDCT or EUS did not result in significant differences for sensitivity. For N staging, EUS showed higher sensitivity (92%) than MRI and MDCT (69 and 73%; p = 0.01 and p = 0.02). MDCT showed better specificity (81%) than EUS and MRI (58 and 73%; p = 0.03 and p = 0.15).

CONCLUSIONS

Our prospective study confirmed the leading role of EUS and MDCT in the staging of gastric cancer and did not prove, at present, the value of the clinical use of MRI.