Gabriele Delconte

MSH3 Protein Expression and Nodal Status in MLH1-Deficient Colorectal Cancers

Purpose: Patients with colorectal cancers (CRC) and high microsatellite instability (MSI) have a better outcome than their chromosome-unstable counterpart. Given the heterogeneity of microsatellite-unstable CRCs, we wanted to see whether any MSI-associated molecular features are specifically associated with prognosis. Experimental Design: One hundred and nine MSI-high CRCs were typed for primary mismatch repair (MMR) defect and for secondary loss of MMR proteins. Frameshifts at seven target genes, mutations in the RAS pathway, and methylation at MLH1/CDKN2A promoters were also searched. The interplay of molecular findings with clinicopathologic features and patient survival was analyzed. Results: Of 84 MLH1-deficient CRCs, 31 (36.9%) had MSH3 and 11 (13.1%) had MSH6 loss (P < 0.001), biallelic frameshift mutations at mononucleotide repeats accounting for most (78%) MSH3 losses. As compared with MSH3-retaining cancers, MLH1-deficient tumors with MSH3 loss showed a higher number of mutated target genes (3.94 ± 1.56 vs. 2.79 ± 1.75; P = 0.001), absence of nodal involvement at pathology [N0; OR, 0.11; 95% confidence interval (CI), 0.04–0.43, P < 0.001], and better disease-free survival (P = 0.06). No prognostic value was observed for KRAS status and for MLH1/CDKN2A promoter methylation. The association between MSH3 loss and N0 was confirmed in an independent cohort of 71 MLH1-deficient CRCs (OR, 0.23; 95% CI, 0.06–0.83, P = 0.02). Conclusions: MLH1-deficient CRCs not expressing MSH3 have a more severe MSI, a lower rate of nodal involvement, and a better postsurgical outcome. Clin Cancer Res; 18(11); 3142–53. ©2012 AACR.

Molecular heterogeneity and prognostic implications of synchronous advanced colorectal neoplasia

Background:It is uncertain whether synchronous colorectal cancers (S-CRCs) preferentially develop through widespread DNA methylation and whether they have a prognosis worse than solitary CRC. As tumours with microsatellite instability (MSI) may confound the effect of S-CRC methylation on outcome, we addressed this issue in a series of CRC characterised by BRAF and MS status.Methods:Demographics, clinicopathological records and disease-specific survival (DSS) were assessed in 881 consecutively resected CRC undergoing complete colonoscopy. All tumours were typed for BRAFc.1799T>A mutation and MS status, followed by search of germ-line mutation in patients with MSI CRC.Results:Synchronous colorectal cancers (50/881, 5.7%) were associated with stage IV microsatellite-stable (MSS) CRC (19/205, 9.3%, P=0.001) and with HNPCC (9/32, 28%, P<0.001). BRAF mutation (60/881, 6.8%) was associated with sporadic MSI CRC (37/62, 60%, P<0.001) but not with S-CRC (3/50, 6.0%, P=0.96). Synchronous colorectal cancer (HR 1.82; 95% CI 1.15–2.87; P=0.01), synchronous advanced adenoma (HR 1.81; 95% CI 1.27–2.58; P=0.001), and BRAFc.1799T>A mutation (HR 2.16; 95% CI 1.25–3.73; P=0.01) were stage-independent predictors of death from MSS CRC. Disease-specific survival of MSI CRC patients was not affected by S-CRC (HR 0.74; 95% CI 0.09–5.75; P=0.77).Conclusion:Microsatellite-stable CRCs have a worse prognosis if S-CRC or synchronous advanced adenoma are diagnosed. The occurrence and the enhanced aggressiveness of synchronous MSS advanced neoplasia are not associated with BRAF mutation.

Early expression of the fractalkine receptor CX3CR1 in pancreatic carcinogenesis.

Background:In pancreatic ductal adenocarcinoma (PDAC), fractalkine receptor CX3CR1 contributes to perineural invasion (PNI). We investigated whether CX3CR1 expression occurs early in PDAC and correlates with tumour features other than PNI.Methods:We studied CX3CR1 and CX3CL1 expression by immunohistochemistry in 104 human PDAC and coexisting Pancreatic Intraepithelial Neoplasia (PanIN), and in PdxCre/LSL-KrasG12D mouse model of PDAC. CX3CR1 expression in vitro was studied by a spheroid model, and in vivo by syngenic mouse graft of tumour cells.Results:In total, 56 (53.9%) PDAC expressed CX3CR1, 70 (67.3%) CX3CL1, and 45 (43.3%) both. CX3CR1 expression was independently associated with tumour glandular differentiation (P=0.005) and PNI (P=0.01). Pancreatic Intraepithelial Neoplasias were more frequently CX3CR1+ (80.3%, P<0.001) and CX3CL1+ (86.8%, P=0.002) than matched cancers. The survival of PDAC patients was better in those with CX3CR1+ tumour (P=0.05). Mouse PanINs were also CX3CR1+ and -CL1+. In vitro, cytokines significantly increased CX3CL1 but not CX3CR1 expression. Differently, CX3CR1 was upregulated in tumour spheroids, and in vivo only in well-differentiated tumours.Conclusion:Tumour differentiation, rather than inflammatory signalling, modulates CX3CR1 expression in PanINs and PDAC. CX3CR1 expression pattern suggests its early involvement in PDAC progression, outlining a potential target for interfering with the PanIN transition to invasive cancer.

Prognostic Value of Colorectal Cancer Biomarkers

Despite the large amount of data in cancer biology and many studies into the likely survival of colorectal cancer (CRC) patients, knowledge regarding the issue of CRC prognostic biomarkers remains poor. The Tumor-Node-Metastasis (TNM) staging system continues to be the most powerful and reliable predictor of the clinical outcome of CRC patients. The exponential increase of knowledge in the field of molecular genetics has lead to the identification of specific alterations involved in the malignant progression. Many of these genetic alterations were proposed as biomarkers which could be used in clinical practice to estimate CRC prognosis. Recently there has been an explosive increase in the number of putative biomarkers able to predict the response to specific adjuvant treatment. In this review we explore and summarize data concerning prognostic and predictive biomarkers and we attempt to shed light on recent research that could lead to the emergence of new biomarkers in CRC.

EUS-guided tissue sampling with a 20-gauge core biopsy needle for the characterization of gastrointestinal subepithelial lesions: A multicenter study

Background and Objective: A new 20-gauge (G) biopsy needle with a core-trap technology has been developed with a large core size and enhanced flexibility. The aim of this multicenter study was to determine the feasibility, efficacy, and safety of EUS-guided fine-needle biopsy (EUS-FNB) with the new 20G needle in diagnosing subepithelial lesions (SELs). Materials and Methods: Retrospectively collected data from consecutive patients with SELs undergoing EUS-FNB with the 20G needle at five centers were analyzed. Results: A total of 50 SELs were included. The mean lesion size was 43.1 ± 17.5 mm. The lesion locations were esophagus (n = 1), stomach (n = 37), distal duodenum (n = 5), rectum (n = 6), and colon (n = 1). The procedure was technically feasible in all patients. Definitive diagnosis with full histological assessment including immunohistochemistry was obtained in 88% (44/50) of the patients. Considering malignant versus benign lesions, the sensitivity, specificity, positive predictive value, and negative predictive value were 85% (95% confidence interval [CI] 70.2–94.3), 100% (95% CI 58.7%–100%), 100% (95% CI 85.1%–100%), and 62.5 (95% CI 27.7–84.8), respectively. No major complications requiring additional care have been observed. Conclusions: In this multicenter study, we found that EUS-FNB with the new 20G core needle is an effective and safe method for the diagnosis of SELs with a high rate of producing adequate histological material and high diagnostic accuracy even from difficult-to-approach anatomical locations.

Ki-67 and presence of liver metastases identify different progression-risk classes in pancreatic neuroendocrine neoplasms (pNEN) undergoing resection

In pancreatic neuroendocrine neoplasms (pNEN), size ≤2 cm and Ki-67 < 3% suggest indolent behavior, but no factor alone predicts prognosis. We investigated factors predictive of tumor progression in 80 pNENs surgically resected in a single Institution from 1995 to 2015. At multivariable analysis the only two independent variables related to PFS were Ki-67 (HR 2.97; 95%CI 1.26-7.02) and presence of synchronous liver metastases (HR 3.60; 95%CI 1.70-7.61). Using Ki-67 < 3% and M0 as reference, the HR for tumor progression was 3.21 (95%CI 1.18-8.74) for M0 patients with Ki-67 3-20%, 5.06 (2.29-11.2) for M1 patients with Ki-67 ≤ 20% and 24.3 (6.64-89.2) for those with Ki-67 > 20%. Tumor size (≤2 vs. >2 cm) was not a predictive factor at any analysis. Intra-class correlation of Ki-67 values on pre-surgical biopsies vs. surgical specimens was 0.99 and Ki-67 classes were correctly identified in 97% of biopsies. Ki-67 and presence of liver metastases are the major prognostic factors in pNEN and identify different progression risks regardless of tumor size. Pre-surgical pNEN biopsy for Ki-67 assessment should be included in the evaluation of patients with 1-2 cm tumors to help in the decision on whether to perform surgical resection.

Preoperative Capecitabine, Oxaliplatin, and Irinotecan in Resectable Gastric or Gastroesophageal Junction Cancer: Pathological Response as Primary Endpoint and FDG-PET Predictions

Objectives: This phase II trial was aimed at assessing the safety and activity of capecitabine, oxaliplatin, and irinotecan (COI regimen) as a preoperative treatment for resectable gastric cancer (GC) or gastroesophageal junction (GEJ) cancer. Methods: Patients affected by T3-T4/N0-N+/M0 GC/GEJ cancer were treated with the COI regimen for 4 cycles followed by restaging and gastroresection with D2 lymphadenectomy. Four postoperative cycles were scheduled. The primary endpoint was pathological response rate according to Becker et al. [Cancer 2003;98:1521-1530]. The potential role of fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) as a predictive biomarker of pathological tumor response was assessed in a subgroup of 19 evaluable patients. Results: Between January 2011 and October 2015, a total of 40 patients were enrolled. After the preoperative phase, 36 out of 40 patients (90%) were considered eligible for surgery: 12 patients (30%) achieved a pathological response. The most frequent grade 3/4 adverse events were diarrhea (27%), nausea (25%), and fatigue (17%). Grade 3 neutropenia occurred in 7.5% of patients. A lower standard uptake value at baseline FDG-PET/CT was associated with pathological response. Conclusion: COI combination is active with a manageable toxicity profile in patients with resectable GC or GEJ cancer. FDG-PET/CT imaging as a surrogate biomarker of pathological response in this setting appears fascinating but should be further investigated.

The role of wireless capsule endoscopy (WCE) in the detection of occult primary neuroendocrine tumors

BACKGROUND AND AIMS Neuroendocrine tumors (NETs) are a heterogeneous group of neoplasms with unclear etiology that may show functioning or non-functioning features. Primary tumor localization often requires integrated imaging. The European Neuroendocrine Tumors Society (ENETS) guidelines proposed wireless-capsule endoscopy (WCE) as a possible diagnostic tool for NETs, if intestinal origin is suspected. However, its impact on therapeutic management is debated. We aimed to evaluate the yield of WCE in detecting intestinal primary tumors in patients showing liver NET metastases when first-line investigations are inconclusive. METHOD Twenty-four patients with a histological diagnosis of metastatic NET from liver biopsy and no evidence of primary lesions at first-line investigations were prospectively studied in an ENETS-certified tertiary care center. Wireless-capsule endoscopy was requested before explorative laparotomy and intra-operative ultrasound. The diagnostic yield of WCE was compared to the surgical exploration. RESULTS Sixteen subjects underwent surgery; 11/16 had positive WCE identifying 16 bulging lesions. Mini-laparotomy found 13 NETs in 11/16 patients (9 small bowel, 3 pancreas, 1 bile ducts). Agreement between WCE and laparotomy was recorded in 9 patients (Sensitivity=75%; Specificity=37.5%; PPV=55%; NPV=60%). Correspondence assessed per-lesions produced similar results (Sensitivity=70%; Specificity=25%; PPV=44%; NPV=50%). No capsule retentions were recorded. CONCLUSIONS Wireless-capsule endoscopy is not indicated as second-line investigation for patients with gastro-entero-pancreatic NETs. In the setting of a referral center, it might provide additional information when conventional investigations are inconclusive about the primary site.

Su1540 Self-Expandable Biodegradable Stent in the Management of Refractory Benign Colorectal Strictures: Preliminary Results From a Pilot Study

Su1540 Self-Expandable Biodegradable Stent in the Management of Refractory Benign Colorectal Strictures: Preliminary Results From a Pilot Study Alessandro Repici, Giacomo Rando, Fabio Romeo, Nico Pagano, Alessandra Carlino, Eva Vitetta, Gabriele Delconte, Giuseppe Strangio, Silvio Danese, Daniel D. Ferreira, Alberto Malesci Servizio di Endoscopia Digestiva, IRCCS Istituto Clinico Humanitas, Rozzano (MI), Italy Self-expanding metal stents (SEMS) are an established treatment for palliation of malignant colorectal strictures and as a bridge to surgery for acute malignant colonic obstruction. Patients with benign colonic strictures may potentially benefit from stent placement, but little and controversial data exist for this indication. Aim of this study was to evaluate the efficacy and safety of biodegradable stents in the management of benign refractory colorectal strictures. A single center pilot study including patients with benign strictures located within 25 from anal verge refractory to mechanical or pneumatic dilation (at least 3 sessions). Exclusion criteria were: presence of concomitant fistula, suspicion of malignancy, diverticulosis, previous stent placment and stricture located too close to the anus ( 5cm). Outcome was evaluated clinically and as ability to pass through the stricture with a regular size colonoscope. Data were prospectively collected in an electronic database and follow-up was scheduled with endoscopic control after 14, 30, 90 days and afterwards at monthly interval by telephone interview. The stent used was an esophageal biodegradable stent (Ella, Czech Rep), in two different size 25 and 30 mm. Stent was placed under fluoroscopic and endoscopic control. Results: 11 consecutive patients (8M/3F, mean age 58.8y) were enrolled from September 2009. The etiologies of the stricture were: postsurgical anastomotic (n 8), radiation-induced (n 2), and Crohn’s (n 1) disease. Mean stricture length was 2.4 cm (2-4 cm). Stent placement was technically successful for all patients. No perforation occurred in the present series. Stent migration occurred in 4 patients after 4 days, 10 days, 14 days and 3 weeks respectively. One of these patients developed an acute obstruction after stent migration and underwent emergency surgery. Two patients are under periodic dilation and one was retreated with a second biodegradable stent. One patient presented with acute bowel occlusion due to fecal impaction 2 months after stent placement and was successfully treated by endoscopy. Mean follow-up was 7.5 months (range 4-14 months). Among the 7 patients who maintained the stent until its complete degradation, 5 remained asymptomatic and didn’t develop stricture recurrence. Two patients (one with radiation-induced and one with post-surgical stricture) developed symptomatic stricture recurrence and are currently treated with periodic dilation. Placement of biodegradable stent may represent a potential therapeutic alternative in patients with refractory colorectal strictures. High migration rate (36.3%) is a major drawback of this approach. The development of dedicated biodegradable colorectal stent (with anti-migration design) which better fit the colorectal anatomy could help in reducing the migration rate.