EUS versus magnetic resonance imaging in staging rectal adenocarcinoma: a diagnostic test accuracy meta-analysis

Accuracy of Baseline Magnetic Resonance Imaging for Staging Rectal Cancer Patients Proceeding Directly to Surgery

BACKGROUND AND OBJECTIVES

High-resolution magnetic resonance imaging (MRI) accuracy for staging preoperative rectal cancer varies across studies. We examined MRI accuracy for T- and N-staging of rectal cancer compared with final histopathology of the resected specimen in a large Australian cohort who did not receive neoadjuvant therapy or radiation.

METHODS

Retrospective analysis of prospectively-collected clinical data from 153 rectal adenocarcinomas locally staged by high-resolution MRI between January 2012 and December 2019 that did not undergo chemoradiotherapy or radiation before surgery. T- and N-stage agreement between MRI and final histopathology was assessed using Kappa statistic. Agreement at each T-stage was evaluated using log-linear modeling. N-staging accuracy was examined using positive and negative predictive values.

RESULTS

Overall agreement between MRI and final histopathology for T-stage and N-stage was 55% and 65%, respectively. Kappa statistic found higher agreement between MRI and final histopathology for T-staging (κ = 0.33) versus N-staging (κ = 0.18). MRI correctly assessed 91% of T1 tumors, 43% of T2 tumors, 65% of T3 tumors, and 80% of T4 tumors. MRI accuracy was higher for N-negative tumors (74.1%) than for N-positive tumors (44.4%).

CONCLUSION

MRI is moderately accurate at staging T1, T3, and T4 rectal tumors but caution when staging tumors as T2 is advised. Greater accuracy for staging N-negative versus N-positive tumors is indicated.

Chinese national clinical practice guidelines on prevention, diagnosis and treatment of early colorectal cancer

BACKGROUND

The incidence and mortality of colorectal cancer (CRC) in China are increasing in recent years. The clarified pathogenesis and detectable precancerous lesions of CRC make it possible to prevent, screen, and diagnose CRC at an early stage. With the development of endoscopic and surgical techniques, the choice of treatment for early CRC is also worth further discussion, and accordingly, a standard follow-up program after treatment needs to be established.

METHODS

This clinical practice guideline (CPG) was developed following the recommended process of the World Health Organization, adopting Grading of Recommendations Assessment, Development and Evaluation (GRADE) in assessing evidence quality, and using the Evidence to Decision framework to formulate clinical recommendations, thereby minimizing bias and increasing transparency of the CPG development process. We used the Reporting Items for practice Guidelines in HealThcare (RIGHT) statement and Appraisal of Guidelines for Research and Evaluation II (AGREE II) as reporting and conduct guides to ensure the guideline's completeness and transparency.

RESULTS

This CPG comprises 46 recommendations concerning prevention, screening, diagnosis, treatment, and surveillance of CRC. In these recommendations, we have indicated protective and risk factors for CRC and made recommendations for chemoprevention. We proposed a suitable screening program for CRC based on the Chinese context. We also provided normative statements for the diagnosis, treatment, and surveillance of CRC based on existing clinical evidence and guidelines.

CONCLUSIONS

The 46 recommendations in this CPG are formed with consideration for stakeholders' values and preferences, feasibility, and acceptability. Recommendations are generalizable to resource-limited settings with similar CRC epidemiology pattern as China.

Rectal adenocarcinoma: Ex vivo 9.4T MRI-correlation with histopathologic treatment response to neoadjuvant chemoradiotherapy

OBJECTIVES

To determine the imaging details and diagnostic information of the treatment response to neoadjuvant chemoradiotherapy (nCRT) of rectal adenocarcinoma at 9.4T magnetic resonance imaging (MRI) by ex vivo.

METHODS

Fifteen cases with locally advanced rectal cancer (LARC) followed by radical surgery after nCRT between September 2022 and February 2023 were recruited. Resected specimens were fixed in a perfluoropolyether-filled test tube and scanned with a 3.0T and 9.4T MRI system ex vivo. The residual tumor depth and MRI-based tumor regression grade (TRG) were subjectively assessed and then compared with the pathological findings.

RESULTS

The ex vivo 9.4T T2WI without fat suppression clearly differentiated tumor tissue, fibrosis and normal rectal wall, which clearly corresponded to the pathologic tissues of the rectal specimens. The TRG could be accurately assessed on ex vivo 9.4T images in 13/15 specimens (86.7%), while in 11/15 specimens (73.3%) on ex vivo 3.0T images.

CONCLUSION

Ex vivo 9.4T MR imaging clearly displayed the components of rectal wall and proved excellent diagnostic performance for evaluating the treatment response to nCRT, which allow radiologists to understand and then assess more accurately the TRG of LARC after nCRT.

Early Rectal Cancer and Local Excision: A Narrative Review

A rise in the incidence of early rectal cancer consequent to bowel-screening programs around the world and an increase in the incidence in young adults has led to a growing interest in organ-sparing treatment options. The rectum, being the most distal portion of the large intestine, is a fertile ground for local excision techniques performed with endoscopic or surgical techniques. Moreover, the advancement in endoscopic optical evaluation and the better definition of imaging techniques allow for a more precise local staging of early rectal cancer. Although the local treatment of early rectal cancer seems promising, in clinical practice, a significant number of patients who could benefit from local excision techniques undergo total mesorectal excision (TME) as the first approach. All relevant prospective clinical trials were identified through a computer-assisted search of the PubMed, EMBASE, and Medline databases until January 2024. This review is dedicated to endoscopic and surgical local excision in the treatment of early rectal cancer and highlights its possible role in current and future clinical practice, taking into account surgical completion techniques and chemoradiotherapy.

Value of biplane transrectal ultrasonography plus micro-flow imaging in preoperative T staging and rectal cancer diagnosis in combination with CEA/CA199 and MRI

BACKGROUND

Rectal cancer is one of the most common malignant tumors and has a high incidence rate and fatality rate. Accurate preoperative T staging of rectal cancer is critical for the selection of appropriate rectal cancer treatment. Various pre-operative imaging methods are available, and the identification of the most accurate method for clinical use is essential for patient care. We investigated the value of biplane transrectal ultrasonography (TRUS) combined with MFI in preoperative staging of rectal cancer and explored the value of combining TRUS plus MFI with CEA/CA199 and MRI.

METHODS

A total of 87 patients from Daping Hospital with rectal cancer who underwent TRUS examination plus MFI were included. Grades of MFI were determined by Alder classification. Among the total patients, 64 underwent MRI and serum CEA/CA199 tests additionally within one week of TRUS. Pathological results were used as the gold standard for cancer staging. Concordance rates between TRUS, MRI, and CEA/CA199 for tumors at different stages were compared.

RESULTS

There were no significant differences between the Alder classification and pathological T staging. The concordance rate of TRUS and MFI for rectal cancer T staging was 72.4% (K = 0.615, p < 0.001). Serum CEA and CA199 levels were significantly different in tumors at different stages and increased progressively by pathological stage (p < 0.001); the accuracy rate was 71.88% (K = 0.599, p < 0.001), while that of MRI was 51.56% (K = 0.303, p < 0.001), indicating that TRUS had higher consistency in the preoperative T staging of rectal cancer. The combination of TRUS, MRI, and CEA/CA199 yielded an accuracy rate of 90.6%, which was higher than that of any method alone.

CONCLUSIONS

Preoperative T staging of rectal cancer from biplane TRUS plus MFI was highly consistent with postoperative pathological T staging. TRUS combined with MRI and serum CEA/CA199 had a greater value in the diagnosis of rectal cancer and a higher diagnostic rate than any examination alone.

Progress in the diagnosis of lymph node metastasis in rectal cancer: a review

Historically, the chief focus of lymph node metastasis research has been molecular and clinical studies of a few essential pathways and genes. Recent years have seen a rapid accumulation of massive omics and imaging data catalyzed by the rapid development of advanced technologies. This rapid increase in data has driven improvements in the accuracy of diagnosis of lymph node metastasis, and its analysis further demands new methods and the opportunity to provide novel insights for basic research. In fact, the combination of omics data, imaging data, clinical medicine, and diagnostic methods has led to notable advances in our basic understanding and transformation of lymph node metastases in rectal cancer. Higher levels of integration will require a concerted effort among data scientists and clinicians. Herein, we review the current state and future challenges to advance the diagnosis of lymph node metastases in rectal cancer.

Impact of the preoperative clinical N stage on the prognosis of patients with colon cancer

AIM

Although preoperative clinical staging (cStage) is performed for most cancer patients, limited information is currently available on the relationship with postoperative prognosis. We herein investigated the relationship between cStage and prognosis of colon cancer (CC) patients, particularly focusing on the presence or absence of clinical lymph node (LN) metastasis.

METHOD

This was a retrospective study on 840 consecutive patients with colon adenocarcinoma who underwent radical resection at our institution between January 2007 and December 2018. A Kaplan-Meier curve was used to analyse the prognosis of two groups: cN(+)pN(-); a group preoperatively diagnosed with clinical LN metastasis positive, but with no pathological LN metastasis postoperatively, and cN(-)pN(-); a group without clinical and pathological LN metastasis. We also investigated whether a clinical diagnosis is a more accurate prognostic factor than other clinical factors.

RESULTS

Among pN(-) cases, the 5-year recurrence-free survival rate was significantly lower in preoperatively diagnosed cN(+) cases than in cN(-) cases (79.4% vs. 95.6%, 3.04 years vs. 3.85 years, p < 0.01). In a multivariate analysis of various preoperative clinical factors in pStage II cases, including high risk factors for pStage II CC, cN(+) was identified as an independent prognostic factor (hazard ratio: 2.06, 95% CI: 1.02-4.27, p = 0.04).

CONCLUSION

Preoperatively over-staged cN cases had a poorer prognosis than cases without over-staging, indicating its potential as a prognostic factor. In addition to already known high risk factors in pStage II cases, the preoperative cStage may be an indication for adjuvant chemotherapy.

Diagnostic performance of endorectal ultrasound combined with shear wave elastography for rectal tumors staging

OBJECTIVE

This study aims to analyze the performance of endorectal ultrasound (ERUS) combined with shear wave elastography (SWE) for rectal tumor staging.

METHODS

Forty patients with rectal tumors who had surgery were enrolled. They underwent ERUS and SWE examinations before surgery. Pathological results were used as the gold standard for tumor staging. The stiffness values of the rectal tumor, peritumoral fat, distal normal intestinal wall, and distal perirectal fat were analyzed. The diagnostic accuracy of ERUS stage, tumor SWE stage, ERUS combined with tumor SWE stage, and ERUS combined with peritumoral fat SWE stage were compared and evaluated by receiver operating characteristic (ROC) curve to select the best staging index.

RESULTS

From T1 to T3 stage, the maximum elasticity (Emax) of the rectal tumor increased gradually (p < 0.05). The cut-off values of adenoma/T1 and T2, T2 and T3 tumors were 36.75 and 85.15kPa, respectively. The diagnostic coincidence rate of tumor SWE stage was higher than that of ERUS stage. Overall diagnostic accuracy of ERUS combined with peritumoral fat SWE Emax restaging was significantly higher than that of ERUS.

CONCLUSIONS

ERUS combined with peritumoral fat SWE Emax for tumor restaging can effectively distinguish between stage T2 and T3 rectal tumors, which provides an effective imaging basis for clinical decisions.

Predictors and Outcomes of Upstaging in Rectal Cancer Patients Who Did Not Receive Preoperative Therapy

BACKGROUND

Preoperative chemoradiation is indicated for clinical stage II and III rectal cancers; however, the accuracy of clinical staging with preoperative imaging is imperfect.

OBJECTIVE

The study aimed to better characterize the incidence and management of clinical and pathologic stage discordances in patients who did not receive preoperative chemoradiation.

DESIGN

This was a retrospective cohort analysis.

SETTINGS

The source of data was the National Cancer Database from 2006 to 2015.

PATIENTS

We identified patients who underwent resection with curative intent for clinical stage I rectal adenocarcinoma without preoperative chemotherapy or radiation.

MAIN OUTCOME MEASURES

We evaluated the characteristics of "upstaged" patients-those with T3/T4 tumors found on pathology (pathologic stage II) and/or with positive regional nodes in the resection specimen (pathologic stage III) compared with those patients who were not upstaged (pathologic stage I). We then used a mixed-effects multivariable survival model to compare overall survival between these groups.

RESULTS

Among 7818 clinical stage I rectal cancer patients who did not receive preoperative therapy, tumor upstaging occurred in 819 (10.6%) and nodal upstaging occurred in 1612 (20.8%). Upstaged patients were more likely than those not upstaged to have higher grade tumors and positive margins. Survival was worse in upstaged patients (hazard ratio [HR], 1.64; 95% CI, 1.4-1.9) but improved among those upstaged patients who received either chemotherapy (HR, 0.71; 95% CI, 0.6-0.9) or chemoradiation (HR, 0.62; 95% CI, 0.5-0.7).

LIMITATIONS

In addition to the inherent limitations of a retrospective cohort study, the National Cancer Database does not record functional outcomes, local recurrence, or disease-specific survival, so we are restricted to the evaluation of overall survival as an oncologic outcome.

CONCLUSIONS

Inaccurate preoperative staging remains a common clinical challenge in the management of rectal cancer. Survival among upstaged patients is improved among those who receive recommended postoperative chemotherapy and/or chemoradiation, yet many patients do not receive guideline-concordant care. See Video Abstract at https://links.lww.com/DCR/B999 .

PREDICTORES Y RESULTADOS DE SOBRE ESTADIFICACIN EN PACIENTES CON CNCER DE RECTO QUE NO RECIBIERON TERAPIA PREOPERATORIA

ANTECEDENTES:La quimio radiación preoperatoria está indicada para los estadios clínicos II y III del cáncer rectal; sin embargo, la precisión de la estadificación clínica con imágenes preoperatorias es imperfecta.OBJETIVO:El objetivo fue mejorar la caracterización de la incidencia y el manejo de la discordancia del estadio clínico y patológico en pacientes que no recibieron quimio radiación preoperatoria.DISEÑO:Este fue un análisis de cohorte retrospectivo.CONFIGURACIÓN:La fuente de datos fue de la Base de datos Nacional del Cáncer entre los años 2006-2015.PACIENTES:Identificamos pacientes que fueron sometidos a resección con intención curativa por adenocarcinoma rectal en estadio clínico I, sin quimioterapia o radiación preoperatoria.PRINCIPALES MEDIDAS DE RESULTADO:Evaluamos las características de los pacientes "sobre estadificados": aquellos con tumores T3/T4 encontrados en patología (estadio patológico II) y/o con ganglios regionales positivos en la muestra de resección (estadio patológico III), en comparación con aquellos pacientes que no fueron sobre estadificados (estadio patológico I). Luego usamos un modelo de supervivencia multivariable de efectos mixtos para comparar la supervivencia general entre estos grupos.RESULTADOS:De entre 7818 pacientes con cáncer de recto, en estadio clínico I, y que no recibieron tratamiento preoperatorio, se produjo una sobre estadificación tumoral en 819 (10,6%) y una sobre estadificación ganglionar en 1612 (20,8%). Los pacientes sobre estadificados tenían más probabilidades que los no sobre estadificados de tener tumores de mayor grado y márgenes positivos. La supervivencia fue peor en los pacientes sobre estadificados (HR 1,64, IC del 95% [1,4, 1,9]), pero mejoró entre los pacientes sobre estadificados que recibieron quimioterapia (HR 0,71, IC del 95% [0,6, 0,9]) o quimio radiación (HR 0,62, 95% IC [0,5, 0,7]).LIMITACIONES:Además de las limitaciones inherente a un estudio de cohorte de tipo retrospectivo, la Base de datos Nacional del Cáncer no registra resultados funcionales, la recurrencia local o la supervivencia específica de la enfermedad, por lo que estamos restringidos a la evaluación de la supervivencia general como un resultado oncológico.CONCLUSIONES:La estadificación preoperatoria inexacta sigue siendo un desafío clínico común en el tratamiento del cáncer de recto. La supervivencia entre los pacientes con sobre estadificación mejora en aquellos que reciben la quimioterapia y/o quimio radioterapia postoperatoria recomendada, aunque muchos pacientes no reciben atención acorde con las guías. Consulte Video Resumen en http://links.lww.com/DCR/B999 . (Traducción-Dr. Osvaldo Gauto ).

Endoluminal ultrasound versus magnetic resonance imaging in assessment of rectal cancer after neoadjuvant therapy

BACKGROUND

Accurate rectal tumor staging guides the choice of treatment options. EUS and MRI are the main modalities for staging.

AIM OF THE WORK

To compare the performance of EUS and MRI for loco-regional staging of anorectal cancer after neo-adjuvant therapy.

METHODS

Seventy-three (37 male, 36 female) patients with rectal cancer after neo-adjuvant chemoradiotherapy were enrolled. Histopathological staging after surgery were used as reference for comparing the yield of loco-regional staging for EUS and MRI. EUS and MRI were done 1 month after completion of neo-adjuvant therapy.

RESULTS

Regarding post-surgical T staging, eight patients had early tumor (T2 = 16 and T1 = 9) and thirty six were locally advanced (T3 = 36), while N staging, forty patients with negative nodes and 33 were positive (N1 = 22 and N2 = 11). Comparing EUS to MRI, it showed a higher sensitivity (95.7% vs. 78.7%), specificity (84.6% vs. 68.0%) and accuracy (91.8% vs. 75.3%) for staging early and locally advanced tumor. Also, it had a higher sensitivity (78.8% vs. 69.7%), specificity (75.0% vs. 65.0%) and accuracy (76.7% vs. 67.1%) for detection of lymph nodes.

CONCLUSION

EUS appears to be more accurate than MRI in loco-regional staging of rectal carcinoma after neo-adjuvant therapy.

Interventional gastroenterology in oncology

Cancer is one of the foremost health problems worldwide and is among the leading causes of death in the United States. Gastrointestinal tract cancers account for almost one third of the cancer-related mortality globally, making it one of the deadliest groups of cancers. Early diagnosis and prompt management are key to preventing cancer-related morbidity and mortality. With advancements in technology and endoscopic techniques, endoscopy has become the core in diagnosis and management of gastrointestinal tract cancers. In this extensive review, the authors discuss the role endoscopy plays in early detection, diagnosis, and management of esophageal, gastric, colorectal, pancreatic, ampullary, biliary tract, and small intestinal cancers.

Diagnosis of rectal cancer based on the Xception-MS network

Objective. Accurate T staging of rectal cancer based on ultrasound images is convenient for doctors to determine the appropriate treatment. To effectively solve the problems of low efficiency and accuracy of traditional methods for T staging diagnosis of rectal cancer, a deep-learning-based Xception-MS diagnostic model is proposed in this paper. Approach. The proposed diagnostic model consists of three steps. First, the model preprocesses rectal cancer images to solve the problem of data imbalance and deficiency of sample size, and reduces the risk of model overfitting. Second, a new Xception-MS network with stronger feature extraction capability, which is a combination of the Xception network and MS module, is proposed. The MS module is a new function module that can more effectively extract multi-scale information from rectal cancer images. In addition, to solve the deficiency of the small sample size of rectal cancer, the proposed network is combined with transfer learning technology. At last, the output layer of the network is modified, in which the global average pooling and a fully connected softmax layer are employed to replace the original ones, and then the rectal cancer 4 classification (T1, T2, T3, T4 staging) is output. Main results. Experiments of rectal cancer T staging are conducted on a dataset of 1078 rectal cancer images in 4 categories collected from the Department of Colorectal Surgery of the Third Affiliated Hospital of Kunming Medical University. The experimental results show that the accuracy, precision, recall and F1 values obtained by the model are 94.66%, 94.70%, 94.65%, and 94.67%, respectively. Significance. The experimental results show that our model is superior to the existing classification models, can effectively and automatically classify ultrasound images of rectal cancer, and can better assist doctors in the diagnosis of rectal cancer.

New scoring system to distinguish deep invasive submucosal and muscularis propria colorectal cancer during colonoscopy: a development and global multicenter external validation study (e-T2 Score)

BACKGROUND AND AIMS

Diagnostics to differentiate deep submucosal invasive (invasion depth ≥1000 μm [T1b]) colorectal cancer (CRC) from muscularis propria invasive (T2) CRC are limited. We aimed to establish and validate a scoring system that differentiates T1b from T2.

METHODS

A multicenter retrospective cross-validation study was performed. Four hundred sixty-one consecutive pathologically confirmed T1b or T2 CRCs were divided into the development (T1b, 222; T2, 189) and internal validation (T1b, 31; T2, 19) cohorts. Eight potential endoscopic findings were evaluated using the development cohort: loss of lobulation, deep depression, demarcated depressed area, protuberance within the depression, expanding appearance, fold convergency, erosion or white plaque, and Borrmann type 2 or 3 tumor. A scoring system that differentiates T1b from T2 was developed, and diagnostic performance was tested using the internal validation cohort by 8 endoscopists. External validation was conducted using 50 CRC images by 4 endoscopists from other institutions, including outside of Japan.

RESULTS

Multivariate analysis identified the following 5 independent predictive endoscopic findings of T2 CRC: deep depression (odds ratio [OR], 2.08; 95% confidence interval [CI], 1.07-4.04), demarcated depressed area (OR, 4.40; 95% CI, 1.39-13.9), 4-fold convergency or more (OR, 3.41; 95% CI, 1.90-6.11), erosion or white plaque (OR, 8.28; 95% CI, 2.77-24.7), and Borrmann type 2 or 3 tumor (OR, 8.76; 95% CI, 3.58-21.5). The area under the receiver-operating characteristic curve (AUROC) was .90 (95% CI, .87-.93) in the development cohort, .80 (95% CI, .76-.85) in the internal validation, and .76 (95% CI, .69-.83) in the external validation.

CONCLUSIONS

We established and validated a new scoring system to differentiate T1b from T2 CRC using 5 simple endoscopic findings.

Endoscopic submucosal dissection for superficial gastrointestinal lesions: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2022

ESGE recommends that the evaluation of superficial gastrointestinal (GI) lesions should be made by an experienced endoscopist, using high definition white-light and chromoendoscopy (virtual or dye-based).ESGE does not recommend routine performance of endoscopic ultrasonography (EUS), computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET)-CT prior to endoscopic resection.ESGE recommends endoscopic submucosal dissection (ESD) as the treatment of choice for most superficial esophageal squamous cell and superficial gastric lesions.For Barrett's esophagus (BE)-associated lesions, ESGE suggests the use of ESD for lesions suspicious of submucosal invasion (Paris type 0-Is, 0-IIc), for malignant lesions > 20 mm, and for lesions in scarred/fibrotic areas.ESGE does not recommend routine use of ESD for duodenal or small-bowel lesions.ESGE suggests that ESD should be considered for en bloc resection of colorectal (but particularly rectal) lesions with suspicion of limited submucosal invasion (demarcated depressed area with irregular surface pattern or a large protruding or bulky component, particularly if the lesions are larger than 20 mm) or for lesions that otherwise cannot be completely removed by snare-based techniques.ESGE recommends that an en bloc R0 resection of a superficial GI lesion with histology no more advanced than intramucosal cancer (no more than m2 in esophageal squamous cell carcinoma), well to moderately differentiated, with no lymphovascular invasion or ulceration, should be considered a very low risk (curative) resection, and no further staging procedure or treatment is generally recommended.ESGE recommends that the following should be considered to be a low risk (curative) resection and no further treatment is generally recommended: an en bloc R0 resection of a superficial GI lesion with superficial submucosal invasion (sm1), that is well to moderately differentiated, with no lymphovascular invasion, of size ≤ 20 mm for an esophageal squamous cell carcinoma or ≤ 30 mm for a stomach lesion or of any size for a BE-related or colorectal lesion, and with no lymphovascular invasion, and no budding grade 2 or 3 for colorectal lesions.ESGE recommends that, after an endoscopically complete resection, if there is a positive horizontal margin or if resection is piecemeal, but there is no submucosal invasion and no other high risk criteria are met, this should be considered a local-risk resection and endoscopic surveillance or re-treatment is recommended rather than surgery or other additional treatment.ESGE recommends that when there is a diagnosis of lymphovascular invasion, or deeper infiltration than sm1, or positive vertical margins, or undifferentiated tumor, or, for colorectal lesions, budding grade 2 or 3, this should be considered a high risk (noncurative) resection, and complete staging and strong consideration for additional treatments should be considered on an individual basis in a multidisciplinary discussion.ESGE recommends scheduled endoscopic surveillance with high definition white-light and chromoendoscopy (virtual or dye-based) with biopsies of only the suspicious areas after a curative ESD.

An endorectal ultrasound-based radiomics signature for preoperative prediction of lymphovascular invasion of rectal cancer

Objective

To investigate whether radiomics based on ultrasound images can predict lymphovascular invasion (LVI) of rectal cancer (RC) before surgery.

Methods

A total of 203 patients with RC were enrolled retrospectively, and they were divided into a training set (143 patients) and a validation set (60 patients). We extracted the radiomic features from the largest gray ultrasound image of the RC lesion. The intraclass correlation coefficient (ICC) was applied to test the repeatability of the radiomic features. The least absolute shrinkage and selection operator (LASSO) was used to reduce the data dimension and select significant features. Logistic regression (LR) analysis was applied to establish the radiomics model. The receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) were used to evaluate the comprehensive performance of the model.

Results

Among the 203 patients, 33 (16.7%) were LVI positive and 170 (83.7%) were LVI negative. A total of 5350 (90.1%) radiomic features with ICC values of ≥ 0.75 were reported, which were subsequently subjected to hypothesis testing and LASSO regression dimension reduction analysis. Finally, 15 selected features were used to construct the radiomics model. The area under the curve (AUC) of the training set was 0.849, and the AUC of the validation set was 0.781. The calibration curve indicated that the radiomics model had good calibration, and DCA demonstrated that the model had clinical benefits.

Conclusion

The proposed endorectal ultrasound-based radiomics model has the potential to predict LVI preoperatively in RC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-022-00813-6.

How Useful Is Endoscopic Ultrasound in Differentiating T3/T4a T Stage of Colorectal Cancer: A Prospective Study

Objective

Endoscopic ultrasound (EUS) is an established method for staging of colorectal cancer. Nevertheless, prior assessments of its T stage accuracy have been limited, particularly ambiguity in assessed T3 and T4a stage. This study was to characterize the EUS image features and pay attention to distinguish T3 from T4a T stage.

Methods

A total of 638 patients who prospectively underwent colorectal EUS were recorded. The final diagnoses were compared with the concurrent or follow-up histopathology. Univariate and multivariate logistic regressions were used to assess variation in diagnostic performance with case attributes.

Results

The accuracies of EUS in classifying colorectal cancer for overall, T1, T2, T3, and T4a stages are 73.04, 62.32, 67.46, 71.26, and 83.52%, respectively. With attention to EUS image features, the lesion penetrates the entire wall and locates below the seminal vesicles or cervix is T3 stage. If the lesion locates above clearly-defined space between the anterior rectal wall and the posterior surface of the seminal vesicles or cervix, we identify as T4a stage; However, when located above seminal vesicles or cervix but on the posterior wall of the rectum, the lesion still considers as T3 stage. The tumor location and histological type are associated with inaccuracy T stage.

Conclusions

EUS provides reliable diagnostic accuracy in the colorectal cancer stage. The seminal vesicles and cervix are the important markers to predict infiltration depth for T3/T4a stage. Furthermore, the tumor location, histological type, and EUS image features for each tumor T stage should warrant attention.

Endorectal Ultrasonography and Pelvic Magnetic Resonance Imaging Show Similar Diagnostic Accuracy in Local Staging of Rectal Cancer: An Update Systematic Review and Meta-Analysis

BACKGROUND

Endorectal Ultrasonography (EUS-ERUS) and pelvic magnetic resonance imaging (MRI) are world-wide performed for the local staging of rectal cancer (RC), but no clear consensus on their indications is present, there being literature in support of both. The aim of this meta-analysis is to give an update regarding the diagnostic test accuracy of ERUS and pelvic MRI about the local staging of RC.

MATERIALS AND METHODS

A systematic literature search from November 2020 to October 2021 was performed to select studies in which head-to-head comparison between ERUS and MRI was reported for the local staging of rectal cancer. Quality and risk of bias were assessed with the QUADAS-2 tool. Our primary outcome was the T staging accuracy of ERUS and MRI for which pooled accuracy indices were calculated using a bivariable random-effects model. In addition, a hierarchical summary receiver operating characteristic curve (hSROC) was created to characterize the accuracy of ERUS and MRI for the staging of T and N parameters. The area under the hSROC curve (AUChSROC) was determined as a measure of diagnostic accuracy.

RESULTS

Seven studies and 331 patients were included in our analysis. ERUS and MRI showed a similar accuracy for the T staging, with AUChSROC curves of 0.91 (95% C.I., 0.89 to 0.93) and 0.87 (95% C.I., 0.84 to 0.89), respectively (p = 0.409). For T staging, ERUS showed a pooled sensitivity of 0.82 (95% C.I. 0.72 to 0.89) and pooled specificity of 0.91 (95% C.I. 0.77-0.96), while MRI had pooled sensitivity and specificity of 0.69 (95% C.I. 0.55-0.81) and 0.88 (95% C.I. 0.79-0.93), respectively. ERUS and MRI showed a similar accuracy in the N staging too, with AUChSROC curves of 0.92 (95% C.I., 0.89 to 0.94) and 0.93 (95% C.I., 0.90 to 0.95), respectively (p = 0.389).

CONCLUSIONS

In conclusion, ERUS and MRI are comparable imaging techniques for the local staging of rectal cancer.

Multidisciplinary management of early rectal cancer - The role of surgical local excision in current and future clinical practice

The implementation of bowel cancer screening programs has led to a rise in the incidence of early rectal cancer. The combination of increased incidence and the growing interest in organ-sparing treatment options has led to an amplified importance of local excision techniques in treatment strategies for early rectal cancer. In addition, developments in new technologies of single-port surgery have popularized surgical techniques. Although local treatment of early rectal cancer seems promising, a multidisciplinary approach is necessary and awareness of the oncological robustness is warranted to enable shared decision-making. This review illustrates the position of surgical local excision in the treatment of early rectal cancer and reflects on its role in current and future clinical practice.

Magnetic Resonance Imaging Evaluation of the Accuracy of Various Lymph Node Staging Criteria in Rectal Cancer: A Systematic Review and Meta-Analysis

Background

Magnetic resonance imaging (MRI)-based lymph node staging remains a significant challenge in the treatment of rectal cancer. Pretreatment evaluation of lymph node metastasis guides the formulation of treatment plans. This systematic review aimed to evaluate the diagnostic performance of MRI in lymph node staging using various morphological criteria.

Methods

A systematic search of the EMBASE, Medline, and Cochrane databases was performed. Original articles published between 2000 and January 2021 that used MRI for lymph node staging in rectal cancer were eligible. The included studies were assessed using the QUADAS-2 tool. A bivariate random-effects model was used to conduct a meta-analysis of diagnostic test accuracy.

Results

Thirty-seven studies were eligible for this meta-analysis. The pooled sensitivity, specificity, and diagnostic odds ratio of preoperative MRI for the lymph node stage were 0.73 (95% confidence interval [CI], 0.68–0.77), 0.74 (95% CI, 0.68–0.80), and 7.85 (95% CI, 5.78–10.66), respectively. Criteria for positive mesorectal lymph node metastasis included (A) a short-axis diameter of 5 mm, (B) morphological standard, including an irregular border and mixed-signal intensity within the lymph node, (C) a short-axis diameter of 5 mm with the morphological standard, (D) a short-axis diameter of 8 mm with the morphological standard, and (E) a short-axis diameter of 10 mm with the morphological standard. The pooled sensitivity/specificity for these criteria were 75%/64%, 81%/67%, 74%/79%, 72%/66%, and 62%/91%, respectively. There was no significant difference among the criteria in sensitivity/specificity. The area under the receiver operating characteristic (ROC) curve values of the fitted summary ROC indicated a diagnostic accuracy rate of 0.75–0.81.

Conclusion

MRI scans have minimal accuracy as a reference index for pretreatment staging of various lymph node staging criteria in rectal cancer. Multiple types of evidence should be used in clinical decision-making.

Multidisciplinary management of elderly patients with rectal cancer: recommendations from the SICG (Italian Society of Geriatric Surgery), SIFIPAC (Italian Society of Surgical Pathophysiology), SICE (Italian Society of Endoscopic Surgery and new technologies), and the WSES (World Society of Emergency Surgery) International Consensus Project

BACKGROUND AND AIMS

Although rectal cancer is predominantly a disease of older patients, current guidelines do not incorporate optimal treatment recommendations for the elderly and address only partially the associated specific challenges encountered in this population. This results in a wide variation and disparity in delivering a standard of care to this subset of patients. As the burden of rectal cancer in the elderly population continues to increase, it is crucial to assess whether current recommendations on treatment strategies for the general population can be adopted for the older adults, with the same beneficial oncological and functional outcomes. This multidisciplinary experts' consensus aims to refine current rectal cancer-specific guidelines for the elderly population in order to help to maximize rectal cancer therapeutic strategies while minimizing adverse impacts on functional outcomes and quality of life for these patients.

METHODS

The discussion among the steering group of clinical experts and methodologists from the societies' expert panel involved clinicians practicing in general surgery, colorectal surgery, surgical oncology, geriatric oncology, geriatrics, gastroenterologists, radiologists, oncologists, radiation oncologists, and endoscopists. Research topics and questions were formulated, revised, and unanimously approved by all experts in two subsequent modified Delphi rounds in December 2020-January 2021. The steering committee was divided into nine teams following the main research field of members. Each conducted their literature search and drafted statements and recommendations on their research question. Literature search has been updated up to 2020 and statements and recommendations have been developed according to the GRADE methodology. A modified Delphi methodology was implemented to reach agreement among the experts on all statements and recommendations.

CONCLUSIONS

The 2021 SICG-SIFIPAC-SICE-WSES consensus for the multidisciplinary management of elderly patients with rectal cancer aims to provide updated evidence-based statements and recommendations on each of the following topics: epidemiology, pre-intervention strategies, diagnosis and staging, neoadjuvant chemoradiation, surgery, watch and wait strategy, adjuvant chemotherapy, synchronous liver metastases, and emergency presentation of rectal cancer.

Pretreatment Apparent Diffusion Coefficient Cannot Predict Histopathological Features and Response to Neoadjuvant Radiochemotherapy in Rectal Cancer: A Meta-Analysis

AIM

Our purpose was to perform a systemic literature review and meta-analysis regarding use of apparent diffusion coefficient (ADC) for prediction of histopathological features in rectal cancer (RC) and to prove if ADC can predict treatment response to neoadjuvant radiochemotherapy (NARC) in RC.

METHODS

MEDLINE library, EMBASE, Cochrane, and SCOPUS database were screened for associations between ADC and histopathology and/or treatment response in RC up to June 2020. Authors, year of publication, study design, number of patients, mean value, and standard deviation of ADC were acquired. The methodological quality of the collected studies was checked according to the Quality Assessment of Diagnostic Studies instrument. The meta-analysis was undertaken by using the RevMan 5.3 software. DerSimonian and Laird random-effects models with inverse-variance weights were used to account the heterogeneity between the studies. Mean ADC values including 95% confidence intervals were calculated.

RESULTS

Overall, 37 items (2,015 patients) were included. ADC values of tumors with different T and N stages and grades overlapped strongly. ADC cannot distinguish RC with a high- and low-carcinoembryonic antigen level. Regarding KRAS status, ADC cannot discriminate mutated and wild-type RC. ADC did not correlate significantly with expression of vascular endothelial growth factor and hypoxia-inducible factor 1a. ADC correlates with Ki 67, with the calculated correlation coefficient: -0.52. The ADC values in responders and nonresponders overlapped significantly.

CONCLUSION

ADC correlates moderately with expression of Ki 67 in RC. ADC cannot discriminate tumor stages, grades, and KRAS status in RC. ADC cannot predict therapy response to NARC in RC.

Submucosal Enhancing Stripe as a Contrast Material-enhanced MRI-based Imaging Feature for the Differentiation of Stage T0-T1 from Early T2 Rectal Cancers

Background Accurate differentiation of stage T0-T1 rectal tumors from stage T2 rectal tumors facilitates the selection of appropriate surgical treatment. MRI is a recommended technique for local staging, but its ability to distinguish T1 from T2 tumors is poor. Purpose To explore the value of a submucosal enhancing stripe (SES), an uninterrupted enhancing band between the rectal tumor and the muscular layer on contrast material-enhanced T1-weighted images, as a potential imaging feature to differentiate T0-T1 from T2 rectal tumors. Materials and Methods This retrospective study included patients with pT0-T1 and pT2 rectal tumors who underwent pretreatment MRI and rectal tumor resection between January 2012 and November 2019. Two radiologists independently evaluated tumor characteristics (SES; status of muscularis propria [SMP]; and tumor shape, location, and size) at MRI. The associations of clinical and imaging characteristics with stage T0-T1 or T2 tumors were assessed, β values were calculated, and predictive models were built. The diagnostic accuracies for the differentiation of T0-T1 tumors from T2 tumors with SES and SMP were compared. Results Data from 431 patients (mean age, 60 years ± 10 [standard deviation]; 261 men) were evaluated. SES (β = 3.9; 95% CI: 3.1, 4.7; P < .001), SMP (β = 1.3; 95% CI: 0.7, 1.9; P < .001), and carpetlike shape (β = 1.6; 95% CI: 0.5, 2.8; P = .01) were independent factors distinguishing T0-T1 tumors from T2 tumors. The diagnostic accuracy was 87% (95% CI: 84, 90; 376 of 431) for SES and 67% (95% CI: 63, 72; 290 of 431) for SMP (P < .001). Conclusion Submucosal enhancing stripe (SES) at contrasted-enhanced MRI, status of muscularis propria (SMP) on T2-weighted images, and tumor shape can serve as independent imaging features to differentiate stage T0-T1 rectal tumors from stage T2 rectal tumors. Moreover, SES is a more accurate feature than is SMP. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Turkbey in this issue.

Biplane transrectal ultrasonography plus ultrasonic elastosonography and contrast-enhanced ultrasonography in T staging of rectal cancer

Background

The aim of this study is to assess biplane transrectal ultrasonography (TRUS) plus ultrasonic elastosonography (UE) and contrast-enhanced ultrasonography (CEUS) in T staging of rectal cancer.

Methods

Between March 2016 and January 2019, 66 rectal cancer patients who completed biplane TRUS plus UE and CEUS for preoperative workup and were treated by primary total mesorectal excision (TME) were retrospectively analyzed.

Results

The accuracy of TRUS plus UE and CEUS in all T staging of rectal cancer was 69.7%. The highest accuracy was achieved in the T3 stage (87.5%), while it was 71.4 and 50.0% in the T1 and T2 stage, respectively. The mean sizes of uT1-T2 lesions and uT3-T4 lesions were 30.0 ± 10.6 mm (range, 10.0–55.0) and 40.2 ± 11.2 mm (range, 14.0–57.0), respectively (p < 0.001). According to the receiver operating characteristic (ROC) curve to predict pT stages (pT1,2 vs. pT3), the optimal cut-off value of lesions in greatest dimension was 28.5 mm by TRUS with areas under the curve (AUC) of 0.769, and the optimal cut-off values of peak systolic velocity (PSV) and resistive index (RI) were 18.8 cm/sec and 0.645, respectively. The AUCs of PSV and RI were 0.588 and 0.555, respectively.

Conclusions

Diagnostic accuracy of TRUS plus UE and CEUS in T staging of rectal cancer does not reach the excellent published study results, especially for patients with early rectal cancer. Tumor sizes, PSV and RI are useful additions for TRUS in T staging of rectal cancer.

MRI cT1-2 rectal cancer staging accuracy: a population-based study

Background

Adequate MRI‐based staging of early rectal cancers is essential for decision‐making in an era of organ‐conserving treatment approaches. The aim of this population‐based study was to determine the accuracy of routine daily MRI staging of early rectal cancer, whether or not combined with endorectal ultrasonography (ERUS).

Methods

Patients with cT1–2 rectal cancer who underwent local excision or total mesorectal excision (TME) without downsizing (chemo)radiotherapy between 1 January 2011 and 31 December 2018 were selected from the Dutch ColoRectal Audit. The accuracy of imaging was expressed as sensitivity, specificity, and positive predictive value (PPV) and negative predictive value.

Results

Of 7382 registered patients with cT1–2 rectal cancer, 5539 were included (5288 MRI alone, 251 MRI and ERUS; 1059 cT1 and 4480 cT2). Among patients with pT1 tumours, 54·7 per cent (792 of 1448) were overstaged by MRI alone, and 31·0 per cent (36 of 116) by MRI and ERUS. Understaging of pT2 disease occurred in 8·2 per cent (197 of 2388) and 27·9 per cent (31 of 111) respectively. MRI alone overstaged pN0 in 17·3 per cent (570 of 3303) and the PPV for assignment of cN0 category was 76·3 per cent (2733 of 3583). Of 834 patients with pT1 N0 disease, potentially suitable for local excision, tumours in 253 patients (30·3 per cent) were staged correctly as cT1 N0, whereas 484 (58·0 per cent) and 97 (11·6 per cent) were overstaged as cT2 N0 and cT1–2 N1 respectively.

Conclusion

This Dutch population‐based analysis of patients who underwent local excision or TME surgery for cT1–2 rectal cancer based on preoperative MRI staging revealed substantial overstaging, indicating the weaknesses of MRI and missed opportunities for organ preservation strategies.

Clinical impact of FDG PET/CT in alimentary tract malignancies: an updated review

The use of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography combined with computed tomography (PET/CT) is well established in the evaluation of alimentary tract malignancies. This review of the literature and demonstration of correlative images focuses on the current role of PET/CT in the diagnosis (including pathologic/clinical staging) and post-therapy follow-up of esophageal, gastric, and colorectal cancers. PET/CT provides utility in the management of esophageal cancer, including detection of distant disease prior to resection. In gastric cancer, PET/CT is useful in detecting solid organ metastases and in characterizing responders vs. non-responders after neoadjuvant chemotherapy, the latter of which have poorer overall survival. In patients with GIST tumors, PET/CT also determines response to imatinib therapy with greater expedience as compared to CECT. For colorectal cancer, PET/CT has proven helpful in detecting hepatic and other distant metastases, treatment response, and differentiating post-radiation changes from tumor recurrence. Our review also highlights several pitfalls in PET/CT interpretation of alimentary tract lesions.