Early regression index (ERI) on MR images as response predictor in esophageal cancer treated with neoadjuvant chemo-radiotherapy: Interim analysis of the prospective ESCAPE trial

PURPOSE

The early regression index (ERI) predicts treatment response in rectal cancer patients. Aim of current study was to prospectively assess tumor response to neoadjuvant chemo-radiotherapy (nCRT) of locally advanced esophageal cancer using ERI, based on MRI.

MATERIAL AND METHODS

From January 2020 to May 2023, 30 patients with esophageal cancer were enrolled in a prospective study (ESCAPE). PET-MRI was performed: i) before nCRT (tpre); ii) at mid-radiotherapy, tmid; iii) after nCRT, 2-6 weeks before surgery (tpost); nCRT delivered 41.4 Gy/23fr with concurrent carboplatin and paclitaxel. For patients that skipped surgery, complete clinical response (cCR) was assessed if patients showed no local relapse after 18 months; patients with pathological complete response (pCR) or with cCR were considered as complete responders (pCR + cCR). GTV volumes were delineated by two observers (Vpre, Vmid, Vpost) on T2w MRI: ERI and other volume regression parameters at tmid and tpost were tested as predictors of pCR + cCR.

RESULTS

Complete data of 25 patients were available at the time of the analysis: 3/25 with complete response at imaging refused surgery and 2/3 were cCR; in total, 10/25 patients showed pCR + cCR (pCR = 8/22). Both ERImid and ERIpost classified pCR + cCR patients, with ERImid showing better performance (AUC:0.78, p = 0.014): A two-variable logistic model combining ERImid and Vpre improved performances (AUC:0.93, p < 0.0001). Inter-observer variability in contouring GTV did not affect the results.

CONCLUSIONS

Despite the limited numbers, interim analysis of ESCAPE study suggests ERI as a potential predictor of complete response after nCRT for esophageal cancer. Further validation on larger populations is warranted.

MRI prediction of pathological response in locally advanced rectal cancer: when apparent diffusion coefficient radiomics meets conventional volumetry

AIM

To investigate the role of diffusion-weighted imaging (DWI), T2-weighted (W) imaging, and apparent diffusion coefficient (ADC) histogram analysis before, during, and after neoadjuvant chemoradiotherapy (CRT) in the prediction of pathological response in patients with locally advanced rectal cancer (LARC).

MATERIALS AND METHODS

Magnetic resonance imaging (MRI) at 1.5 T was performed in 43 patients with LARC before, during, and after CRT. Tumour volume was measured on both T2-weighted (V_T2W) and on DWI at b=1,000 images (V_b,1,000) at each time point, hence the tumour volume reduction rate (ΔV_T2W and ΔV_b,1,000) was calculated. Whole-lesion (three-dimensional [3D]) first-order texture analysis of the ADC map was performed. Imaging parameters were compared to the pathological tumour regression grade (TRG). The diagnostic performance of each parameter in the identification of complete responders (CR; TRG4), partial responders (PR; TRG3) and non-responders (NR; TRG0-2) was evaluated by multinomial regression analysis and receiver operating characteristics curves.

RESULTS

After surgery, 11 patients were CR, 22 PR, and 10 NR. Before CRT, predictions of CR resulted in an ADC value of the 75th percentile and median, with good accuracy (74% and 86%, respectively) and sensitivity (73% and 82%, respectively). During CRT, the best predictor of CR was ΔV_T2W (-58.3%) with good accuracy (81%) and excellent sensitivity (91%). After CRT, the best predictors of CR were ΔV_T2W (-82.8%) and ΔV_{b, 1,000} (-86.8%), with 84% accuracy in both cases and 82% and 91% sensitivity, respectively.

CONCLUSIONS

The median ADC value at pre-treatment MRI and ΔV_T2W (from pre-to-during CRT MRI) may have a role in early and accurate prediction of response to treatment. Both ΔV_T2W and ΔV_b,1,000 (from pre-to-post CRT) can help in the identification of CR after CRT.

Could perfusion heterogeneity at dynamic contrast-enhanced MRI be used to predict rectal cancer sensitivity to chemoradiotherapy?

AIM

To evaluate whether perfusion heterogeneity of rectal cancer prior to chemoradiotherapy (CRT) using histogram analysis of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) quantitative parameters can predict response to treatment.

MATERIALS AND METHODS

Twenty-one patients with histologically proven rectal adenocarcinoma were enrolled prospectively. All patients underwent 1.5 T DCE-MRI before CRT. Tumour volumes were drawn on Ktrans and Ve maps, using T2-weighted (W) images as reference, and the following first-order texture parameters of Ve and Ktrans values were extracted: 25th, 50th, 75th percentile, mean, standard deviation, skewness, and kurtosis. After CRT, patients underwent surgery and according with Rödel's tumour regression grade (TRG), they were classified as poor responders "non-GR" (TRG 0-2) and good responders "GR" (TRG 3-4). Differences between GR and non-GR in DCE-MRI first-order texture parameters were evaluated using the Mann-Whitney test, and their role in the prediction of response was investigated using receiver operating characteristic (ROC) curve analysis.

RESULTS

Sixteen (76%) patients were classified as GR and five (24%) were non-GR. Skewness and kurtosis of Ve was significantly higher in non-GR (4.886±1.320 and 36.402±24.486, respectively) than in GR patients (1.809±1.280, p=0.003 and 6.268±8.130, p= 0.011). Ve skewness <3.635 was able to predict GR with an area under the ROC curve (AUC) of 0.988, sensitivity 93.8%, specificity 80%, and accuracy 90.5%. Ve kurtosis <21.095 was able to predict response with an AUC of 0.963, sensitivity 93.8%, specificity 80%, and accuracy 90.5%. Other parameters were not different between groups or predictors of response.

CONCLUSION

Ve skewness and kurtosis seem to be promising in the prediction of response to CRT in rectal cancer patients.

Low Incidence of Hereditary Nonpolyposis Colorectal Cancer Syndrome in a Selected Area of the Lombardy Cancer Registry

Aims and background

Epidemiological investigations on the frequency of hereditary nonpolyposis colorectal cancer (HNPCC) syndrome are few and have shown a variable worldwide incidence ranging from 1% to 7% of all colorectal cancers (CRCs). In Italy, relevant differences have been observed: 2.8-3% of all CRCs in northern regions and less than 1% in southern regions. The aim of the present study was to investigate the HNPCC incidence in a selected area of northern Italy belonging to the Lombardy Cancer Registry.

Methods and study design

We analyzed 197 consecutive patients with newly diagnosed CRCs, histologically verified, and resident in two areas of the Lombardy Cancer Registry. For each case, genetic counseling with at least three generations pedigree reconstruction, HNPCC classification according to Amsterdam criteria, molecular analysis for microsatellite instability and immunohistochemistry for hMLH1 and hMSH2 were performed.

Results

A very low frequency (0.5%) of HNPCC fulfilling the Amsterdam criteria was found in comparison to the other Italian areas. Such an incidence seems to be due to actual population differences and reflects a genetic heterogeneity.

Conclusions

The data underline the importance of a precise knowledge of actual HNPCC incidence in different populations in order to optimize effectiveness and efficiency of screening programs for the disease.

Factors influencing liver fibrosis and necroinflammation in HIV/HCV coinfection and HCV monoinfection

OBJECTIVES

To define differences in liver histology between HIV/HCV coinfection and HCV monoinfection, and to investigate possible causative factors.

METHODS

Liver biopsies (LBs) from 440 consecutive HIV/HCV-coinfected patients (Group HIV/HCV) and 374 consecutive HCV-monoinfected patients (Group HCV) were evaluated for necroinflammation and fibrosis (Ishak) by a pathologist unaware of the clinical and laboratory data. All patients were HBsAg-negative, with no history of alcohol abuse and naïve to anti-HCV treatment. At LB, 78.4% of patients in Group HIV/HCV were on an antiretroviral regimen.

RESULTS

HIV/HCV-coinfected patients compared to the HCV-monoinfected patients were younger (p < 0.0001), more frequently males (p < 0.0001), and had HCV genotype 3 (p < 0.0001); they showed a good immunological condition (CD4+ cell count: 518 ± 166 cells/mm(3)). Patients in Group HIV/HCV more frequently showed a fibrosis score ≥4 (27.5 vs. 20.6%, p < 0.05) and a necroinflammation score ≥9 (25.9 vs. 13.4%; p < 0.0001). The prevalence of patients with fibrosis score ≥4 was significantly higher in older age classes in both Group HIV/HCV (p < 0.005) and Group HCV (p < 0.05). A necroinflammation score ≥9 was significantly higher in older age classes only in Group HIV/HCV (p < 0.05). A multivariate analysis for Group HIV/HCV revealed that the patient age and nadir of CD4+ cell count were independently associated to higher degrees of fibrosis, the patient age and antiretroviral treatment were associated to higher degrees of necroinflammation, and HCV genotype 3 was associated to higher degrees of steatosis.

CONCLUSION

The data suggest a need for early anti-HCV treatment in both HCV-monoinfected and HIV/HCV-coinfected patients.

No evidence of enteroviruses in the intestine of patients with type 1 diabetes

AIMS/HYPOTHESIS

The purpose of this study was to investigate whether the gut mucosa is a reservoir for enterovirus persistence in patients with type 1 diabetes.

METHODS

Small intestine biopsy samples from 25 individuals at different stages of type 1 diabetes, 21 control individuals and 27 individuals with coeliac disease were analysed for the presence of enterovirus RNA by using both radioactive in-situ hybridisation and real-time RT-PCR and for the presence of enterovirus proteins by immunostaining with antibodies against VP1 and VP4-2-3 capsid proteins and virus polymerase. Lymphocytic enteropathy and serum anti-VP1 antibodies were also evaluated at the time of biopsy. Moreover, high-throughput sequencing was performed to identify viral transcripts or genomes.

RESULTS

Enterovirus was not detected by in-situ hybridisation or RT-PCR in any of the individuals tested. Immunohistology revealed a few stained cells in the intestinal epithelium in a low number of individuals, with no difference between diabetic and non-diabetic individuals. Levels of serum IgG against VP1 did not differ between control individuals and those with diabetes or coeliac disease and no evidence of diabetes-related lymphocytic enteropathy was detected. High-throughput sequencing did not reveal specific enterovirus sequences in the gut mucosa of individuals with type 1 diabetes.

CONCLUSIONS/INTERPRETATION

Prolonged/persistent enterovirus infections in gut mucosa are not common in patients with type 1 diabetes.

TNM staging of neoplasms of the endocrine pancreas: results from a large international cohort study

BACKGROUND

Both the European Neuroendocrine Tumor Society (ENETS) and the International Union for Cancer Control/American Joint Cancer Committee/World Health Organization (UICC/AJCC/WHO) have proposed TNM staging systems for pancreatic neuroendocrine neoplasms. This study aims to identify the most accurate and useful TNM system for pancreatic neuroendocrine neoplasms.

METHODS

The study included 1072 patients who had undergone previous surgery for their cancer and for which at least 2 years of follow-up from 1990 to 2007 was available. Data on 28 variables were collected, and the performance of the two TNM staging systems was compared by Cox regression analysis and multivariable analyses. All statistical tests were two-sided.

RESULTS

Differences in distribution of sex and age were observed for the ENETS TNM staging system. At Cox regression analysis, only the ENETS TNM staging system perfectly allocated patients into four statistically significantly different and equally populated risk groups (with stage I as the reference; stage II hazard ratio [HR] of death = 16.23, 95% confidence interval [CI] = 2.14 to 123, P = .007; stage III HR of death = 51.81, 95% CI = 7.11 to 377, P < .001; and stage IV HR of death = 160, 95% CI = 22.30 to 1143, P < .001). However, the UICC/AJCC/WHO 2010 TNM staging system compressed the disease into three differently populated classes, with most patients in stage I, and with the patients being equally distributed into stages II-III (statistically similar) and IV (with stage I as the reference; stage II HR of death = 9.57, 95% CI = 4.62 to 19.88, P < .001; stage III HR of death = 9.32, 95% CI = 3.69 to 23.53, P = .94; and stage IV HR of death = 30.84, 95% CI = 15.62 to 60.87, P < .001). Multivariable modeling indicated curative surgery, TNM staging, and grading were effective predictors of death, and grading was the second most effective independent predictor of survival in the absence of staging information. Though both TNM staging systems were independent predictors of survival, the UICC/AJCC/WHO 2010 TNM stages showed very large 95% confidence intervals for each stage, indicating an inaccurate predictive ability.

CONCLUSION

Our data suggest the ENETS TNM staging system is superior to the UICC/AJCC/WHO 2010 TNM staging system and supports its use in clinical practice.

Characterization of innate responses elicited by neoadjuvant radio-chemotherapy for rectal cancer

e15044

Background: The neoadjuvant chemo-radiotherapy (CT-RT) has improved the treatment of locally advanced rectal cancer reducing the local recurrence. However a survival benefit has not been reached yet. In order to increase the rate of pathological complete remissions in our Institution we intensified both the CT schedule adding oxaliplatin to 5-FU and the RT program with tomotherapy. The aim of this study was to verify: whether the pattern of innate response elicited by the neoadjuvant CT-RT is heterogeneous among pts and whether this information can be used to identify which pts will benefit from the treatment. Methods: We collected samples of T3N+M0 rectal cancer pts before, during and after neoadjuvant CT-RT (3 cycles of oxaliplatin + 5-FU; 45 Gy). At each time point we characterized circulating monocytes by flow cytometry, infiltrating macrophages by immunoistochemistry (IHC) and selected inflammatatory molecules by ELISA.Results: We recruited so far 25 pts, of whom 10 have reached the surgery with three pathological complete remission and four down staging. No substantial changes were detectable in the number of circulating monocytes. In contrast we observed a clear expansion of CD14/CD86 and CD14/CD163 double positive subsets. This event was transient and apparently causally related to the treatment since it abated at the later time point. Moreover, it correlated with sensitivity to the treatment: 5/7 pts who underwent disease regression had an early and transitory increase of the number of CD14/CD86 and CD14/CD163 positive cells, which was absent or negligible in non responder pts. The IHC study revealed a massive tumoral infiltration by macrophages which displayed clear features of alternative M2 polarization as assessed by expression of the CD163 and 206 scavenger receptors. A subset of pts had elevated PTX3 and low CRP concentration at the onset of treatment. PTX3 concentration abated after the first CT cycle. Conclusions: These data suggest that neoadjuvant CT-RT modulates the cellular components of innate immune responses, that could represent valuable predictive factors.

No significant financial relationships to disclose.

Ghrelin-producing epsilon cells in the developing and adult human pancreas

AIMS/HYPOTHESIS

While the mechanisms of specification and the reciprocal relationships of the four types of endocrine cell (alpha, beta, delta and pancreatic polypeptide cells) within the human endocrine pancreas are well described in adults and during fetal development, ghrelin-immunoreactive cells (epsilon cells) remain poorly understood.

METHODS

We studied epsilon cells in 24 human fetal pancreases between 11 and 39 weeks of development and in 32 pancreases from adult organ donors.

RESULTS

We observed single epsilon cells scattered in primitive exocrine tissue from gestational week 13 in developing pancreas. Later in the developmental process, epsilon cells started to aggregate into clusters. From gestational week 21, epsilon cells were observed located around developing islets, forming an almost continuous layer at the peripheral rim of the islets. They remain localised on the mantle of the islets, although at different amounts, in the adult pancreas. Co-production of ghrelin with insulin, glucagon or somatostatin was not detected during fetal development. Co-production with pancreatic polypeptide was evident sporadically. Epsilon cells co-produced NK2 homeobox 2 and ISL LIM homeobox 1, but not NK6 homeobox 1 and paired box 6. A quantitative analysis was performed in the adult pancreas: there was an average of 1.17 + 1.17 epsilon cells per islet, the relative epsilon cell volume was 0.14 + 0.16% and the epsilon cell mass was 0.13 + 0.15 g. Neither sex nor age affected the epsilon cell mass, although there was a significant inverse correlation with BMI.

CONCLUSIONS/INTERPRETATION

During fetal development epsilon cells show an ontogenetic and morphogenetic pattern that is distinct from that of alpha and beta cells.

Endoscopic ultrasound-guided application of a new internally gas-cooled radiofrequency ablation probe in the liver and spleen of an animal model: a preliminary study

BACKGROUND AND STUDY AIMS

In a previous study, a new flexible bipolar hybrid cryotherm probe was applied with success to the pancreas of a living pig. Here we evaluated feasibility, efficacy, and safety of its application to the porcine liver and spleen.

MATERIAL AND METHODS

Ten applications to the liver and nine to the spleen were performed in 19 pigs. Power input (16-18 W) and simultaneous cooling with CO(2) (standardized pressure: 675 psi) as the cryogenic agent were investigated. Application time varied from 120 seconds to 900 seconds. The ablation area was measured by endoscopic ultrasound (EUS) after ablation (T0), and before euthanasia (T1). Gross pathology (T2) and histology after necropsy represented the gold standard. The interval from treatment to euthanasia was 1 or 2 weeks.

RESULTS

For both organs the correlation between EUS and gross pathology was good (correlation coefficient R(liver) = 0.71; R(spleen) = 0.73). EUS tended to overestimate the area of the ablated zone. EUS observed a time-dependent ablation area: we demonstrated a positive trend of lesion size (T1) over time in liver tissue (R = 0.51 (P = 0.1)). In the spleen we found a clear correlation of lesion area T2 and application time (R = 0.75, P = 0.01). There were no complications.

CONCLUSIONS

Selective EUS-guided transgastric cryotherm ablation of the liver and spleen in a pig model is feasible and safe. The new bipolar probe creates a time-dependent ablation area without any complications, and opens a field of new potential indications of RF-ablative therapies.

Collagenous colitis: a case series with confocal laser microscopy and histology correlation

Confocal laser endomicroscopy (CLE) was carried out in seven patients with chronic watery diarrhea (three men; age range 68 - 84 years) to find the correspondence between CLE and histological findings in collagenous colitis. On the basis of the CLE images, two to five biopsies were performed in various segments of the colon. The endoscopic and histological diagnoses of collagenous colitis were made blindly. The quality of the CLE images was quantified from 0 (the endoscopist could not visualize the corresponding histologic equivalent) to 3 (the endoscopist could identify >or= 80 % of the corresponding histologic equivalent). Four out of seven patients had histological findings of collagenous colitis. Correspondence between histology and CLE images yielded the following scores: 3 for epithelial architecture, 3 for goblet cells, 3 for vessels, and 2 for inflammatory infiltrate. In collagenous colitis patients, CLE identified a well-defined "shell" around the crypts, corresponding to the increase in the thickness of the subepithelial collagenous plate evidenced by histology. CLE appears to be a promising means of identifying typical collagenous colitis features.

Endoscopic ultrasound-guided application of a new hybrid cryotherm probe in porcine pancreas: a preliminary study

BACKGROUND AND STUDY AIMS

Open, laparoscopic, or percutaneous radiofrequency (RF) ablation of the pancreas is still dangerous, whereas endoscopic ultrasound (EUS)-guided ablation might reduce risk because it is less invasive and provides real-time monitoring. We aimed to demonstrate the feasibility of transluminal RF ablation and to evaluate the efficacy and safety of a new flexible bipolar ablation probe combining RF and cryotechnology.

METHODS

14 ablations were performed in 14 pigs. Energy input (16 W) and simultaneous cryogenic cooling with carbon dioxide (650 psi) were standardized. Application time range was 120 - 900 seconds. Ablation area was measured by EUS immediately after ablation (area T0), and before euthanasia (area T1). Macroscopic findings (area T2) and histological findings after necropsy served as gold standard. The interval from application to euthanasia was either 1 or 2 weeks.

RESULTS

The correlation between EUS findings (area T1) and macroscopic appearance (area T2) was good ( R = 0.89). The correlation between the T2 ablation area and the application time showed a fitted ratio of 2.3 ( P < 0.0001) with a 1-week interval and 0.2 ( P = 0.01) with a 2-week interval. No pig died because of the procedure. Two pigs showed histochemical pancreatitis, which was clinically overt in one. Necropsy additionally revealed one burn to the gastric wall and four gut adhesions.

CONCLUSIONS

Selective transluminal RF ablation of the pancreas under EUS control in a living pig model is feasible. The new flexible bipolar probe creates an ablation area with extent related to the duration of application, and with fewer complications than conventional RF ablation techniques.

Arterial vs pancreatic phase: which is the best choice in the evaluation of pancreatic endocrine tumours with multidetector computed tomography (MDCT)?

PURPOSE

The aim of this study was to assess whether the pancreatic phase may replace the arterial phase in the evaluation of endocrine pancreatic tumours.

MATERIALS AND METHODS

Twenty-nine endocrine pancreatic lesions with definitive morphological and immunohistochemical characterisation after surgical treatment (n=24) or fine-needle-aspiration cytology under endoscopic ultrasonography guidance (n=5) were retrospectively evaluated. All lesions were studied with triple-phase 16-row multidetector computed tomography (MDCT). Images obtained during each phase were separately interpreted by two senior radiologists experienced in pancreatic pathology and who were blinded to surgical results. Endocrine tumour and normal pancreas attenuation and the mean absolute tumour-to-gland attenuation difference were measured in each phase, and data were analysed with Student's t test. Visualisation of arterial vascular abnormalities and hypervascular liver metastases in the arterial and pancreatic phases and the diagnostic contribution of the two phases were compared.

RESULTS

For both radiologists, the mean absolute tumour-to-gland attenuation difference was significantly higher (p<0.05) in the pancreatic phase (40+/-53 HU and 34+/-56 HU) than in the arterial phase (31+/-38 HU and 26+/-43 HU). There were no differences in the detection of arterial vascular abnormalities or hypervascular liver metastases in the two phases. The diagnostic contribution was higher in the pancreatic phase.

CONCLUSIONS

In our experience, the pancreatic phase can replace the arterial phase in the evaluation of pancreatic endocrine tumours.

Sentinel node mapping during laparoscopic distal gastrectomy for gastric cancer

BACKGROUND

The goal of this study was to evaluate the feasibility and accuracy of sentinel node (SN) mapping with endoscopic submucosal blue dye injection during laparoscopic distal gastrectomy for gastric cancer.

METHODS

Thirty-four patients affected by gastric adenocarcinoma without gross clinical serosal invasion and distant metastasis were prospectively enrolled. At the start of the surgery, 2 ml of 2% patent blue was endoscopically injected into the submucosal layer at four points around the site of the primary tumor. Sentinel nodes were defined as nodes that were stained by the blue dye within 5-10 min after the dye injection. After identification and removal of sentinel lymph nodes, each patient underwent laparoscopic distal gastrectomy with D1 (n = 2) or D2 (n = 32) lymphadenectomy.

RESULTS

Of the 34 patients, 14 had positive nodules (41%). SNs were detectable as blue nodes in 27 (80%) of 34 patients. The mean number of dissected lymph nodes per patient was 31 +/- 10 (range = 16-64) and the mean number of blue nodes was 1.5 (range = 1-4). Only five (sensitivity 36%) of 14 N(+) patients had at least one metastatic lymph node among the SNs identified. In these 14 patients the sentinel node was traced in 12 cases. Sentinel node status diagnosed the lymph node status with 74% accuracy. In early gastric cancer (n = 18), three patients had lymph node metastasis. These early gastric cancer patients with nodal metastases had at least one metastatic lymph node among the SNs identified (sensitivity 100%).

CONCLUSIONS

Blue dye SN mapping during laparoscopic distal gastrectomy seems to be a feasible and accurate diagnostic tool for detecting lymph node metastasis in patients with early-stage gastric cancer in which the accuracy of the method was 100%. However, in more advanced gastric cancer the results are not satisfactory. Validation of this method requires further studies on technical issues, including selection of the tracers.

Sentinel node mapping during laparoscopic distal gastrectomy for gastric cancer

BACKGROUND

The goal of this study was to evaluate the feasibility and accuracy of sentinel node (SN) mapping with endoscopic submucosal blue dye injection during laparoscopic distal gastrectomy for gastric cancer.

METHODS

Thirty-four patients affected by gastric adenocarcinoma without gross clinical serosal invasion and distant metastasis were prospectively enrolled. At the start of the surgery, 2 ml of 2% patent blue was endoscopically injected into the submucosal layer at four points around the site of the primary tumor. Sentinel nodes were defined as nodes that were stained by the blue dye within 5-10 min after the dye injection. After identification and removal of sentinel lymph nodes, each patient underwent laparoscopic distal gastrectomy with D1 (n = 2) or D2 (n = 32) lymphadenectomy.

RESULTS

Of the 34 patients, 14 had positive nodules (41%). SNs were detectable as blue nodes in 27 (80%) of 34 patients. The mean number of dissected lymph nodes per patient was 31 +/- 10 (range = 16-64) and the mean number of blue nodes was 1.5 (range = 1-4). Only five (sensitivity 36%) of 14 N(+) patients had at least one metastatic lymph node among the SNs identified. In these 14 patients the sentinel node was traced in 12 cases. Sentinel node status diagnosed the lymph node status with 74% accuracy. In early gastric cancer (n = 18), three patients had lymph node metastasis. These early gastric cancer patients with nodal metastases had at least one metastatic lymph node among the SNs identified (sensitivity 100%).

CONCLUSIONS

Blue dye SN mapping during laparoscopic distal gastrectomy seems to be a feasible and accurate diagnostic tool for detecting lymph node metastasis in patients with early-stage gastric cancer in which the accuracy of the method was 100%. However, in more advanced gastric cancer the results are not satisfactory. Validation of this method requires further studies on technical issues, including selection of the tracers.

Optical coherence tomography compared with histology of the main pancreatic duct structure in normal and pathological conditions: an 'ex vivo study'

BACKGROUND AND STUDY AIMS

Optical coherence tomography permits high-resolution imaging of tissue microstructures by a probe inserted into the main pancreatic duct through a standard ERCP catheter. The aim of this study was to compare optical coherence tomography images of the main pancreatic duct with histology and identify the optical coherence tomography pattern of the normal and pathological structure of the main pancreatic duct.

PATIENTS AND METHODS

Multiple sections of neoplastic and non-neoplastic segments of 10 consecutive surgical pancreatic specimens obtained from patients with pancreatic head adenocarcinoma were investigated by optical coherence tomography scanning within 1h of resection. One hundred optical coherence tomography findings were then compared with the corresponding histopathological diagnoses.

RESULTS

Main pancreatic duct wall architecture appeared at optical coherence tomography investigation as a three-layer structure with a different back-scattered signal from each layer. Optical coherence tomography imaging was concordant with histology in 81.8% and 18.75% of sections with normal tissue and chronic inflammatory changes. The K statistic between the two procedures was equal to 0.059 for non-neoplastic main pancreatic duct wall appearance. In all neoplastic sections optical coherence tomography showed a subverted layer architecture with heterogeneous back-scattering of the signal and was concordant with histology.

CONCLUSIONS

Optical coherence tomography provided images of main pancreatic duct wall structure that were concordant with histology in 100% of cases in presence of neoplastic ductal changes and did not have false-positive or negative results. Optical coherence tomography images were also concordant with histology in about 80% of cases with normal main pancreatic duct structure; however, the differential diagnosis between normal tissue and chronic pancreatitis or dysplastic changes appeared very difficult.

Main pancreatic duct, common bile duct and sphincter of Oddi structure visualized by optical coherence tomography: An ex vivo study compared with histology

BACKGROUND

Optical coherence tomography has been proposed to obtain high-resolution imaging of tissue structure of GI tract. Up till now, the optical coherence tomography appearance of the common bile duct, main pancreatic duct and sphincter of Oddi wall structure has not yet been defined.

AIMS

To compare, in a prospective study, optical coherence tomography images of pancreato-biliary ductal system with histology and identify the optical coherence tomography pattern of the normal wall structure of the ducts.

METHODS

Multiple sections of non-neoplastic segments of five consecutive ex vivo human pancreatic specimens were investigated by optical coherence tomography scanning within 1h of resection. Sixty optical coherence tomography images were compared with the corresponding histological findings.

RESULTS

Optical coherence tomography appearance of normal common bile duct, main pancreatic duct and sphincter of Oddi is characterized by a differentiated three-layer architecture with a regular surface and a homogeneous back-scattered signal, corresponding to the single layer of epithelial cells, the connective-muscular layer and the muscular or acinar structure, respectively. Optical coherence tomography and histology findings were concordant in all cases.

CONCLUSIONS

Optical coherence tomography was able to provide in real-time images of wall structure of the normal common bile duct, main pancreatic duct and sphincter of Oddi that are similar to those obtained by histology. These results suggest that optical coherence tomography could enable high-resolution images to be obtained from the pancreato-biliary system during an ERCP procedure.

[Diagnostic criteria and classification of gastro-intestinal pancreatic endocrine tumors]

In this presentation the gastrointestinal pancreatic endocrine tumors (ETs) are subdivided into well differentiated ETs and poorly differentiated ETs. Well differentiated ETs are subclassified into ETs with benign behavior, ETs with uncertain behavior and well differentiated endocrine carcinomas. The criteria allowing a distinction among these main types of neoplasms are listed according to the site of origin of the ETs. In addition, the main functional types of ETs of the pancreas, stomach, duodenum, jejunum, ileum, appendix and large bowel are briefly described.

Immunohistochemical pattern of hMSH2/hMLH1 in familial and sporadic colorectal, gastric, endometrial and ovarian carcinomas with instability in microsatellite sequences

Alterations of DNA mismatch repair (MMR) genes are involved in carcinogenesis of sporadic and inherited human cancers characterised by instability of DNA microsatellite sequences (MSI). MSI tumours are usually identified using molecular analysis. In the present investigation, hMLH1 and hMSH2 immunohistochemistry was tested in order to evaluate the utility of this method in predicting MMR deficiency. Colorectal (72), gastric (68), endometrial (44) and ovarian (17) carcinomas were independently evaluated for familial history, histological type of tumour, MSI status and immunohistochemical results. Loss of expression of either hMLH1 or hMSH2 was observed in 51 of 55 (92.8%) MSI tumours, while 145 of 146 microsatellite stable (MSS) tumours expressed both the hMLH1 and hMSH2 gene products. Independently of tumour site, an overall agreement between immunohistochemical and molecular results was observed in 15 hereditary non-polyposis colorectal cancer-related tumours. Among sporadic tumours, only 2 of 60 colorectal and 2 of 66 gastric carcinomas, displaying MSI, expressed both hMLH1 and hMSH2 gene products. All 39 endometrial and 16 ovarian tumours presented a concordant molecular and immunohistochemical profile. These data show that immunohistochemistry is an accurate and rapid method to predict the presence of defective DNA MMR genes and to identify both sporadic and familial MSI tumours.

The value of microsatellite instability in the detection of HNPCC families and of sporadic colorectal cancers with special biological features: an investigation on a series of 100 consecutive cases

BACKGROUND

Microsatellite instability (MI) is a biological characteristic of most tumors involved in hereditary non-polyposis colorectal cancer (HNPCC). This disease appears to be caused by germline mutations in mismatch repair (MMR) genes, which are responsible for repairing single base-pair mismatches. At least five human genes participate in MMR. MI also occurs in 10%-15% of sporadic colorectal cancers. Because MI detection has been suggested as an alternative diagnostic tool for identification of HNPCC families, in this study we analyzed the MI pattern in 100 consecutive colorectal carcinomas in order to correlate them with the clinicopathologic features and family histories of the patients.

PATIENTS AND METHODS

A series of 100 colorectal cancers was evaluated for MI with 10 polymerase chain reaction primer sets. Instability results were compared with family history and other clinical and biological characteristics.

RESULTS

MI was detected in 36 of 100 cancers, 27 of which showed low instability and nine a high instability. The low- and high-instability cases showed similar clinicopathological characteristics, and significantly positive associations were observed between MI and mucinous histological type (P = 0.0001) and MI and peritumoral lymphocytic infiltration (P = 0.01). A single HNPCC family was identified in the high-grade MI group, while two families belonged to the MI-negative group.

CONCLUSIONS

Our data suggest that MI screening is probably not an efficient strategy for identifying HNPCC cases. MI does, however, appear capable of defining a category of colorectal cancers with favourable prognostic features and should be investigated at least in all cases of mucinous adenocarcinomas.