MRI for Local Staging of Colon Cancer: Can MRI Become the Optimal Staging Modality for Patients With Colon Cancer?

Diagnostic Performance of MRI and FDG PET/CT for Preoperative Locoregional Staging of Colon Cancer: Systematic Review and Meta-Analysis

Background: CT is the standard-of-care test for colon cancer (CC) preoperative locoregional staging, but has limited diagnostic performance. More accurate preoperative staging would guide selection among expanding patient-tailored treatment options. Objective: To evaluate the diagnostic performance of MRI for T and N staging and of FDG PET/CT for N staging in CC locoregional staging through systematic review. Evidence Acquisition: PubMed, Embase, and Cochrane Library were searched through December 31, 2023 for studies reporting diagnostic performance of MRI or FDG PET/CT for primary (nonrectal) CC before resection without neoadjuvant therapy using histopathology as reference. Study quality was assessed using the QUADAS-2 tool. Publication bias was assessed with Deeks' funnel plot. Primary outcomes were estimated pooled predictive values, stratified by T and N categories for MRI and N categories for PET/CT. Secondary outcomes were pooled sensitivity and specificity. Evidence Synthesis: The systematic review included 11 MRI studies (686 patients) and five PET/CT studies (408 patients). Thirteen studies had at least one risk of bias or concern of applicability. Deeks' funnel plot asymmetry indicated possible publication bias in MRI studies for differentiation of T3cd-4 from T1-3ab disease and N- from N+ disease. For MRI, for discriminating T1-2 from T3-4 disease, PPV was 64.8% (95% CI [52.9-75.5%]), and NPV was 88.9% (95% CI [82.7-93.7%]); for discriminating T1-3ab from T3cd-4 disease, PPV was 83.4% (95% CI [75.0-90.3%]), and NPV was 74.6% (95% CI [58.2-86.7%]); for discriminating T1-3 from T4 disease, PPV was 94.0% (95% CI [89.4-97.3%]), and NPV was 39.9% (95% CI [24.9-56.6%]); for discriminating N- from N+ disease, PPV was 74.9% (95% CI [69.3-80.0%]), and NPV was 53.9% (95% CI [45.3-62.0%]). For PET/CT, for discriminating N- from N+ disease, PPV was 76.4% (95% CI [67.9-85.1%]), and NPV was 68.2% (95% CI [56.8-78.6%]). Across outcomes, MRI and PET/CT exhibited pooled sensitivity of 55.1-81.4% and pooled specificity of 70.3-88.1%. Conclusion: MRI had strongest predictive performance for T1-2 and T4 disease. MRI and PET/CT had otherwise limited predictive values, sensitivity, and specificity for evaluated outcomes related T and N staging. Clinical Impact: MRI and FDG PET/CT had overall limited utility for preoperative locoregional staging in colon cancer.

Assessment of the Diagnostic Accuracy of CT as Compared to MRI in Detecting Metastases in Patients With Colorectal Cancer

This study aimed to compare the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) in detecting metastases of colorectal cancer (CRC) in a hospital in Najran, Saudi Arabia. A total of 51 patients with CRC were included in the study. The radiological findings of metastatic lesions and the diagnostic accuracy measures of CT compared to MRI were analyzed. The results showed that CT had a false negative rate of 7.8%, a false positive rate of 7.8%, a true negative rate of 27.5%, and a true positive rate of 56.9% in detecting metastases. Diagnostic accuracy measures varied based on the number of metastatic lesions, with higher sensitivity observed for cases with fewer lesions. Gender, timing of imaging in relation to surgical intervention, and administration of nonsurgical therapy showed significant associations with diagnosis mismatch between CT and MRI. The site of metastases and the site of the primary tumor in the colon also demonstrated significant associations with diagnosis mismatch. The size of the largest metastasis detected by MRI was significantly associated with diagnosis mismatch. The overall diagnostic accuracy of CT in detecting any metastases, compared to MRI as the reference standard, was estimated to have a sensitivity of 87.8%, a specificity of 77.8%, a positive predictive value of 87.8%, and a negative predictive value of 77.8%. This study provides valuable insights into the comparative diagnostic performance of CT and MRI in detecting metastases of CRC, highlighting the importance of considering patient characteristics, disease outcome, and tumor characteristics in the interpretation of imaging results.

Accuracy of Clinical Staging of Localized Colon Cancer: A National Cancer Database Cohort Analysis

BACKGROUND

This study aimed to assess concordance between clinical and pathologic assessment of colon cancer.

PATIENTS AND METHODS

A retrospective cohort analysis of patients with stage I-III colon cancer in the National Cancer Database (2010-2019) was conducted. Concordance between clinical and pathologic assessment of colon cancer was calculated using Kappa coefficients and 95% confidence intervals (CIs).

RESULTS

A total of 125,473 patients (51.2% female; mean age 68.2 years) were included. There was moderate concordance between clinical and pathologic T stage (Kappa = 0.606, 95%CI: 0.602-0.609) and between clinical and pathologic N stage (Kappa = 0.506, 95%CI: 0.501-0.511). For right-sided colon cancer, there was moderate agreement between clinical and pathologic T stage (Kappa = 0.594, 95%CI: 0.589-0.599) and N stage (Kappa = 0.530, 95%CI: 0.523-0.537). For left-sided colon cancer, there was substantial agreement between clinical and pathologic T stage (Kappa = 0.624, 95%CI: 0.619-0.630) and moderate agreement between N stage (Kappa 0.472, 95%CI: 0.463-0.480). Sensitivity of clinical assessment of T and N stage ranged from 64.3% to 77.2% and 41.6% to 54.5%, respectively. Specificity ranged from 96.7% to 97.7% for T stage and 95.7% to 97.3% for N stage.

CONCLUSIONS

Clinical assessment of T and N stages of colon cancer had good diagnostic accuracy with moderate concordance with the final pathologic stage. While clinical assessment was highly specific with < 3% of patients being over-staged, it had modest sensitivity, especially for detection of nodal involvement. Diagnostic accuracy of clinical assessment of right and left colon cancers was similar, except for higher sensitivity and accuracy of assessment of nodal involvement in right than left colon cancers.

Comparative evaluation of CT and MRI in the preoperative staging of colon cancer

The aim of this study is to compare the diagnostic performance of magnetic resonance imaging (MRI) against computed tomography (CT) in various aspects of local staging in colon cancer patients. This study was a prospective single arm diagnostic accuracy study. All consecutive adult patients with confirmed colon cancer that met the current criteria for surgical resection were considered as eligible. Diagnostic performance assessment included T (T1/T2 vs T3/T4 and < T3ab vs > T3cd) and N (N positive) staging, serosa and retroperitoneal surgical margin (RSM) involvement and extramural vascular invasion (EMVI). Imaging was based on a 3 Tesla MRI system and the evaluation of all sequences (T1, T2 and diffusion-weighted imaging-DWI series) by two independent readers. CT scan was performed in a 128 row multidetector (MD) CT scanner (slice thickness: 1 mm) with intravenous contrast. Pathology report was considered as the gold standard for local staging. Sensitivity (SE), specificity (SP), and area under the curve (AUC) were calculated for both observers. MRI displayed a higher diagnostic performance over CT in terms of T1/T2 vs T3/T4 (SE: 100% vs 83.9%, SP: 96.6% vs 81%, AUC: 0.825 vs 0.983, p < 0.001), N positive (p < 0.001) and EMVI (p = 0.023) assessment. An excellent performance of MRI was noted in the T3ab vs T3cd (CT AUCReader1: 0.636, AUCReader2: 0.55 vs MRI AUCReader1: 0.829 AUCReader2 0.846, p = 0.01) and RSM invasion diagnosis. In contrast to these, MRI did not perform well in the identification of serosa invasion. MRI had a higher diagnostic yield than CT in several local staging parameters.

Imaging in the era of risk-adapted treatment in colon cancer

The treatment landscape for patients with colon cancer is continuously evolving. Risk-adapted treatment strategies, including neoadjuvant chemotherapy and immunotherapy, are slowly finding their way into clinical practice and guidelines. Radiologists are pivotal in guiding clinicians toward the most optimal treatment for each colon cancer patient. This review provides an overview of recent and upcoming advances in the diagnostic management of colon cancer and the radiologist's role in the multidisciplinary approach to treating colon cancer.

Evaluation of colon cancer prognostic factors by CT and MRI: an up-to-date review

Colorectal cancer (CRC) is a significant global health concern. Prognostication of CRC traditionally relies on the Union for International Cancer Control (UICC) and American Joint Committee on Cancer (AJCC) TNM staging classifications, yet clinical outcomes often vary independently of stage. Despite similarities, rectal and colon cancers are distinct in their diagnostic methodologies and treatments, with MRI and CT scans primarily used for staging rectal and colon cancers, respectively. This paper examines the challenges in accurately assessing prognostic factors of colon cancer such as primary tumor extramural extension, retroperitoneal surgical margin (RSM) involvement, extramural vessel invasion (EMVI), and lymph node metastases through preoperative CT and MRI. It highlights the importance of these factors in risk stratification, treatment decisions, and surgical planning for colon cancer patients. Advancements in imaging techniques are crucial for improving clinical management and optimizing patient outcomes, underscoring the necessity for ongoing research to refine diagnostic methods and incorporate novel findings into practice.

Construction of a nomogram based on clinicopathologic features to predict the likelihood of No. 253 lymph node metastasis in rectal cancer patients

PURPOSE

To explore the high-risk factors for rectal cancer No.253 lymph node metastasis (LNM) and to construct a risk nomogram for the individualized prediction of No.253 LNM.

METHODS

This was a retrospective analysis of 425 patients with rectal cancer who underwent laparoscopic-assisted radical surgery. Independent risk factors for rectal cancer No.253 LNM was identified using multivariate logistic regression analysis, and a risk prediction nomogram was constructed based on the independent risk factors. In addition, the performance of the model was evaluated by discrimination, calibration, and clinical benefit.

RESULTS

Multivariate logistic regression analysis showed that No.253 lymphadenectasis on CT (OR 10.697, P < 0.001), preoperative T4-stage (OR 4.431, P = 0.001), undifferentiation (OR 3.753, P = 0.004), and preoperative Ca199 level > 27 U/ml (OR 2.628, P = 0.037) were independent risk factors for No.253 LNM. A nomogram was constructed based on the above four factors. The calibration curve of the nomogram was closer to the ideal diagonal, indicating that the nomogram had a better fitting ability. The area under the ROC curve (AUC) was 0.865, which indicated that the nomogram had high discriminative ability. In addition, decision curve analysis (DCA) showed that the model could show better clinical benefit when the threshold probability was between 1% and 50%.

CONCLUSION

Preoperative No.253 lymphadenectasis on CT, preoperative T4-stage, undifferentiation, and elevated preoperative Ca199 level were found to be independent risk factors for the No.253 LNM. A predictive model based on these risk factors can help surgeons make rational clinical decisions.

Complete mesocolic excision and extended lymphadenectomy: Where should we stand?

Debate regarding the risks and merits of complete mesocolic excision and extended lymphadenectomy is ongoing, particularly for right-sided colon cancers. In this article, we hope to provide a succinct yet encompassing review of the relevant literature. We posit that complete mesocolic excision with D3 dissection is indicated in select patients with colon cancers, particularly those distal to the cecum.

Diffusion-Weighted MRI as a Quantitative Imaging Biomarker in Colon Tumors

PURPOSE

To assess the use of quantitative diffusion-weighted MRI (DW-MRI) as a diagnostic imaging biomarker in differentiating between benign colon adenoma, early, and advanced cancer of the colon, as well as predicting lymph node involvement, and finally comparing mucinous-producing colon cancer with adenomas and non-mucinous colon cancer.

METHOD

Patients with a confirmed tumor on colonoscopy were eligible for inclusion in this study. Using a 3.0 Tesla MRI machine, the main tumor mean apparent diffusion coefficient (mADC) was obtained. Surgically resected tumor specimens served as an endpoint, except in mucinous colon cancers, which were classified based on T2 images.

RESULTS

A total of 152 patients were included in the study population. The mean age was 71 years. A statistically significant mADC mean difference of -282 × 10-6 mm2/s [-419--144 95% CI, p < 0.001] was found between colon adenomas and early colon cancer, with an AUC of 0.80 [0.68-0.93 95% CI] and an optimal cut off value of 1018 × 10-6 mm2/s. Only a small statistically significant difference (p = 0.039) in mADC was found between benign tumors and mucinous colon cancer. We found no statistical difference in mADC mean values between early and advanced colon cancer, and between colon cancer with and without lymph node involvement.

CONCLUSION

Quantitative DW-MRI is potentially useful for determining whether a colonic tumor is benign or malignant. Mucinous colon cancer shows less diffusion restriction when compared to non-mucinous colon cancer, a potential pitfall.

Nationwide practice in CT-based preoperative staging of colon cancer and concordance with definitive pathology

INTRODUCTION

In an era of exploring patient-tailored treatment options for colon cancer, preoperative staging is increasingly important. This study aimed to evaluate completeness and reliability of CT-based preoperative locoregional colon cancer staging in Dutch hospitals.

MATERIALS AND METHODS

Patients who underwent elective oncological resection of colon cancer without neoadjuvant treatment in 77 Dutch hospitals were evaluated between 2011 and 2021. Completeness of T-stage was calculated for individual hospitals and stratified based on a 60% cut-off. Concordance between routine CT-based preoperative locoregional staging (cTN) and definitive pathological staging (pTN) was examined.

RESULTS

A total of 59,558 patients were included with an average completeness of 43.4% and 53.4% for T and N-stage, respectively. Completeness of T-stage improved from 4.9% in 2011-2014 to 74.4% in 2019-2021. Median completeness for individual hospitals was 53.9% (IQR 27.3-80.5%) and were not significantly different between low and high-volume hospitals. Sensitivity and specificity for T3-4 tumours were relatively low: 75.1% and 76.0%, respectively. cT1-2 tumours were frequently understaged based on a low negative predictive value of 56.8%. Distinction of cT4 and cN2 disease had a high specificity (>95%), but a very low sensitivity (<50%). Positive predictive values of <60% indicated that cT4 and cN1-2 were often overstaged. Completeness and time period did not influence reliability of staging.

CONCLUSION

Completeness of locoregional staging of colon cancer improved during recent years and varied between hospitals independently from case volume. Discriminating cT1-2 from cT3-4 tumours resulted in substantial understaging and overstaging, additionally cT4 and cN1-2 were overstaged in >40% of cases.

Radiologic T staging of colon cancer: renewed interest for clinical practice

Radiologic imaging, especially MRI, has long been the mainstay for rectal cancer staging and patient selection for neoadjuvant therapy prior to surgical resection. In contrast, colonoscopy and CT have been the standard for colon cancer diagnosis and metastasis staging with T and N staging often performed at the time of surgical resection. With recent clinical trials exploring the expansion of the use of neoadjuvant therapy beyond the anorectum to the remainder of the colon, the current and future state of colon cancer treatment is evolving with a renewed interest in evaluating the role radiology may play in the primary T staging of colon cancer. The performance of CT, CT colonography, MRI, and FDG PET-CT for colon cancer staging will be reviewed. N staging will also be briefly discussed. It is expected that accurate radiologic T staging will significantly impact future clinical decisions regarding the neoadjuvant versus surgical management of colon cancer.

MRI Evaluation of Rectal Cancer Lymph Node Staging Using Apparent Diffusion Coefficient

Introduction Colorectal cancer is the third most diagnosed cancer globally. Lymph node metastases significantly affect prognosis, emphasizing the importance of early detection and management. Despite significant advances in conventional MRI's role in staging, improvements in advanced functional imaging such as diffusion-weighted imaging (DWI) in identifying lymph node metastases persist. Objectives The aim is to evaluate the effectiveness of apparent diffusion coefficient (ADC) MRI in evaluating lymph node staging in rectal cancer. Patients and methods In a prospective study, 89 patients with stage II-III rectal cancer were grouped into two treatments: pre-operative FOLFOX4 chemotherapy and standard pre-operative chemoradiotherapy. All underwent 1.5T MRI, with T2-weighted and DWI sequences. A radiologist defined regions of interest on the tumor, lymph nodes, and intact rectal wall to calculate ADC values. Results Rectal cancer ADC's receiver operating characteristic curve had an area under the curve (AUC) of 0.688 (P < 0.001), with optimal ADC cutoff at 0.99 x 10-3 mm2/s (sensitivity: 75%, specificity: 83%). For lymph nodes, AUC was 0.508 (P < 0.001), with a cutoff of 0.9 x 10-3 mm2/s (sensitivity: 78%, specificity: 67%). No correlation between tumor and lymph node ADC values was observed. In chemotherapy patients, "healthy" inguinal lymph nodes had higher ADC values than affected ones pre-treatment (P = 0.001), a disparity fading post-treatment (P = 0.313). For chemoradiotherapy patients, the ADC difference persisted pre and post-treatment (P = 0.001). Conclusion The study of ADC-MRI showed different ADC values between tumors and lymph nodes and highlighted ADC differences between treatment groups. Notably, no correlation was observed between tumor and lymph node ADC values. However, differences were apparent when comparing "healthy" inguinal nodes with lymph nodes affected by cancer.

Abdominal Ultrasonography After Transrectal Filling With Contrast Agents in Colorectal Cancer With Severely Stenotic Lesions

OBJECTIVE

Abdominal ultrasonography after transrectal filling with contrast agent (AU-TFCA) was retrospectively evaluated with respect to determination of T stage and lesion length in patients with colorectal cancer (CRC) who had previously failed colonoscopy because of severe intestinal stenosis.

METHODS

The population comprised 83 patients with CRC with intestinal stenosis and previously failed colonoscopy who underwent AU-TFCA, and in addition contrast-enhanced computed tomography (CECT) and/or magnetic resonance imaging (MRI), 2 wk before surgery. The diagnostic performance of AU-TFCA and CECT/MRI was evaluated relative to the post-operative pathological results (PPRs) by paired sample t-test, receiver operator characteristic (ROC) curve, Pearson's χ²-test and κ and intraclass correlation coefficients.

RESULTS

The T staging identified via AU-TFCA, but not CECT/MRI, was relatively consistent with that of the PPRs (linearly weighted κ coefficient: 0.558, p < 0.001, and linearly weighted κ coefficient: 0.237, p < 0.001, respectively). The overall diagnostic accuracy of T staging based on AU-TFCA (83.1%) was significantly higher than that based on CECT/MRI (50.6%). Regarding lesion length, the results of AU-TFCA and PPRs were comparable (t = 1.852, p = 0.068), but those of CECT/MRI and PPRs were significantly different (t = 8.450, p < 0.001).

CONCLUSION

AU-TFCA is effective in evaluation of lesion length and T stage in patients with severely stenotic CRC lesions who previously failed colonoscopy. The diagnostic accuracy of AU-TFCA is significantly better compared with that of CECT/MRI.

Imaging of colon and rectal cancer

Colon and rectal cancer imaging has traditionally been performed to assess for distant disease (typically lung and liver metastases) and to assess the resectability of the primary tumor. With technological and scientific advances in imaging and the evolution of treatment options, the role of imaging has expanded. Radiologists are now expected to provide a precise description of primary tumor invasion extent, including adjacent organ invasion, involvement of the surgical resection plane, extramural vascular invasion, lymphadenopathy, and response to neoadjuvant treatment, and to monitor for recurrence after clinical complete response.

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.

A Clinicopathological Feature-Based Nomogram for Predicting the Likelihood of D3 Lymph Node Metastasis in Right-Sided Colon Cancer Patients

BACKGROUND

Despite advancements in treating right-sided colon cancer patients, the ideal scope of lymphadenectomy remains controversial.

OBJECTIVE

Our objective was to investigate the likelihood of D3 lymph node metastasis in right-sided colon cancer patients and develop a clinicopathological feature-based nomogram for D3 lymphadenectomy.

DESIGN

We retrospectively analyzed 286 right-sided colon cancer patients who underwent D3 lymphadenectomy. The patients were divided into 2 groups based on whether D3 lymph node metastasis was positive. Then, univariable and multivariable logistic regression analyses were performed to obtain independent risk factors for predicting D3 lymph node metastasis. Moreover, we performed receiver operating characteristic curve analyses to evaluate the predictive power of the model.

SETTING

This study was conducted at Nanfang Hospital of Southern Medical University in China.

PATIENTS

A total of 286 consecutive patients who underwent right hemicolectomy and D3 lymphadenectomy as a primary treatment for right-sided colon cancer between January 2016 and December 2019 were enrolled in this study.

MAIN OUTCOME MEASURES

The primary measures were independent risk factors for predicting D3 lymph node metastasis in right-sided colon cancer.

RESULTS

The D3 lymph node metastasis rate in right-sided colon cancer patients was 16.1% (46/286). D3 lymphadenectasis on CT, lymphatic invasion, and T4 tumors were filtered out as independent risk factors for D3 lymph node metastasis according to the multivariable logistic regression analysis. We established a nomogram that predicted D3 lymph node metastasis of right-sided colon cancer on the combination of the 3 factors with an area under the curve of 0.717 (95% CI, 0.629-0.806).

LIMITATIONS

This was a retrospective study from a single center.

CONCLUSIONS

We developed a valuable clinicopathological feature-based nomogram to predict the incidence of D3 lymph node metastasis in right-sided colon cancer patients. Patients with D3 lymphadenectasis on CT, preoperative T4 tumors, and lymphatic invasion should undergo D3 lymphadenectomy. See Video Abstract at http://links.lww.com/DCR/B852 .

UN NOMOGRAMA BASADO EN CARACTERSTICAS CLNICOPATOLGICAS PARA PREDECIR LA PROBABILIDAD DE METSTASIS EN GANGLIOS LINFTICOS D EN PACIENTES CON CNCER DE COLON DERECHO

ANTECEDENTES:A pesar de los avances en el tratamiento de pacientes con cáncer de colon derecho, el ámbito ideal de la linfadenectomía sigue siendo controvertido.OBJETIVO:Investigar la probabilidad de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon derecho y desarrollar un nomograma basado en características clínico-patológicas basado para la linfadenectomía D3.DISEÑO:Analizamos retrospectivamente a 286 pacientes con cáncer de colon derecho que se sometieron a linfadenectomía D3. Los pacientes se dividieron en dos grupos en función de si eran positivos para metástasis en los ganglios linfáticos D3. Luego, se realizaron análisis de regresión logística univariable y multivariable para obtener factores de riesgo independientes para predecir metástasis en los ganglios linfáticos D3. Además, realizamos análisis de las curvas de características operatorias del receptor para evaluar el poder predictivo del modelo.SEDE:Este estudio se realizó en el Hospital Nanfang de la Universidad Médica del Sur en China.PACIENTES:Un total de 286 pacientes consecutivos que se sometieron a hemicolectomía derecha y linfadenectomía D3 como tratamiento primario para el cáncer de colon derecho entre enero de 2016 y diciembre de 2019 se inscribieron en este estudio.PRINCIPALES MEDIDAS DE RESULTADO:Las medidas primarias fueron factores de riesgo independientes para predecir las metástasis en ganglios linfáticos D3 en el cáncer de colon derecho.RESULTADOS:La tasa de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon del lado derecho fue del 16,1% (46/286). El aumento de tamaño de ganglios D3 en la TC, la invasión linfática y los tumores T4 se filtraron como factores de riesgo independientes de metástasis en los ganglios linfáticos D3 de acuerdo con el análisis de regresión logística multivariable. Establecimos un nomograma que predijo metástasis en los ganglios linfáticos D3 del cáncer de colon derecho en la combinación de los tres factores con un área bajo la curva de 0,717 (IC del 95%, 0,629-0,806).LIMITACIONES:Este fue un estudio retrospectivo de un solo centro.CONCLUSIONES:Desarrollamos un valioso nomograma basado en características clínico-patológicas para predecir la incidencia de metástasis en los ganglios linfáticos D3 en pacientes con cáncer de colon derecho. Los pacientes con crecimiento de ganglios D3 en TC, tumores con clasificación preoperatoria T4 e invasión linfática, deben ser sometidos a linfadenectomía D3. Consulte Video Resumen en http://links.lww.com/DCR/B852 . (Traducción-Dr. Juan Carlos Reyes ).

Tailoring the clinical management of colorectal cancer by 18F-FDG PET/CT

Colorectal cancer (CRC) is among the most commonly diagnosed gastrointestinal malignancies worldwide. It is inadequate to handle in terms of staging and restaging only based on morphological imaging modalities and serum surrogate markers. And the correct and timely staging of CRC is imperative to prognosis and management. When compared to established sequential, multimodal conventional diagnostic methods, the molecular and functional imaging ¹⁸F-FDG PET/CT shows superiorities for tailoring appropriate treatment maneuvers to each patient. This review aims to summarize the utilities of ¹⁸F-FDG PET/CT in CRC, focusing on primary staging, follow-up assessment of tumor responses and diagnostic of recurrence. In addition, we also summarize the technical considerations of PET/CT and the conventional imaging modalities in those patients who are either newly diagnosed with CRC or has already been treated from this cancer.

Prognostic value of elastic lamina staining in patients with stage III colon cancer

OBJECTIVE

The objectives of this study were to analyze the difference between the preoperative radiological and postoperative pathological stages of colorectal cancer (CRC) and explore the feasibility of elastic lamina invasion (ELI) as a prognostic marker for patients with stage III colon cancer.

METHODS

A total of 105 consecutive patients underwent radical surgery (R0 resection) for stage III colon cancer at the Cancer Hospital of China Medical University between January 2015 and December 2017. Clinicopathological features, including radiological stage and elastic lamina staining, were analyzed for prognostic significance in stage III colon cancer.

RESULTS

A total of 105 patients with stage III colon cancer who met the criteria and had complete data available were included. The median follow-up period of survivors was 41 months. During the follow-up period, 33 (31.4%) patients experienced recurrence after radical resection, and the 3-year disease-free survival (DFS) rate was 64.8%. The consistency between preoperative radiological and postoperative pathological staging was poor (κ = 0.232, P < 0.001). The accuracy of ≤ T2 stage diagnoses was 97.1% (102/105), that of T3 stage was 60.9% (64/105), that of T4a stage was 68.6% (72/105) and that of T4b stage was 91.4% (96/105). The DFS rate of T3 ELI (+) patients was significantly lower than that of both T3 ELI (-) patients (P = 0.000) and pT4a patients (P = 0.013). The DFS rate of T3 ELI (-) patients was significantly higher than that of pT4b patients (P=0.018). T3 ELI (+) (HR (Hazard ratio), 8.444 [95% CI, 1.736-41.067]; P = 0.008), T4b (HR, 57.727[95% CI, 5.547-600.754]; P = 0.001), N2 stage (HR, 10.629 [95% CI, 3.858-29.286]; P < 0.001), stage III (HR, 0.136 [95% CI, 0.31-0.589]; P = 0.008) and perineural invasion (PNI) (HR, 8.393 [95% CI, 2.094-33.637]; P = 0.003) were independent risk factors for postoperative recurrence of stage III colon cancer.

CONCLUSIONS

The consistency between preoperative radiological and postoperative pathological staging was poor, especially for tumors located in the ascending colon and descending colon. Elastic lamina staining is expected to become a stratified indicator of recurrence risk for patients with stage III colon cancer and a guide for individualized adjuvant chemotherapy, thus improving patient prognosis.

Colon Cancer Diagnosis Based on Machine Learning and Deep Learning: Modalities and Analysis Techniques

The treatment and diagnosis of colon cancer are considered to be social and economic challenges due to the high mortality rates. Every year, around the world, almost half a million people contract cancer, including colon cancer. Determining the grade of colon cancer mainly depends on analyzing the gland's structure by tissue region, which has led to the existence of various tests for screening that can be utilized to investigate polyp images and colorectal cancer. This article presents a comprehensive survey on the diagnosis of colon cancer. This covers many aspects related to colon cancer, such as its symptoms and grades as well as the available imaging modalities (particularly, histopathology images used for analysis) in addition to common diagnosis systems. Furthermore, the most widely used datasets and performance evaluation metrics are discussed. We provide a comprehensive review of the current studies on colon cancer, classified into deep-learning (DL) and machine-learning (ML) techniques, and we identify their main strengths and limitations. These techniques provide extensive support for identifying the early stages of cancer that lead to early treatment of the disease and produce a lower mortality rate compared with the rate produced after symptoms develop. In addition, these methods can help to prevent colorectal cancer from progressing through the removal of pre-malignant polyps, which can be achieved using screening tests to make the disease easier to diagnose. Finally, the existing challenges and future research directions that open the way for future work in this field are presented.

Estimation of colon cancer grade and metastatic lymph node involvement using DWI/ADC sequences

BACKGROUND

The potential benefit of neoadjuvant chemotherapy (NAC) in colon cancer is under evaluation. There is a need to improve preoperative non-invasive diagnostics using techniques that provide more accurate staging information in assessing patient eligibility for NAC.

PURPOSE

To investigate the link between the tumor grade (pathohistological confirmed) and the N status (corresponding to lymph node involvement) with apparent diffusion coefficient (ADC) values.

MATERIAL AND METHODS

A total of 17 patients planned for surgical resection had a biopsy confirming colon carcinoma and participated in the study. Abdominal magnetic resonance imaging with diffusion-weighted imaging/ADC sequence was recorded before surgery. The tumor and all visible lymph nodes were manually delineated directly on a grayscale ADC map for every single slice and detected to access the total tumor and summarized lymph node volume. The mean ADC value was further calculated for the mean tumor and mean lymph node values.

RESULTS

Low-grade tumors had a mean ADC equivalent to 1225 ± 170×10^-6 mm²/s, and the coefficient of high-grade tumors was 1444 ± 69×10^-6 mm²/s. The group of patients with positive lymph nodes in operative tissue samples (N+) exhibited lower mean ADC values (1023 ± 142×10^-6 mm²/s) as opposed to the group without metastatic lymph nodes (N-) with ADC values of 1260 ± 231×10^-6 mm²/s.

CONCLUSION

The mean whole-tumor ADC is associated with the histological tumor grade, and the mean ADC value of whole-volume abdominal lymph nodes could assume real nodal infiltration.

Overview of the Large Bowel Assessment Using Magnetic Resonance Imaging: Different Techniques for Current and Emerging Clinical Applications

Radiological assessments of the small and large bowel are essential in daily clinical practice. Over plain film X-ray and ultrasound, cross-sectional techniques are considered the most comprehensive imaging modalities. In fact, computed tomography and magnetic resonance imaging take great advantage of the three-dimensional appraisal and the extensive evaluation of the abdominal cavity, allowing intestinal evaluation as well as detection of extra-intestinal findings. In this context, the chief advantage of computed tomography is the fast scan time, which is crucial for emergency cases. Nonetheless, it is undeniably impaired using ionizing radiation. As the awareness of radiation exposure is a topic of increasing importance, magnetic resonance imaging is not only becoming a mere alternative but also a primary imaging technique used in assessing intestinal diseases. Specifically, the evaluation of the large bowel through MRI can be still considered relatively uncharted territory. Although it has demonstrated superior accuracy in the assessment of some clinical entities from inflammatory bowel disease to rectal carcinoma, its role needs to be consolidated in many other conditions. Moreover, different technical methods can be applied for colonic evaluation depending on the specific disease and segment involved. This article aims to provide a thorough overview of the techniques that can be utilized in the evaluation of the large bowel and a discussion on the major findings in different colonic pathologies of primary interest.

Transabdominal Ultrasonography for Preoperative Diagnosis of Lymph Node Metastasis in Colon Cancer: A Retrospective Cohort Study

Background/Aim

Although computed tomography (CT) is the standard modality for diagnosing lymph node metastasis (LNM), transabdominal ultrasonography (US) can be useful due to its high spatial resolution and use of Doppler signals to precisely analyse lymph nodes. This study aimed to evaluate the accuracy of US for lymph node assessment, establish US-based diagnostic criteria for LNM, and compare the capability of US with that of CT for the diagnosis of LNM.

Patients and Methods

This retrospective, single-institution, cohort study included patients who underwent radical surgery for clinical stage 0-III colon cancer, between March 2012 and February 2019.

Results

Overall, 34.9% (66/189) of patients had pathological LNM. The optimal US diagnostic criteria were 1) short axis ≥7 mm and short/long ratio ≥0.75 and 2) at least two of the following: the absence of hilar echoes, expansive appearance, or peripheral/mixed vascularity by the colour Doppler and/or contrast-enhanced method. Compared to CT, US showed a higher diagnostic sensitivity (54.5% vs. 43.9%; p=0.296), higher concordance with the number of pathological LNM (correlation coefficient: US, 0.42; CT, 0.27) and pathological N diagnosis (weighted ĸ: US, 0.35; CT, 0.18), and higher sensitivity for advanced LNM, including multiple LNMs (47.4% vs. 18.4%; p=0.014) and N2 stage (27.8% vs. 5.6%; p=0.177).

Conclusion

US has higher sensitivity than CT for diagnosing LNM in colon cancer, along with a more accurate preoperative diagnosis of the N stage. Additionally, US may be more helpful than CT alone for preoperatively deciding the appropriateness of neoadjuvant treatment in colon cancer with advanced LNM.

CT and 3 Tesla MRI in the TN Staging of Colon Cancer: A Prospective, Blind Study

(1) Background: Computer tomography (CT) scanning is currently the standard method for staging of colon cancer; however, the CT based preoperative local staging is far from optimal. The purpose of this study was to investigate the sensitivity and specificity of magnetic resonance imaging (MRI) compared to CT in the T- and N-staging of colon cancer. (2) Methods: Patients underwent a standard contrast-enhanced CT examination. For the abdominal MRI scan, a 3 Tesla unit was used, including diffusion weighted imaging (DWI). Experienced radiologists reported the CT and MRI scans blinded to each other and the endpoint of the pathological report. (3) Results: From 2018 to 2021, 134 patients received CT and MRI scans. CT identified 118 of the 134 tumors, whereas MRI identified all tumors. For discriminating between stage T3ab and T3cd, the sensitivity of CT was 51.1% and of MRI 80.0% (p = 0.02). CT and MRI showed a sensitivity of 21.4% and 46.4% in detecting pT4 tumors and a specificity of 79.0% and 85.0%, respectively. (4) Conclusion: Compared to CT, the sensitivity of MRI was statistically significantly higher in staging advanced T3cd and T4 tumors. MRI has the potential to be used in the treatment planning of colon cancer.

Interindividual Comparison of Frequency-Selective Nonlinear Blending to Conventional CT for Detection of Focal Liver Lesions Using MRI as the Reference Standard

Background: Diagnosing liver lesions is challenging. CT is used for primary diagnosis; however, its contrast resolution is limited. Investigating methods for better detection of liver lesions is important. Objective: To evaluate the effect of frequency-selective nonlinear blending (NLB) on the detectability of liver lesions on CT. Methods: Retrospective search yielded 109 patients with malignant and benign liver lesions (n = 356; 191 principally diagnosed, 165 incidental findings) underwent contrast-enhanced CT (CECT) in portal venous phase and liver MRI between January 2012 and December 2017. Nonlinear blending (NLB) was applied to CECTs, and three readers rated image quality (5-point Likert scale) in blinded, independent, and randomized fashion. Focal lesions (n = 356) were evaluated for lesion identification and categorization to assess sensitivity. For 191 lesions (primary diagnosis) two readers evaluated CECT and NLB CT to compare size and subjective measurement accuracy. A fourth reader conducted ROI measurements for calculation of contrast-to-noise ratio (CNR), and a fifth reader reviewed MRI as standard of reference. Statistics included interobserver agreement, quantitative comparisons of CNR, lesion size, and subjective image analyses of image quality and sensitivity of detecting liver lesions. Results: Three readers rated image quality of NLB CT higher than for CECT (NLB CT, 4 [10% and 90% percentile: 4, 5]; CECT, 2 [1, 3]; p < .001). CECT showed good interreader agreement (interclass coefficient [ICC], 0.81 [95% CI, 0.76¬-0.85]); NLB CT also (ICC, 0.75 [95% CI, 0.69-0.79]). Mean CNR of liver lesions was increased using NLB (CECT, 4.18 [range, 1.67-9.06]; NLB CT, 12.49 [range, 6.18-23.39]; p < .001). Bland-Altman analysis of lesion size showed reduced underestimation from 2.5 mm (SD, 9.2 [95% CI, 1.2-3.9]) in CECT to 0.1 mm (SD, 3.9 [95% CI, -0.68 to 0.46) for NLB CT (concordance correlation coefficient, 0.99). Sensitivity for detecting liver lesions was increased to 86% for NLB CT (CECT, 76%). Conclusion: Frequency-selective NLB of CECT allows increased image quality and CNR, more precise size measurement, and higher sensitivity for detecting liver lesions. Clinical Impact: NLB CT improves liver lesion detection and increases the accuracy of lesion size measurement, which is important when considering local ablation or liver transplant.

The added value of full and reduced field-of-view apparent diffusion coefficient maps for the evaluation of extramural venous invasion in rectal cancer

OBJECTIVE

To investigate the added value of the quantitative analysis of full and reduced field-of-view apparent diffusion coefficient (fADC and rADC) maps for evaluating extramural venous invasion (EMVI) in rectal cancer.

MATERIALS AND METHODS

A total of 94 rectal cancer patients who underwent direct surgical resection were enrolled in this prospective study. The EMVI status of each patient was evaluated on T2-weighted imaging. The mean values of fADC and rADC within the whole tumor were obtained, and histogram parameters were also extracted. Multivariate binary logistic regression analysis was used to analyze independent predictors of EMVI and construct combined models. Receiver operating characteristic (ROC) curves were applied to assess the diagnostic performance.

RESULTS

The energy, skewness, total energy, and kurtosis of fADC map, and the energy and total energy of rADC map were significantly different between the EMVI-positive and EMVI-negative groups (all P < 0.05). Multivariate logistic regression analysis revealed that kurtosis of fADC and circumferential percentage of tumor were independent predictors of EMVI (odds ratio 1.684 and 2.647, P = 0.020 and 0.009). These two parameters combined with subjective evaluation demonstrated the superior diagnostic performance with the area under the ROC curve, sensitivity, specificity, and accuracy of 0.841 (95% CI 0.752-0.909), 0.739, 0.803, and 0.809, respectively.

CONCLUSION

Whole-tumor histogram analysis of ADC map could potentially provide additional information to improve the diagnostic efficiency for assessing EMVI in rectal cancer, which may be beneficial for treatment decision-making.

Machine learning-based quantitative analysis of barium enema and clinical features for early diagnosis of short-segment Hirschsprung disease in neonate

OBJECTIVE

To develop a mathematical model based on a combination of clinical and radiologic features (barium enema) for early diagnosis of short-segment Hirschsprung disease (SHSCR) in neonate.

METHODS

The analysis included 54 neonates with biopsy-confirmed SHSCR (the cases) and 59 neonates undergoing barium enema for abdominal symptoms but no Hirschsprung disease (the control). Colon shape features extracted from barium enema images and clinical features were used to develop diagnostic models using support vector machine (SVM) and L2-regularized logistic regression (LR). The training cohort included 32 cases and 37 controls; testing cohort consisted 22 cases and 22 controls. Results were compared to interpretation by 2 radiologists.

RESULTS

In the analysis by radiologists, 87 out of 113 cases were correctly classified. Six SHSCR cases were mis-classified into the non-HSCR group. In the remaining 20 cases, radiologists were unable to make a decision. Both the SVM and LR classifiers contained five clinical features and four shape features. The performance of the two classifiers was similar. The best model had 86.36% accuracy, 81.82% sensitivity, and 90.91% specificity. The AUC was 0.9132 for the best-performing SVM classifier and 0.9318 for the best-performing LR classifier.

CONCLUSION

A combination of clinical features and colon shape features extracted from barium enemas can be used to improve early diagnosis of SHSCR in neonate.

Does preoperative neoadjuvant chemotherapy impact short-term surgical outcomes in patients with locally advanced colon cancer?

BACKGROUND

Preoperative neoadjuvant chemotherapy (NAC) for colon cancer in advanced stages is associated with improved outcomes and tumor regression. The aim of our study was to identify outcomes in patients with colon cancer who received preoperative NAC.

METHODS

A 4-year analysis of the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) was performed. We included patients with locally advanced colon cancer (non-metastatic T3, T4 with or without nodal involvement) who underwent colon cancer resection. Patients were stratified into two groups (NAC and No-NAC). Our outcome measures were anastomotic leaks, hospital length of stay (LOS), 30-day complications, 30-day mortality, and 30-day readmissions. We performed a multi-variable logistic regression analysis.

RESULTS

We analyzed 90,055 patients of which 7694 (NAC: 7.8 % (n = 599) and No-NAC: 92.2% (n = 7095)) met the inclusion criteria and included in the analysis. Mean age was 67 ± 13 years, 51% were males, and 72% were whites. Patients in the NAC group were more likely to be younger (60 ± 12 years vs. 68 ± 13 years, p < 0.01) and males (62% vs. 50%, p < 0.01) compared to No-NAC. On regression analysis, preoperative NAC was independently associated with higher odds of anastomotic leak (OR 1.35 [1.05-1.97], p = 0.03) and 30-day readmission (OR 1.54 [1.24-2.05], p < 0.01) in reference to No-NAC. However, no association was found between NAC and 30-day complications and 30-day mortality.

CONCLUSIONS

Preoperative NAC might be associated with adverse outcomes of anastomotic leaks and 30-day readmissions, however does not appear to impact 30-day complications nor 30-day mortality.

Neoadjuvant chemotherapy in locally advanced colon cancer: a systematic review and meta-analysis

BACKGROUND

There is increasing evidence to support the use of neoadjuvant chemotherapy (NAC) in locally advanced colon cancer (LACC). However, its safety, efficacy and side effect profile is yet to be completely elucidated. This review aims to assess NAC regimens, duration, compare completion rates, intra-operative and post-operative complication profiles and oncological outcomes, in order to provide guidance for clinical practice and further research.

METHODS

PubMed, EMBASE and MEDLINE were searched for a systematic review of the literature from 2000 to 2020. Eight eligible studies were included, with a total of 1213 patients, 752 (62%) of whom received NAC. Of the eight studies analysed, two were randomised controlled trials comparing neoadjuvant chemotherapy followed by oncological resection to upfront surgery and adjuvant chemotherapy, three were prospective single-arm phase II trials analysing neoadjuvant chemotherapy followed by surgery only, one was a retrospective study comparing neoadjuvant chemotherapy followed by surgery versus surgery first followed by adjuvant chemotherapy and the remaining two were single-arm retrospective studies of neoadjuvant chemotherapy followed by surgery.

RESULTS

All cases of LACC were determined and staged by computed tomography; majority of the studies defined LACC as T3 with extramural depth of 5 mm or more, T4 and/or nodal positivity. NAC administered was either folinic acid, fluorouracil and oxaliplatin (FOLFOX) or capecitabine and oxaliplatin (XELOX) with the exception of one study which utilised 5-fluorouracil and mitomycin. Most studies had NAC completion rates of above 83% with two notable exceptions being Zhou et al. and The Colorectal Cancer Chemotherapy Study Group of Japan who both recorded a completion rate of 52%. Time to surgery from completion of NAC ranged on average from 16 to 31 days. The anastomotic leak rate in the NAC group ranged from 0 to 4.5%, with no cases of postoperative mortality. The R0 resection rate in the NAC group was 96.1%. Meta-analysis of both RCTs included in this study showed that neoadjuvant chemotherapy increased the likelihood of a negative resection margin T3/4 advanced colon cancer (pooled relative risk of 0.47 with a 95% confidence interval) with no increase in adverse consequence of anastomotic leak, wound infection or return to theatre.

CONCLUSIONS

Our systematic review and meta-analysis show that NAC is safe with an acceptable side effect profile in the management of LACC. The current data supports an oncological benefit for tumour downstaging and increased in R0 resection rate.

Proper surgical extent for clinical Stage I right colon cancer

Purpose:

Pre-operative evaluation identifying clinical-stage affects the decision regarding the extent of surgical resection in right colon cancer. This study was designed to predict a proper surgical resection through the prognosis of clinical Stage I right colon cancer.

Patients and Methods:

We included patients who were diagnosed with clinical and pathological Stage I right-sided colon cancer, including appendiceal, caecal, ascending, hepatic flexure and proximal transverse colon cancer, between August 2010 and December 2016 in two tertiary teaching hospitals. Patients who underwent open surgeries were excluded because laparoscopic surgery is the initial approach for colorectal cancer in our institutions.

Results:

Eighty patients with clinical Stage I and 104 patients with pathological Stage I were included in the study. The biopsy reports showed that the tumour size was larger in the clinical Stage I group than in the pathological Stage I group (3.4 vs. 2.3 cm, P < 0.001). Further, the clinical Stage I group had some pathological Stage III cases (positive lymph nodes, P = 0.023). The clinical Stage I group had a higher rate of distant metastases (P = 0.046) and a lower rate of overall (P = 0.031) and cancer-specific survival (P = 0.021) than the pathological Stage I group. Compared to pathological Stage II included in the period, some of the survival curves were located below the pathological Stage II, but there was no statistical difference.

Conclusion:

The study results show that even clinical Stage I cases, radical resection should be considered in accordance with T3 and T4 tumours.

The Impact of Patient Characteristics and Tumor Biology on the Accuracy of Preoperative Staging of Colon Cancer in Denmark. A Nationwide Cohort Study

Simple Summary

The roles of mismatch repair and other colon tumor characteristics were investigated in a nationwide registry study with data extracted from the Danish Colorectal Cancer Group. Mismatch repair can arise during DNA replication. In this study, 6102 patients were included with a median age of 72 (range 23–97 years). The mismatch repair was deficient in 24% and proficient in 76%. Mismatch repair deficiency impacted the accuracy of the preoperative staging of colon cancer. In the future, mismatch repair status should be taken into consideration in the clinical staging of colon cancer.

Abstract

Background: Colon cancer is a common disease in western populations. The aim of this study was to assess the impact of mismatch repair (MMR) deficiency and other patient and tumor characteristics on the accuracy of preoperative staging by comparing histopathological T- and N-categories of the resected specimen with the preoperative clinical stage in a nationwide cohort of patients treated for colon cancer by elective bowel resection with curative intent. Methods: A register study of a cohort extracted from the Danish Colorectal Cancer Group (DCCG) database, which holds prospective data on all new cases of colon and rectum cancer in Denmark. Patients diagnosed with colon cancer and treated with an elective bowel resection with curative intent in the years 2016–2019 were analyzed. Results: A total of 6102 patients were included (n = 3161 (52%) men and n = 2941 (48%) women) with a median age of 72 years (range 23–97 years). MMR was deficient in 24% of the patients and proficient in 76%. MMR deficiency, tumor sidedness and histopathological type were significant predictors of the accuracy of preoperative staging of colon cancer in univariate and multivariate analysis. MMR status in particular showed a strong impact on the risk of overstaging. Conclusions: MMR deficiency, but also tumor sidedness and to some degree histopathological type, impacted the accuracy of preoperative staging of colon cancer. MMR status should be taken into consideration in everyday clinical staging.

I, Six JL, Ferji K, Jaafar J, Boer JC, Plebanski M, Uskoković V, Mohamud R. Nanoparticles and Gut Microbiota in Colorectal Cancer

Recent years have witnessed an unprecedented growth in the research area of nanomedicine. There is an increasing optimism that nanotechnology applied to medicine will bring significant advances in the diagnosis and treatment of various diseases, including colorectal cancer (CRC), a type of neoplasm affecting cells in the colon or the rectum. Recent findings suggest that the role of microbiota is crucial in the development of CRC and its progression. Dysbiosis is a condition that disturbs the normal microbial environment in the gut and is often observed in CRC patients. In order to detect and treat precancerous lesions, new tools such as nanotechnology-based theranostics, provide a promising option for targeted marker detection or therapy for CRC. Because the presence of gut microbiota influences the route of biomarker detection and the route of the interaction of nanoparticle/drug complexes with target cells, the development of nanoparticles with appropriate sizes, morphologies, chemical compositions and concentrations might overcome this fundamental barrier. Metallic particles are good candidates for nanoparticle-induced intestinal dysbiosis, but this aspect has been poorly explored to date. Herein, we focus on reviewing and discussing nanotechnologies with potential applications in CRC through the involvement of gut microbiota and highlight the clinical areas that would benefit from these new medical technologies.

Prediction of false-negative extramural venous invasion in patients with rectal cancer using multiple mathematical models of diffusion-weighted imaging

PURPOSE

To investigate the parameters from mono-exponential, stretched-exponential, and intravoxel incoherent motion diffusion-weighted imaging (DWI) models for evaluating false-negative extramural venous invasion (EMVI) on conventional magnetic resonance imaging (MRI) in rectal cancer patients.

MATERIAL AND METHODS

Seventy-two rectal cancer patients with negative EMVI on conventional MRI who underwent direct surgical resection were enrolled in this prospective study. The apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), distributed diffusion coefficient (DDC), and water molecular diffusion heterogeneity index (α) values within the whole tumor were obtained to identify the patients with false-negative EMVI. Receiver operating characteristic (ROC) curves were applied to evaluate the diagnostic performance. Multivariate binary logistic regression analysis was conducted to determine the independent risk factors.

RESULTS

The DDC, D*, f, and α values were significantly different in the EMVI-positive and EMVI-negative groups (P =  0.018, and P <  0.001, respectively). The D*, f, and α values demonstrated good diagnostic performance with area under the ROC curve (AUC) of 0.861, 0.824, and 0.854, respectively. The combined model, including D*, α, and tumor location, proved superior diagnostic performance with the AUC, sensitivity, specificity, and accuracy of 0.971, 0.917, 0.967, and 0.931, respectively. The AUC of the combined model was significantly higher than that of the D*, f, and DDC (P = 0.004, 0.045, and 0.002, respectively).

CONCLUSION

Multi-b-value DWI may be a potential tool for identifying micro-EMVI in rectal cancer. The combination of DWI parameters and tumor location leads to superior diagnostic performance.

The Role of Neoadjuvant Chemotherapy in Locally Advanced Colon Cancer

Neoadjuvant systemic therapy has many potential advantages over up-front surgery, including tumor downstaging, early treatment of micrometastatic disease, and providing an in vivo test of tumor biology. Due to these advantages, neoadjuvant therapy is becoming the standard of care for an increasing number of tumor types. Currently, colon cancer patients are still routinely treated with up-front surgery, and neoadjuvant systemic therapy is not yet standard. Limitations to widespread use of neoadjuvant therapy have included inaccurate radiological staging, concerns about tumor progression while undergoing preoperative treatment rendering a patient incurable, and a lack of randomized data demonstrating benefit. However, there is great interest in neoadjuvant chemotherapy, and a number of trials are under way. Early follow up of the first phase III trial of neoadjuvant chemotherapy for colon cancer demonstrated tumor downstaging and suggested an improvement in disease-free survival with neoadjuvant chemotherapy, and it is hoped that this will translate into longer-term overall survival benefit. Clinicians should closely watch this developing field, consider the option of neoadjuvant chemotherapy for colon cancer patients, and actively seek out opportunities for their patients to participate in ongoing clinical trials to further inform this field in future.

Local Staging of Colon Cancer: A Cross-Sectional Analysis for Diagnostic Performance of Magnetic Resonance Imaging and by Experience

Preoperative magnetic resonance imaging was analyzed by four radiologists regarding local tumor staging (T and N) and the presence of extramural vascular involvement. An astonishingly high sensitivity for the detection of T 3/4 tumors (κ (quadratic weighted statistics constant) = 0.67), with considerably lower sensitivity for T 3 cd/4 tumors (κ = 0.51), high sensitivity for serosal involvement 76-87% (κ = 0.65) and extramural vascular involvement (87-98%, κ = 0.56). Sensitivity and specificity for lymph node involvement is lower (κ = 0.57). Magnetic resonance imaging with adequate experience can accurately detect tumors with invasion through the bowel wall and their prognostic factors.

Impact of visceral adipose tissue on the accuracy of T-staging by CT in colon cancer

OBJECTIVE

Accuracy of preoperative T-staging for colon cancer remains disappointing and may potentially influenced by patients' individual characteristics including visceral adipose tissue (VAT). We sought to clarify the impact of VAT on the accuracy of T-staging by CT.

METHODS

This study of 216 consecutive patients who underwent elective surgery was conducted in a single cancer center, to control other potentially confounding factors. Patients were divided into accurate- and mis-staging groups according to the comparison between preoperative CT-defined (cT) and postoperative pathologic T-stages (pT). Patients' individual characteristics, including CT-based VAT at L2/L3 level, age, sex, body mass index (BMI), tumor location, present of bowel obstruction and pathologic subtype, were compared between the two groups. Association between VAT and mis-staging was assessed using multivariate logistic regression to adjust for confounders.

RESULTS

Of the 216 patients, 84 (39%) were mis-staged by CT. The mean VAT in accurate-staging group was significantly higher than that in mis-staging group (146.8 ± 66.1 cm² vs 98.1 ± 44.7 cm², P < 0.001), with an optimal cutoff point of 122 cm² for predicting mis-staging. After partial adjustment, a lower VAT (< 122 cm², P < 0.001) and proximal location of tumor (P = 0.004) were independent factors associated with higher probability of mis-staging. Compared to VAT ≥ 122 cm² as the reference, VAT < 122 cm² exhibited an odds ratio of 2.701 (95% confidence intervals [CI], 1.618-3.907) for the probability of mis-staging.

CONCLUSION

A lower-VAT is associated with an increased probability of inaccurate clinical T-staging in colon cancer.

Identification of Novel Transcriptome Signature as a Potential Prognostic Biomarker for Anti-Angiogenic Therapy in Glioblastoma Multiforme

Simple Summary

Neoadjuvant chemotherapy is commonly used in several solid tumor malignancies, but remains understudied in the setting of locally advanced colon cancer. Advantages of this strategy extrapolated from other disease sites include early treatment of micro-metastatic disease, the ability to decrease local disease burden potentially leading to more effective resections and improved treatment tolerability. Approaches for accurate staging and safe administration of systemic treatment are being investigated in large, randomized clinical trials, but available data are either not mature enough or have not demonstrated a convincing argument for adoption into standard practice warranting further investigation.

Abstract

Early stage colon cancer is typically managed with surgical resection, although not all patients experience a durable remission. Adjuvant chemotherapy with a fluoropyrimidine, with or without oxaliplatin, is commonly utilized to increase the chance of cure, but its efficacy in the neoadjuvant setting is not well established. Preoperative chemotherapy has demonstrated safety and efficacy in other gastrointestinal malignancies, but there is a paucity of data from large, prospective randomized trials, although multiple are ongoing. In this review, we will discuss the theoretical risks and benefits, logistical difficulties, and available safety and efficacy data pertaining to the use of chemotherapy in locally advanced colon cancer.

MR image-based radiomics to differentiate type Ι and type ΙΙ epithelial ovarian cancers

OBJECTIVES

Epithelial ovarian cancers (EOC) can be divided into type I and type II according to etiology and prognosis. Accurate subtype differentiation can substantially impact patient management. In this study, we aimed to construct an MR image-based radiomics model to differentiate between type I and type II EOC.

METHODS

In this multicenter retrospective study, a total of 294 EOC patients from January 2010 to February 2019 were enrolled. Quantitative MR imaging features were extracted from the following axial sequences: T2WI FS, DWI, ADC, and CE-T1WI. A combined model was constructed based on the combination of these four MR sequences. The diagnostic performance was evaluated by ROC-AUC. In addition, an occlusion test was carried out to identify the most critical region for EOC differentiation.

RESULTS

The combined radiomics model exhibited superior diagnostic capability over all four single-parametric radiomics models, both in internal and external validation cohorts (AUC of 0.806 and 0.847, respectively). The occlusion test revealed that the most critical region for differential diagnosis was the border zone between the solid and cystic components, or the less compact areas of solid component on direct visual inspection.

CONCLUSIONS

MR image-based radiomics modeling can differentiate between type I and type II EOC and identify the most critical region for differential diagnosis.

KEY POINTS

• Combined radiomics models exhibited superior diagnostic capability over all four single-parametric radiomics models, both in internal and external validation cohorts (AUC of 0.834 and 0.847, respectively). • The occlusion test revealed that the most crucial region for differentiating type Ι and type ΙΙ EOC was the border zone between the solid and cystic components, or the less compact areas of solid component on direct visual inspection on T2WI FS. • The light-combined model (constructed by T2WI FS, DWI, and ADC sequences) can be used for patients who are not suitable for contrast agent use.

The impact of mismatch repair status to the preoperative staging of colon cancer: implications for clinical management

Aims: We sought to investigate if mismatch repair (MMR) status influences the preoperative staging of local colon cancer. Methods: Data from 590 patients in the Danish Colorectal Cancer Group national clinical database who were operated on for stage I-III colon cancer in 2010-15 were included. MMR status was determined by immunohistochemistry. Results: 22.9% had deficient(d) MMR tumors. Correlation of the clinical and pathological T-category was significant for both groups. The correlation of pre- and postoperative N-category was inferior (p >0.05) in dMMR cancers compared to a significant (p <0.01) correlation in proficient MMR cancers. 64.8% of dMMR tumors assessed node-positive demonstrated no sign of metastatic involvement at the postoperative assessment. Conclusion: MMR status seems to impact the accuracy of preoperative lymph node staging.

Diffusion-Weighted Imaging in Oncology: An Update

To date, diffusion weighted imaging (DWI) is included in routine magnetic resonance imaging (MRI) protocols for several cancers. The real additive role of DWI lies in the "functional" information obtained by probing the free diffusivity of water molecules into intra and inter-cellular spaces that in tumors mainly depend on cellularity. Although DWI has not gained much space in some oncologic scenarios, this non-invasive tool is routinely used in clinical practice and still remains a hot research topic: it has been tested in almost all cancers to differentiate malignant from benign lesions, to distinguish different malignant histotypes or tumor grades, to predict and/or assess treatment responses, and to identify residual or recurrent tumors in follow-up examinations. In this review, we provide an up-to-date overview on the application of DWI in oncology.

Contrast-enhanced CT imaging for the assessment of lymph node status in patients with colorectal cancer

The aim of the present study was to identify a novel strategy that predicts the metastatic status of lymph nodes (LNs) in patients diagnosed with colorectal cancer, using detailed characteristics of contrast-enhanced CT scan images. A total of 284 preoperative CT scans derived from patients diagnosed with colorectal cancer at Second Affiliated Hospital, Zhejiang University School of Medicine between January 2013 and July 2018 were retrospectively reviewed. A total of 794 LNs were assessed for size, margins, morphology and subtle internal enhancements in the equilibrium phase. Imaging features were analyzed by two abdominal radiologists (Department of Radiology, Second Affiliated Hospital, Zhejiang University School of Medicine and Departments of Radiology; Shaoxing Second Hospital Departments of Radiology, Shaoxing Second Hospital) in a blind manner. If the conclusions were not concordant, the final score was determined by a senior radiologist who specialized in abdominal radiology for ≥30 years. According to the histopathology results, 27.3% (217/794) of LNs were metastatic (LN+). In addition, LNs >10 mm in size demonstrated sensitivity, specificity, positive predictive values (PPVs) and negative predictive values (NPVs) of 47.0, 80.9, 48.1 and 80.2%, respectively [odds ratio (OR), 3.77; 95% confidence interval (CI), 2.69–5.28]. LNs in the shape of a kidney bean (middle fat depression like kidney) and/or those with an oblong shape were more likely to be metastasis negative LNs (LN-), while lobulated and irregular LNs were more likely to be LN+. In magnified images, internal enhancement characteristics of LN- were defined as homogeneous, spotted, striped and core enhancing. By contrast, rim and heterogeneity enhancement features for LN+ demonstrated sensitivity, specificity, PPVs and NPVs of 46.5, 89.9, 63.5 and 81.7%, respectively (OR, 7.79; 95% CI, 5.33–11.40). The results demonstrated that the internal enhancement features of LNs may be used as a predictor of metastasis. The detailed benign characteristics, such as homogeneity, spotted, striped and core enhancement of LNs may facilitate the identification of LN- in patients with colorectal cancer.

Reporting colon cancer staging using a template

•

Template reporting increases key colon tumour descriptors.

•

Template reporting was used for less than a third of the patients.

•

High risk of underreporting.

Purpose

The purpose of this study was to evaluate the effect of completeness of the radiological reports in primary local staging colon cancer when using a template.

Methods

The study used primary staging reports retrieved from the departments RIS/PACS. Five key tumour descriptors were evaluated within each report: tumour morphology (polypoid or annular), information on tumour breach of the colon wall (≥ T3), tumour out-growth in mm, nodal status and TNM in conclusion. The failure to provide a description of the presence or absence of a feature in a report counted as ‘not reported’. To allow comparisons between reporting styles, the template or free-text style of reporting was also recorded.

Results

During a two year period, a total of 666 patients CT reports were evaluated at the colorectal center multidisciplinary team (MDT) conference. In 200 of these reports a template was used. Information on tumour morphology (polypoid or annular) was present in 81% of the template reports vs 9% in free-text style. The figures in percentage for information on tumour breach of the colon wall (≥ T3) were 93% vs 48 %, tumour out-growth in mm: 51% vs 17%, nodal status: 99% vs 86% and TNM in conclusion: 98% vs 51%. P < 0.0001.

Conclusion

The present study provides additional support for the routine use of template reports to improve imaging reporting standards in colonic cancer.

Tumor and nodal staging of colon cancer: accuracy of preoperative computed tomography at a Swedish high-volume center

Background

When deciding treatment options for patients with colon cancer, accurate staging is required. In Sweden, the main preoperative evaluation modality to determine tumor and nodal stage is computed tomography (CT).

Purpose

The aim of this study was to investigate how well the preoperative (CT-determined) clinical tumor and nodal stage (cTN) correlated with the postoperative histopathological stage (pTN). Another aim was to validate the tumor and nodal stage data in the Swedish Colorectal Cancer Registry (SCRCR).

Material and Methods

The SCRCR was used to identify patients with colon cancer, treated at a Swedish high-volume center during 2013-2016 (n = 974). Data were gathered from medical records regarding cTN and pTN stage, and predefined patient and tumor variables. The agreement between cTN and pTN was analyzed using kappa statistics.

Results

After excluding patients with either pre- or postoperative TN stage missing, 383 patients remained for further analyses. The analyses showed an agreement between cT and pT of κ: 0.27 and between cN and pN of κ: 0.21 (fair agreement). When comparing tumors with low (T1-3; N0) versus high risk (T4; N1-2), the kappa value was 0.19 (slight agreement). When comparing the SCRCR to medical records, 78% of completely staged tumors had been correctly reported.

Conclusion

The agreement between cTN and pTN was low in this study population, indicating a need for enhanced precision of the preoperative staging process. A high frequency of erroneous preoperative staging data in the SCRCR shows the need for further efforts of ensuring correct data transfers into the registry.

Performance comparison between MRI and CT for local staging of sigmoid and descending colon cancer

PURPOSE

To compare the diagnostic performance of MRI and CT for local staging of sigmoid and descending colon cancer, with pathological results as the reference standard.

METHOD

This retrospective study included 116 patients with sigmoid or descending colon cancer who underwent both MRI and CT before surgery. MRI and CT images were separately reviewed by two independent and blinded radiologists to assess the following features: T-stage, presence of extramural extension (T3-4 disease), lymph node metastases (N+), and extramural vascular invasion (EMVI+). Diagnostic performance with sensitivity and specificity for detecting positive status (T3-4, N+ or EMVI+) were assessed using receiver-operating-characteristic (ROC) curve, and compared between MRI and CT.

RESULTS

MRI achieved correct T-stage in 81 of 116 patients (69.8 %) while CT in 66 (56.9 %). For detecting T3-4 disease, MRI showed better performance than CT with area under the curve (AUC) of 0.888 versus 0.712 (P =  0.002) and specificity of 81.82 % versus 54.6 % (P =  0.011). No significance was found in sensitivity between two modalities (89.2 % versus 83.1 %, P =  0.302). For detecting N+ disease, performance of MRI and CT were similar (AUC, 0.670 versus 0.650, P =  0.412). For detecting EMVI+, MRI showed better performance than CT (AUC, 0.780 versus 0.575, P =  0.012) with significantly higher sensitivity (68.6 % versus 40.0 %, P =  0.031) and similar specificity (both are 84.3 %).

CONCLUSIONS

MRI may offer more superior diagnostic performance than CT for detecting T3-4 disease and EMVI, thereby supporting its alternative application to CT in local staging of colon cancer.