Rate Of Positive Resection Margin Research Articles

Comparison of short-term outcomes of laparoscopic surgery, robot-assisted laparoscopic surgery, and open surgery for lateral lymph-node dissection for rectal cancer: a network meta-analysis.

This study attempted to compare short-term outcomes of laparoscopic surgery (LS), robot-assisted laparoscopic surgery (RS), and open surgery (OS) for lateral lymph-node dissection (LLND) in treatment of rectal cancer through network meta-analysis.Embase, Web of Science, PubMed, and The Cochrane Library databases were searched to collect cohort studies on outcomes of LS, RS, and OS for LLND for rectal cancer. Newcastle-Ottawa Scale (NOS) was utilized to evaluate the quality of cohort studies. Primary outcomes should at least include one of the following clinical outcome measures: operative time, blood loss, total lymph-node harvest, positive resection margin rate, postoperative complications, and postoperative hospital stay. A network meta-analysis was conducted using STATA software.Fourteen cohort studies including 8612 patients were eligible for inclusion. The network meta-analysis results showed that, in terms of intraoperative outcomes, the RS group had the longest operative time, while the OS group had the shortest; the LS and RS groups had significantly less blood loss than the OS group. In terms of histological outcomes, there were no significant differences in the total number of lymph nodes harvested and the positive margin rate among the LS, RS, and OS groups (P > 0.05). Regarding postoperative outcomes, the OS group had the highest probability of postoperative complications and the longest hospital stay, followed by the LS group, with the RS group being the lowest.RS was the best method in blood loss, postoperative complication rate, and postoperative hospital stay, followed by LS. OS had the shortest operative time and the highest blood loss.

Trends in management and outcomes of colon cancer in the United States over 15 years: Analysis of the National Cancer Database.

Management of colon cancer has changed over the last few decades. We assessed the trends in management and outcomes using the US National Cancer Database (NCDB). A retrospective analysis of all patients with colonic adenocarcinoma between 2005 and 2019 was conducted. The cohort was divided into three equal time periods: Period 1 (2005-2009), Period 2 (2010-2014), and Period 3 (2015-2019) to examine treatment and outcomes trends. The primary outcome was 5-year overall survival (OS). The study included 923,275 patients. A significant increase in patients with stage IV disease was noted in Period 3 compared to Period 1 (47.9% vs. 27.9%, respectively), whereas a reciprocal reduction was seen in patients with locally advanced disease (stage II: 20.8%-12%; stage III: 14.5%-7.7%). Use of immunotherapy significantly increased from 0.3% to 7.6%. Mean 5-year OS increased (43.6 vs. 42.1 months) despite the increase in metastatic disease and longer time from diagnosis to definitive surgery (7 vs. 14 days). A reduction in 30-day readmission (5.1%-4.2%), 30- (3.9%-2.8%), and 90-day mortality (7.1%-5%) was seen. Laparoscopic and robotic surgery increased from 45.8% to 53.1% and 2.9% to 12.7%, respectively. Median postoperative length of hospital stay decreased by 2 days. Rate of positive resection margins (7.2%-6%) and median number of examined lymph nodes (14-16) also improved. Minimally invasive surgery and immunotherapy for colon cancer significantly increased in recent years. Patient outcomes including OS improved over time.

Impact of trans-anal versus laparoscopic total mesorectal excision on the surgical and pathologic outcomes of patients with rectal cancer: meta-analysis of randomized controlled trials.

Despite its profound impact on the oncologic outcomes of rectal cancer, the most optimal surgical approach to total mesorectal excision (TME) has not been identified yet. All previous meta-analyses on this subject have been based on observational studies. This meta-analysis was conducted to assess the surgical and oncologic outcomes of laparoscopic TME (LaTME) compared to trans-anal TME (TaTME), utilizing only randomized controlled trials. Systematic review and meta-analysis of randomized controlled trials. We searched electronic databases (MEDLINE, Cochrane CENTRAL, Clinicaltials.gov) from 2010 onwards, for all published clinical trials comparing TaTME to LaTME. Results are presented as risk ratios, with 95% CI, and pooled using the random effects model. A total of 1691 patients, from 6 eligible randomized controlled trials, were included for analysis. Analyzed data showed no significant difference in morbidity (RR: 0.85, p = 0.15), mortality (RR: 0.50, p = 0.44), conversion to open (RR: 0.40, p = 0.07), or anastomotic leakage (RR: 0.73, p = 0.10) between TaTME and LaTME. There was also no difference in the rate of positive distal resection margin (DRM) (RR: 0.55, p = 0.10) or positive circumferential resection margin (CRM) (RR: 0.67, p = 0.30). Patients undergoing TaTME were more likely to have a complete TME (RR: 1.06, p = 0.002) and shorter hospital stays (RR: - 0.97, p < 0.00001). Patients undergoing TaTME for rectal cancer were more likely to have a complete TME when compared to LaTME, though this did not translate into improved distal or circumferential resection margin. Additionally, TaTME and LaTME had similar surgical outcomes except for shorter length of stay with TaTME.

Laparoscopic rectal cancer resection yields comparable clinical and oncological results with shorter hospital stay compared to open access: a 5-year national cohort

PurposeAlthough widely applied, the results following laparoscopic rectal resection (LRR) compared to open rectal resection (ORR) are still debated. The aim of this study was to assess clinical short- and long-term results as well as oncological resection quality following LRR or ORR for cancer in a 5-year national cohort.MethodsData from the Norwegian Registry for Gastrointestinal Surgery and the Norwegian Colorectal Cancer Registry were retrieved from January 2014 to December 2018 for patients who underwent elective resection for rectal cancer. Primary end point was 5-year overall survival. Secondary end points were local recurrence rates within 5 years, oncological resection quality, and short-term outcome measures.ResultsA total of 1796 patients were included, of whom 1284 had undergone LRR and 512 ORR. There was no difference in 5-year survival rates between the groups after adjusting for relevant covariates with Cox regression analyses. Crude 5-year survival was 77.1% following LRR compared to 74.8% following ORR (p = 0.015). The 5-year local recurrence rates were 3.1% following LRR and 4.1% following ORR (p = 0.249). Length of hospital stay was median 8.0 days (quartiles 7.0–13.0) after ORR compared to 6.0 (quartiles 4.0–8.0) days after LRR. After adjusting for relevant covariates, estimated additional length of stay after ORR was 3.1 days (p < 0.001, 95% CI 2.3–3.9). Rates of positive resection margins and number of harvested lymph nodes were similar. There were no other significant differences in short-term outcomes between the groups.ConclusionLRR was performed with clinical and oncological outcomes similar to ORR, but with shorter hospital stay.

The role of image-guided volume-adapted high-dose-rate endorectal brachytherapy boost in total neoadjuvant treatment of distal locally advanced rectal cancer.

3611 Background: Endorectal brachytherapy has been used as palliative or preoperative treatment for advanced or locally advanced rectal cancer, with moderate radiation induced toxicity. This study aimed to explore the efficacy of high-dose-rate 192Ir brachytherapy combined with external beam radiotherapy (EBRT) in total neoajuvant treatment (TNT) of distal rectal cancer. Methods: From January 2017 to December 2022, eligible rectal adenocarcinoma patients were assessed as clinical stage II -III, with primary tumor located in distal rectum (≤5 cm from anal verge). The local staging was determined using endorectal ultrasound and magnetic resonance imaging (MRI). In addition, cases included in this study underwent preoperative semiweekly endorectal brachytherapy of 8-12Gy/2-3F/1-1.5w, followed by EBRT of 45-50.4Gy/25-28F, fluorouracil-based concurrent and consolidation chemotherapy. The brachytherapy was image-guided volume-adapted, and delivered by multi-channel 192Ir source applicators with different diameters. Radiation proctitis was graded from 0 to 4 using Radiation Therapy Oncology Group (RTOG) criteria. Results: A total of 40 cases were enrolled in this retrospective study, biopsy-proven and diagnosed as clinical stage II (n = 8), stage III (n = 32). The rates of T4 and positive circumferential resection margin (CRM) were 35% and 87.5% respectively. The median value of the interval from completion of radiotherapy to operation was 86 days (interquartile range: 75-98 days). After neoadjuvant treatment, 2 cases were undergoing the watch-and-wait strategy with sustained clinical complete response (cCR), 38 patients received operation and R0 resection rate was 97.4%. The pathological complete response (pCR) rate was 28.9%, and major pathological regression rate was 67.5%. The theoretical rate of anus preservation was 62.5%, including 6 of 21 cases underwent abdominoperineal resection but achieved pCR, 17 cases underwent low anterior resection or intersphincteric resection, and 2 cases with sustained cCR. After a median follow-up of 37 months (range 12-68 months), the 3-year disease-free survival, local-regional reccurence-free survival and overall survival was 81.1% (95%CI: 64.3%-91.2%), 94.9% (95%CI: 80.6%-98.5%) and 96.9% (95%CI: 82.1%-99.4%), respectively. No patients experienced Grade ≥3 radiation proctitis. The median Wexner fecal incontinence score of anus-preserving cases was 1 (range 0-8). Subgroup analysis showed that the complete response rate (pCR or sustained cCR) was lower in cases received 2 fractions brachytherapy than those received 3 fractions (27.8% vs 36.4%). Conclusions: The addition of image-guided volume-adapted high-dose-rate 192Ir endorectal brachytherapy boost to TNT could improve the pathological tumor response and anus preservation rate in distal locally advanced rectal cancer.

Cathepsin protease expression in infiltrative soft tissue sarcomas: cathepsin-K correlates with infiltrative tumor growth and clinical outcomes.

Cathepsin proteases, activated in the lysosomes, are upregulated in many cancers. Intraoperative detection systems of microscopic residual tumor using cathepsin-mediated release of fluorescent nanoparticles may guide surgical excisions to improve local control. We sought to define the genetic and proteomic expression of cathepsins and their clinicopathological correlates in myxofibrosarcoma and undifferentiated pleomorphic sarcoma (UPS)-soft tissue sarcomas with high rates of positive resection margins and local recurrence-and to establish a cellular justification for cathepsin-dependent systems to identify residual cancer in the resection bed. Real-time quantitative polymerase chain reaction analysis of 58 fresh-frozen tumor specimens revealed that 56 (97%) had elevated mRNA expression of ≥1 cathepsin, including cathepsin-B (79%), cathepsin-K (59%), cathepsin-L (71%), and -S (71%). Immunohistochemical analysis of these fresh-frozen specimens revealed that 98% of tumors were positive for one or more of cathepsin-B (85%), cathepsin-K (50%), cathepsin-L (63%), and -S (10%). Strong cathepsin-K expression was associated with greater risks of local recurrence (hazard ratio, 3.78; p=0.044) and disease-specific mortality (hazard ratio, 3.70; p=0.025). Immunohistochemical analysis of 33 formalin-fixed paraffin-embedded block samples revealed that 97% were positive for cathepsin-B (88%), cathepsin-K (76%), cathepsin-L (52%), or -S (52%) at the tumor periphery; cathepsin-K positivity correlated with a radiographic tail-like sign (p=0.004) and microscopic infiltrative growth (p=0.020). We conclude that cathepsins are broadly overexpressed in myxofibrosarcoma and UPS, and cathepsin-K may be an immunohistochemical marker of local infiltration and poorer prognosis that could be used to guide precision surgery.

Cutaneous Squamous Cell Carcinoma in Immunocompromised Patients-A Comparison between Different Immunomodulating Conditions.

Immunosuppression is strongly associated with an increased risk of developing cutaneous squamous cell carcinoma (cSCC). Studies on solid organ transplant recipients (SOTR) and chronic lymphocytic leukemia (CLL) patients have already demonstrated higher rates of aggressive cSCC tumors in these populations compared to immunocompetent controls. Studies on other immunosuppressed patient groups are scarce. This study was aimed at assessing the effects of different immunomodulating conditions on patients diagnosed with cSCC. We sought to compare the clinical features, treatments, and survival rates among the different study groups, as well as outcomes to those of immunocompetent controls with cSCC. A retrospective analysis of 465 cSCC patients, both immunosuppressed (IS) and immunocompetent controls. Etiologies for immunosuppression included SOTR, CLL, chronic kidney disease (CKD), psoriasis, rheumatoid arthritis (RA) and systemic lupus erythematous (SLE). Compared to the control group, IS patients demonstrated several significant differences. These include higher rates of positive resection margins, higher recurrence rates, and multiple SCC tumors. Patients in the IS group, who were also given immunomodulating agents, demonstrated even lower survival rates. Cox regression analysis demonstrated statistically significant decreased overall survival (OS) rates for IS patients compared to the controls (OR = 1.9, p = 0.031). SOTR patients tend to have multiple cSCC tumors (35%), with the highest number of primary tumors compared to controls (2.54 tumors per patient on average, p < 0.001), but also compared to all other IS groups. The average SCC lesion size in the SOTR group was the smallest, measuring at 13.5 mm, compared to the control group and all other IS groups. Decreased survival rates were seen on Cox regression analysis compared to controls (HR = 2.4, p = 0.001), but also to all other IS groups. CLL patients also had the highest rates of positive margins compared to controls (36% vs. 9%, p < 0.01) and to all other IS groups. They were also most likely to get adjuvant or definitive oncological treatments, either radiotherapy or chemotherapy, compared to controls (36% vs. 15%, p = 0.02) and to other IS groups. Patients in the CKD group demonstrated the highest rates for multiple cSCC (OR = 4.7, p = 0.001) and the worst rates of survival on Cox regression analysis (HR = 3.2, p = 0.001). Both rheumatoid arthritis and psoriasis patients demonstrated the shortest disease-free survival rates (2.9y ± 1.1, 2.3y ± 0.7, respectively), compared to controls (4.1y ± 2.8) and to all other IS groups. Among cSCC patients, immunosuppression due to SOTR, CLL, CKD, RA, and psoriasis is associated with worse outcomes compared to controls and other IS groups. These patients should be regarded as high-risk for developing aggressive cSCC tumors. This study is the first to assess and compare cSCC outcomes among multiple IS patient groups.

Abstract P1-09-10: Factors associate with borderline or invaded margins in breast cancer surgery at the Val d’Aurelle Montpellier CRLC

Abstract Factors associate with borderline or invaded margins in breast cancer surgery at the Val d’Aurelle Montpellier CRLC Véronique Mboua Batoum*, Esther Dina Bell, Christianne Nsahlai, Junie Annick Metogo Ntsama, Esther Juliette Meka, Marian Gutowski, Simon Thezenas, William Jacot *Corresponding autor : vbatoum@gmail.com Introduction: The inadequate status of the resection margins after breast cancer surgery is an important predictor of local tumor recurrence. The objective of our study was to determine the factors associated with positive or invaded resection margins. Methodology: Our retrospective study included a cohort of 652 patients with early invasive breast cancer who underwent breast cancer conserving surgery at the Val d’Aurelle Regional Cancer Center. We defined positive margins as those with a distance of less than or equal to 2 mm from the tumour. The data were analysed using STATA® 10.0 software. Results: In our study, The median distance from the tumour to the surgical resection site was 5mm [0.0 - 35.0mm]. Resection margins were positive in 208 patients (31.9%). The rate of positive resection margins was significantly higher in non-menopausal patientss (P =0,0050), in those with tumours less than 2 cm in size (P = 0,0004), with ductal carcinoma in situ (DCIS) component and without lymph node involvement (P =0,0082). Re-excision surgery was performed in 229 patients (35.1%). Conclusion: Consideration of each of these factors associated with positive resection margins shoud help the surgeons to perform a wider excision, in other to obtain clear resection margin during the initial breast cancer surgery. Key words: breast cancer, conservative surgery, resection margins, risk factors for positive margins Citation Format: veronique M. Mboua Batoum, esther D. Dina Bell. Factors associate with borderline or invaded margins in breast cancer surgery at the Val d’Aurelle Montpellier CRLC [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-09-10.

Long-term outcomes of upfront robotic rectal cancer surgery: a single-center, retrospective cohort study in Japan.

The purpose of this study was to evaluate the long-term outcomes of robotic rectal cancer surgery and to examine the risk factors for recurrence. In a high-volume center in Japan, we retrospectively enrolled patients with pStage I-III rectal cancer within 15cm of the anal verge who underwent robotic surgery from 2011 to 2017. Almost all patients underwent upfront surgery, and lateral lymph-node dissection (LLND) was performed for patients with locally advanced lower rectal cancer. We evaluated the 5-year overall survival (OS), relapse-free survival (RFS), and cumulative local recurrence (LR) rates and examined the risk factors for the RFS. We evaluated 488 patients who underwent robotic rectal cancer surgery, including 5.1% who underwent preoperative chemoradiotherapy to obtain clear resection margins and 33.6% who underwent LLND. There were 203, 87, and 198 patients with pStage I, II, and III, respectively, and the positive resection margin rate was 1.0%. The 5-year OS, RFS, and LR rates were 95.5%, 81.7%, and 2.2%, respectively. The independent risk factors for the RFS were the presence of venous invasion, extramural tumor deposits without lymph-node structure, and pT ≥ 3. This study demonstrated the favorable long-term outcomes of robotic rectal cancer surgery.

Open Versus Laparoscopic Surgery in the Management of Adrenocortical Carcinoma: A Systematic Review and Meta-analysis.

Laparoscopic surgery is considered a standard treatment for benign adrenal tumors; however, no consensus has been reached on the optimal resection technique for adrenocortical carcinomas. This study aims to evaluate the safety and efficacy of laparoscopic surgery and open surgery in the management of adrenocortical carcinoma. The Cochrane, Embase, PubMed, Scopus, and Web of Science databases were searched for articles from inception to May 2022, by two independent reviewers using the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. The review was registered prospectively on the PROSPERO database (CRD42022316050). From 183 studies screened, 11 studies met the eligibility criteria, with a total of 1617 patients with adrenocortical carcinoma undergoing either laparoscopic surgery (n = 472) or open surgery (n = 1145). Open surgery demonstrated a lower rate of positive resection margin compared with laparoscopic surgery (odds ratio [OR] 1.52, 95% confidence interval [CI] 1.10-2.10; I2 = 0%). Additionally, open surgery had more favorable overall survival (OR 0.56, 95% CI 0.44-0.72; I2 = 0%) and recurrence-free rates (OR 0.60, 95% CI 0.42-0.85; I2 = 38%) than laparoscopic surgery at 3years. Hospital stay was shorter for laparoscopic surgery than open surgery (mean difference - 2.49days, 95% CI - 2.95 to - 2.04; I2 = 45%). Open surgery should still be considered the standard operative approach; however, laparoscopic surgery could be regarded as an effective and safe operation for selected adrenocortical carcinoma cases with appropriate laparoscopic expertise. Further randomized controlled studies with tumor stage- and resection margin-dependent survival analysis are necessary to ascertain the safety and efficacy of the treatment.

Outcomes of Local Excision Compared to Radical Excision of Rectal Gastrointestinal Stromal Tumors: A Propensity-Score Matched Analysis of the NCDB.

Gastrointestinal stromal tumors (GISTs) account for <1% of gastrointestinal cancers. The present study aimed to assess the outcomes of local and radical excision of non-metastatic rectal GISTs. This study was a retrospective cohort analysis of patients with non-metastatic rectal GISTs in the NCDB. Patients were divided according to the surgical approach into local and radical excision and were compared in regard to the baseline characteristics and outcomes. A propensity-score matched analysis was performed to match the two groups for baseline confounders. The main outcomes were 5-year overall survival (OS), surgical margins, hospital stay, short-term mortality, and readmission. 228 patients (54.8% male) with rectal GISTs were included. Before matching, 127 (55.7%) patients underwent local excision and 101 (44.3%) had radical excision. Patients who underwent local excision had more cT1-T2 and low-grade GISTs whereas patients who had radical excision received more neoadjuvant systemic treatment. After matching for clinical T stage, tumor grade, and neoadjuvant systemic therapy, 52 patients were included in each group. Local excision had a significantly higher rate of positive resection margins (42.2% vs. 19.1%, p = 0.02) and a shorter hospital stay (0 vs. 3days, p < 0.001) than radical excision. The two groups had similar mean OS (139.8 vs. 133.1months, p = 0.52). Local excision was associated with a significantly higher incidence of positive resection margins and shorter hospital stay, yet similar overall survival to radical excision.

"Infiltrative" Versus "Mass-Forming" Pancreatic Cancer: A New Radiological Classification System for Pancreatic Head Ductal Carcinoma and Its Pathological Correlation.

Resectability in localized pancreatic ductal adenocarcinoma (PDAC) is deemed through radiological criteria. Despite initial evaluation classifying tumors as "resectable," they often have ill-defined borders that can result in more extensive cancer than predicted on final pathology analysis. We attempt to categorize these tumors radiologically and define them as "infiltrative" and contrast them to more well-defined or "mass-forming" tumors and assess their correlation with surgical oncological outcomes. We hypothesize that mass-forming lesions will result in fewer positive resection margins. Patients diagnosed with PDAC of the head of the pancreas and who underwent subsequent curative intent resection between 2016 and 2018 were included. A retrospective chart review of patients was conducted and computed tomography images at the time of diagnosis were reviewed by two radiologists and scored as "mass forming" or "infiltrative" using a newly developed classification system. These classifications were then correlated with margin status. Sixty-eight consecutive pancreatoduodenectomies performed for PDAC from 2016 to 2018 were identified. After screening, 54 patients were eligible for inclusion. Radiologically defined mass-forming lesions had a trend toward a lower rate of positive resection margins (35.7% vs. 50.0%; p = 0.18), specifically the bile duct margin and pancreas margin as well as an overall larger size (4.03 cm vs. 3.25 cm, p = 0.02) compared with infiltrative lesions. We propose a new radiological definition of PDAC into "mass forming" and "infiltrative," a nomenclature that resonates with other tumor sites. Infiltrative lesions trended toward a higher rate of positive resection margins. This classification may help tailor therapy for infiltrative tumors toward a neoadjuvant approach even if they appear resectable.

473. SAFETY AND USEFULNESS OF LARYNX- PRESERVING HIGH-LEVEL CERVICAL ANASTOMOSIS FOR CERVICAL ESOPHAGEAL CANCER

Abstract In cases of cervical esophageal cancer, total Pharyngo-Laryngo-Esophagectomy is often performed when the oral edge of the primary tumor is less than 2 cm from the esophageal entrance. In our hospital, we provide neo-adjuvant chemotherapy for cervical esophageal cancer and perform larynx-preserving esophagectomy whenever possible. The aim of this study was to evaluate the safety and efficacy of larynx- preserving high-level cervical anastomosis for cervical esophageal cancer. 41 patients underwent larynx- preserving esophagectomy for cervicothoracic esophageal cancer between January 2009 and September 2021 at our hospital were included. The distance from the oral edge of the primary tumor to the esophageal entrance was measured by esophagography and endoscopy. Patients with the distance of 2 cm or less were classified as the high cervical anastomosis group (H group: n=23), and patients with the distance of 2.1 cm or more were classified as the low cervical anastomosis group (L group: n=18). We compared the short-term and long-term results between the H and L groups. There were no differences between H and L groups in terms of patient characteristics, such as clinical depth of tumor invasion, grading of lymph node metastasis, frequency neo-adjuvant chemotherapy. The incidence of postoperative complications was similar in the two groups such as pneumonia, anastomotic leakage, anastomotic stenosis, recurrent nerve palsy. In histopathological examination, the rate of positive proximal resection margin was significantly higher in H group. (34.8 vs 5.6%(P=0.028). 3-year recurrence-free survival rate and 3-year survival rate were similar in the two groups. The anastomotic recurrence rates did not differ between the two groups. (5.0 vs 5.9% (P=0.715)) In the H group, the rate of positive proximal resection margin was significantly higher. However, there was no difference in the anastomotic recurrence rate and the 3-year survival rate between the two groups. Therefore, we believe that larynx- preserving high-level cervical anastomosis is useful to maintain QOL in cervical esophageal cancer patients with the oral edge of the primary tumor is less than 2 cm from the esophageal entrance.

Does Robotic Liver Surgery Enhance R0 Results in Liver Malignancies during Minimally Invasive Liver Surgery?-A Systematic Review and Meta-Analysis.

Simple SummaryThe resection margin status is one of the most relevant oncological factors in liver cancer surgery. Whether robotic liver surgery enhances R0 results in liver malignancies during minimally invasive liver surgery is not yet completely clear. We conducted a systematic review with meta-analysis to compare robotic and laparoscopic approaches in liver surgery with particular attention to the resection margin status in liver malignancies.Background: Robotic procedures are an integral part of modern liver surgery. However, the advantages of a robotic approach in comparison to the conventional laparoscopic approach are the subject of controversial debate. The aim of this systematic review and meta-analysis is to compare robotic and laparoscopic liver resection with particular attention to the resection margin status in malignant cases. Methods: A systematic literature search was performed using PubMed and Cochrane Library in accordance with the PRISMA guidelines. Only studies comparing robotic and laparoscopic liver resections were considered for this meta-analysis. Furthermore, the rate of the positive resection margin or R0 rate in malignant cases had to be clearly identifiable. We used fixed or random effects models according to heterogeneity. Results: Fourteen studies with a total number of 1530 cases were included in qualitative and quantitative synthesis. Malignancies were identified in 71.1% (n = 1088) of these cases. These included hepatocellular carcinoma, cholangiocarcinoma, colorectal liver metastases and other malignancies of the liver. Positive resection margins were noted in 24 cases (5.3%) in the robotic group and in 54 cases (8.6%) in the laparoscopic group (OR = 0.71; 95% CI (0.42–1.18); p = 0.18). Tumor size was significantly larger in the robotic group (MD = 6.92; 95% CI (2.93–10.91); p = 0.0007). The operation time was significantly longer in the robotic procedure (MD = 28.12; 95% CI (3.66–52.57); p = 0.02). There were no significant differences between the robotic and laparoscopic approaches regarding the intra-operative blood loss, length of hospital stay, overall and severe complications and conversion rate. Conclusion: Our meta-analysis showed no significant difference between the robotic and laparoscopic procedures regarding the resection margin status. Tumor size was significantly larger in the robotic group. However, randomized controlled trials with long-term follow-up are needed to demonstrate the benefits of robotics in liver surgery.

145: THE USE OF MACHINE LEARNING FOR REAL-TIME DETECTION OF OESOPHAGEAL AND GASTRIC CANCER BASED ON DIFFUSE REFLECTANCE SPECTROSCOPY: A VALIDATION STUDY

Abstract Background and aim The lack of a fast and accurate intraoperative tumour margin assessment tool contributes to high positive circumferential resection margin rates for oesophageal and gastric cancers, which is associated with local recurrence and poor long-term survival. Diffuse reflectance spectroscopy (DRS) can provide non-invasive, accurate, and real-time tissue classification based on quantification of light reflectance in tissue, providing a unique optical fingerprint of the tissue. This study aimed to validate the use of DRS for discrimination between normal and cancerous tissues based on ex-vivo gastric and oesophageal cancer resection specimens. Methods Consecutive patients undergoing resections for gastric and oesophageal carcinomas at a tertiary referral centre in London between July 2020 and June 2021 were included. Reflectance data in the 468-720 nm spectral range were recorded on ex-vivo specimens within 15 minutes of surgical specimen excision. Based on video recordings of the data acquisition procedure and probe tip tracking, sampling sites were correlated with histological reports manually labeled as either normal or cancer (Figure 1). Following spectral data normalisation and feature selection, four supervised machine learning approaches were tested for classification using 5-fold cross-validation. Overall classification accuracy and Area Under the Curve (AUC) across machine learning approaches were compared. Results A total of 32 patients (median age 68, 75% male) were included. 11,862 mean spectra (2990 spectra for normal oesophagus, 4628 for normal stomach, 2305 for gastric cancer, and 1939 for oesophageal cancer) were collected. For oesophageal cancer, classification accuracy was 96.22 ± 0.50 and AUC was 99.24 ± 0.19, while for gastric cancer, the accuracy was 93.86 ± 0.66, and AUC 98.50 ± 0.28 for gastric cancer. For both malignancy types, Extreme Gradient Boosting was the best performing classifier. The differences in spectral data between patients receiving neoadjuvant treatment and treatment naïve were non-significant. Conclusion Machine learning can be used to accurately differentiate between normal and cancerous oesophageal and gastric tissues in an ex-vivo setting, based on DRS data. Features used for class discrimination should be investigated to find possible physiological correlates of spectral data differences. Future intraoperative validation is required to assess the utility of this technology for real-time tumour margin mapping and its effect on long-term outcomes.

As time goes by–developments in surgery for esophageal cancer in the new millennium

Summary Background In the last two decades, both treatment options and epidemiological features of cancer have changed. We studied the influence of related parameters on the outcome of patients undergoing resection for esophageal carcinoma. Methods We analyzed 499 consecutive patients who underwent esophagectomy for carcinoma since January 2000, comparing 2000–2010 with 2011–2021 and examining changes over time. Results The percentage of men (87.9 vs. 86.9%; p = 0.74) in the two groups was unchanged, whereas mean age increased significantly from 60.8 to 65.2 years (p = 0.000). There was a trend towards an increase of adenocarcinoma (gamma = 0.120, ASE = 0.055). Despite significantly increasing use of induction chemoradiotherapy (p = 0.000) from 7.14% in 2000 to 68.9% in 2021 the distribution of pT, pN stage, grading and the rate of positive lateral resection margins remained unchanged. When comparing the two periods, the overall 30-day mortality was 4.4 vs. 4.2% (p = 0.56), recurrence-free survival was 36.9 vs. 38% at 60 months and 33.9 vs. 36.4% at 120 months (p = 0.93). Tumor-associated survival was 41.1 vs. 45% at 60 months and 35.5 vs. 38.7% at 120 months (p = 0.78). None of the survival rates differed significantly. A multivariable analysis of year of surgery, age, sex, histological subtype, grading, pT, pN, lateral resection margin, and induction therapy showed that only higher pT (p = 0.01), positive pN (p = 0.000), positive lateral margin (p = 0.003), squamous cell carcinoma (p = 0.04) and higher grading (p = 0.026) had a statistically significant, independent, negative influence on prognosis. Conclusion Optimized noninvasive and invasive therapeutic modalities have produced only marginal improvement in the prognosis of esophageal cancer within the last two decades.

Structured training curriculums for transanal total mesorectal excision in China: refinement is needed.

BackgroundTransanal total mesorectal excision (TaTME) is an alternative for mid-low rectal cancer. In China, this procedure has been performed in high-volume centers with structured training curriculums. The efficacy of the TaTME structured training curriculums in China is still unclear. This multicenter study aimed to explore the effectiveness of the structured training curriculums in China.MethodsSeven high-volume centers in China participated in this study. The first 25 patients who underwent TaTME in each center were enrolled. In the cohort, patients were divided into 3 groups. The first 5 procedures (group 1) were performed under proctoring according to the requirement of structured training curriculums. The latter 20 cases without proctoring were split into 2 groups (10 cases in each group, groups 2 and 3) according to the order of operation date. The baseline characteristics, perioperative complications, and pathological outcomes were compared between groups 1 and 2, as well as between groups 2 and 3.ResultsSymptomatic anastomotic leakage (AL) occurred in 18.6% of the patients in group 2 compared with 5.7% in group 1 (P1=0.08) and 5.0% in group 3 (P2=0.04). Seven (11.3%) patients in group 2 developed defecation disorders whereas no patients had this complication in group 3 (P2=0.02). Compared with group 2, the operative time was shorter (235 vs. 223 min, P2=0.40), while the rates of intraoperative complications (15.7% vs. 5.7%, P2=0.10), postoperative complications (31.3% vs. 25.7%, P2=0.06), AL (20.0% vs. 8.6%, P2=0.04), and positive distal resection margin (DRM) (7.5% vs. 2.9%, P2=0.27) were lower in group 3.ConclusionsThe effect of the structured training curriculums was acceptable but needed further improvement. The prevalence of anastomosis-related complications and the quality control of specimens are still not optimal, and measures for refinement (for example, more cases under proctoring) are needed in the curriculums.

Minimally Invasive Pancreatoduodenectomy in Patients with Abnormal Vascular Anatomy: Surgical Techniques and Clinical Outcomes

Introduction: Minimally Invasive Pancreatoduodenectomy(MIPD) is a complex procedure where abnormal vascular anatomy(AVA), compared to normal vascular anatomy(NVA), can add to the surgical difficulty and risks. In particular, right or common hepatic artery (RHA and CHA, respectively) anomalies can be a source of serious problems. Hence preoperative planning and intraoperative care are paramount. Herein we present a video showing MIPD in case of AVA, discuss our protocol and surgical techniques, and compare results in patients with AVA involving the HA versus NVA. Methods: Data of patients undergoing MIPD(2015-2020) were analysed. Preoperative CT-angiography was performed in all patients. A SMA-first approach was performed in all patients with AVA while a hybrid left/anterior/posterior approach was adopted in NVA. The bile duct was divided at last in NVA patients, while biliary division was performed earlier in patients with AVA or with tumours adherent to the SMV/PV, thus allowing a cranio-caudal and caudo-cranial dissection. Results: among 83 patients, 25 showed AVA: 10 had a LHA from the LGA and 15(18%) had a replaced RHA(n=11)/CHA(n=4). These latter were compared with 68 with NVA. Operative time, blood loos and conversion rates were similar in both groups. Postoperative outcomes were similar, except for significantly lower rates of PPH in AVA patients. Moreover there was no difference in the rates of positive resection margins and number of harvested nodes (table 1). Conclusions: preoperative identification of AVA, SMA-first approach, early biliary division, and cranio-caudal-cranial approach can mitigate the added anatomical challenge, thus ensuring a safe and sound oncological MIPD.

Variation in the volume-outcome relationship after rectal cancer surgery in the United States: Retrospective study with implications for regionalization

BackgroundPrevious studies have demonstrated improved outcomes for patients with rectal cancer treated at higher-volume hospitals. However, little is known whether heterogeneity in this effect exists. The objective was to test whether the effect of increased annual rectal cancer resection volume on outcomes is consistent across all hospitals treating rectal cancer. MethodsAdult stage I to III patients who underwent surgical resection for rectal adenocarcinoma from 2004 to 2016 were identified in the National Cancer Database. ResultsWe included 120,522 patients treated at 763 hospitals in this retrospective cohort study. Higher volume was linearly and incrementally related to outcomes in unadjusted analyses. In adjusted models, for an average patient at the average hospital, the effect of increasing the annual caseload of rectal cancer resections by 20 resections per year was associated with 8%, (hazard ratio = 0.92, 95% confidence interval = 0.87, 0.97), 18% (odds ratio = 0.82, 95% confidence interval = 0.70, 0.98), and 16% (odds ratio = 0.84, 95% confidence interval = 0.73, 0.95) relative reductions in 5-year overall survival, 30-, and 90-day mortality, respectively, and with a 19% (odds ratio = 1.19, 95% confidence interval = 1.04, 1.36) relative increase in the rate of neoadjuvant chemoradiation. These effects varied by individual hospitals such that 39% of hospitals do not see any benefit in 5-year overall survival associated with higher volumes. Increased volume was associated with lower positive circumferential resection margin rates at 19% of the hospitals. ConclusionThis study confirms that higher-volume hospitals have improved outcomes after rectal cancer surgery. However, there exists significant variation in these effects induced by individual within-hospital effects. Regionalization policies may need to be flexible in identifying the hospitals that would achieve enhanced benefits from treating a larger volume of patients.

Quality Indicators of Transanal Total Mesorectal Excision (TaTME) for Rectal Cancer

Abstract Introduction Transanal total mesorectal excision (TaTME) has revolutionized the surgical techniques for lower-third rectal cancer. The aim of the present study was to analyze the outcomes of quality indicators of TaTME for rectal cancer compared with laparoscopic TME (LaTME). Methods A cohort prospective study with 50 (14 female and 36 male) patients, with a mean age of 67 (range: 55.75 to 75.25) years, who underwent surgery for rectal cancer. In total, 20 patients underwent TaTME, and 30, LaTME. Every TaTME procedure was performed by experienced colorectal surgeons. The sample was divided into two groups (TaTME and LaTME), and the quality indicators of the surgery for rectal cancer were analyzed. Results There were no statistically significant differences regarding the patients and the main characteristics of the tumor (age, gender, American Society of Anesthesiologists [ASA] score, body mass index [BMI], tumoral stage, neoadjuvant therapy, and distance from the tumor to the external anal margin) between the two groups. The rates of: postoperative morbidity (TaTME: 35%; LaTME: 30%; p = 0.763); mortality (0%); anastomotic leak (TaTME: 10%; LaTME: 13%; p = 0.722); wound infection (TaTME: 0%; LaTME: 3.3%; p = 0.409); reoperation (TaTME: 5%; LaTME: 6.6%; p = 0.808); and readmission (TaTME: 5%; LaTME: 0%; p = 0.400), as well as the length of the hospital stay (TaTME: 13.5 days; LaTME: 11 days; p = 0.538), were similar in both groups. There were no statistically significant differences in the rates of positive circumferential resection margin (TaTME: 5%; LaTME: 3.3%; p = 0.989) and positive distal resection margin (TaTME: 0%; LaTME: 3.3%; p = 0.400), the completeness of the TME (TaTME: 100%; LaTME: 100%), and the number of lymph nodes harvested (TaTME: 15; LaTME: 15.5; p = 0.882) between two groups. Conclusion Transanal total mesorectal excision is a safe and feasible surgical procedure for middle/lower-third rectal cancer.