Staging Of Rectal Cancer Research Articles

Lack of Hierarchical Survival Prognosis in AJCC Staging for Colon and Rectal Cancer—Implications for Future Summary Stage Classification

BackgroundCurrent staging for colorectal cancer utilizing the American Joint Committee on Cancer (AJCC) TNM framework groups disease based on extent and provides important prognostic information. Ideally, increasing summary stage should reflect worse prognosis (hierarchical logic). We evaluated survival as a function of stage within the 8th edition AJCC staging system for colorectal cancer. MethodsPatients with non-metastatic primary colorectal cancer diagnosed 2010-2016 were identified from the National Cancer Database. Survival curves were used to determine whether staging was hierarchical for colorectal cancer. Multivariable modeling was used to identify relative contributions of variables (z-score) to overall survival, and hazard ratio (HR)-based groupings were constructed. ResultsAmong 270,584 colon and 53,846 rectal cancer patients, AJCC summary staging was non-hierarchical (e.g. HR IIC=2.92, HR IIIA=0.85-1.31). Multivariable analysis demonstrated that high T category (T4a, T4b) confers the greatest mortality risk (colon: T4a HR 2.76, T4b HR 3.04; rectum: T4a HR 3.29, T4b HR 3.73), while high T category as well as high N category (colon: T4a z=66.9, T4b z=64.6, N2b z=55.7; rectum: T4b z=31.1, N2b z=25.1) contributed substantially to the survival model. Arranging T and N groupings by HR and subsequent organizing them using HR-based groupings resulted in hierarchical organization of these groupings. ConclusionsCurrent AJCC summary stage groups for patients with stage I-III colorectal cancer are non-hierarchical. High T category has a greater impact on survival than N category for early N disease, while high N category is more important for early T disease. This results in paradoxically better observed survival with some stage III cancer subgroups compared to stage II subgroups. An organizational framework based on HR groupings is hierarchical and provides more accurate prognostic information.MicroAbstract: Current staging for colorectal cancer utilizing the TNM framework groups disease based on extent and provides important prognostic information. Ideally, increasing summary stage should reflect worse prognosis (i.e. hierarchical staging groups). However, upon analyzing data from the National Cancer Database, current AJCC 8th edition summary stage groups for patients with stage I-III colorectal cancer were found to be non-hierarchical. This results in paradoxically better observed survival with some stage III cancer subgroups compared to stage II subgroups. An organizational framework based on HR groupings is hierarchical and provides more accurate prognostic information.

Rectal Cancer and Lateral Lymph Node Staging: Interobserver Agreement and Success in Predicting Locoregional Recurrence.

Objectives: To evaluate the agreement among radiologists in the evaluation of rectal cancer staging and restaging (after neoadjuvant therapy) and assess whether locoregional recurrence can be predicted with this information. Materials and Methods: Pre-neoadjuvant and after-neoadjuvant therapy magnetic resonance imaging (MRI) examinations of 239 patients diagnosed with locally advanced rectal cancer were retrospectively reviewed by three radiologists. The agreement between the MRI findings (localization of tumor involvement, tumor coverage pattern, external sphincter involvement, mucin content of the mass and lymph node, changes in the peritoneum, MRI T stage, distance between tumor and MRF, submucosal sign, classification of locoregional lymph node, and EMVI) was discussed at the September 2023 meeting of the Society of Abdominal Radiology (SAR) and the interobserver and histopathological findings were examined. The patients were evaluated according to locoregional rectal cancer and lateral lymph node (LLN) staging, and re-staging was performed using MRI images after neoadjuvant treatment. The ability of the locoregional and LLN staging system to predict locoregional recurrence was evaluated. Results: Among the parameters examined, for the MRI T stage and distance between the tumor and the MRF, a moderate agreement (kappa values: 0.61-0.80) was obtained, while for all other parameters, the interobserver agreement was notably high (kappa values 0.81-1.00). LLNs during the restaging with an OR of 2.1 (95% CI = 0.33-4.87, p = 0.004) and a distance between the tumor and the MRF of less than 1 mm with an OR of 2.1 (95% CI = 1.12-3.94, p = 0.023) affected locoregional recurrence. A multivariable Cox regression test revealed that the restaging of lymph nodes among the relevant parameters had an impact on locoregional recurrence, with an OR of 1.6 (95% CI = 0.32-1.82, p = 0.047). With the LLN staging system, an increase in stage was observed in 37 patients (15.5%), and locoregional recurrence was detected in 33 of them (89.2%) (p < 0.001). Conclusions: LLN staging is not only successful in predicting locoregional recurrence among MRI parameters but is also associated with a very high level of interobserver agreement. The presence of positive LLN in the restaging phase is one of the most valuable MRI parameters for poor prognosis.

Neoadjuvant chemoradiation for down staging of locally-advanced rectal cancer, and assessment of clinical response with digital rectal examination, magnetic resonance imaging and colonoscopy

Background: In this era of total neoadjuvant treatment (TNT) followed by rectal preservation non-operative management (NOM) or wait and watch (WW) approach for non-metastatic locally-advanced rectal cancer (LARC), reliable and reproducible response evaluation to neoadjuvant therapies forms the cornerstone. Through this study, we try to evaluate clinical response of locally-advanced rectal cancer to neoadjuvant chemoradiation (CRT) in terms of downstaging and total mesorectal excision (TME), and the accuracy of digital rectal examination (DRE), magnetic resonance imaging (MRI) and colonoscopy in the assessment of clinical response to neoadjuvant CRT. Methods: Histologically proven locally advanced rectal adenocarcinoma patients, after pretreatment evaluation, were considered for neoadjuvant chemoradiation, i.e., intensity-modulated radiation therapy (IMRT) with 5-fluorouracil (5-FU) and leucovorin-based concurrent chemotherapy. Patients were evaluated 6-8 weeks after completion of CRT and clinical response assessed by means of DRE, colonoscopy and MRI of pelvis. Following surgery, pathological response was assessed on the final histopathological examination (HPE). Results: Twenty-two patients were accrued for this protocol, of which, 15 (68.2%) were male and 7 (31.8%) were female. Downstaging and TME was achieved in 90.9% of the patients. The sensitivity of DRE, colonoscopy and MRI to detect a complete response was 66.67% and specificity was 94.74%. There were no severe toxicities or deaths reported. Conclusions: Neoadjuvant concurrent chemoradiotherapy with bolus 5-FU and leucovorin is an accepted modality of treatment for locoregionally-advanced rectal cancer, which offers higher rates of downstaging and TME. Digital rectal examination, colonoscopy and MRI together can be reliably used to assess response following neoadjuvant CRT.

Synthetic double inversion recovery imaging for rectal cancer T staging evaluation: imaging quality and added value to T2-weighted imaging

ObjectiveTo assess the image quality of synthetic double inversion recovery (SyDIR) imaging and enhance the value of T2-weighted imaging (T2WI) in evaluating T stage for rectal cancer patients.MethodsA total of 112 pathologically confirmed rectal cancer patients were retrospectively selected after undergoing MRI, including synthetic MRI. The image quality of T2WI and SyDIR imaging was compared based on signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), overall picture quality, presence of motion artifacts, lesion edge sharpness, and conspicuity. The concordance between MRI and pathological staging results, using T2WI alone and the combination of T2WI and SyDIR for junior and senior radiologists, was assessed using the Kappa test. The area under the receiver operating characteristic curve (AUC) was used to assess the diagnostic efficacy of extramural infiltration in rectal cancer patients.ResultsNo significant differences in imaging quality were observed between conventional T2WI and SyDIR (p = 0.07–0.53). The combination of T2WI and SyDIR notably improved the staging concordance between MRI and pathology for both junior (kappa value from 0.547 to 0.780) and senior radiologists (kappa value from 0.738 to 0.834). In addition, the integration of T2WI and SyDIR increased the AUC for diagnosing extramural infiltration for both junior (from 0.842 to 0.918) and senior radiologists (from 0.917 to 0.938).ConclusionThe combination of T2WI and SyDIR increased the consistency of T staging between MRI and pathology, as well as the diagnostic performance of extramural infiltration, which would benefit treatment selection.Critical relevance statementSyDIR sequence provides additional diagnostic value for T2WI in the T staging of rectal cancer, improving the agreement of T staging between MRI and pathology, as well as the diagnostic performance of extramural infiltration.Key PointsSynthetic double inversion recovery (SyDIR) and T2WI have comparable image quality.SyDIR provides rectal cancer anatomical features for extramural infiltration detections.The combination of T2WI and SyDIR improves the accuracy of T staging in rectal cancer.Graphical

MR staging of rectal cancer: Comparison between the 2012 and 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guidelines

PurposeTo compare the adherence of the interpretation and reporting staging system, respectively proposed in the 2012 and 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guidelines for Magnetic Resonance Imaging (MRI) staging of rectal cancer, focusing on the improvement offered by the criteria introduced by 2016 ESGAR guidelines. MethodFifty-six patients affected by rectal cancer were included; 25/56 patients underwent upfront surgery; 31 underwent to neo-adjuvant chemo-radiotherapy before surgery. All patients underwent 3 T MRI examination for local staging. All MR exams were evaluated by two radiologists with 20- and 4-years’ experience, who were blinded to each other; the T and N stages, the Mesorectal Fascia (MRF) status and the Extramural Vascular Invasion (EMVI) were assessed according to both 2012 and 2016 ESGAR guidelines. The correlation between radiological and pathological findings, as well as the MRI staging were evaluated. ResultsAs to the expert reviewer, no significant differences were found by comparing the MR T and N stages, T and N restaging, MRF status and EMVI according to 2012 and 2016 ESGAR guidelines. As to the 4-years’ experience radiologist the MR staging agreement between 2012 and 2016 guidelines was “moderate” in N-stage evaluation and “fair” in T-restaging evaluation. No significant discrepancies were found for other parameters. ConclusionsMRI is a reliable method in rectal cancer staging/restaging. The assessment of T-restaging is improved by adopting the 2016 ESGAR guidelines, especially for non-expert readers; this result could be justified by the introduction of diffusion-weighted imaging. On the contrary, the newest guidelines do not improve the diagnostic performance in assessing nodal staging and restaging.

Editorial Comment: Finding Consensus in Rectal Cancer Staging Pelvic MRI.

Editorial Comment: Finding Consensus in Rectal Cancer Staging Pelvic MRI.

Training program for radiologists for improving the multidisciplinary approach for the treatment of rectal cancer

BACKGROUND: Diagnosis and treatment of patients with colorectal cancer is a multidisciplinary task. The transition to a new edition of clinical guidelines for the treatment of colorectal cancer in 2024, while maintaining the routine approach to MR staging of malignant neoplasms of this localization, reduces the level of continuity between medical specialists. AIM: To improve the quality and completeness of MR diagnostics of malignant neoplasms of the rectum to ensure continuity and improve the multidisciplinary approach. MATERIALS AND METHODS: A retrospective analysis of the completeness of compliance with the parameters of TNM 8 (2017) and the MRI subclassification T3 of rectal cancer was carried out on 137 MRI scans of the pelvic organs and protocols with conclusions to them. Based on the results of the analysis, educational training and a conclusion template for radiologists were developed and conducted, after which the MR images were re-evaluated. Before and after the training, the most fully evaluated MRI scans by radiologists were provided to medical experts to form a “second opinion”. The results obtained made it possible to calculate the absolute and relative number of consensuses (coinciding in all parameters of the conclusions) and to identify cases of rectal cancer restaging that require changes in treatment tactics. RESULTS: Before the educational training, only 11% of MRI scans and their reports met the requirements of the modern protocol. After the training, 78% of the images were completed in compliance with all requirements. Particular difficulties and the majority of “discrepancies” in conclusions arose when determining the depth of tumor invasion into the mesorectal tissue; measuring the distance from the tumor and/or affected lymph node to the mesorectal fascia or edge of the levator ani muscle and identifying signs of extramural vascular invasion. It was not possible to achieve complete consensus in all cases on these parameters. CONCLUSION: The analysis of MRI scans of the pelvic organs, the development and implementation of educational training to improve the interpretation of medical images, made it possible to significantly improve the staging of rectal cancer and ensure proper continuity in the implementation of a multidisciplinary approach.

Role of Diffusion-Weighted Magnetic Resonance Imaging in Detection of Lymph Node Metastasis in Rectal Cancer

Abstract Background Rectal cancer is one of the most common malignancies of the digestive tract, ranking first in the worldwide incidence of malignant tumors. The early diagnosis, accurate staging and early treatment of rectal cancer are key to improve the five-year survival rate. Rectal MRI plays a crucial role in evaluating rectal cancer by providing multiple prognostic findings and imaging features that guide proper patient management. Aim of the Work to evaluate the performance of diffusion-weighted MRI (DWI) for the detection of lymph nodes and for differentiating between benign and metastatic nodes during primary rectal cancer staging. Patients and Methods the study was carried out at Ain Shams University Hospitals, Radiodiagnosis Department on 35 patients, 29 patients were histopathologically proven rectal carcinoma underwent surgical resection and 6 cases were potentially free of cancer considered as control. Results We found that the size of metastatic lymph nodes on DWI was significantly larger than that of non-metastatic lymph nodes (0.97± 0.37 vs. 0.4± 0.17 cm), most of malignant nodes had rounded shape (55.6 %) vs. oval shaped (70.6%) in benign nodes and almost all of metastatic lymph nodes had irregular margin (97.2%) while all benign nodes appeared having smooth margin. The mean ADC value was significantly lower for metastatic lymph nodes than non-metastatic lymph nodes (1.21± 0.54 vs. 1.51± 0.51 x 103 mm²/sec). In addition, for evaluation of lymph node metastasis that reflects the primary tumor characteristics, the LN/T ratio (defined as the ratio of lymph node ADC value to the primary tumor ADC value) was calculated. It was significantly lower for metastatic lymph nodes than non-metastatic lymph nodes (1.06± 0.37 vs. 1.65± 0.73). Receiver operating characteristic curve analysis revealed that the best performing cutoffs were 0.5 cm for lymph node size, 0.987 x 103 mm²/ sec for ADC value, and 0.762 for LN/T ratio. Accuracy was significantly greater for lymph nodes with irregular margin (92.3%), than LN/T ratio (78.5%) than for lymph node size (62.0%) or ADC value (74.8%). Conclusion Preoperative DWI, especially the margin of lymph nodes as well as LN/T ADC ratio, are recommended for evaluation of lymph node metastasis in patient with rectal cancer.

Endoscopic mesorectal dissection for precise rectal cancer staging: trespassing the boundaries of lumenal rectal interventions

Endoscopic mesorectal dissection for precise rectal cancer staging: trespassing the boundaries of lumenal rectal interventions

Recent advances in the diagnosis of rectal cancer and evaluation of clinical treatment efficacy using magnetic resonance imaging

Accurate preoperative tumor staging is essential for precise treatment of rectal cancer, and magnetic resonance imaging (MRI) is the preferred method. In addition to accurately determining tumor (T) and stages node (N), MRI can also be used to evaluate factors related to the prognosis of rectal cancer, such as depth of tumor invasion into the muscular layer, extramural vascular invasion of the tumor, and distance to the circumferential resection margin. MRI is also an important method for evaluating tumor regression after neoadjuvant therapy, and quantitative biomarkers of functional MRI can objectively reflect treatment efficacy. Moreover, MRI can predict response after neoadjuvant therapy, local recurrence rate, and disease-free survival before treatment. The present article reviews recent advances in the preoperative diagnosis and staging of rectal cancer, reassessment after neoadjuvant therapy, and evaluation of clinical treatment efficacy using MRI.

Initial case series experience with robotic-assisted transanal minimally invasive surgery performed with da Vinci single-port system for the excision of rectal cancer.

Transanal minimally invasive surgery (TAMIS) is widely used for rectal lesion excision. Robot-assisted TA TAMIS (R-TAMIS) may improve surgical ergonomics. The introduction of the da Vinci Single-Port (SP) robot, designed for endoluminal surgery, has brought new possibilities. Our primary objective herein was to assess the technical and oncological feasibility and efficacy of Single-port robotic TAMIS (SPR-TAMIS) in rectal cancer excision. The secondary objective was to analyze the perioperative outcomes. We included 14 consecutive patients with rectal cancer who underwent SPR-TAMIS between April 2021 and February 2023. Patient data, surgical details, and clinical outcome data were collected to assess the safety and feasibility of SPR-TAMIS. The median participant age was 72years, and full-thickness excision was performed without specimen fragmentation in all cases. The median tumor diameter was 2.7cm, positioned between 10cm proximally and 7cm distally from the anal verge. Negative margins were achieved in 93% of cases, with one case requiring further resection. The median operative time was 175min, and the median hospital stay was 5days. No intraoperative conversion from SPR-TAMIS to laparoscopic or conventional transanal excision was required. No mortalities or major postoperative complications occurred; however, one patient (7.1%) experienced minor morbidity manifesting as wound dehiscence (Clavien-Dindo grade I). No recurrence was observed during the 24-month follow-up. In our early experience, SPR-TAMIS is a safe and feasible surgery for selected early stage rectal cancers, offering enhanced visualization and stable maneuverability transanally. This platform may have potential advantages for the excision of larger or more proximal lesions.

The role of superior hemorrhoidal vein ectasia in the preoperative staging of rectal cancer.

The prognosis of colorectal cancer has continuously improved in recent years thanks to continuous progress in both the therapeutic and diagnostic fields. The specific objective of this study is to contribute to the diagnostic field through the evaluation of the correlation between superior hemorrhoidal vein (SHV) ectasia detected on computed tomography (CT) and Tumor (T), Node (N), and distant metastasis (M) examination and mesorectal fascia (MRF) invasion in the preoperative staging of rectal cancer. Between January 2018 and April 2022, 46 patients with histopathological diagnosis of rectal cancer were retrospectively enrolled, and the diameter of the SHV was evaluated by CT examination. The cutoff value for SHV diameter used is 3.7mm. The diameter was measured at the level of S2 during portal venous phase after 4× image zoom to reduce the interobserver variability. The parameters evaluated were tumor location, detection of MRF infiltration (defined as the distance < 1mm between the tumor margins and the fascia), SHV diameter, detection of mesorectal perilesional lymph nodes, and detection of metastasis. A total of 67.39% (31/46) of patients had SHV ectasia. All patients with MRF infiltration (4/46, 7.14%) presented SHV ectasia (average diameter of 4.4mm), and SHV was significantly related with the development of liver metastases at the moment of primary staging and during follow-up. SHV ectasia may be related to metastasis and MRF involvement; therefore, it could become a tool for preoperative staging of rectal cancer.

Preoperative prediction of rectal Cancer staging combining MRI deep transfer learning, radiomics features, and clinical factors: accurate differentiation from stage T2 to T3

BackgroundThis study evaluates the efficacy of integrating MRI deep transfer learning, radiomic signatures, and clinical variables to accurately preoperatively differentiate between stage T2 and T3 rectal cancer. MethodsWe included 361 patients with pathologically confirmed stage T2 or T3 rectal cancer, divided into a training set (252 patients) and a test set (109 patients) at a 7:3 ratio. The study utilized features derived from deep transfer learning and radiomics, with Spearman rank correlation and the Least Absolute Shrinkage and Selection Operator (LASSO) regression techniques to reduce feature redundancy. Predictive models were developed using Logistic Regression (LR), Random Forest (RF), Decision Tree (DT), and Support Vector Machine (SVM), selecting the best-performing model for a comprehensive predictive framework incorporating clinical data.Results After removing redundant features, 24 key features were identified. In the training set, the area under the curve (AUC)values for LR, RF, DT, and SVM were 0.867, 0.834, 0.900, and 0.944, respectively; in the test set, they were 0.847, 0.803, 0.842, and 0.910, respectively. The combined model, using SVM and clinical variables, achieved AUCs of 0.946 in the trainingset and 0.920 in the test set.ConclusionThe study confirms the utility of a combined model of MRI deep transfer learning, radiomic features, and clinical factors for preoperative classification of stage T2 vs. T3 rectal cancer, offering significant technological support for precise diagnosis and potential clinical application.

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.

Imaging Modalities for Preoperative Staging of Rectal Cancer in Developing Countries: A Comparative Study of F-FDG PET/CT and MRI

Rectal cancer represents a significant health care challenge globally, demanding accurate pre-operative staging to guide therapeutic interventions and prognostic estimations.This study aims to compare the efficacy and use of F-FDGPET/CT and MRI in preoperative staging of rectal cancer in developing countries such as india. Using a cross-sectional study design, a total of 70 patients diagnosed with rectal cancer were prospectively enrolled and equally divided Into group A and group B. For group A f- fdg PET/CT and for group B MRI was conducted. The primary outcome measures were accuracy, sensitivity, and specificity of each imaging modalityin detecting local tumor extent (T stage), lymph nodeinvolvement (N stage), and distant metastasis (M stage). Histopathological biopsy was taken for each patient and considered as reference standard. Data were analyzed using descriptive statistics and diagnostic accuracy measures.Results showed that both F-FDG PET/CT (71.4%) and MRI(75..5%) had high accuracy in T staging, with comparablesen sitivity (F -FDG PET/CT - 59.6%, MRI - 72.0%) and specificity ( F -FDG- 94.8% , MRI - 82.2%). MRI showed higher sensitivity ( 78.6%) in detecting lymph node involvement than F-FDG PET/CT (72.2%) .F-FDG PET/xCT demonstrated higher sensitivity in detecting distant metastasis compared to MRI. Conclusion: F-FDG PET/CT and MRI are comparable for preoperative staging of rectal cancer, with their own limitations and benifits . MRI provides detailed information about the local tissue involvement, and presence of lymph node metastases where as F-FDG PET/CT is more helpful in detecting distant metastases. But as MRI is more readily available and is more cost effective than F-FDG PET/CT in developing countries such as india, it should be used as the imaging modality of choice for pre - operative staging of rectal cancer.

Imaging and Metabolic Diagnostic Methods in the Stage Assessment of Rectal Cancer.

Rectal cancer (RC) is a prevalent malignancy with significant morbidity and mortality rates. The accurate staging of RC is crucial for optimal treatment planning and patient outcomes. This review aims to summarize the current literature on imaging and metabolic diagnostic methods used in the stage assessment of RC. Various imaging modalities play a pivotal role in the initial evaluation and staging of RC. These include magnetic resonance imaging (MRI), computed tomography (CT), and endorectal ultrasound (ERUS). MRI has emerged as the gold standard for local staging due to its superior soft tissue resolution and ability to assess tumor invasion depth, lymph node involvement, and the presence of extramural vascular invasion. CT imaging provides valuable information about distant metastases and helps determine the feasibility of surgical resection. ERUS aids in assessing tumor depth, perirectal lymph nodes, and sphincter involvement. Understanding the strengths and limitations of each diagnostic modality is essential for accurate staging and treatment decisions in RC. Furthermore, the integration of multiple imaging and metabolic methods, such as PET/CT or PET/MRI, can enhance diagnostic accuracy and provide valuable prognostic information. Thus, a literature review was conducted to investigate and assess the effectiveness and accuracy of diagnostic methods, both imaging and metabolic, in the stage assessment of RC.

1297 Factors Influencing Lymph Node Retrieval and Staging in Colorectal Cancer Resections: A Single-Centre Study

Abstract Aim The American Joint Committee on Cancer (AJCC) recommends examination of a minimum of 12 total dissected lymph nodes to stage rectal cancer accurately. This study aimed to explore the factors influencing lymph node (LN) retrieval and their impact on nodal positivity and N category in colorectal cancer (CRC) staging. Method This retrospective single-centre study included patients with CRC who underwent laparoscopic excision by a single colorectal surgeon between July 2021 and July 2023. Data were extracted from the hospital's electronic database, with exclusion criteria for benign conditions. Results The average number of LNs in this cohort was 17.95±6.55. At least 12 LNs were recovered in 90.91% of the cases. The right colon was the most common tumour site. Right hemicolectomy, transverse colon resection, and sigmoid colectomy achieved 100% compliance with the adequate retrieval criteria. An increase in LN retrieval was observed with higher T stages. A positive linear correlation was observed between the number of harvested LNs and the length of the resected bowel. No significant difference in LN yield was observed between node-positive and node-negative cases. Conclusions Tumour site emerged as a significant factor influencing LN retrieval in CRC resections. While age and sex showed no substantial impact, tumour size and extent of resected bowel positively correlated with LN counts. The overall lymph node yield had no effect on node positivity, indicating that, following a careful inspection of the specimen, a lower lymph node yield may be deemed sufficient.

Total mesorectal excision quality in rectal cancer surgery affects local recurrence rate but not distant recurrence and survival: population-based cohort study.

The quality of the total mesorectal excision specimen in rectal cancer surgery is assessed with a three-tier grade (mesorectal, intramesorectal and muscularis propria). This study aimed to analyse the prognostic impact of the total mesorectal excision grade on survival, and to identify risk factors for intramesorectal and muscularis propria resection in a population-based setting. All patients in the Swedish Colorectal Cancer Registry with rectal cancer stage I-III ≤ 10 cm from the anal verge, diagnosed 2015-2019, undergoing total mesorectal excision were analysed. Clinical, surgical and pathological data were retrieved and analysed for the following primary outcomes: local and distant recurrence and overall and relative survival; secondary outcomes were risk factors for total mesorectal excision grading (intramesorectal or muscularis propria resection). Of note, postoperative death < 30 days or recurrence within 90 days were exclusion criteria for survival and recurrence analysis. Recurrence-free patients with less than 3 years follow-up, and patients lacking data regarding recurrence, were also excluded from recurrence analyses. Overall, of 7979 patients treated during the study interval, 1499 patients were eligible for recurrence, 2441 patients for survival and 2476 patients for risk-factor analyses, of which 75% were graded mesorectal, 17% intramesorectal and 8% muscularis propria. Median follow-up for survival was 42 (1-77) months. The worst total mesorectal excision grading (muscularis propria resection) was an independent risk factor for local recurrence in multivariable analysis (HR 2.73, 95% c.i. 1.07 to 7.0, P = 0.036). Total mesorectal excision grade had no impact on distant recurrence or survival. Female sex, tumour level <5 cm, abdominoperineal resection, minimally invasive surgery (laparoscopic and robotic), high blood loss, long duration of surgery and intraoperative perforation were independent risk factors for worse total mesorectal excision grading (intramesorectal and/or muscularis propria resection) in multivariable analyses. Muscularis propria resection increases the risk of local recurrence but does not seem to affect distant recurrence or survival.

Radiology reporting in rectal cancer using magnetic resonance imaging: Comparison of reporting completeness between different reporting styles and structure.

The radiology report is vital for providing imaging information to guide patient treatment, and template-based reporting can potentially increase the reporting completeness. In 2014, a national reporting template for radiological staging of rectal cancer using magnetic resonance imaging (MRI) was implemented in Sweden. To evaluate the impact of the national reporting template by comparing and analysing differences in content and completeness in MRI reports between 2010 and 2016. Focus was to compare reporting completeness (i) between different reporting years and (ii) between three defined reporting styles. 493 MRI reports were gathered from 10 hospitals in four healthcare regions in Sweden, comprising 243 reports from 2010 and 250 reports from 2016. Reports were classified into three reporting styles: Expanded structured, Minimised structured, and Unstructured, and analysed using qualitative content analysis based on the national template. In 2010, all reports adhered to Unstructured reporting. In 2016, 44, 42, and 164 reports were conformant to Expanded structured, Minimised structured, and Unstructured reporting, respectively. A comparison between the years revealed a reporting completeness of 48% for 2010 reports and 72% for 2016 reports. Among the 2016 reporting styles, Unstructured reporting had the largest gap compared to the national template, with completeness at 64% versus 77.5% for Minimised structured reporting and 93% for Expanded structured reporting. Implementation of template-based reporting according to Expanded structure is key to conform to national decided evidence-based practice for radiological staging of rectal cancer.

Anatomic Basis of Rectal Cancer Staging: Clarifying Controversies and Misconceptions.

Rectal MRI provides a detailed depiction of pelvic anatomy; specifically, the relationship of the tumor to key anatomic structures, including the mesorectal fascia, anterior peritoneal reflection, and sphincter complex. However, anatomic inconsistencies, pitfalls, and confusion exist, which can have a strong impact on interpretation and treatment. These areas of confusion include the definition of the rectum itself, specifically differentiation of the rectum from the anal canal and the sigmoid colon, and delineation of the high versus low rectum. Other areas of confusion include the relative locations of the mesorectal fascia and peritoneum and their significance in staging and treatment, the difference between the mesorectal fascia and circumferential resection margin, involvement of the sphincter complex, and evaluation of lateral pelvic lymph nodes. The impact of these anatomic inconsistencies and sources of confusion is significant, given the importance of MRI in depicting the anatomic relationship of the tumor to critical pelvic structures, to triage surgical resection and neoadjuvant chemoradiotherapy with the goal of minimizing local recurrence. Evolving treatment paradigms also place MRI central in management of rectal cancer. ©RSNA, 2024.