Circumferential Resection Margin Status Research Articles

A systematic review and meta-analysis of oncological outcomes with transanal total mesorectal excision for rectal cancer.

Transanal total mesorectal (taTME) excision is a method used to assist in the radical removal of the rectum. By adopting the concept of natural orifice surgery, it offers potential benefits over conventional techniques. Early enthusiasm for this strategy led to its rapid and widespread adoption. The imposing of a local moratorium was precipitated by the discovery in Norway of an uncommon multifocal pattern of locoregional recurrence. The aim of this systematic review and meta-analysis was to determine the incidence of local recurrence after taTME for rectal cancer. Conforming to the Cochrane Handbook for Systematic Reviews of Interventions and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines checklist, a systematic review and meta-analysis was conducted. This included case series and comparative studies between taTME and preferentially laparoscopic procedures published between 2010 and 2021. There were a total of 1175 studies retrieved. After removal and screening for quality and relevance, the final analysis contained 40 studies. The local recurrence rate following taTME was 3.4% (95% CI 2.9%-3.9%, I2 = 0%) in 4987 patients with follow-up durations ranging from 0.7 to 5.5 years. Compared with laparoscopic TME, local recurrence was not statistically different for the taTME group (p = 0.076); however, it was less probable (OR = 0.51, 95% CI 0.24-1.09, I2 = 0%). Systemic recurrence and circumferential resection margin status were secondary outcomes; however, the differences were not statistically significant. Our data suggest that the local recurrence for regular laparoscopic and transanal TME surgeries may be comparable, suggesting that taTME can be performed without influencing locoregional oncological outcomes in patients treated at specialized institutions and who have been cautiously selected.

Prediction of pathologic complete response to neoadjuvant chemoradiation in locally advanced rectal cancer.

To investigate the predictive factors of pathologic complete response (pCR) in locally advanced rectal cancer (LARC) patients who had been treated with neoadjuvant chemoradiation (nCRT). For this retrospective study, 53 LARC patients (37 males and 16 females; age range 25 to 79 years) were selected. Clinical characteristics, baseline mrTNM staging, MR gross tumor volumes (GTV), and pCR were evaluated. The diagnostic accuracy of GTV for predicting pCR was calculated. Among 53 LARC patients, 15 patients achieved pCR (28.3%), while 38 patients achieved non-pCR. Only three (5.7%) out of 53 patients did not downstage after nCRT. GTV and tumor differentiation were the significant prognostic parameters for predicting pCR. A tumor volume threshold of 21.1 cm3 was determined as a predictor for pCR, with a sensitivity of 84% and specificity of 47%. In addition, GTV was associated with mrN stage, circumferential resection margin (CRM) status, extramural vascular invasion (EMVI) status, and pretreatment serum CEA level. Tumor volume and tumor differentiation have significant predictive values in preoperative assessment of pCR among LARC patients. These findings aid clinicians to discriminate those patients who may likely benefit from preoperative regimens and to make optimal treatment plans.

A comparison of whole-mount and conventional sections for pathological mesorectal extension and circumferential resection margin assessment after total mesorectal excision

IntroductionThe objective of the study is to compare 2 techniques for histological handling of rectal cancer specimens, namely whole-mount in a large block vs conventional sampling using small blocks, for mesorectal pathological assessment of circumferential resection margin status and depth of tumor invasion into the mesorectal fat. MethodsThis is a prospective study including 27 total mesorectal excision specimens of rectal cancer from patients treated for primary rectal carcinoma between 2020 and 2022 in a specialized multidisciplinary Colorectal Unit. For each total mesorectal excision specimen, 2 contiguous representative tumoral slices were selected and comparatively analyzed with whole-mount and small blocks macroscopic dissection techniques, enabling comparison between them in the same surgical specimen. The agreement between the 2 techniques to assess the distance of the tumor from the circumferential resection margin as well as the depth of tumor invasion was evaluated with the Student’s t-test for paired samples, Pearson’s correlation coefficient, and the Bland-Altman method comparison analysis. ResultsComplete mesorectal excision was observed in 8% of cases. Circumferential resection margin involvement was observed in only one case (4 %). The whole-mount and small block techniques obtained similar results when we assessed the distance to the circumferential resection margin (t-test P = 0.8, r = 0.92) and the depth of mesorectal infiltration (t-test P = 0.6, r = 0.95). ConclusionsBoth gross dissection techniques (whole-mount vs multiple small cassettes) are equivalent and reliable to assess the distance to circumferential resection margin and the depth of mesorectal infiltration in the mesorectal fat in rectal cancer staging.

Quality of Surgical Outcome Reporting in Randomised Clinical Trials of Multimodal Rectal Cancer Treatment: A Systematic Review.

Randomised controlled trials (RCTs) continue to provide the best evidence for treatment options, but the quality of reporting in RCTs and the completeness rate of reporting of surgical outcomes and complication data vary widely. The aim of this study was to measure the quality of reporting of the surgical outcome and complication data in RCTs of rectal cancer treatment and whether this quality has changed over time. Eligible articles with the keywords ("rectal cancer" OR "rectal carcinoma") AND ("radiation" OR "radiotherapy") that were RCTs and published in the English, German, Polish, or Italian language were identified by reviewing all abstracts published from 1982 through 2022. Two authors independently screened and analysed all studies. The quality of the surgical outcome and complication data was assessed based on fourteen criteria, and the quality of RCTs was evaluated based on a modified Jadad scale. The primary outcome was the quality of reporting in RCTs and the completeness rate of reporting of surgical results and complication data. A total of 340 articles reporting multimodal therapy outcomes for 143,576 rectal cancer patients were analysed. A total of 7 articles (2%) met all 14 reporting criteria, 13 met 13 criteria, 27 met from 11 to 12 criteria, 36 met from 9 to 10 criteria, 76 met from 7 to 8 criteria, and most articles met fewer than 7 criteria (mean 5.5 criteria). Commonly underreported criteria included complication severity (15% of articles), macroscopic integrity of mesorectal excision (17% of articles), length of stay (18% of articles), number of lymph nodes (21% of articles), distance between the tumour and circumferential resection margin (CRM) (26% of articles), surgical radicality according to the site of the primary tumour (R0 vs. R1 + R2) (29% of articles), and CRM status (38% of articles). Inconsistent surgical outcome and complication data reporting in multimodal rectal cancer treatment RCTs is standard. Standardised reporting of clinical and oncological outcomes should be established to facilitate comparing studies and results of related research topics.

Development of a joint prediction model based on both the radiomics and clinical factors for preoperative prediction of circumferential resection margin in middle-low rectal cancer using T2WI images.

A circumferential resection margin (CRM) is an independent risk factor for local recurrence, distant metastasis, and poor overall survival of rectal cancer. In this study, we developed and validated a radiomics prediction model to predict perioperative surgical margins in patients with middle and low rectal cancer following neoadjuvant treatment and for decisions about treatment plans for patients. This study retrospectively analyzed 275 patients from center 1(training cohort) and 120 patients from center 2(verification cohort) with rectal cancer diagnosed at two centers from July 2020 to July 2022 who underwent neoadjuvant therapy and had their CRM status confirmed by preoperative high-resolution magnetic resonance imaging (MRI) scans. Radiomics signatures were extracted and screened from MRI images and a radiomics signature was built by the least absolute shrinkage and selection operator (LASSO) logistic regression model, which was combined with clinical signatures to construct a nomogram. The receiver operating characteristic (ROC) curve and area under the curve (AUC) value, sensitivity, specificity, positive predictive value, negative predictive value, and calibration curve were used to evaluate the predictive performance of the model. In our research, the combined model has the best performance. In the training group, the radiomics model based on high-spatial-resolution T2-weighted imaging (HR-T2WI), clinical model and combined model demonstrated an AUC of 0.819 (0.802-0.833), 0.843 (0.822-0.861), and 0.910 (0.880-0.940), respectively. In the validation group, they demonstrated an AUC of 0.745 (0.715-0.788), 0.827 (0.798-0.850), and 0.848 (0.779-0.917), respectively. The calibration curve confirmed the clinical applicability of the model. The individualized prediction model established by combining radiomics signatures and clinical signatures can efficiently and objectively predict perioperative margin invasion in patients with middle and low rectal cancer.

Prognostic value of circumferential radial margin involvement in esophagectomy for esophageal cancer: a case series.

Residual tumor at the proximal or distal margin after esophagectomy is associated with worse survival outcomes; however, the significance of the circumferential resection margin (CRM) remains controversial. In this study, we sought to evaluate the prognostic significance of the CRM in patients with esophageal cancer undergoing resection. We identified patients who underwent esophagectomy for pathologic T3 esophageal cancer from 2000 to 2019. Patients were divided into three groups: CRM- (residual tumor >1mm from the CRM), CRM-close (residual tumor >0 to 1mm from the CRM), and CRM+ (residual tumor at the surgical CRM). CRM was also categorized and analyzed per the Royal College of Pathologists (RCP) and College of American Pathologists (CAP) classifications. Of the 519 patients included, 351 (68%) had CRM-, 132 (25%) had CRM-close, and 36 (7%) had CRM+. CRM+ was associated with shorter disease-free survival [DFS; CRM+ vs. CRM-: hazard ratio (HR), 1.53 [95% CI, 1.03-2.28]; P =0.034] and overall survival (OS; CRM+ vs. CRM-: HR, 1.97 [95% CI, 1.32-2.95]; P <0.001). Survival was not significantly different between CRM-close and CRM-. After adjustment for potential confounders, CAP+ was associated with poor oncologic outcomes (CAP+ vs. CAP-: DFS: HR, 1.47 [95% CI, 1.00-2.17]; P =0.050; OS: HR, 1.93 [95% CI, 1.30-2.86]; P =0.001); RCP+ was not (RCP+ vs. RCP-: DFS: HR, 1.21 [95% CI, 0.97-1.52]; P =0.10; OS: HR, 1.21 [95% CI, 0.96-1.54]; P =0.11). CRM status has critical prognostic significance for patients undergoing esophagectomy: CRM+ was associated with worse outcomes, and outcomes between CRM-close and CRM- were similar.

Reporting of Circumferential Resection Margin in Rectal Cancer Surgery

Circumferential resection margin (CRM) in rectal cancer surgery is a major prognostic indicator associated with local recurrence and overall survival. Facility rates of CRM positivity have recently been established as a new quality measure by the Commission on Cancer (CoC); however, the completeness of CRM status reporting is not well characterized. To describe the changes in CRM reporting and factors associated with low rates of reporting. A retrospective cohort study was conducted using data from the National Cancer Database between January 2010 and December 2019. Data were analyzed between October 1, 2021, and February 1, 2022. Data from the National Cancer Database included patients diagnosed with nonmetastatic rectal adenocarcinoma receiving surgical treatment at CoC-accredited facilities throughout the US. Patient, tumor, and facility-level factors. Facilities were divided by surgical volume, safety-net status, and CoC facility type. Circumferential resection margin missingness rates. A total of 110 571 patients (59.3% men) with rectal adenocarcinoma who underwent curative-intent surgery at 1307 CoC-accredited hospitals were included for analysis. Reporting of CRM improved over the study period, with a mean (SE) missing 12.0% (0.32%) decreased from 16.3% (0.36%). Academic facilities had a higher missingness than other facility types (14.3% vs 10.5%-12.7%; P < .001). Mean (SE) rates of missingness were similar between hospitals of varying volume (lowest quartile: 12.2% [0.93%] vs highest quartile: 12.4% [0.53%]; P = .96). Cases in which fewer than 12 lymph nodes were removed had higher rates of missingness (18.1% vs 11.4%; P < .001). Increased odds of CRM missingness were noted with T category (odds ratio [OR], 1.50; 95% CI, 1.35-1.65) and N category (OR, 2.00; 95% CI, 1.82-2.20). Black race was associated with missingness (OR, 1.13; 95% CI, 1.06-1.14). Although CRM positivity reporting has improved over the last decade, the findings of this study suggest there is substantial room for improvement as it becomes a quality standard. Missingness appears to be associated with poor performance on other quality metrics and facility type. This measure appears to be ideal for targeted institution-level feedback to improve quality of care nationally.

MRI-based Radiomics Model for Preoperative Prediction of Lateral Pelvic Lymph Node Metastasis in Locally Advanced Rectal Cancer

To develop a magnetic resonance imaging (MRI)-based radiomics model for preoperative prediction of lateral pelvic lymph node (LPLN) metastasis (LPLNM) in patients with locally advanced rectal cancer MATERIALS AND METHODS: We retrospectively enrolled 263 patients with rectal cancer who underwent total mesorectal excision and LPLN dissection. Radiomics features from the primary lesion and LPLNs on baseline MRI images were utilized to construct a radiomics model, and their radiomics scores were combined to develop a radiomics scoring system. A clinical prediction model was developed using logistic regression. A hybrid predicting model was created through multivariable logistic regression analysis, integrating the radiomics score with significant clinical risk factors (baseline Carcinoembryonic Antigen (CEA), clinical circumferential resection margin status, and the short axis diameter of LPLN). This hybrid model was presented with a hybrid clinical-radiomics nomogram, and its calibration, discrimination, and clinical usefulness were assessed. A total of 148 patients were included in the analysis and randomly divided into a training cohort (n=104) and an independent internal testing cohort (n=44). The hybrid clinical-radiomics model exhibited the highest discrimination, with an area under the receiver operating characteristic (AUC) of 0.843 [95% confidence interval (CI), 0.706-0.968]in the testing cohort compared to the clinical model [AUC (95% CI)=0.772 (0.589-0.856)]and radiomics model [AUC (95% CI)=0.731 (0.613-0.849)]. The hybrid prediction model also demonstrated good calibration, and decision curve analysis confirmed its clinical usefulness. This study developed a hybrid MRI-based radiomics model that incorporates a combination of radiomics score and significant clinical risk factors. The proposed model holds promise for individualized preoperative prediction of LPLNM in patients with locally advanced rectal cancer. The data presented in this study are available on request from the corresponding author.

How reliable is restaging MRI after neoadjuvant therapy in rectal cancer?

Despite the pivotal role of magnetic resonance imaging (MRI) in rectal cancer staging and evaluation, the reliability of restaging MRI after neoadjuvant therapy is still debatable. This study aimed to assess the accuracy of restaging MRI by comparing post-neoadjuvant MRI findings with those of the final pathology. This study was a retrospective review of the medical records of adult rectal cancer patients who had restaging MRI following neoadjuvant therapy and prior to rectal cancer resection in a NAPRC-certified rectal cancer centre between 2016 and 2021. The study compared findings of preoperative, post-neoadjuvant MRI with final pathology relative to T stage, N stage, tumour size, and circumferential resection margin (CRM) status. A total of 126 patients were included in the study. We found fair concordance (kappa -0.316) for T stage between restaging MRI and pathology report, and slight concordance for N stage and CRM status (kappa -0.11, kappa = 0.089, respectively). Concordance rates were lower for patients following total neoadjuvant treatment (TNT) or with a low rectal tumour. In total, 73% of patients with positive N pathology status had negative N status in the restaging MRI. Sensitivity and specificity regarding positive CRM in post-neoadjuvant treatment MRI were 45.45% and 70.4%, respectively. We found low concordance levels between restaging MRI and pathology regarding TN stage and CRM status. Concordance levels were even lower for patients after TNT regimen and with a low rectal tumour. In the era of TNT and watch-and-wait approach, we should not rely solely on restaging MRI to make post-neoadjuvant treatment decisions.

Using deep learning to recognize local advanced rectal cancer in CT images.

e15624 Background: Colorectal cancer was the most prevalent malignant disease in developed country and cause 45% mortality rate. Rectal cancer accounted 40% of this disease and is difficult to treat due to its anatomical position. Preoperative neoadjuvant radio-chemotherapy for local advanced rectal cancer can increase circumferential resection margin (CRM) which lead to lower local recurrence rate. MRI was suggested as staging methods for CRM status and nodal evaluation. However, MRI resources were much less than CT scans. CT scans was prevalent and can provide substantial agreement in CRM evaluation under experienced specialist. This study tries to use deep learning to detect local advanced rectal cancer in CT images at initiation of treatment as advisement for neoadjuvant chemoradiotherapy. Methods: From 2010.10.1~2021.12.31, rectal cancer patients with cT3-4 lesion was included. Collect high quality CT images with DICOM files in tumor segment. cT1-2, low rectal lesions, non-CRC cases were not included. Non-contrast and artificial defect images were also excluded. CT images were labeled as” diseased “ when CRM were threatened ( &lt; 2mm). All images were labeled according to judgment of 2 specialist. The data were separated into 2 parts. One for AI model training and testing, another for external validation. The training testing dataset was achieved by deep learning neuro network and evaluating model accuracy performance. Then the model was applied into external validation dataset for real-world testing, evaluating coherent rate between AI and the Dr. decision. Furthermore, to see the cancer survival outcomes according to AI model prediction results. Results: From 2010.10.1~2022.12.31, 1256 rectal cancer cases images were included. 706 cases (889 CT series, 5958 images) with cT3-4 lesions and high quality DICOM files were eligible. 620 cases (803 series, 5318 images) with cT3-4 lesions were classified in training validation set. 1907 (35.9%) images were diseased, 3411 (64.1%) images were normal. 86 clinical stage 2-3 cases (640 images) directly underwent resection during 2014.12.1-2017.5.31 were classified as external validation group. For recognizing CRM+ local advanced rectal cancer by EfficientNetB0, the algorithm achieved an area under the receiver operating characteristic curve (AUC): 0.91 (86.1% accuracy). For External validation set, the sensitivity for AI to detect CRM+ by Dr was 80%; 88% (by images; by cases), the specificity was 68%; 66% (by images; by cases). The survival curve (local recurrence rate, DFS, OS) was also superior in AI- group than AI+ group which was comparable with the results of Dr. Conclusions: Deep Learning can detect local advanced rectal cancer in CT images and prediction results also implicate poor disease outcome.

Patterns of Care and Outcomes of Rectal Cancer Patients from the Iowa Cancer Registry: Role of Hospital Volume and Tumor Location

BackgroundCentralization of rectal cancer surgery has been associated with high-quality oncologic care. However, several patient, disease and system-related factors can impact where patients receive care. We hypothesized that patients with low rectal tumors would undergo treatment at high-volume centers and would be more likely to receive guideline-based multidisciplinary treatment. MethodsAdults who underwent proctectomy for stage II/III rectal cancer were included from the Iowa Cancer Registry and supplemented with tumor location data. Multinomial logistic regression was employed to analyze factors associated with receiving care in high-volume hospital, while logistic regression for those associated with ≥ 12 lymph node yield, pre-operative chemoradiation and sphincter-preserving surgery. ResultsOf 414 patients, 38%, 39%, and 22% had low, mid, and high rectal cancers, respectively. Thirty-two percent were > 65 years, 38% female, and 68% had stage III tumors. Older age and rural residence, but not tumor location, were associated with surgical treatment in low-volume hospitals. Higher tumor location, high-volume, and NCI-designated hospitals had higher nodal yield (≥ 12). Hospital-volume was not associated with neoadjuvant chemoradiation rates or circumferential resection margin status. Sphincter-sparing surgery was independently associated with high tumor location, female sex, and stage III cancer, but not hospital volume. ConclusionsLow tumor location was not associated with care in high-volume hospitals. High-volume and NCI-designated hospitals had higher nodal yields, but not significantly higher neoadjuvant chemoradiation, negative circumferential margin, or sphincter preservation rates. Therefore, providing educational/quality improvement support in lower volume centers may be more pragmatic than attempting to centralize rectal cancer care among high-volume centers.

The future insights of evaluating the circumferential resection margin (CRM) status in oesophageal cancer: A 12-year cohort study.

The future insights of evaluating the circumferential resection margin (CRM) status in oesophageal cancer: A 12-year cohort study.

Can CT Pelvimetry Be Used to Predict Circumferential Resection Margin Positivity in Laparoscopic Resection of Middle and Lower Rectum Cancer?

Background Previous studies have shown that pelvimetry can be valuable in predicting surgical difficulties in rectal cancer operations. However, its usability in predicting circumferential resection margin (CRM) involvement remains debatable. This study investigated the factors affecting CRM status and the importance of computed tomography (CT) pelvimetry in predicting CRM involvement in laparoscopic resection of middle and lower rectal cancer. Methodology In this study, we retrospectively investigated the data of 111 patients who underwent a laparoscopic operation for middle and lower rectum cancer at Ankara University Faculty of Medicine, Department of Surgical Oncology between January 2014 and January 2020. The predictive value of CT pelvimetry and other variables on the CRM statuswas analyzed. Results The following four pelvic parameters differed significantly between the genders: transverse diameter of the pelvic inlet (p = 0.024), anteroposterior diameter of the pelvic outlet (p = 0.003), transverse diameter of the pelvic outlet (p < 0.001), and pelvic depth (p < 0.001). The effect of pelvic anatomic parameters on CRM involvement was not found to be significant. It was found that tumor height from the anal verge (p = 0.004), tumor size (p < 0.001), and gender (p = 0.033) were significant risk factors for CRM involvement. Survival was poor in patients with male gender (p = 0.032), perineural invasion (p < 0.001), and grade 3 tumor. Conclusions In this study, no benefit was found in predicting CRM positivity from CT pelvimetry in the laparoscopic resection of middle and lower rectal cancer. Besides, tumor height from the anal verge, tumor size, and gender were important factors for CRM positivity. Although our study sheds light on this issue, prospective randomized studies with larger sample sizes are needed.

Effect of circumferential resection margin status on survival and recurrence in esophageal squamous cell carcinoma with neoadjuvant chemoradiotherapy.

BackgroundThe aim of this study was to investigate whether circumferential resection margin (CRM) status has an impact on survival and recurrence in esophageal squamous cell carcinoma after neoadjuvant chemoradiotherapy.MethodsWe screened patients with esophageal squamous cell carcinoma who underwent esophagectomy from January 2017 to December 2019. The CRM was reassessed. Patients were grouped into a CRM of 1 mm or less (0 < CRM ≤ 1 mm) and a CRM greater than 1 mm (CRM>1 mm). The impact of CRM on survival was investigated using Kaplan–Meier analysis and Cox regression modeling. The optimal CRM cut point was evaluated using restricted cubic spline curve.ResultsA total of 89 patients were enrolled in this study. The CRM status was an independent risk factor for the prognosis (HR: 0.35, 95% CI: 0.16-0.73). Compared with a CRM of 1 mm or less, a CRM greater than 1 mm had better overall survival (HR: 0.35, 95% CI: 0.16-0.73, log-rank P = 0.011), longer disease-free survival (HR: 0.51, 95% CI: 0.27-0.95, log-rank P = 0.040), and less recurrence (HR: 0.44, 95% CI: 0.23-0.85, log–rank P = 0.015). We visualized the association between CRM and the hazard ratio of survival and identified the optimal cut point at 1 mm.ConclusionsA CRM greater than 1 mm had better survival and less recurrence compared to a CRM of 1 mm or less. A more radical resection with adequate CRM could benefit survival in patients with esophageal squamous cell carcinoma after neoadjuvant therapy.

Assessment of mesorectal fascia status in MRI compared with circumferential resection margin after total mesorectal excision and predictors of involved margins

BackgroundCircumferential resection margin is an important prognosticator for total mesorectal excision outcome. We investigated the status of mesorectal fascia on magnetic resonance imaging compared with circumferential resection margin on pathology and factors associated with status change. MethodsThis was a retrospective analysis of a prospective database of rectal cancer patients who underwent surgery. Mesorectal fascia status on magnetic resonance imaging done before neoadjuvant therapy and circumferential resection margin status on pathology were compared. The study outcomes were factors associated with a margin status conversion between magnetic resonance imaging and pathology, and predictors of involved circumferential resection margin. ResultsIn total, 244 patients (average follow-up of 25.4 months) were included. Eighty-one (33.2%) patients had potentially involved mesorectal fascia in magnetic resonance imaging and 12 (4.9%) had involved circumferential resection margin in pathology. A total of 2.8% of patients had a conversion of clear mesorectal fascia in magnetic resonance imaging to involved circumferential resection margin. Abdominoperineal resection was significantly associated with this status change (odds ratio: 25, 95% confidence interval: 2.4–255.8, P = .007). In total, 7.4% of patients with potentially involved mesorectal fascia had persistently involved circumferential resection margin. Lack of total neoadjuvant therapy was associated with higher, yet statistically insignificant, odds of persistently involved circumferential resection margin (odds ratio: 12, 95% confidence interval: 0.65–220.8, P = .09). The significant independent predictors of involved circumferential resection margin were body mass index (odds ratio: 1.2, P = .016) and abdominoperineal resection (odds ratio: 4.22, P = .04). ConclusionChange of clear mesorectal fascia in magnetic resonance imaging to an involved circumferential resection margin in pathology was recorded in 2.8% of patients; abdominoperineal resection might be associated with this change. Approximately 7% of patients had persistent involvement of circumferential resection margin as determined by pathology. Omission of total neoadjuvant therapy might be associated with persistent margin involvement.

Feasibility of the semi-opened method of specimen resection for a circumferential resection margin in rectal cancer surgery: a multicenter study.

A circumferential resection margin (CRM) > 1mm is a surrogate marker of oncologic outcomes in rectal cancer patients. In Japan, because the mesentery is removed from the rectum, the CRM cannot be measured. This multicenter prospective study evaluates the feasibility of a resected specimen processing method that allows CRM measurement. Fifty patients with rectal cancer were enrolled. Resected specimens were processed as previously reported. The primary outcomes were CRM measurement and the rate of CRM positivity. The secondary outcomes were the quality of total mesorectal excision, the possibility to visualize and sample the tumor, the number of harvested lymph nodes, and comparison between the pathological CRM and preoperative mesorectal fascia (MRF) involvement. This study was registered in the University Hospital Medical Information Network (UMIN) Clinical Trials Registry under identification number UMIN000031735. The CRM was measurable in all patients and found to be positive in three (6%). We confirmed tumor localization, sampled the tumor, and measured the distal margin in all patients. A median of 20 lymph nodes were harvested. The concordance rate between preoperative MRF involvement and pathological CRM status was 90%. A semi-opened rectal specimen with transverse slicing is a feasible method for measuring the CRM.

Positive circumferential resection margin in locally advanced esophageal cancer: an updated systematic review and meta-analysis.

The impact of positive circumferential resection margin on prognosis in esophageal cancer is under controversy. Previous systematic reviews and meta-analyses had limitations. This updated systematic review and meta-analysis aimed to assess the prognostic impact of positive circumferential resection margin in esophageal cancer.PubMed and Web of Science were searched for studies investigating the association between circumferential resection margin status and prognosis in esophageal cancer. Study population were focused on T3 and/or T4a patients. Study selection was based on availability of survival information (Kaplan-Meier curves and adjusted analysis). Random-effects models were used to summarize hazard ratios for overall survival and disease-free survival.According to College of American Pathologists criteria, circumferential resection margin-positive patients had shorter median overall survival (P < 0.0001) and shorter median disease-free survival (P < 0.0001) compared with circumferential resection margin-negative patients. The pooled hazard ratios for overall survival and disease-free survival were 2.06 (95% confidence interval, 1.68-2.53; P < 0.0001) and 2.00 (95% confidence interval, 1.41-2.84; P < 0.0001), respectively. According to the Royal College of Pathologists criteria, circumferential resection margin-positive patients had shorter median overall survival (P < 0.0001) and shorter median disease-free survival (P < 0.0001) compared with circumferential resection margin-negative patients. The pooled hazard ratios for overall survival and disease-free survival were 1.31 (95% confidence interval, 1.16-1.48; P < 0.0001) and 1.31 (95% confidence interval, 1.09-1.57; P < 0.0001), respectively.ompared with negative circumferential resection margin, positive circumferential resection margin is associated with worse survival outcomes in esophageal cancer.

Diagnostic Accuracy of CT for Evaluating Circumferential Resection Margin Status in Resectable or Borderline Resectable Pancreatic Head Cancer: A Prospective Study Using Axially Sliced Surgical Pathologic Correlation

ObjectiveCT plays a central role in determining the resectability of pancreatic cancer, which directs the use of neoadjuvant therapy. This study aimed to assess the diagnostic accuracy of CT in predicting circumferential resection margin (CRM) involvement in patients with resectable or borderline resectable pancreatic head cancer.Materials and MethodsSeventy-seven patients who were scheduled for upfront surgery for resectable or borderline resectable pancreatic head cancer were prospectively enrolled, and 75 patients (38 male and 37 female; mean age ± standard deviation, 68 ± 11 years) were finally analyzed. The CRM status was evaluated separately for the superior mesenteric artery (SMA) and posterior and superior mesenteric vein/portal vein (SMV/PV) margins. Three independent radiologists reviewed the preoperative CT images and evaluated the resection margin status. The reference standard for CRM status was pathologic examination of pancreaticoduodenectomy specimens in an axial plane perpendicular to the axis of the second portion of the duodenum. The diagnostic accuracy of CT was assessed for overall CRM involvement, defined as involvement of the SMA or posterior margins (per-patient analysis), and involvement of each of the three resection margins (per-margin analysis). The data were pooled using a crossed random effects model.ResultsForty patients had pathologically confirmed overall CRM involvement in pancreatic cancer, while CRM involvement was not seen in 35 patients. For overall CRM involvement, the pooled sensitivity and specificity were 15% (95% confidence interval: 7%–49%) and 99% (96%–100%), respectively. For each of the resection margins, the pooled sensitivity and specificity were 14% (9%–54%) and 99% (38%–100%) for the SMA margin, 12% (8%–46%) and 99% (97%–100%) for the posterior margin; and 37% (29%–53%) and 96% (31%–100%) for the SMV/PV margin, respectively.ConclusionCT showed very high specificity but low sensitivity in predicting pathological CRM involvement in pancreatic cancer.

Impact of circumferential tumor location of mid to low rectal cancer on oncologic outcomes after preoperative chemoradiotherapy.

PurposeSome studies have suggested that circumferential tumor location (CTL) of rectal cancer may affect oncological outcomes. However, studies after preoperative chemoradiotherapy (CRT) are rare. This study aimed to evaluate the impact of CTL on oncologic outcomes of patients with mid to low rectal cancer who received preoperative CRT.MethodsPatients with mid to low rectal cancer who underwent total mesorectal excision after CRT from January 2013 to December 2018 were included in this retrospective study. The impact of CTL on the pathological circumferential resection margin (CRM) status, local recurrence-free survival (LRFS), disease-free survival (DFS), and overall survival (OS) was analyzed.ResultsOf the 381 patients, 98, 70, 127, and 86 patients were categorized into the anterior, posterior, lateral, and circumferential tumor groups, respectively. Tumor location was not significantly associated with the pathological CRM involvement (anterior, 12.2% vs. posterior, 14.3% vs. lateral, 11.0% vs. circumferential, 17.4%; P = 0.232). Univariate analyses revealed no correlation between CTL and 3-year LRFS (93.0% vs. 89.1% vs. 91.5% vs. 88%, P = 0.513), 3-year DFS (70.3% vs. 70.2% vs. 75.3% vs. 75.7%, P = 0.832), and 5-year OS (74.7% vs. 78.0% vs. 83.9% vs. 78.2%, P = 0.204). Multivariate analysis identified low rectal cancer and pathological CRM involvement as independent risk factors for all survival outcomes (all P < 0.05).ConclusionCTL of rectal cancer after preoperative CRT was not significantly associated with the pathological CRM status, recurrence, and survival.

EP.TU.370A 5-year re-audit of quality indicators for potentially curative rectal cancer resections by a single surgeon

Abstract Aim High quality operations with low rates of tumour perforation and circumferential resection margin (CRM) positivity are associated with improved long-term outcomes following surgery for rectal cancer. Previous audit has demonstrated lower rates of tumour perforation and CRM positivity by a single surgeon compared to the published standards. Our aim is to re-audit this surgeons’ outcomes for curative rectal resections. Methods Data was collected retrospectively for all potentially curative rectal resections over a 5-year period performed by a single surgeon using a local database and electronic care records. The CRM status and tumour perforation status were considered. Other end points included the rate of local recurrence, survival and length of stay. Results Fifty-one patients underwent rectal resections with curative intent, with a median age of 67. Complete resection (R0) was achieved in 94.1% of cases; 3.92% were found to have nodes less than 1mm from the margin and 1.96% were found to have tumour deposit less than 1mm from the margin – these cases were considered to be an R1 resection. Tumour perforation was present in 3.92% of cases, all of which had occurred pre-operatively. Local recurrence was found in 5.88% of cases and 90-day mortality was 1.96%. Median length of hospital stay was 7 days. Conclusion Our data demonstrates sustained high quality surgical outcomes with low tumour perforation rates and CRM positivity rates which compare favourably with the published standards to date. Local recurrence rates are comparable to published standards and 90-day mortality continues to be low.