Multicenter International Study of the Consensus Immunoscore for the Prediction of Relapse and Survival in Early-Stage Colon Cancer.

Background: The prognostic value of Immunoscore was evaluated in Stage II/III colon cancer (CC) patients, but it remains unclear in Stage I/II, and in early-stage subgroups at risk. An international Society for Immunotherapy of Cancer (SITC) study evaluated the pre-defined consensus Immunoscore in tumors from 1885 AJCC/UICC-TNM Stage I/II CC patients from Canada/USA (Cohort 1) and Europe/Asia (Cohort 2). METHODS: Digital-pathology is used to quantify the densities of CD3+ and CD8+ T-lymphocyte in the center of tumor (CT) and the invasive margin (IM). The time to recurrence (TTR) was the primary endpoint. Secondary endpoints were disease-free survival (DFS), overall survival (OS), prognosis in Stage I, Stage II, Stage II-high-risk, and microsatellite-stable (MSS) patients. RESULTS: High-Immunoscore presented with the lowest risk of recurrence in both cohorts. In Stage I/II, recurrence-free rates at 5 years were 78.4% (95%-CI, 74.4−82.6), 88.1% (95%-CI, 85.7−90.4), 93.4% (95%-CI, 91.1−95.8) in low, intermediate and high Immunoscore, respectively (HR (Hi vs. Lo) = 0.27 (95%-CI, 0.18−0.41); p < 0.0001). In Cox multivariable analysis, the association of Immunoscore to outcome was independent (TTR: HR (Hi vs. Lo) = 0.29, (95%-CI, 0.17−0.50); p < 0.0001) of the patient's gender, T-stage, sidedness, and microsatellite instability-status (MSI). A significant association of Immunoscore with survival was found for Stage II, high-risk Stage II, T4N0 and MSS patients. The Immunoscore also showed significant association with TTR in Stage-I (HR (Hi vs. Lo) = 0.07 (95%-CI, 0.01−0.61); P = 0.016). The Immunoscore had the strongest (69.5%) contribution χ2 for influencing survival. Patients with a high Immunoscore had prolonged TTR in T4N0 tumors even for patients not receiving chemotherapy, and the Immunoscore remained the only significant parameter in multivariable analysis. CONCLUSION: In early CC, low Immunoscore reliably identifies patients at risk of relapse for whom a more intensive surveillance program or adjuvant treatment should be considered.

Clinical Performance of the Consensus Immunoscore in Colon Cancer in the Asian Population from the Multicenter International SITC Study.

BACKGROUND: In this study, we evaluated the prognostic value of Immunoscore in patients with stage I−III colon cancer (CC) in the Asian population. These patients were originally included in an international study led by the Society for Immunotherapy of Cancer (SITC) on 2681 patients with AJCC/UICC-TNM stages I−III CC. METHODS: CD3+ and cytotoxic CD8+ T-lymphocyte densities were quantified in the tumor and invasive margin by digital pathology. The association of Immunoscore with prognosis was evaluated for time to recurrence (TTR), disease-free survival (DFS), and overall survival (OS). RESULTS: Immunoscore stratified Asian patients (n = 423) into different risk categories and was not impacted by age. Recurrence-free rates at 3 years were 78.5%, 85.2%, and 98.3% for a Low, Intermediate, and High Immunoscore, respectively (HR[Low-vs-High] = 7.26 (95% CI 1.75−30.19); p = 0.0064). A High Immunoscore showed a significant association with prolonged TTR, OS, and DFS (p < 0.05). In Cox multivariable analysis stratified by center, Immunoscore association with TTR was independent (HR[Low-vs-Int+High] = 2.22 (95% CI 1.10−4.55) p = 0.0269) of the patient's gender, T-stage, N-stage, sidedness, and MSI status. A significant association of a High Immunoscore with prolonged TTR was also found among MSS (HR[Low-vs-Int+High] = 4.58 (95% CI 2.27−9.23); p ≤ 0.0001), stage II (HR[Low-vs-Int+High] = 2.72 (95% CI 1.35−5.51); p = 0.0052), low-risk stage-II (HR[Low-vs-Int+High] = 2.62 (95% CI 1.21−5.68); p = 0.0146), and high-risk stage II patients (HR[Low-vs-Int+High] = 3.11 (95% CI 1.39−6.91); p = 0.0055). CONCLUSION: A High Immunoscore is significantly associated with the prolonged survival of CC patients within the Asian population.

Randomized Phase 2 Study Comparing Pathological Responses of Resected Colorectal Cancer Metastases after Bevacizumab with mFOLFOX6 or FOLFIRI (BEV-ONCO Trial).

Retrospective studies reported that preoperative oxaliplatin-based chemotherapy increased pathological response (PR) in patients resected for colorectal liver metastases (CRLM). This multicenter prospective randomized (1/1) phase II trial evaluated PR on resected CRLM after preoperative mFOLFOX6 (arm A) or FOLFIRI (arm B) + bevacizumab. The primary endpoint was the major pathological response rate (MPRR), defined as the percentage of patients presenting CRLMs with mean tumor regression grade (TRG) < 3. Secondary endpoints included safety, progression-free survival (PFS) and overall survival (OS). Out of 65 patients, 57 patients (28 and 29 in arm A/B) were resected for CRLM (one patient with lung metastases). Clinical and treatment characteristics were similar in both arms. One-month postoperative complications were 39.3%/31.0% in arm A/B (p = 0.585). MPRR and complete PR were 32.1%/20.7% (p = 0.379) and 14.3%/0.0% (p = 0.052) in arm A/B, respectively. PFS and OS were not different. Patients with PR among all CRLMs (max TRG ≤ 3; 43.8% of patients) had a lower risk of relapse (PFS: HR = 0.41, 95%CI = 0.204−0.840, p = 0.015) and a tendency towards better survival (OS: HR = 0.34, 95%CI = 0.104−1.114, p = 0.075). The homogeneity of PR was associated with improved PFS/OS. This trial fails to demonstrate a significant increase in MPRR in patients treated with mFOLFOX6-bevacizumab but confirms PR as an important prognostic factor.

Sessile Serrated Lesion of the Appendix in a Teenage Girl.

According to the literature, serrated lesions and polyps of the appendix are extremely rare in children or teenagers. Herein, we present the pathologic and molecular features of a sessile serrated lesion (SSL) that was incidentally found in the appendix of a teenage girl. Our findings not only illustrate that appendiceal SSL may occur in young patients such as teenagers but also confirm further that BRAF V600E mutation may be found in a subset of these neoplastic lesions.

Prognostic assessment of resected colorectal liver metastases integrating pathological features, RAS mutation and Immunoscore.

Surgical resection of colorectal liver metastases combined with systemic treatment aims to maximize patient survival. However, recurrence rates are very high postsurgery. In order to assess patient prognosis after metastasis resection, we evaluated the main patho-molecular and immune parameters of all surgical specimens. Two hundred twenty-one patients who underwent, after different preoperative treatment, curative resection of 582 metastases were analyzed. Clinicopathological parameters, RAS tumor mutation, and the consensus Immunoscore (I) were assessed for all patients. Overall survival (OS) and time to relapse (TTR) were estimated using the Kaplan-Meier method and compared by log-rank tests. Cox proportional hazard models were used for uni- and multivariate analysis. Immunoscore and clinicopathological parameters (number of metastases, surgical margin, histopathological growth pattern, and steatohepatitis) were associated with relapse in multivariate analysis. Overall, pathological score (PS) that combines relevant clinicopathological factors for relapse, and I, were prognostic for TTR (2-year TTR rate PS 0-1: 49.8.% (95% CI: 42.2-58.8) versus PS 2-4: 20.9% (95% CI: 13.4-32.8), hazard ratio (HR) = 2.54 (95% CI: 1.82-3.53), p < 0.0000; and 2-year TTR rate I 0: 25.7% (95% CI: 16.3-40.5) versus I 3-4: 60% (95% CI: 47.2-76.3), HR = 2.87 (95% CI: 1.73-4.75), p = 0.0000). Immunoscore was also prognostic for OS (HR [I 3-4 versus I 0] = 4.25, 95% CI: 1.95-9.23; p = 0.0001). Immunoscore (HR [I 3-4 versus I 0] = 0.27, 95% CI: 0.12-0.58; p = 0.0009) and RAS mutation (HR [mutated versus WT] = 1.66, 95% CI: 1.06-2.58; p = 0.0265) were significant for OS. In conclusion, PS including relevant clinicopathological parameters and Immunoscore permit stratification of stage IV colorectal cancer patient prognosis in terms of TTR and identify patients with higher risk of recurrence. Immunoscore remains the major prognostic factor for OS.

Multicenter International Society for Immunotherapy of Cancer Study of the Consensus Immunoscore for the Prediction of Survival and Response to Chemotherapy in Stage III Colon Cancer.

PURPOSE: The purpose of this study was to evaluate the prognostic value of Immunoscore in patients with stage III colon cancer (CC) and to analyze its association with the effect of chemotherapy on time to recurrence (TTR). METHODS: An international study led by the Society for Immunotherapy of Cancer evaluated the predefined consensus Immunoscore in 763 patients with American Joint Committee on Cancer/Union for International Cancer Control TNM stage III CC from cohort 1 (Canada/United States) and cohort 2 (Europe/Asia). CD3+ and cytotoxic CD8+ T lymphocyte densities were quantified in the tumor and invasive margin by digital pathology. The primary end point was TTR. Secondary end points were overall survival (OS), disease-free survival (DFS), prognosis in microsatellite stable (MSS) status, and predictive value of efficacy of chemotherapy. RESULTS: Patients with a high Immunoscore presented with the lowest risk of recurrence, in both cohorts. Recurrence-free rates at 3 years were 56.9% (95% CI, 50.3% to 64.4%), 65.9% (95% CI, 60.8% to 71.4%), and 76.4% (95% CI, 69.3% to 84.3%) in patients with low, intermediate, and high immunoscores, respectively (hazard ratio [HR; high v low], 0.48; 95% CI, 0.32 to 0.71; P = .0003). Patients with high Immunoscore showed significant association with prolonged TTR, OS, and DFS (all P < .001). In Cox multivariable analysis stratified by participating center, Immunoscore association with TTR was independent (HR [high v low], 0.41; 95% CI, 0.25 to 0.67; P = .0003) of patient's sex, T stage, N stage, sidedness, and microsatellite instability status. Significant association of a high Immunoscore with prolonged TTR was also found among MSS patients (HR [high v low], 0.36; 95% CI, 0.21 to 0.62; P = .0003). Immunoscore had the strongest contribution χ2 proportion for influencing survival (TTR and OS). Chemotherapy was significantly associated with survival in the high-Immunoscore group for both low-risk (HR [chemotherapy v no chemotherapy], 0.42; 95% CI, 0.25 to 0.71; P = .0011) and high-risk (HR [chemotherapy v no chemotherapy], 0.5; 95% CI, 0.33 to 0.77; P = .0015) patients, in contrast to the low-Immunoscore group (P > .12). CONCLUSION: This study shows that a high Immunoscore significantly associated with prolonged survival in stage III CC. Our findings suggest that patients with a high Immunoscore will benefit the most from chemotherapy in terms of recurrence risk.

A Diagnostic Biopsy-Adapted Immunoscore Predicts Response to Neoadjuvant Treatment and Selects Patients with Rectal Cancer Eligible for a Watch-and-Wait Strategy.

PURPOSE: No biomarker to personalize treatment in locally advanced rectal cancer (LARC) is currently available. We assessed in LARC whether a diagnostic biopsy-adapted immunoscore (ISB) could predict response to neoadjuvant treatment (nT) and better define patients eligible to an organ preservation strategy ("Watch-and-Wait"). EXPERIMENTAL DESIGN: Biopsies from two independent cohorts (n 1 = 131, n 2 = 118) of patients with LARC treated with nT followed by radical surgery were immunostained for CD3+ and CD8+ T cells and quantified by digital pathology to determine ISB. The expression of immune-related genes post-nT was investigated (n = 64 patients). Results were correlated with response to nT and disease-free survival (DFS). The ISB prognostic performance was further assessed in a multicentric cohort (n = 73 patients) treated by Watch-and-Wait. RESULTS: ISB positively correlated with the degree of histologic response (P < 0.001) and gene expression levels for Th1 orientation and cytotoxic immune response, post-nT (P = 0.006). ISB high identified patients at lower risk of relapse or death compared with ISB low [HR, 0.21; 95% confidence interval (CI), 0.06-0.78; P = 0.009]. Prognostic performance of ISB for DFS was confirmed in a validation cohort. ISB was an independent parameter, more informative than pre- (P < 0.001) and post-nT (P < 0.05) imaging to predict DFS. ISB combined with imaging post-nT discriminated very good responders that could benefit from organ preservation strategy. In the "Watch-and-Wait" cohort (n = 73), no relapse was observed in patients with ISB high (23.3%). CONCLUSIONS: ISB predicts response to nT and survival in patients with LARC treated by surgery. Its usefulness in the selection of patients eligible for a Watch-and-Wait strategy is strongly suggested.

Combined excision and ablation of ampullary tumors with biliary or pancreatic intraductal extension is effective even in malignant neoplasms.

Background: The feasibility and outcome of endoscopic resection in ampullary tumors with intraductal growth remains unclear. Objective: To assess the safety, feasibility and outcomes of these patients treated by thermal ablation. Methods: Retrospective observational study. All consecutive patients who underwent an endoscopic snare papillectomy with a 6-month minimum follow-up were included. Ablation was performed with cystotomes and soft/forced coagulation. Successful endoscopic treatment was defined as no adenomatous residual tissue or recurrence observed at follow-up. Results: Of 86 patients presenting with an ampullary tumor, 73 (58 ± 14 years old, 49% men, 34% familial adenomatous polyposis) (median tumor size: 20 mm, range: 8-80) were included. En bloc and curative resection rates were achieved in 46.6% and 83.6%, respectively.Intraductal ingrowth was seen in 18 (24.7%) patients and histologically confirmed in 12 (16.4%). Intraductal ablation achieved a 100% success rate, with a 20-month median follow-up. Most of these patients had malignant forms (n = 8, 66.7%), with a higher adenocarcinoma rate (33.3% versus 3.3%, p = 0.001) compared to extraductal tumors.Overall, there was a 20.5% complication rate with no significant differences between both groups (p = 0.676). Conclusions: Intraductal ablation achieves a high therapeutic success rate in ampullary tumors with ≤20 mm ductal extension, even in malignant forms or biliary and pancreatic involvement. The technique is feasible, cheap and safe and may avoid major surgery.

[An unusual case of olmesartan induced enteropathy]. / Un cas inhabituel d'entéropathie secondaire à la prise d'olmesartan.

Olmesartan induced enteropathy was first described in 2012. It is a rare adverse effect of this antihypertensive drug. The clinical presentation commonly includes severe chronic diarrhea leading to weight loss and a variable degree of dehydration. Histological findings are most commonly observed in the duodenum and consist of partial or total villous atrophy, increased intraepithelial lymphocytes and inflammation in the lamina propria. Involvement of gastric and colic mucosa has also been described. We report on the case of a 63-year-old man, treated by olmesartan, who presented with severe chronic diarrhea. Biopsies from different levels of the gastrointestinal tract revealed a pandigestive intraepithelial lymphocytosis.

Risk factors for conversion to snare resection during colorectal endoscopic submucosal dissection in an expert Western center.

BACKGROUND: There are limited data regarding the risk factors and consequences of conversion to endoscopic mucosal resection (rescue EMR) during colorectal endoscopic submucosal dissection (ESD) in Western centers. METHODS: This was a retrospective analysis of a prospectively collected database, from which 225 consecutive ESDs performed between 2013 and 2017 were selected. Of the included patients, 39 (18.6 %) required rescue EMR. Pre- and per-procedure characteristics were evaluated to determine the features associated with the need for rescue EMR. Outcomes and complications were also assessed. RESULTS: 210 patients were included, with median tumor size of 40 mm (range 20 - 110) and most tumors being in a non-rectal location (66.2 %). When compared with full ESD, rescue EMR was significantly associated with lower rates of en bloc resection (43.6 % vs. 100 %) and complete resection (R0 status; 28.2 % vs. 88.9 %), and with a higher rate of recurrence (5.1 % vs. 0 %) and more need for surgery (15.4 % vs. 3.5 %). In multivariable analysis, non-lifting (adjusted odds ratio [ORa] 3.06, 95 % confidence interval [CI] 1.23 - 7.66; P = 0.02), nongranular-type laterally spreading tumor (LST-NG; ORa 2.56, 95 %CI 1.10 - 5.99; P = 0.03), and difficult retroflexion (OR 3.22, 95 %CI 1.01 - 10.28; P = 0.049) were independent risk factors associated with conversion to rescue EMR, while tumor size and location were not. CONCLUSIONS: During ESD, the presence of poor lifting, LST-NG morphology, and a difficult retroflexed approach were factors associated with the need to convert to rescue EMR. Conversion to rescue EMR remains a valuable strategy.

The Link between the Multiverse of Immune Microenvironments in Metastases and the Survival of Colorectal Cancer Patients.

Treatment of metastatic colorectal cancer is based upon the assumption that metastases are homogeneous within a patient. We quantified immune cell types of 603 whole-slide metastases and primary colorectal tumors from 222 patients. Primary lesions, and synchronous and metachronous metastases, had a heterogeneous immune infiltrate and mutational diversity. Small metastases had frequently a low Immunoscore and T and B cell score, while a high Immunoscore was associated with a lower number of metastases. Anti-epidermal growth factor receptor treatment modified immune gene expression and significantly increased T cell densities in the metastasis core. The predictive accuracy of the Immunoscore from a single biopsy was superior to the one of programmed cell death ligand 1 (PD-L1). The immune phenotype of the least-infiltrated metastasis had a stronger association with patient outcome than other metastases.

Evolution of Metastases in Space and Time under Immune Selection.

We examined how the immune microenvironment molds tumor evolution at different metastatic organs in a longitudinal dataset of colorectal cancer. Through multiplexed analyses, we showed that clonal evolution patterns during metastatic progression depend on the immune contexture at the metastatic site. Genetic evidence of neoantigen depletion was observed in the sites with high Immunoscore and spatial proximity between Ki67+ tumor cells and CD3+ cells. The immunoedited tumor clones were eliminated and did not recur, while progressing clones were immune privileged, despite the presence of tumor-infiltrating lymphocytes. Characterization of immune-privileged metastases revealed tumor-intrinsic and tumor-extrinsic mechanisms of escape. The lowest recurrence risk was associated with high Immunoscore, occurrence of immunoediting, and low tumor burden. We propose a parallel selection model of metastatic progression, where branched evolution could be traced back to immune-escaping clones. The findings could inform the understanding of cancer dissemination and the development of immunotherapeutics.

Comparative analysis of ESD versus EMR in a large European series of non-ampullary superficial duodenal tumors.

BACKGROUND AND STUDY AIMS: The choice of endoscopic submucosal dissection (ESD) or endoscopic mucosal resection (EMR) in non-ampullary superficial duodenal tumors (NASDTs) is challenging and the benefits of ESD remain unclear. The aim was to comparatively analyze the feasibility, outcomes and safety of these techniques in these lesions. PATIENTS AND METHODS: This is an observational and retrospective study. All consecutive patients presenting with NASDTs who underwent EMR or ESD between 2005 and 2017 were included. The following main outcomes were comparatively evaluated: en-bloc and complete (R0) resection rates, and local recurrence. Secondary outcomes were perforation and delayed bleeding. RESULTS: One hundred sixty-six tumors in 150 patients (age: 66 years, range: 31 - 83, 42.7 % males) were resected by ESD (n = 37) or EMR (n = 129) and included. The median procedure time (81 vs. 50 min, P  = 0.007) and tumor size (25 vs. 20 mm, P  = 0.01) were higher in the ESD group. The global malignancy rate was 50.3 %. There were no differences in en-bloc resection (29.7 % vs. 44.2 %, P  = 0.115), complete resection (19.4 % vs. 35.5 %, P  = 0.069), and local recurrence (14.7 % vs. 16.7 %, P  = 0.788) rates. Tumor size was associated with recurrence (28 vs. 20 mm, P  = 0.008), with a median follow-up of 6.5 months. Focal recurrence (n = 22, 13.3 %) was treated endoscopically in 86.4 %. En-bloc resection in the ESD group was comparable in large ( ≥ 20 mm) and small lesions (27.6 % vs. 37.5 %, P  = 0.587), while this outcome decreased significantly in large lesions resected by EMR (17.4 % vs. 75 %, P  < 0.001). Nine perforations were confirmed in 6 lesions (16.2 %) resected by ESD and 3 (2.3 %) by EMR ( P  = 0.001). Endoscopic therapy was successful in all but 1 patient (88.9 %) presenting with a delayed perforation. CONCLUSIONS: ESD may be an alternative to EMR and surgery in selected NASDTs, such as large duodenal tumors where EMR achieves low en-bloc resection rates and the local recurrence may be higher. However, this technique may have a higher risk of perforations.

ESD versus EMR in non-ampullary superficial duodenal tumors: a systematic review and meta-analysis.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) has been developed as an option for treatment of esophageal, gastric and colorectal lesions. However, there is no consensus on the role of ESD in duodenal tumors. METHODS: This systematic review and meta-analysis compared ESD and endoscopic mucosal resection (EMR) in sporadic non-ampullary superficial duodenal tumors (NASDTs), including local experience. We conducted a search in PubMed, Scopus and the Cochrane library up to August 2017 to identify studies that compared both techniques reporting at least one main outcome (en-bloc/complete resection, local recurrence). Pooled outcomes were calculated under fixed and random-effect models. Subgroup analyses were conducted. RESULTS: A total of 753 patients presenting with 784 NASDTs (242 ESD, 542 EMR) in 14 studies were included. Tumor size (MD: 5.88, [CI95 %: 2.15, 9.62], P  = 0.002, I 2  = 79 %) and procedure time (MD: 65.65, [CI95 %: 40.39, 90.92], P  < 0.00001, I 2  = 88 %) were greater in the ESD group. En-bloc resection rate was significantly higher in Asian studies (OR: 2.16 [CI95 %: 1.15, 4.08], P  = 0.02, I 2 : 46 %). ESD provided a higher complete resection rate (OR: 1.63 [I95 %: 1.06, 2.50], P  = 0.03, I 2 : 59 %), but there was no risk difference in the risk of local recurrence (RD: - 0.03 [CI95 %: - 0.07, 0.01], P  = 0.15, I 2 : 0 %) or delayed bleeding. ESD was associated with an increased number of intraoperative perforations [RD: 0.12 (CI95 %: 0.04, 0.20), P  = 0.002, I 2 : 56 %] and emergency surgery for delayed perforations. The inclusion of eligible studies was limited to retrospective series with inequalities in comparative groups. CONCLUSIONS: Duodenal ESD for NASDTs may achieve higher en-bloc and complete resections at the expense of a greater perforation rate compared to EMR. The impact on local recurrence remains uncertain.

International validation of the consensus Immunoscore for the classification of colon cancer: a prognostic and accuracy study.

BACKGROUND: The estimation of risk of recurrence for patients with colon carcinoma must be improved. A robust immune score quantification is needed to introduce immune parameters into cancer classification. The aim of the study was to assess the prognostic value of total tumour-infiltrating T-cell counts and cytotoxic tumour-infiltrating T-cells counts with the consensus Immunoscore assay in patients with stage I-III colon cancer. METHODS: An international consortium of 14 centres in 13 countries, led by the Society for Immunotherapy of Cancer, assessed the Immunoscore assay in patients with TNM stage I-III colon cancer. Patients were randomly assigned to a training set, an internal validation set, or an external validation set. Paraffin sections of the colon tumour and invasive margin from each patient were processed by immunohistochemistry, and the densities of CD3+ and cytotoxic CD8+ T cells in the tumour and in the invasive margin were quantified by digital pathology. An Immunoscore for each patient was derived from the mean of four density percentiles. The primary endpoint was to evaluate the prognostic value of the Immunoscore for time to recurrence, defined as time from surgery to disease recurrence. Stratified multivariable Cox models were used to assess the associations between Immunoscore and outcomes, adjusting for potential confounders. Harrell's C-statistics was used to assess model performance. FINDINGS: Tissue samples from 3539 patients were processed, and samples from 2681 patients were included in the analyses after quality controls (700 patients in the training set, 636 patients in the internal validation set, and 1345 patients in the external validation set). The Immunoscore assay showed a high level of reproducibility between observers and centres (r=0·97 for colon tumour; r=0·97 for invasive margin; p<0·0001). In the training set, patients with a high Immunoscore had the lowest risk of recurrence at 5 years (14 [8%] patients with a high Immunoscore vs 65 (19%) patients with an intermediate Immunoscore vs 51 (32%) patients with a low Immunoscore; hazard ratio [HR] for high vs low Immunoscore 0·20, 95% CI 0·10-0·38; p<0·0001). The findings were confirmed in the two validation sets (n=1981). In the stratified Cox multivariable analysis, the Immunoscore association with time to recurrence was independent of patient age, sex, T stage, N stage, microsatellite instability, and existing prognostic factors (p<0·0001). Of 1434 patients with stage II cancer, the difference in risk of recurrence at 5 years was significant (HR for high vs low Immunoscore 0·33, 95% CI 0·21-0·52; p<0·0001), including in Cox multivariable analysis (p<0·0001). Immunoscore had the highest relative contribution to the risk of all clinical parameters, including the American Joint Committee on Cancer and Union for International Cancer Control TNM classification system. INTERPRETATION: The Immunoscore provides a reliable estimate of the risk of recurrence in patients with colon cancer. These results support the implementation of the consensus Immunoscore as a new component of a TNM-Immune classification of cancer. FUNDING: French National Institute of Health and Medical Research, the LabEx Immuno-oncology, the Transcan ERAnet Immunoscore European project, Association pour la Recherche contre le Cancer, CARPEM, AP-HP, Institut National du Cancer, Italian Association for Cancer Research, national grants and the Society for Immunotherapy of Cancer.

Evaluation of the correlation between KRAS mutated allele frequency and pathologist tumorous nuclei percentage assessment in colorectal cancer suggests a role for zygosity status.

Evaluation of molecular tumour heterogeneity relies on the tumorous nuclei percentage (TNP) assessment by a pathologist, which has been criticised for being inaccurate and suffering from interobserver variability. Based on the 'Big Bang theory' which states that KRAS mutation in colorectal cancer is mostly homogeneous, we investigated this issue by performing a critical analysis of the correlation of the KRAS mutant allele fraction with the TNP in 99 colorectal tumour samples with a positive KRAS mutation status as determined by next-generation sequencing. Our results yield indirect evidence that the KRAS zygosity status influences the correlation between these parameters and we show that a well-trained pathologist is indeed capable of accurately assessing TNP. Our findings indicate that tumour zygosity, a feature which has largely been neglected until now, should be taken into account in future studies on (colorectal) molecular tumour heterogeneity.

Accuracy of Pancreatic Neuroendocrine Tumour Grading by Endoscopic Ultrasound-Guided Fine Needle Aspiration: Analysis of a Large Cohort and Perspectives for Improvement.

INTRODUCTION: Since the WHO Classification of Tumours of the Digestive System has been published in 2010, resected pancreatic neuroendocrine tumours (pNETs) are graded as grade 1 (G1), grade 2 (G2) or grade 3 (G3) using the Ki67 labelling index (Ki67-LI). Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is often used for diagnosis, but few studies have assessed its value for grading. AIMS: The aims of this study were to compare the Ki67-LI obtained by cytological grading (cG) with that obtained by histological grading (hG) and to assess (1) the influence of tumour size and the number of counted cells on FNA grading as well as (2) the overall survival (OS) and progression-free survival based on cG. MATERIALS AND METHODS: EUS-FNA was performed for 102 pNETs (57 resected). cG (200 cells counted) was done on all FNAs. For 29 FNAs, >2,000 cells were counted (14 resected). A comparison was made between hG and cG for the 57 resected patients. Patients were followed up until June 2016. RESULTS: cG was consistent with hG in 39 of 57 patients with a concordance rate of 72% using a Ki67-LI cut-off of 5% for G1/G2. For Ki67-LI absolute values, the correlation was r = 0.443 and increased to r = 0.824 (p < 0.001) when only FNAs with >2,000 cells were counted. Twenty-one of 22 pNETs <2 cm had the same grading on cG and hG, whereas grading was discordant for 15 of 16 pNETs >2 cm. Thirty-eight patients died after 70.5 months of follow-up. OS for the whole cohort was 235 months and differed between cG1 (235 months), cG2 (36.3 months) and cG3 (10.9 months). CONCLUSION: cG of pNETs is more accurate when tumours measure <2 cm and more cells are counted on FNA. Discrepancies are seen between G2 tumours which are often considered G1 on FNA due to tumour heterogeneity. EUS-FNA is valuable to distinguish between patients with good (cG1) and poor (cG3) prognosis.