Impact of neoadjuvant chemoradiotherapy on pathologic response in pancreatic ductal adenocarcinoma: A systematic review and meta-analysis.

BACKGROUND: The impact of chemoradiotherapy on pathologic response, resection margin, and survival benefit is still debated. The aim of this study was to compare the rate of pathologic complete response (pCR) in surgical resection following neoadjuvant chemotherapy vs. chemoradiotherapy, and secondarily, to compare the rate of R0 resection and Overall Survival (OS). METHODS: A systematic review on MEDLINE/PubMed, Embase, Cochrane, Web of Science and Google Scholar was conducted for studies published between 2012 and 2024 (PROSPERO CRD42022341467). All studies reporting clinical outcomes of patients with Pancreatic ductal adenocarcinoma (PDAC) following neoadjuvant therapy were considered eligible for inclusion. A meta-analysis comparing the rate of pCR, R0 resection rate, and 3-year OS following Chemotherapy vs chemoradiotherapy in patients was performed. The overall quality of evidence was evaluated using a GRADE approach. RESULTS: Out of 5194 potentially relevant studies, 29 studies were considered eligible for full-text assessment, and 11 studies were included in the systematic review and in the meta-analysis. Of these, five were retrospective single-center, five retrospective multi-center studies, and one was a phase II multi-center RCT. Overall, 1830 Chemotherapy patients and 2299 Chemoradiotherapy patients were included in the meta-analysis. A statistically significant increased rate of pCR and R0 resections were found in chemoradiotherapy patients (OR 3.58, 95 % CI 2.47-5.18, p ≤ 0.00001) (OR 1.49, 95 % CI 1.17-1.90, p = 0.001), whereas 3-year OS (OR 1.07, 95 % CI 0.84-1.36, p = 0.6) did not differ significantly. CONCLUSIONS: Chemoradiotherapy may have a positive impact on pathologic response and R0 resection rate, whereas a survival benefit was not reported.

Prognostic value of major pathological response following neoadjuvant therapy for non resectable pancreatic ductal adenocarcinoma.

BACKGROUND: The aim of this study is to evaluate the impact of major pathological response on overall survival (OS) in borderline resectable and locally advanced pancreatic ductal adenocarcinoma following neoadjuvant treatment, and to identify predictors of major pathological response. METHODS: Patients surgically resected following neoadjuvant treatment between 2010 and 2020 at the Pederzoli Hospital were retrospectively analyzed. Pathologic response was assessed using the College of American Pathologists (CAP) score, and major pathological response was defined as CAP 0-1. OS was estimated and compared using the Kaplan-Meier method and log-rank test. A logistic and Cox regression model were performed to identify predictors of major pathologic response and OS. RESULTS: Overall, 200 patients were included in the study. A major and complete pathological response were observed in 52(26.0%) and 15(7.3%) patients respectively. The 1-, 3-, 5-year OS was 92.7, 67.2, and 41.7%, and 71.0, 37.4, and 20.8% in patients with or without major pathologic response respectively (log-rank test p < 0.001). Major pathologic response was confirmed as independent predictor of OS (OR 0.50 95%CI 0.29-0.88, p = 0.01). Post-treatment CA19-9 normalization (OR 4.20 95%CI 1.14-10.35, p = 0.02) and radiological post-treatment tumor residual size<25 mm (OR 2.71 95%CI 1.27-5.79, p = 0.01) were found to be independent predictors of major pathologic response. CONCLUSION: Patients experienced a major pathological response after neoadjuvant treatment have an increased survival, and major pathologic response is an independent predictor of OS. A normal CA19-9 value and radiological tumor size at restaging are confirmed to be independent predictors of major pathologic response.

Nodal staging with MRI after neoadjuvant chemo-radiotherapy for locally advanced rectal cancer: a fast and reliable method.

OBJECTIVES: In patients with locally advanced rectal carcinoma (LARC), negative nodal status after neoadjuvant chemoradiotherapy (nCRT) may allow for rectum-sparing protocols rather than total mesorectal excision; however, current MRI criteria for nodal staging have suboptimal accuracy. The aim of this study was to compare the diagnostic accuracy of different MRI dimensional criteria for nodal staging after nCRT in patients with LARC. MATERIALS AND METHODS: Patients who underwent MRI after nCRT for LARC followed by surgery were retrospectively included and divided into a training and a validation cohort of 100 and 39 patients, respectively. Short-, long-, and cranial-caudal axes and volume of the largest mesorectal node and nodal status based on European Society of Gastrointestinal Radiology consensus guidelines (i.e., ESGAR method) were assessed by two radiologists independently. Inter-reader agreement was assessed in the training cohort. Histopathology was the reference standard. ROC curves and the best cut-off were calculated, and accuracies compared with the McNemar test. RESULTS: The study population included 139 patients (median age 62 years [IQR 55-72], 94 men). Inter-reader agreement was high for long axis (κ = 0.81), volume (κ = 0.85), and ESGAR method (κ = 0.88) and low for short axis (κ = 0.11). Accuracy was similar (p > 0.05) for long axis, volume, and ESGAR method both in the training (71%, 74%, and 65%, respectively) and in the validation (83%, 78%, and 75%, respectively) cohorts. CONCLUSION: Accuracy of the measurement of long axis and volume of the largest lymph node is not inferior to the ESGAR method for nodal staging after nCRT in LARC. CLINICAL RELEVANCE STATEMENT: In MRI restaging of rectal cancer, measurement of the long axis or volume of largest mesorectal lymph node after preoperative chemoradiotherapy is a faster and reliable alternative to ESGAR criteria for nodal staging. KEY POINTS: • Current MRI criteria for nodal staging in locally advanced rectal cancer after chemo-radiotherapy have suboptimal accuracy and are time-consuming. • Measurement of long axis or volume of the largest mesorectal lymph node on MRI showed good accuracy for assessment of loco-regional nodal status in locally advanced rectal cancer. • MRI measurement of the long axis and volume of largest mesorectal lymph node after chemo-radiotherapy could be a faster and reliable alternative to ESGAR criteria for nodal staging.

Diagnostic accuracy of state-of-the-art rectal MRI sequences for the diagnosis of extramural vascular invasion in locally advanced rectal cancer after preoperative chemoradiotherapy: dos or maybes?

OBJECTIVES: The aim of this study was to determine the accuracy of three state-of-the-art MRI sequences for the detection of extramural venous invasion (EMVI) in locally advanced rectal cancer (LARC) patients after preoperative chemoradiotherapy (pCRT). METHODS: This retrospective study included 103 patients (median age 66 years old [43-84]) surgically treated with pCRT for LARC and submitted to preoperative contrast-enhanced pelvic MRI after pCRT. T2-weighted, DWI, and contrast-enhanced sequences were evaluated by two radiologists with expertise in abdominal imaging, blinded to clinical and histopathological data. Patients were scored according to the probability of EMVI presence on each sequence using a grading score ranging from 0 (no evidence of EMVI) to 4 (strong evidence of EMVI). Results from 0 to 2 were ranked as EMVI negative and from 3 to 4 as EMVI positive. ROC curves were drawn for each technique, using histopathological results as reference standard. RESULTS: T2-weighted, DWI, and contrast-enhanced sequences demonstrated an area under the ROC curve (AUC) respectively of 0.610 (95% CI: 0.509-0.704), 0.729 (95% CI: 0.633-0.812), and 0.624 (95% CI: 0.523-0.718). The AUC of DWI sequence was significantly higher than that of T2-weighted (p = 0.0494) and contrast-enhanced (p = 0.0315) sequences. CONCLUSIONS: DWI is more accurate than T2-weighted and contrast-enhanced sequences for the identification of EMVI following pCRT in LARC patients. CLINICAL RELEVANCE STATEMENT: MRI protocol for restaging locally advanced rectal cancer after preoperative chemoradiotherapy should routinely include DWI due to its higher accuracy for the diagnosis of extramural venous invasion compared to high-resolution T2-weighted and contrast-enhanced T1-weighted sequences. KEY POINTS: • MRI has a moderately high accuracy for the diagnosis of extramural venous invasion in locally advanced rectal cancer after preoperative chemoradiotherapy. • DWI is more accurate than T2-weighted and contrast-enhanced T1-weighted sequences in the detection of extramural venous invasion after preoperative chemoradiotherapy of locally advanced rectal cancer. • DWI should be routinely included in the MRI protocol for restaging locally advanced rectal cancer after preoperative chemoradiotherapy.

Molecular Determinants of Peritoneal Dissemination in Gastric Adenocarcinoma.

BACKGROUND: Peritoneal dissemination represents a poor prognostic indicator in gastric cancer. Despite a comprehensive molecular characterization of this disease, no peritoneal dissemination-specific signature has been identified, limiting the tailoring of the surgical and oncological treatments. In this review, we outline the available literature focusing on the role of the different molecular pathways involved in the acquisition of peritoneal metastatic dissemination. SUMMARY: According to our results, several molecular determinants are associated with peritoneal carcinomatosis and are involved in several cellular and molecular carcinogenetic processes. However, a comprehensive understanding of the complex molecular landscape of gastric carcinosis is still lacking. KEY MESSAGES: More efforts should be made toward the integration of molecular and histologic data to perform a risk prediction assessment of peritoneal dissemination based on molecular profiling and histological evaluation.

The impact of anastomotic leak on long-term oncological outcomes after low anterior resection for mid-low rectal cancer: extended follow-up of a randomised controlled trial.

PURPOSE: The impact of anastomotic leaks (AL) on oncological outcomes after low anterior resection for mid-low rectal cancer is still debated. The aim of this study was to evaluate overall survival (OS), disease-free survival (DFS), and local and distant recurrence in patients with AL following low anterior resection. METHODS: This is an extension of a multicentre RCT (NCT01110798). Kaplan-Meier method and the log-rank test were used to estimate and compare the 3-, 5-, and 10-year OS and DFS, and local and distant recurrence in patients with and without AL. Predictors of OS and DFS were evaluated using the Cox regression analysis as secondary aim. RESULTS: Follow-up was available for 311 patients. Of them, 252 (81.0%) underwent neoadjuvant chemoradiotherapy and 138 (44.3%) adjuvant therapy. AL occurred in 63 (20.3%) patients. At a mean follow-up of 69.5 ± 31.9 months, 23 (7.4%) patients experienced local recurrence and 49 (15.8%) distant recurrence. The 3-, 5-, and 10-year OS and DFS were 89.2%, 85.3%, and 70.2%; and 80.7%, 75.1%, and 63.5% in patients with AL, and 88.9%, 79.8% and 72.3%; and 83.7, 74.2 and 62.8%, respectively in patients without (p = 0.89 and p = 0.84, respectively). At multivariable analysis, AL was not an independent predictor of OS (HR 0.65, 95%CI 0.34-1.28) and DFS (HR 0.70, 95%CI 0.39-1.25), whereas positive circumferential resection margins and pathological stage impaired both. CONCLUSIONS: In the context of modern multimodal rectal cancer treatment, AL does not affect long-term OS, DFS, and local and distant recurrence in patients with mid-low rectal cancer.

Prognostic significance of additional histologic features for subclassification of pathological T3 colon cancer.

BACKGROUND: Additional histologic features of T3 colon cancer, such as tumour depth invasion beyond muscularis propria and elastic lamina invasion (ELI), have taken interest for a more accurate staging. METHODS: Patients with pT3 and pT4a (control group) colon adenocarcinoma were retrospectively collected from our institutional database. The study group was divided according to depth of tumour invasion < 5 mm and ≥ 5 mm, and into ELI - and ELI + . Chi-square test was used to compare the clinicopathological characteristics. OS and DFS were estimated using Kaplan-Meier method and compared with the log-rank test. Univariable and multivariable Cox proportional hazard models were employed to assess the effect on OS and DFS. RESULTS: Out of 290 pT3 tumours, 168 (58%) had a depth of tumour invasion < 5 mm and 122 (42%) ≥ 5 mm. The 5-year OS and DFS were 85.2, 68.7 and 60.9%, and 81.4, 73.9 and 60.1% in pT3 < 5 mm, pT3 ≥ 5 mm, and pT4a respectively (p = 0.001, p = 0.072). Considering ELI - (n = 157, 54%) and ELI + (n = 133, 46%), the 5-year OS and DFS were 78.9, 76.7, and 60.9%, and 75.5, 81.5, and 60.1% in ELI - , ELI + and pT4a respectively (p = 0.955, p = 0.462). At multivariable analysis, the depth of invasion was found to be an independent predictive factor for OS (HR 2.04, 95%CI 1.28-3.24, p = 0.003) and DFS (HR 1.98, 95%CI 1.24-3.18, p = 0.004), while ELI did not result a prognostic factor for OS nor DFS. CONCLUSION: In pT3 colon cancer, depth of tumour invasion ≥ 5 mm is an independent risk factor for OS and DFS, whereas ELI did not result a prognostic factor affecting OS nor DFS.

Long-Term Outcomes of Local Excision Following Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer.

BACKGROUND: Local excision might represent an alternative to total mesorectal excision for patients with locally advanced rectal cancer who achieve a major or complete clinical response after neoadjuvant chemoradiotherapy. METHODS: Between August 2005 and July 2011, 63 patients with mid-low rectal adenocarcinoma who had a major/complete clinical response after neoadjuvant chemoradiotherapy were enrolled in a multicenter prospective phase 2 trial and underwent transanal full thickness local excision. The main endpoint of this study was to evaluate the 5- and 10-year overall, relapse-free, local, and distant relapse-free survival, which were calculated by applying the Kaplan-Meier method. The rate of patients with rectum preserved and without stoma were also calculated. RESULTS: Of 63 patients, 38 (60%) were male and 25 (40%) were female, with a median (range) age of 64 (25-82) years. At baseline, the following clinical stages were found: cT2, n = 21 (33.3%); cT3, n = 42 (66.6%), 39 (61.9%) patients were cN+. At a median (range) follow-up of 108 (32-166) months, the estimated cumulative 5- and 10-year overall survival, relapse-free survival, local recurrence-free survival, and distant recurrence-free survival were 87% (95% CI 76-93) and 79% (95% CI 66-87), 89% (95% CI 78-94) and 82% (95% CI 66-91), both 91% (95% CI 81-96), and 90% (95% CI 80-95) and 86% (95% CI 73-93), respectively. Overall, 49 (77.8%) patients had their rectum preserved, and 54 (84.1%) were stoma-free. CONCLUSION: In highly selected patients, the local excision approach after neoadjuvant chemoradiotherapy is associated with excellent long-term outcomes, high rates of rectum preservation and absence of permanent stoma.

MRI T2-weighted sequences-based texture analysis (TA) as a predictor of response to neoadjuvant chemo-radiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC).

PURPOSE: To determine whether MRI T2-weighted sequences-based texture analysis (TA) can predict histopathological tumor regression grade (TRG) in patients with locally advanced rectal cancer (LARC) undergoing neoadjuvant chemo-radiotherapy (nCRT). METHODS: Data on patients undergoing curative-intent surgery for LARC were collected. Patients with a complete pathological response, or TRG1 according to Mandard's system were classified as responders, while patients with TRG ≥ 2 were classified as non-responders. Tumor TA was performed on each patient's paraxial T2w MRI in both pre- and post-nCRT scans, in order to extract histograms, gray-level co-occurrence matrix (GLCM) and run-length matrix (RLM) texture parameters. For features that showed a significant difference between the two groups, a receiver operating characteristic (ROC) curve was drawn. RESULTS: Overall, 62 patients with LARC, treated with nCRT and resective surgery at our institution between 2013 and 2019 were identified. Only post-nCRT GLCM maximum probability showed a significant difference between the two groups (2909 ± 4479 in responders vs. 6515 ± 8990 in non- responders; p = 0.039); at the ROC curve, Youden index showed a sensitivity of 14% and a specificity of 100% for this parameter. CONCLUSIONS: MRI T2-weighted sequences-based TA was not effective in predicting pathological complete response to nCRT in patients with LARC. Further studies are needed to thoroughly investigate the potential of MRI TA in this setting.

Rectal Sparing Approach after preoperative Radio- and/or Chemo-therapy (ReSARCh): a prospective, multicenter, observational study.

BACKGROUND: Rectal-sparing approaches for patients with rectal cancer who achieved a complete or major response following neoadjuvant therapy constitute a paradigm of a potential shift in the management of patients with rectal cancer; however, their role remains controversial. The aim of this study was to investigate the feasibility of rectal-sparing approaches to preserve the rectum without impairing the outcomes. METHODS: This prospective, multicenter, observational study investigated the outcomes of patients with clinical stage II-III mid-low rectal adenocarcinoma treated with any neoadjuvant therapy, and either transanal local excision or watch-and-wait approach, based on tumor response (major or complete) and patient/surgeon choice. The primary endpoint of the study was rectum preservation at a minimum follow-up of 2 years. Secondary endpoints were overall, disease-free, local and distant recurrence-free, and stoma-free survival at 3 years. RESULTS: Of the 178 patients enrolled in 16 centers, 112 (62.9%) were managed with local excision and 66 (37.1%) with watch-and-wait. At a median (interquartile range) follow-up of 36.1 (30.6-45.6) months, the rectum was preserved in 144 (80.9%) patients. The 3-year rectum-sparing, overall survival, disease-free survival, local recurrence-free survival, and distant recurrence-free survival was 80.6% (95% CI 73.9-85.8), 97.6% (95% CI 93.6-99.1), 90.0% (95% CI 84.3-93.7), 94.7% (95% CI 90.1-97.2), and 94.6% (95% CI 89.9-97.2), respectively. The 3-year stoma-free survival was 95.0% (95% CI 89.5-97.6). The 3-year regrowth-free survival in the watch-and-wait group was 71.8% (95% CI 59.9-81.2). CONCLUSIONS: In rectal cancer patients with major or complete clinical response after neoadjuvant therapy, the rectum can be preserved in about 80% of cases, without compromising the outcomes.

Treatment and Prognosis of Fibrolamellar Hepatocellular Carcinoma: a Systematic Review of the Recent Literature and Meta-analysis.

BACKGROUND: Fibrolamellar hepatocellular carcinoma (FL-HCC) is a rare disease and current efforts are focused on the prognosis and on the development of efficient and specific treatments. This study aimed to review the latest evidence regarding FL-HCC treatment and prognosis. METHODS: A systematic review of the literature over the past 10 years regarding FL-HCC, and meta-analysis of 1-, 3-, and 5-year overall survival (OS) comparing FL-HCC and conventional HCC were performed. RESULTS: Overall, 1567 articles were screened, of them 21 were selected for the systematic review, and 6 for meta-analysis. Twenty-one studies included a total of 2168 patients with FL-HCC, with a median age ranging from 11 to 56 years. The majority of patients underwent surgical resection or liver transplantation. After a median follow-up ranging from 24 to 58 months, 1-year OS was 67-100% and 5-year OS was 28-65%. A total of 743 patients with FL-HCC and 163,472 with conventional HCC were included in the meta-analysis. There was a significantly improved 1-, 3-, and 5-years OS in the FL-HCC group compared to the conventional HCC group, although high heterogeneity was found. When excluding population-based studies, and including 96 FL-HCC and 221 conventional HCC patients, the heterogeneity was low, and the meta-analysis showed a significantly longer 1-year OS in patients with FL-HCC than conventional HCC; however, there were no differences at 3- and 5-years OS. CONCLUSIONS: Surgical resection for FL-HCC is currently the only curative treatment available. FL-HCC is plagued by high-recurrence rates and poor long-term outcomes which may be related to the absence of specific treatment for advanced and recurrent disease.

Robotic Resection of Giant Duodenal Hamartoma After 18Fluorodeoxyglucose Positron Emission Tomography Magnetic Resonance Imaging (18FDG PET-MRI).

Brunner's gland hamartoma is a rare duodenal lesion. Resection for benign neoplasms of the duodenum should be considered in case of malignant potential or in case of symptomatic lesions. An accurate preoperative staging is mandatory in order to allow minimally invasive surgical approach, and to avoid under- or overtreatment. Endoscopic ultrasonography (EUS), Computed tomography (CT) scan, Magnetic Resonance Imaging (MRI) and PET/CT are techniques widely used for gastrointestinal tumor staging. We report a case of a 41-year-old female presenting a giant lesion of the second portion of the duodenum. Pathological examination of multiple forceps biopsies was inconclusive for histological characterization of the lesion. After a clinical staging including Esophagusgastroduodenoscopy, EUS, and CT scan, a Hybrid 18FDG PET/MRI was performed to assess the malignant potential of the lesion and the relation between polyp base and Vater's papilla. After multidisciplinary meeting, the patient underwent robotic transduodenal excision. The post-operative course was uneventful, and the patient was discharged on post-operative day 5. Final pathologic report consists in a histologically of Brunner's Glands Hamartoma. This is the first report on the role of 18FDG PET/MRI in staging and planning treatment of bulky low malignant duodenal lesion. An accurate staging with 18FDG PET/MRI could be very useful in the planning the management of duodenal lesion with uncertain malignant potential in order to avoid under- and overtreatment.

Rectal Sparing Approaches after Neoadjuvant Treatment for Rectal Cancer: A Systematic Review and Meta-Analysis Comparing Local Excision and Watch and Wait.

Local Excision (LE) or Watch and Wait (WW) for patients with complete clinical response or near-complete clinical response after neoadjuvant chemoradiotherapy (nCRT) were proposed to avoid morbidity and impairment of quality of life after rectal resection. The aim of this study is to perform a systematic review of the literature, and to compare rectal-sparing approaches, in terms of rectum-preservation rate, local control, and distant recurrences. A systematic review and meta-analysis were performed of studies published until July 2022 (PROSPERO, registration CRD42022341480), and the quality of evidence was assessed using a GRADE approach. Seven retrospective studies and one prospective trial were included. In six studies, patients were treated with standard long-course nCRT, and in two with Total Neoadjuvant Therapy (TNT). Overall, there were 213 and 188 patients in WW and LE group, respectively, and no difference was found between WW and LE when considering rectum-preservation rate (OR 0.80 95%CI 0.31-2.01, p = 0.63), local disease (OR 1.60 95%CI 0.75-3.42, p = 0.22), locoregional failure (OR 0.85 95%CI 0.20-3.66, p = 0.83) and distant recurrence (OR 0.76 95%CI 0.37-1.55, p = 0.45). Studies directly comparing WW and LE are still lacking, even though no differences between WW and LE in terms of rectum-preservation, local control, and distant recurrences have been found.

Impact of DNA mismatch repair proteins deficiency on number and ratio of lymph nodal metastases in colorectal adenocarcinoma.

BACKGROUND: Approximately 15 % of colorectal adenocarcinomas (CRCs) are characterized by an altered expression of DNA mismatch repair (MMR) proteins (i.e. MMR deficiency [MMRd]). Lymph node ratio (LNR) represents one of the most important prognostic markers in non-advanced CRCs. No significant data are available regarding LNR distribution depending on MMR status. PURPOSE OF THE STUDY: The aim of the present work was to compare pathological and clinical characteristics of MMRd tumors versus MMR proficient (MMRp) cases. Particular attention was paid to how these molecular sub-groups relate to the LNR. MATERIALS AND METHODS: A mono-Institutional series of 1037 consecutive surgically treated stage I-IV CRCs were retrospectively selected and data were obtained from pathological reports. Cases were characterized for MMR/MSI status by means of immunohistochemistry or for microsatellite instability (MSI) analysis. RESULTS: MMRd/MSI tumors (n = 194; 18.7 %) showed significant differences in comparison to MMRp lesions for sex (female prevalence 50.5 % vs 40.7 %; p = 0.013), age (74.2 vs 69.2; p < 0.001), location (right side; p < 0.001), diameter (larger than MMRp; p < 0.001), growth pattern (expansive pattern of growth; p < 0.001), peri- (p = 0.0002) and intra-neoplastic (p = 0.0018) inflammatory infiltrate, presence of perineural invasion (p < 0.001), stage (lower stage at presentation; p < 0.001), grade (higher prevalence of high-grade tumors; p < 0.001), and LNR (lower; p < 0.001). CONCLUSIONS: MMRd/MSI tumors are a distinct molecular CRC subtype characterized by a significantly lower LNR in comparison to MMRp lesions. These data further support the prognostic impact of MMRd/MSI status in early-stage CRCs.

Multiple colorectal adenomas syndrome: The role of MUTYH mutation and the polyps' number in clinical management and colorectal cancer risk.

BACKGROUND & AIMS: Multiple colorectal adenomas (MCRAs) can result from APC (AFAP) or biallelic MUTYH (MAP) mutations, but most patients are wild type and referred to as non-APC/MUTYH polyposis (NAMP). We aim to examine the risk of colorectal cancer (CRC) and the role of endoscopy in managing patients with MCRAs, with a specific focus on clinical features and genotype. METHODS: Records of MRCAs between 2000 and 2022 were retrospectively analysed. Patients were divided according to the genotype (MAP vs. NAMP) and the number of categorised polyps' burden (group 1: 10-24, group 2: 25-49, and group 3: 50-99 adenomas). Predictors of outcome were CRC-free survival (CRC-FS) and Surgery free-survival (S-FS). RESULTS: 220 patients were enrolled (NAMP n = 178(80.0%)). CRC at diagnosis was more frequent in group 3 (p = 0.01), without significant differences between the genotypes (p = 0.20). At a follow-up of 83(41-164) months, 15(7%) patients developed CRC during surveillance. CRC-FS was not correlated to genotype (p = 0.07) or polyps' number (p = 0.33), while S-FS was similar in MAP and NAMP (p = 0.22) and lower in groups 2 and 3 (p = 0.0001). CONCLUSIONS: MAP and NAMP have the same CRC risk and no difference in treatment. Endoscopic surveillance compared favorably with surgery in avoiding CRC risk, even in patients with more severe colorectal polyposis.

COVID-19 free pathways decrease postoperative complications in patients undergoing elective colorectal surgery.

Background: To reduce the exposition risk to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in surgical patients more prone to develop serious forms of Coronavirus disease 2019, a reorganization that previewed the creation "COVID-19-free" hospitals or units was pursued. The aim of this study was to quantify the effect of clear pathways to reduce the risk of SARS-Cov-2 transmission, on postoperative complications. Methods: Data of all consecutive patients undergoing surgical procedure for colorectal diseases, between November 2019 and July 2020 in two Italian referral centers, were retrospectively analyzed. Patients were divided into two groups: the ones underwent surgical procedures during the period before the pandemic from November 2019 to March 2020 (Group 1) (before-COVID), and those who underwent surgical procedure from April to July 2020 during the pandemic (Group 2) (during-COVID pandemic). Results: Overall, 264 patients were collected, 168 (63.4%) in Group 1 and 96 (36.4%) Group 2. Preoperative characteristics were similar between groups; during the pandemic there was a higher proportion of patients who underwent surgical procedures for malignancy compared with the period before the pandemic (92.7% vs 72%; p = 0.001). Patients in Group 2 had a lower rate of postoperative general complications (21.9% vs 34.5%; p = 0.03) and a lower rate of surgical complications (14.6% vs 25%; p = 0.05). No difference in term of medical complications, infections, and intraoperative complications were found. Minimally invasive approach (OR 0.46; 95% CI 0.04-0.83; p = 0.01) and isolation of patients (OR, 0.18; 95% CI, 0.04-0.83; p = 0.03) were independently associated with lower risk of postoperative complications. Conclusion: In this cohort study COVID-19-free pathways were significantly associated with low rate of postoperative morbidity in patients undergoing colorectal elective surgery.

Predictors of Metastatic Lymph Nodes at Preoperative Staging CT in Gastric Adenocarcinoma.

Background. The aim of this study was to identify the most accurate computed-tomography (CT) dimensional criteria of loco-regional lymph nodes (LNs) for detecting nodal metastases in gastric cancer (GC) patients. Methods. Staging CTs of surgically resected GC were jointly reviewed by two radiologists, considering only loco-regional LNs with a long axis (LA) ≥ 5 mm. For each nodal group, the short axis (SA), volume and SA/LA ratio of the largest LN, the sum of the SAs of all LNs, and the mean of the SA/LA ratios were plotted in ROC curves, taking the presence/absence of metastases at histopathology for reference. On a per-patient basis, the sums of the SAs of all LNs, and the sums of the SAs, volumes, and SA/LA ratios of the largest LNs in all nodal groups were also plotted, taking the presence/absence of metastatic LNs in each patient for reference. Results. Four hundred and forty-three nodal groups were harvested during surgery from 107 patients with GC, and 173 (39.1%) were metastatic at histopathology. By nodal group, the sum of the SAs showed the best Area Under the Curve (AUC), with a sensitivity/specificity of 62.4/72.6% using Youden's index with a >8 mm cutoff. In the per-patient analysis, the sum of the SAs of all LNs in the loco-regional nodal groups showed the best AUC with a sensitivity/specificity of 65.6%/83.7%, using Youden's index with a >39 mm cutoff. Conclusion. In patients with GC, the sum of the SAs of all the LNs at staging CT is the best predictor among dimensional LNs criteria of both metastatic invasion of the nodal group and the presence of metastatic LNs.