Clinical lymph node staging in colorectal cancer; a flip of the coin?

Identifying baseline rectal MRI features as predictive indicators for local recurrence and metastatic disease in rectal cancer treated with surgical resection and neoadjuvant therapy or surgical resection alone

BACKGROUND

To identify baseline rectal MRI characteristics that may serve as predictive factors for recurrence in patients with rectal adenocarcinoma after surgical resection.

METHODS

This retrospective, single-center study included 269 consecutive patients (median age, 55 years [interquartile range, 47-65]; 144 men and 125 women) diagnosed with rectal cancer from January 2015-December 2017 who underwent baseline rectal MRI followed by surgical resection. MRI characteristics were collected from rectal MRI synoptic reports. Recurrence-free survival was defined as the time between surgical resection and recurrence (local recurrence and/or metastatic disease) or death. Statistical analysis included Cox proportional hazards to determine associations between baseline rectal MRI/clinical characteristics and recurrence.

RESULTS

The median recurrence-free survival in the study sample was 6.4 years. Baseline rectal MRI characteristics associated with recurrence at univariable analysis were: age > 55 years (P = 0.044), low rectal tumor location (P = 0.04), craniocaudal length ≥ 5.0 cm (P = 0.007), anal canal involvement (P = 0.011), presence of suspicious total mesorectal excision (TME) lymph nodes > 0.5 cm (P = 0.03), mesorectal fascia involvement (P = 0.04), T3 stage (P = 0.024), T4 stage (P = 0.008), and M1 stage (P = 0.024). At multivariable analysis, only age > 55 years (P = 0.012) and the presence of suspicious TME lymph nodes > 0.5 cm (P = 0.049) remained associated with recurrence.

CONCLUSION

Advanced age and the presence of suspicious TME adenopathy > 0.5 cm on baseline rectal MRI are associated with higher risk of recurrent disease in patients with resected rectal cancer.

Optimal lymph node yield for long-term survival in elderly patients with right-sided colon cancer: a large population-based cohort study

BACKGROUND

Although the recommended minimal lymph node yield (LNY) in colon cancer is 12, this standard remains controversial in elderly patients with right-sided colon cancer (RSCC) due to insufficient evidence. This study aims to clarify this issue by assessing the relationship between LNY and long-term survival in elderly patients with RSCC.

METHODS

Data from the SEER database (split into 7:3 training and testing sets) and patients from the colorectal surgery departments of two tertiary hospitals in China (validation set) were analyzed. Elderly patients with stages I-III RSCC undergoing resection were included. The correlation between LNY and overall survival (OS) was evaluated by a multivariate model and the application of the restricted cubic spline curve (RCS). The odds ratios (ORs) for stage migration and the hazard ratios (HRs) for OS with increased LNY were estimated using Locally Weighted Scatterplot Smoothing (LOWESS), with structural breakpoints identified using the Chow test.

RESULTS

The distribution of LNY was similar across the training (median: 18, IQR [14, 23]), testing (median: 18, IQR [14, 23]), and validation (median: 17, IQR [14, 20]) sets. Increasing LNY was associated with significantly improved OS in all datasets (Training set: HR = 0.983; Testing set: HR = 0.981; Validation set: HR = 0.944, all P < 0.001) after adjusting for confounders. Cut-point analysis identified an optimal LNY threshold of 18, validated across datasets, effectively discriminating survival probabilities.

CONCLUSIONS

A higher LNY is associated with improved survival. Our findings robustly support 18 LNYs as the optimal threshold for assessing the quality of lymph node dissection and prognosis stratification in elderly patients with RSCC.

Risk of recurrence following transanal endoscopic microsurgery without neoadjuvant or adjuvant treatment in T2 rectal cancer

BACKGROUND

Transanal endoscopic microsurgery (TEM) is only curative treatment for T1 rectal cancer with low-risk features. In T2 cancer, TEM is not recommended but could be used as a palliative procedure and/or in patients unfit for surgery. Few studies exist investigating recurrence after TEM for T2 rectal cancer.

METHOD

Retrospective, population-based study using the Swedish Colorectal Cancer Registry. Included patients had T2 rectal adenocarcinoma treated with TEM or surgery without neoadjuvant or adjuvant therapy between 2009 and 2021. Patients lost to follow-up, with syn/metachronous tumours or unknown recurrence status were excluded. Patient characteristics, perioperative morbidity, local and distant recurrence were compared.

RESULTS

63 patients treated with TEM and 894 with surgery. Median age was 81 and 70 (p < 0.01). 59 % and 23 % respectively were ASA III-IV (p < 0.01). TEM tumours were more distal, 37 % vs 16 % in the lower third of the rectum (p < 0.01). There were no severe complications after TEM compared to 6 % following surgery (p = 0.04). 5-year local recurrence was 33 % after TEM and 2 % after surgery (HR = 25.58, (p < 0.01). 5-year distant recurrence rate was 9 % after TEM and 7 % after surgery (HR = 0.49, (p = 0.27). Mean time to local recurrence was 16 months after TEM, 34 months after surgery, time to distant recurrence 22 months after both.

CONCLUSION

TEM for T2 rectal cancer has high risk of local recurrence and cannot be recommended when intent is curative. TEM could be an option for patients unfit for surgery.

Neoadjuvant chemotherapy in locally advanced colon cancer: A systematic review with proportional meta-analysis

Neoadjuvant chemotherapy is suggested in locally advanced colon cancer. Data on improved long-term oncological outcomes are lacking, which hampers the implementation in clinical practice. This systematic review provides an overview of the benefits and drawbacks of neoadjuvant chemotherapy in patients with locally advanced colon cancer. A systematic literature search was performed using Embase (OVID), MEDLINE (OvidSP), and the Cochrane Library. Studies reporting on the efficacy of neoadjuvant chemotherapy in patients with operable, locally advanced colon cancer without metastases at the time of diagnosis were considered eligible for inclusion. An overview of short- and long-term outcomes of neoadjuvant chemotherapy is provided based on available literature. Additionally, proportional meta-analyses were performed using MedCalc Statistical Software version 19.2.6. A total of 17 unique studies were included in this review, 3 randomised controlled trials and 14 prospective single-arm or retrospective studies. The maximum reported dropout before surgery was 7.8 % in the neoadjuvant chemotherapy group. A histopathological complete response after neoadjuvant chemotherapy was observed in 0-4.8 % of the patients. The occurrence of anastomotic leaks was less than 8 % for both patients treated with neoadjuvant chemotherapy and patients treated with upfront surgery. Neoadjuvant chemotherapy is a safe alternative for adjuvant chemotherapy based on the dropout rate before surgery and the peri-operative morbidity and peri-operative mortality. Robust long-term survival outcomes are lacking and serious concerns regarding the risk of overtreatment have been expressed. Hence, neoadjuvant chemotherapy might be considered in a select group of patients with locally advanced colon cancer.

Selection of rectal cancer patients for organ preservation after neoadjuvant therapy: value of T2W-MRI signal intensity

BackgroundOrgan preservation strategies have been widely implemented for rectal cancer (RC) patients with a good response after neoadjuvant chemoradiation (nCRT). However, to accurately select eligible patients remains one of the key diagnostic challenges.PurposeTo identify eligible candidates for organ preservation after nCRT in RC, by identifying luminal response and lymph node metastases, based on T2W-MRI signal intensities.Material and MethodsA total of 171 RC patients underwent MRI before and after nCRT. The primary tumor (pre-nCRT-MRI) and tumor remnant (post-nCRT-MRI) were manually delineated. Ten signal intensity features were extracted and delta features were calculated by subtraction. Histopathological evaluation classified patients as lymph node negative (ypN0) or positive (ypN+), and as good responders (GR) or partial/poor responders (PR). Five models were constructed based on the timing of imaging.Results42/170 (25%) patients had ypN+, and 72/152 (47%) patients were considered GR. Univariate analysis showed 13/40 signal intensity features were significantly different between luminal response groups and 4/40 between nodal response groups. In multivariate analysis, the Baseline + Restaging-model yielded the best results for both luminal and nodal response with AUCs in the test set of 0.81 (95% CI=0.67-0.95) and 0.74 (95% CI=0.59-0.90), respectively. To identify PR, the Delta-model yielded an AUC of 0.72 (95% CI=0.56-0.89) and the Delta + Restaging-model an AUC of 0.81 (95% CI=0.67-0.95), both were not able to differentiate nodal response. The models including solely baseline or restaging features were not predictive.ConclusionT2W-MRI signal intensities of the primary rectal tumor are related to the luminal and nodal response after nCRT and hold promise to identify patients eligible for organ preservation.

Evaluation of MRI characterisation of histopathologically matched lymph nodes and other mesorectal nodal structures in rectal cancer

PURPOSE

To evaluate current MRI-based criteria for malignancy in mesorectal nodal structures in rectal cancer.

METHOD

Mesorectal nodal structures identified on baseline MRI as lymph nodes were anatomically compared to their corresponding structures histopathologically, reported as lymph nodes, tumour deposits or extramural venous invasion. All anatomically matched nodal structures from patients with primary surgery and all malignant nodal structures from patients with neoadjuvant treatment were included. Mixed-effects logistic regression models were used to evaluate the morphological criteria irregular margin, round shape, heterogeneous signal and nodal size, as well as the combined 2016 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus criteria, with histopathological nodal status as the gold standard.

RESULTS

In total, 458 matched nodal structures were included from 46 patients (mean age, 67.7 years ± 1.5 [SD], 27 men), of which 19 received neoadjuvant treatment. The strongest associations in the univariable model were found for short-axis diameter ≥ 5 mm (OR 21.43; 95% CI: 4.13-111.29, p < 0.001) and heterogeneous signal (OR 9.02; 95% CI: 1.33-61.08, p = 0.024). Only size remained significant in multivariable analysis (OR 12.32; 95% CI: 2.03-74.57, p = 0.006). When applying the ESGAR consensus criteria to create a binary classification of nodal status, the OR of malignant outcome for nodes with positive ESGAR was 8.23 (95% CI: 2.15-31.50, p = 0.002), with corresponding sensitivity and specificity of 54% and 85%, respectively.

CONCLUSION

The results confirm the role of morphological and size criteria in predicting lymph node metastases. However, the current criteria might not be accurate enough for nodal staging.

KEY POINTS

Question Pretreatment lymph node staging in rectal cancer is challenging, and the ESGAR consensus criteria are not fully validated. Findings Although the ESGAR criteria correlated with malignant outcomes, diagnostic performance in terms of particular sensitivity, but also specificity, was not high. Clinical relevance Accurate nodal staging in rectal cancer is crucial for individual treatment planning. However, this validation of the current ESGAR consensus criteria suggests that these should be used with caution.

Diagnostic accuracy and treatment benefit of PET/CT in staging of colorectal cancer compared to conventional imaging

BACKGROUND

Until recently the use of positron emission tomography (PET) CT for staging in colorectal cancer (CRC) has been limited to the detection of distant metastasis in advanced disease. But with the introduction of neoadjuvant treatments in CRC, accurate pre-treatment staging has become more relevant.

AIMS

The aim of the study was to assess the staging accuracy for nodal and distant metastasis of PET/CT compared to computed tomography (CT) alone in CRC. Secondary endpoints were overall survival (OS) and cost of CT compared to PET/CT.

METHODS

A retrospective analysis of 539 cases with CRC staged with PET/CT and or CT between 2015 and 2021 in a Swiss tertiary referral center was performed. In 471 patients for nodal staging and 479 for staging of distant metastasis the clinical stage of both modalities was compared with pathological stage.

RESULTS

The distribution of UICC stages (n = 479) was as follows: Stage I 62 cases (12.9 %), Stage II 127 cases (26.5 %), Stage III 199 cases (41.5 %), Stage IV 91 cases (19.0 %). CT alone compared to PET was able to predict nodal involvement with a sensitivity of 55.2 % (95%CI 5.7-59.7 %) and 66.7 % (95%CI 62.4-70.9 %), respectively. The specificity was 67.0 % (95%CI 62.8-71.3 %) for CT and 63.6 % (95%CI 59.3-68.0 %) for PET. The positive predictive value was 49.5 % for CT vs. 51.8 % for PET. The sensitivity of metastasis detection was 53.6 % (95%CI 49.1-58.1 %) for CT and 82.5 % (95%CI 79.1-85.9 %) for PET.

CONCLUSIONS

PET/CT showed higher sensitivity in the detection of lymph node involvement and metastases in CRC patients compared to CT alone.

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.

Management of Locally Advanced Rectal Cancer: ASCO Guideline

ASCO Guidelines provide recommendations with comprehensive review and analyses of the relevant literature for each recommendation, following the guideline development process as outlined in the ASCO Guidelines Methodology Manual. ASCO Guidelines follow the ASCO Conflict of Interest Policy for Clinical Practice Guidelines.Clinical Practice Guidelines and other guidance ("Guidance") provided by ASCO is not a comprehensive or definitive guide to treatment options. It is intended for voluntary use by providers and should be used in conjunction with independent professional judgment. Guidance may not be applicable to all patients, interventions, diseases or stages of diseases. Guidance is based on review and analysis of relevant literature, and is not intended as a statement of the standard of care. ASCO does not endorse third-party drugs, devices, services, or therapies and assumes no responsibility for any harm arising from or related to the use of this information. See complete disclaimer in Appendix 1 and 2 (online only) for more.PURPOSETo provide evidence-based guidance for clinicians who treat patients with locally advanced rectal cancer.METHODSA systematic review of the literature published from 2013 to 2023 was conducted to identify relevant systematic reviews, phase II and III randomized controlled trials (RCTs), and observational studies where applicable.RESULTSTwelve RCTs, two systematic reviews, and one nonrandomized study met the inclusion criteria for this systematic review. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.RECOMMENDATIONSFollowing assessment with magnetic resonance imaging, for patients with microsatellite stable or proficient mismatch repair locally advanced rectal cancer, total neoadjuvant therapy (TNT; ie chemoradiation [CRT] and chemotherapy) should be offered as initial treatment for patients with tumors located in the lower rectum and/or patients who are at higher risk for local and/or distant metastases. Patients without higher-risk factors may discuss chemotherapy with selective CRT depending on extent of response, TNT, or neoadjuvant long-course CRT or short-course radiation. For patients who are candidates for TNT, the preferred timing for chemotherapy is after radiation, and neoadjuvant long-course CRT is preferred over short-course radiation therapy (RT), however short-course RT may also be a viable treatment option depending on circumstances. Nonoperative management may be discussed as an alternative to total mesorectal excision for patients who have a clinical complete response to neoadjuvant therapy. For patients whose tumors are microsatellite instability-high or mismatch repair deficient, immunotherapy is recommended.Additional information is available at http://www.asco.org/gastrointestinal-cancer-guidelines.

Plasma Methylated SEPT9 as a Novel Biomarker for Predicting Liver Metastasis in Colorectal Cancer

This study aimed to explore the role of plasma methylated SEPT9 (mSEPT9) in predicting liver metastasis (LM) in colorectal cancer (CRC) patients. The clinicopathological information of 115 consecutive CRC patients were collected. The differences of clinical characteristics and several biomarkers between CRC patients with LM and those with non-liver metastasis (NM) were analyzed. Multivariate logistic regression analysis was used to identify the risk factors for predicting LM in CRC patients. Receiver operating characteristic curve (ROC) analysis was applied to investigate the sensitivity and specificity of potential biomarkers in indicating the presence of LM in CRC. Compared with the CRC without LM, the levels of plasma mSEPT9 and carcinoembryonic antigen (CEA) were significantly increased in CRC with LM. Multivariate logistic regression analysis showed that plasma mSEPT9 was an independent risk factor for predicting LM in CRC. ROC curves showed that mSEPT9 and CEA could efficiently distinguish LM from NM in CRC. The area under the curve (AUC) of mSEPT9 was 0.850, which was slightly higher than that of CEA (0.842). The optimal cut-off value of mSEPT9 was 35.09 with a sensitivity of 81.82% and a specificity of 73.33%, both similar with that of CEA (sensitivity 87.27% and specificity 75.00%). In addition, the combination of mSEPT9 and CEA had a higher specificity than CEA alone (81.70% Vs 75.00%). Our findings suggest, for the first time, that plasma mSEPT9 might serve as a potential biomarker to predict LM in CRC, which deserves further in-depth study.

Feasibility of indocyanine green (ICG) fluorescence in ex vivo pathological dissection of colorectal lymph nodes-a pilot study

Accurate lymph node (LN) retrieval during colorectal carcinoma resection is pivotal for precise N-staging and the determination of adjuvant therapy. Current guidelines recommend the examination of at least 12 mesocolic or mesorectal lymph nodes for accurate staging. Traditional histological processing techniques, reliant on visual inspection and palpation, are time-consuming and heavily dependent on the examiner's expertise and availability. Various methods have been documented to enhance LN retrieval from colorectal specimens, including intra-arterial ex vivo methylene blue injection. Recent studies have explored the utility of indocyanine green (ICG) fluorescence imaging for visualizing pericolic lymph nodes and identifying sentinel lymph nodes in colorectal malignancies. This study included 10 patients who underwent colon resection for malignant tumors. During surgery, intravenous ICG dye and an endoscopic camera were employed to assess intestinal perfusion. Post-resection, ex vivo intra-arterial administration of ICG dye was performed on the specimens, followed by routine histological processing and an ICG-assisted lymph node dissection. The objective was to evaluate whether ICG imaging could identify additional lymph nodes compared to routine manual dissection and to assess the clinical relevance of these findings. For each patient, a minimum of 12 lymph nodes (median = 25.5, interquartile range = 12.25, maximum = 33) were examined. ICG imaging facilitated the detection of a median of three additional lymph nodes not identified during routine processing. Metastatic lymph nodes were found in four patients however no additional metastatic nodes were detected with ICG assistance. Our findings suggest that ex vivo intra-arterial administration of indocyanine green dye can augment lymph node dissection, particularly in cases where the number of lymph nodes retrieved is below the recommended threshold of 12.

A Concept for Preoperative and Intraoperative Molecular Imaging and Detection for Assessing Extent of Disease of Solid Tumors

The authors propose a concept of "systems engineering," the approach to assessing the extent of diseased tissue (EODT) in solid tumors. We modeled the proof of this concept based on our clinical experience with colorectal carcinoma (CRC) and gastrinoma that included short and long-term survival data of CRC patients. This concept, applicable to various solid tumors, combines resources from surgery, nuclear medicine, radiology, pathology, and oncology needed for preoperative and intraoperative assessments of a patient's EODT. The concept begins with a patient presenting with biopsy-proven cancer. An appropriate preferential locator (PL) is a molecule that preferentially binds to a cancer-related molecular target (i.e., tumor marker) lacking in non-malignant tissue and is the essential element. Detecting the PL after an intravenous injection requires the PL labeling with an appropriate tracer radionuclide, a fluoroprobe, or both. Preoperative imaging of the tracer's signal requires molecular imaging modalities alone or in combination with computerized tomography (CT). These include positron emission tomography (PET), PET/CT, single-photon emission computed tomography (SPECT), SPECT/CT for preoperative imaging, gamma cameras for intraoperative imaging, and gamma-detecting probes for precise localization. Similarly, fluorescent-labeled PLs require appropriate cameras and probes. This approach provides the surgeon with real-time information needed for R0 resection.

Trends in incidence, treatment, and relative survival of colorectal cancer in the Netherlands between 2000 and 2021

BACKGROUND

The epidemiology of colorectal cancer (CRC) has changed rapidly over the years. The aim of this study was to assess the trends in incidence, treatment, and relative survival (RS) of patients diagnosed with CRC in the Netherlands between 2000 and 2021.

PATIENTS AND METHODS

2 75667 patients diagnosed with CRC between 2000 and 2021 were included from the Netherlands Cancer Registry. Analyses were stratified for disease extent (localised: T1-3N0M0; regional: T4N0M0/T1-4N1-2M0; distant: T1-4N0-2M1) and localisation (colon; rectum). Trends were assessed with joinpoint regression.

RESULTS

CRC incidence increased until the mid-2010s but decreased strongly thereafter to rates comparable with the early 2000s. Amongst other trend changes, local excision rates increased for patients with localised colon (2021: 13.6 %) and rectal cancer (2021: 34.9 %). Moreover, primary tumour resection became less common in patients with distant colon (2000-2021: 60.9-12.5 %) or rectal cancer (2000-2021: 47.8-6.9 %), while local treatment of metastases rates increased. Five-year RS improved continuously for localised and regional colon (97.7 % and 72.0 % in 2017, respectively) and rectal cancer (95.2 % and 76.3 % in 2017, respectively). The rate of anti-cancer treatments decreased in distant colon (2010-2021: 80.3 % to 67.2 %; p < 0.001) and rectal cancer (2011-2021: 86.0 % to 77.0 %; p < 0.001). The improvement of five-year RS stagnated for distant colon (2010-2017: 11.2 % to 11.9 %; average percentage of change [APC]: 2.1, 95 % confidence interval [CI]: -7.6, 4.7) and rectal cancer (2009-2017: 12.7 % to 15.6 %; APC: 1.4, 95 % CI: -19.1, 5.5).

CONCLUSIONS

Major changes in the incidence and treatment of CRC between 2000 and 2021 were identified and quantified. Five-year RS increased continuously for patients with localised and regional CRC, but stagnated for patients with distant CRC, likely caused by decreased rates of anti-cancer treatment in this group.

Evolution of clinical nature, treatment and survival of locally recurrent rectal cancer: Comparative analysis of two national cross-sectional cohorts

BACKGROUND

In the Netherlands, use of neoadjuvant radiotherapy for rectal cancer declined after guideline revision in 2014. This decline is thought to affect the clinical nature and treatability of locally recurrent rectal cancer (LRRC). Therefore, this study compared two national cross-sectional cohorts before and after the guideline revision with the aim to determine the changes in treatment and survival of LRRC patients over time.

METHODS

Patients who underwent resection of primary rectal cancer in 2011 (n = 2094) and 2016 (n = 2855) from two nationwide cohorts with a 4-year follow up were included. Main outcomes included time to LRRC, synchronous metastases at time of LRRC diagnosis, intention of treatment and 2-year overall survival after LRRC.

RESULTS

Use of neoadjuvant (chemo)radiotherapy for the primary tumour decreased from 88.5% to 60.0% from 2011 to 2016. The 3-year LRRC rate was not significantly different with 5.1% in 2011 (n = 114, median time to LRRC 16 months) and 6.3% in 2016 (n = 202, median time to LRRC 16 months). Synchronous metastasis rate did not significantly differ (27.2% vs 33.7%, p = 0.257). Treatment intent of the LRRC shifted towards more curative treatment (30.4% vs. 47.0%, p = 0.009). In the curatively treated group, two-year overall survival after LRRC diagnoses increased from 47.5% to 78.7% (p = 0.013).

CONCLUSION

Primary rectal cancer patients in 2016 were treated less often with neoadjuvant (chemo)radiotherapy, while LRRC rates remained similar. Those who developed LRRC were more often candidate for curative intent treatment compared to the 2011 cohort, and survival after curative intent treatment also improved substantially.

Lymph node regression after neoadjuvant chemoradiotherapy in rectal cancer

AIMS

Lymph node metastases (LNM) are one of the most important prognostic indicators in solid tumours and a major component of cancer staging. Neoadjuvant therapy might influence nodal status by induction of regression. Our aim is to determine the prevalence and role of regression of LNM on outcomes in patients with rectal cancer.

METHODS AND RESULTS

Four independent study populations of rectal cancer patients treated with similar regimens of chemoradiotherapy were pooled together to obtain a total cohort of 469 patients. Post-treatment nodal status (ypN) and signs of tumour regression (Reg) were incorporated to form three-tiered (ypN- Reg+, ypN- Reg- and ypN+) and four-tiered (ypN- Reg+, ypN- Reg-, ypN+ Reg+ and ypN+ Reg-) classifications. In our cohort, 31% of patients presented with ypN+ rectal cancer. As expected, we found significantly worse overall survival (OS) in ypN+ patients compared to ypN- patients (P = 0.002). The percentage of ypN- patients with lymph nodes with complete regression was 20% in our cohort. While node-negative patients with and without regression had similar OS (P = 0.09), disease-free survival (DFS) was significantly better in node-negative patients with regression (P = 0.009).

CONCLUSIONS

Regression in lymph nodes is frequent, and node-negative patients with evidence of lymph node regression have better DFS compared to node-negative patients without such evidence.

Application of Texture and Volume Model Analysis to Dedicated Axillary High-resolution 3D T2-weighted MR Imaging: A Novel Method for Diagnosing Lymph Node Metastasis in Patients with Clinically Node-negative Breast Cancer

PURPOSE

To evaluate the effectiveness of the texture analysis of axillary high-resolution 3D T2-weighted imaging (T2WI) in distinguishing positive and negative lymph node (LN) metastasis in patients with clinically node-negative breast cancer.

METHODS

Between December 2017 and May 2021, 242 consecutive patients underwent high-resolution 3D T2WI and were classified into the training (n = 160) and validation cohorts (n = 82). We performed manual 3D segmentation of all visible LNs in axillary level I to extract the texture features. As the additional parameters, the number of the LNs and the total volume of all LNs for each case were calculated. The least absolute shrinkage and selection operator algorithm and Random Forest were used to construct the models. We constructed the texture model using the features from the LN with the largest least axis length in the training cohort. Furthermore, we constructed the 3 models combining the selected texture features of the LN with the largest least axis length, the number of LNs, and the total volume of all LNs: texture-number model, texture-volume model, and texture-number-volume model. As a conventional method, we manually measured the largest cortical diameter. Moreover, we performed the receiver operating curve analysis in the validation cohort and compared area under the curves (AUCs) of the models.

RESULTS

The AUCs of the texture model, texture-number model, texture-volume model, texture-number-volume model, and conventional method in the validation cohort were 0.7677, 0.7403, 0.8129, 0.7448, and 0.6851, respectively. The AUC of the texture-volume model was higher than those of other models and conventional method. The sensitivity, specificity, positive predictive value, and negative predictive value of the texture-volume model were 90%, 69%, 49%, and 96%, respectively.

CONCLUSION

The texture-volume model of high-resolution 3D T2WI effectively distinguished positive and negative LN metastasis for patients with clinically node-negative breast cancer.

Extranodal Extension at Pretreatment MRI and the Prognostic Value for Patients with Rectal Cancer

Background Detection of extranodal extension (ENE) at pathology is a poor prognostic indicator for rectal cancer, but whether ENE can be identified at pretreatment MRI is, to the knowledge of the authors, unknown. Purpose To evaluate the performance of pretreatment MRI in detecting ENE using a matched pathologic reference standard and to assess its prognostic value in patients with rectal cancer. Materials and Methods This single-center study included a prospective development data set consisting of participants with rectal adenocarcinoma who underwent pretreatment MRI and radical surgery (December 2021 to January 2023). MRI characteristics were identified by their association with ENE-positive nodes (χ2 test and multivariable logistic regression) and the performance of these MRI features was assessed (area under the receiver operating characteristic curve [AUC]). Interobserver agreement was assessed by Cohen κ coefficient. The prognostic value of ENE detected with MRI for predicting 3-year disease-free survival was assessed by Cox regression analysis in a retrospective independent validation cohort of patients with locally advanced rectal cancer (December 2019 to July 2020). Results The development data set included 147 participants (mean age, 62 years ± 11 [SD]; 87 male participants). The retrospective cohort included 110 patients (mean age, 60 years ± 9; 79 male participants). Presence of vessel interruption and fusion (both P < .001), heterogeneous internal structure, and the broken-ring and tail signs (odds ratio range, 4.10-23.20; P value range, <.001 to .002) were predictors of ENE at MRI, and together achieved an AUC of 0.91 (95% CI: 0.88, 0.93) in detecting ENE. Interobserver agreement was moderate for the presence of vessel interruption and fusion (κ = 0.46 for both) and substantial for others (κ = 0.61-0.67). The presence of ENE at pretreatment MRI was independently associated with worse 3-year disease-free survival (hazard ratio, 3.00; P = .02). Conclusion ENE can be detected at pretreatment MRI, and its presence was associated with worse prognosis for patients with rectal cancer. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Eberhardt in this issue.

Multicenter Evaluation of a Weakly Supervised Deep Learning Model for Lymph Node Diagnosis in Rectal Cancer at MRI

Purpose To develop a Weakly supervISed model DevelOpment fraMework (WISDOM) model to construct a lymph node (LN) diagnosis model for patients with rectal cancer (RC) that uses preoperative MRI data coupled with postoperative patient-level pathologic information. Materials and Methods In this retrospective study, the WISDOM model was built using MRI (T2-weighted and diffusion-weighted imaging) and patient-level pathologic information (the number of postoperatively confirmed metastatic LNs and resected LNs) based on the data of patients with RC between January 2016 and November 2017. The incremental value of the model in assisting radiologists was investigated. The performances in binary and ternary N staging were evaluated using area under the receiver operating characteristic curve (AUC) and the concordance index (C index), respectively. Results A total of 1014 patients (median age, 62 years; IQR, 54-68 years; 590 male) were analyzed, including the training cohort (n = 589) and internal test cohort (n = 146) from center 1 and two external test cohorts (cohort 1: 117; cohort 2: 162) from centers 2 and 3. The WISDOM model yielded an overall AUC of 0.81 and C index of 0.765, significantly outperforming junior radiologists (AUC = 0.69, P < .001; C index = 0.689, P < .001) and performing comparably with senior radiologists (AUC = 0.79, P = .21; C index = 0.788, P = .22). Moreover, the model significantly improved the performance of junior radiologists (AUC = 0.80, P < .001; C index = 0.798, P < .001) and senior radiologists (AUC = 0.88, P < .001; C index = 0.869, P < .001). Conclusion This study demonstrates the potential of WISDOM as a useful LN diagnosis method using routine rectal MRI data. The improved radiologist performance observed with model assistance highlights the potential clinical utility of WISDOM in practice. Keywords: MR Imaging, Abdomen/GI, Rectum, Computer Applications-Detection/Diagnosis Supplemental material is available for this article. Published under a CC BY 4.0 license.

The diagnostic accuracy of local staging in colon cancer based on computed tomography (CT): evaluating the role of extramural venous invasion and tumour deposits

PURPOSE

The shift from adjuvant to neoadjuvant treatment in colon cancer demands the radiological selection of patients for systemic therapy. The aim of this study was to evaluate the accuracy of the CT-based TNM stage and high-risk features, including extramural venous invasion (EMVI) and tumour deposits, in the identification of patients with histopathological advanced disease, currently considered for neoadjuvant treatment (T3-4 disease).

METHODS

All consecutive patients surgically treated for non-metastatic colon cancer between January 2018 and January 2020 in a referral centre for colorectal cancer were identified retrospectively. All tumours were staged on CT according to the TNM classification system. Additionally, the presence of EMVI and tumour deposits on CT was evaluated. The histopathological TNM classification was used as reference standard.

RESULTS

A total of 176 patients were included. Histopathological T3-4 colon cancer was present in 85.0% of the patients with CT-detected T3-4 disease. Histopathological T3-4 colon cancer was present in 96.4% of the patients with CT-detected T3-4 colon cancer in the presence of both CT-detected EMVI and CT-detected tumour deposits. Histopathological T0-2 colon cancer was present in 50.8% of the patients with CT-detected T0-2 disease, and in 32.4% of the patients without CT-detected EMVI and tumour deposits.

CONCLUSION

The diagnostic accuracy of CT-based staging was comparable with previous studies. The presence of high-risk features on CT increased the probability of histopathological T3-4 colon cancer. However, a substantial part of the patients without CT-detected EMVI and tumour deposits was diagnosed with histopathological T3-4 disease. Hence, more accurate selection criteria are required to correctly identify patients with locally advanced disease.

Abandonment of Routine Radiotherapy for Nonlocally Advanced Rectal Cancer and Oncological Outcomes

Importance

Neoadjuvant short-course radiotherapy was routinely applied for nonlocally advanced rectal cancer (cT1-3N0-1M0 with >1 mm distance to the mesorectal fascia) in the Netherlands following the Dutch total mesorectal excision trial. This policy has shifted toward selective application after guideline revision in 2014.

Objective

To determine the association of decreased use of neoadjuvant radiotherapy with cancer-related outcomes and overall survival at a national level.

Design, Setting, and Participants

This multicenter, population-based, nationwide cross-sectional cohort study analyzed Dutch patients with rectal cancer who were treated in 2011 with a 4-year follow-up. A similar study was performed in 2021, analyzing all patients that were surgically treated in 2016. From these cohorts, all patients with cT1-3N0-1M0 rectal cancer and radiologically unthreatened mesorectal fascia were included in the current study. The data of the 2011 cohort were collected between May and October 2015, and the data of the 2016 cohort were collected between October 2020 and November 2021. The data were analyzed between May and October 2022.

Main Outcomes and Measures

The main outcomes were 4-year local recurrence and overall survival rates.

Results

Among the 2011 and 2016 cohorts, 1199 (mean [SD] age, 68 [11] years; 430 women [36%]) of 2095 patients (57.2%) and 1576 (mean [SD] age, 68 [10] years; 547 women [35%]) of 3057 patients (51.6%) had cT1-3N0-1M0 rectal cancer and were included, with proportions of neoadjuvant radiotherapy of 87% (2011) and 37% (2016). Four-year local recurrence rates were 5.8% and 5.5%, respectively (P = .99). Compared with the 2011 cohort, 4-year overall survival was significantly higher in the 2016 cohort (79.6% vs 86.4%; P < .001), with lower non-cancer-related mortality (13.8% vs 6.3%; P < .001).

Conclusions and Relevance

The results of this cross-sectional study suggest that an absolute 50% reduction in radiotherapy use for nonlocally advanced rectal cancer did not compromise cancer-related outcomes at a national level. Optimizing clinical staging and surgery following the Dutch total mesorectal excision trial has potentially enabled safe deintensification of treatment.

MRI-predicted extramural vascular invasion and tumour deposit are main predictors of disease-free survival in patients undergoing surgical resection for rectal cancer

BACKGROUND

MRI is crucial in staging patients with rectal cancer and planning treatment. The aim was to analyse the prognostic role of MRI-predicted tumour deposits and/or extramural vascular invasion (mrTD/EMVI) in a cohort of patients with rectal cancer undergoing surgical resection, with selective neoadjuvant chemoradiotherapy (nCRT).

METHOD

Retrospective analysis of a single-centre cohort of consecutive patients with rectal cancer undergoing low anterior resection or abdominoperineal excision between 2008 and 2020. Unit policy was selective nCRT for MRI-predicted threatened or involved circumferential resection margin (mrCRM), or radiologically involved pelvic sidewall nodes. The primary outcome was disease-free survival. Secondary outcomes were rates of local recurrence, distant recurrence and overall survival.

RESULTS

A total of 314 patients were analysed. Median age was 65 years (female/male: 114/200). A total of 54/314 (17%) had nCRT and 35 patients (11%) underwent abdominoperineal excision. Median follow-up was 64 months. Overall, local recurrence was detected in 18/314 (5.7%) and distant recurrence in 45/314 (14.3%). In patients not receiving nCRT (n = 260), local recurrence was detected in 11/260 (4.2%) and distant recurrence in 35/260 (13.5%). Disease-free survival was 80.5% at 5 years. Specifically, disease-free survival was 89% in mrTD/EMVI-negative and mrCRM-negative, 67% in mrTD/EMVI-positive and mrCRM-negative, and 64% in the mrCRM-positive rectal cancer (log-rank, P < 0.001). On multivariable Cox-regression analysis mrTD/EMVI was the only MRI variable associated with disease-free survival (hazard ratio 2.95; P < 0.001).

CONCLUSION

mrTD/EMVI is a major prognostic indicator. Rectal cancer patients with mrCRM-negative and mrTD/EMVI-negative have excellent long-term outcomes with surgery alone. Patients with mrTD/EMVI-positive should be selectively stratified for neoadjuvant treatments in future clinical trials.

Combined endoscopic and laparoscopic surgery (CELS) for early colon cancer in high-risk patients

BACKGROUND

Local excision of early colon cancers could be an option in selected patients with high risk of complications and no sign of lymph node metastasis (LNM). The primary aim was to assess feasibility in high-risk patients with early colon cancer treated with Combined Endoscopic and Laparoscopic Surgery (CELS).

METHODS

A non-randomized prospective feasibility study including 25 patients with Performance Status score ≥ 1 and/or American Society of Anesthesiologists score ≥ 3, and clinical Union of International Cancer Control stage-1 colon cancer suitable for CELS resection. The primary outcome was failure of CELS resection, defined as either: Incomplete resection (R1/R2), local recurrence within 3 months, complication related to CELS within 30 days (Clavien-Dindo grade ≥ 3), death within 30 days or death within 90 days due to complications to surgery.

RESULTS

Fifteen patients with clinical T1 (cT1) and ten with clinical T2 (cT2) colon cancer and without suspicion of metastases were included. Failure occurred in two patients due to incomplete resections. Histopathological examination classified seven patients as having pT1, nine as pT2, six as pT3 adenocarcinomas, and three as non-invasive tumors. In three patients, the surgical strategy was changed intraoperatively to conventional colectomy due to tumor location or size. Median length of stay was 1 day. Seven patients had completion colectomy performed due to histological high-risk factors. None had LNM.

CONCLUSIONS

In selected patients, CELS resection was feasible, and could spare some patients large bowel resection.

Prognostic Significance of Enlarged Lymph Nodes in Stage II Colorectal Cancer

BACKGROUND

Many studies have reported a correlation between lymph node metastasis and prognosis in patients with colorectal cancer. However, the clinical significance of enlarged lymph nodes for prognosis has scarcely been explored.

OBJECTIVE

This study aimed to assess the clinical significance of enlarged lymph nodes in stage II colorectal cancer.

DESIGN

This is a multicenter retrospective observational study with a median follow-up period of 66.8 months.

SETTINGS

Patients' medical records were retrospectively collected from the Japanese Study Group for Postoperative Follow-up of Colorectal Cancer database.

PATIENTS

This study included 2212 patients with stage II colorectal cancer who underwent surgical resection between January 2009 and December 2012. Patients were classified into the enlarged lymph node and nonenlarged lymph node groups and their data were compared.

MAIN OUTCOME MEASURES

Clinicopathological characteristics and prognoses of the 2 groups were compared. The main outcomes measured were recurrence-free survival and overall survival.

RESULTS

The enlarged lymph node group showed significantly better overall survival and recurrence-free survival in pT4b cases but not in pT3 or pT4a cases. In pT4b cases, an enlarged lymph node (HR, 0.53; 95% CI, 0.29-0.98) was an independent prognostic factor for longer recurrence-free survival, whereas a rectal lesion (HR, 3.46; 95% CI, 1.90-6.29) was an independent prognostic factor for shorter recurrence-free survival. An enlarged lymph node was associated with a lower distant recurrence rate (HR, 0.49; 95% CI, 0.26-0.92) and a tendency to correlate with better overall survival (HR, 0.50; 95% CI, 0.22-1.14).

LIMITATIONS

The retrospective design may have increased the risk of selection bias. Inadequate information regarding enlarged lymph nodes is another study limitation.

CONCLUSIONS

This study showed that enlarged lymph nodes are associated with a favorable prognosis in patients with pT4b stage II colorectal cancer. See Video Abstract at http://links.lww.com/DCR/C246 .

IMPORTANCIA PRONSTICA DE LOS GANGLIOS LINFTICOS AGRANDADOS EN EL CNCER COLORRECTAL EN ESTADIO II

ANTECEDENTES:Muchos estudios han informado una correlación entre la metástasis en los ganglios linfáticos y el pronóstico en pacientes con cáncer colorrectal. Sin embargo, apenas se ha explorado la importancia clínica de los ganglios linfáticos agrandados para el pronóstico.OBJETIVO:El objetivo fue evaluar la importancia clínica de los ganglios linfáticos agrandados en el cáncer colorrectal en estadio II.DISEÑO:Este es un estudio observacional retrospectivo multicéntrico con una mediana de seguimiento de 66,8 meses.CONFIGURACIÓN:Los registros médicos de los pacientes se recopilaron retrospectivamente de la base de datos del Grupo de estudio japonés para el seguimiento posoperatorio del cáncer colorrectal.PACIENTES:Incluimos 2212 pacientes con cáncer colorrectal en estadio II que se sometieron a resección quirúrgica entre enero de 2009 y diciembre de 2012. Los pacientes se clasificaron en grupos de ganglios linfáticos agrandados y no agrandados y se compararon sus datos.PRINCIPALES MEDIDAS DE RESULTADO:Se compararon las características clinicopatológicas y los pronósticos de los dos grupos. Los principales resultados medidos fueron la supervivencia sin recurrencia y la supervivencia general.RESULTADOS:El grupo de ganglios linfáticos agrandados mostró una supervivencia general significativamente mejor y una supervivencia libre de recurrencia en los casos pT4b, pero no en los casos pT3 ni pT4a. En los casos de pT4b, el agrandamiento de los ganglios linfáticos (CRI, 0,53; IC 95 %, 0,29-0,98) fue un factor pronóstico independiente para una supervivencia sin recidiva más prolongada, mientras que la lesión rectal (CRI, 3,46; IC 95%, 1,90-6,29) fue un factor pronóstico independiente para RFS más cortos. Los ganglios linfáticos agrandados se relacionaron con una tasa más baja de recurrencia a distancia (CRI, 0,49; IC 95%, 0,26-0,92) y una tendencia a correlacionarse con una mejor supervivencia general (CRI, 0,50; IC 95%, 0,22-1,14).LIMITACIONES:El diseño retrospectivo puede haber aumentado el riesgo de sesgo de selección. La información inadecuada sobre el agrandamiento de los ganglios linfáticos es otra limitación del estudio.CONCLUSIONES:Este estudio mostró que los ganglios linfáticos agrandados están asociados con un pronóstico favorable en pacientes con cáncer colorrectal pT4b en estadio II. Consulte Video Resumen en http://links.lww.com/DCR/C246 . ( Traducción - Dr. Mauricio Santamaria ).

Diagnostic accuracy of CT for local staging of colon cancer: A nationwide study in the Netherlands

OBJECTIVE

To determine the accuracy of computed tomography (CT)-based staging in selecting high-risk colon cancer patients who would benefit from neoadjuvant chemotherapy while avoiding overtreatment.

METHODS

Data of adult patients diagnosed with non-metastatic primary colon cancer in 2005-2020, who underwent surgical resection without neoadjuvant chemotherapy, were retrospectively collected from the Netherlands Cancer Registry. Agreement between clinical and pathological evaluation for each T and N stage was calculated. Sensitivity and specificity analyses were conducted to predict T3-T4 and N1-N2 stages, with histopathology as the reference standard.

RESULTS

Data from 44,471 patients (median age, 71 years, 50% female) were evaluated. We included 38,915 patients with complete T stage and 39,565 patients with complete N stage for analyses. The overall clinical-pathological agreement for T stage was 59% and for N stage 57%. The sensitivity and specificity of CT to detect T3-T4 tumours were 80% (95% confidence interval (CI): 0.79, 0.80) and 76% (95% CI: 0.75, 0.77), respectively, with a positive predictive value (PPV) of 92% (95% CI: 0.92, 0.92). The sensitivity and specificity of CT to detect N1-N2 category were 62% (95% CI: 0.61, 0.63) and 70% (95% CI: 0.69, 0.71), respectively, with PPV 60% (95% CI: 0.59, 0.60).

CONCLUSION

CT-based staging shows limited accuracy in selecting colon cancer patients who would benefit from neoadjuvant therapy without risking overtreatment. Detection of lymph node metastases with CT remains unreliable.

Pearls and pitfalls of structured staging and reporting of rectal cancer on MRI: an international multireader study

OBJECTIVES

To investigate uniformity and pitfalls in structured radiological staging of rectal cancer.

METHODS

Twenty-one radiologists (12 countries) staged 75 rectal cancers on MRI using a structured reporting template. Interobserver agreement (IOA) was calculated as the percentage agreement between readers (categorical variables) and Krippendorff's α (continuous variables). Agreement with an expert consensus served as a surrogate standard of reference to estimate diagnostic accuracy. Polychoric correlation coefficients were used to assess correlations between diagnostic confidence and accuracy (=agreement with expert consensus).

RESULTS

Uniformity to diagnose high-risk (≥cT3 ab) versus low-risk (≤cT3 cd) cT-stage, cN0 versus cN+, lateral nodes and tumour deposits, MRF and sphincter involvement, and solid versus mucinous tumours was high with IOA > 80% in the majority of cases (and >80% agreement with expert consensus). Results for assessing extramural vascular invasion, cT-stage (cT1-2/cT3/cT4a/cT4b), cN-stage (cN0/N1/N2), relation to the peritoneal reflection, extent of sphincter involvement (internal/intersphincteric/external) and morphology (solid/annular/semi-annular) were considerably poorer. IOA was high (α = 0.72-0.84) for tumour height/length and extramural invasion depth, but low for tumour-MRF distance and number of (suspicious) nodes (α = 0.05-0.55). There was a significant positive correlation between diagnostic confidence and accuracy (=agreement with expert consensus) (p < 0.001-p = 0.003).

CONCLUSIONS

- Several staging items lacked sufficient reproducibility.- Results for cT- and N-staging g improved when using a dichotomized stratification.- Considering the significant correlation between diagnostic confidence and accuracy, a confidence level may be incorporated into structured reporting for specific items with low reproducibility.

ADVANCES IN KNOWLEDGE

Although structured reporting aims to achieve uniformity in reporting, several items lack sufficient reproducibility and might benefit from dichotomized assessment and incorporating confidence levels.

A systematic review of automated segmentation of 3D computed-tomography scans for volumetric body composition analysis

Automated computed tomography (CT) scan segmentation (labelling of pixels according to tissue type) is now possible. This technique is being adapted to achieve three-dimensional (3D) segmentation of CT scans, opposed to single L3-slice alone. This systematic review evaluates feasibility and accuracy of automated segmentation of 3D CT scans for volumetric body composition (BC) analysis, as well as current limitations and pitfalls clinicians and researchers should be aware of. OVID Medline, Embase and grey literature databases up to October 2021 were searched. Original studies investigating automated skeletal muscle, visceral and subcutaneous AT segmentation from CT were included. Seven of the 92 studies met inclusion criteria. Variation existed in expertise and numbers of humans performing ground-truth segmentations used to train algorithms. There was heterogeneity in patient characteristics, pathology and CT phases that segmentation algorithms were developed upon. Reporting of anatomical CT coverage varied, with confusing terminology. Six studies covered volumetric regional slabs rather than the whole body. One study stated the use of whole-body CT, but it was not clear whether this truly meant head-to-fingertip-to-toe. Two studies used conventional computer algorithms. The latter five used deep learning (DL), an artificial intelligence technique where algorithms are similarly organized to brain neuronal pathways. Six of seven reported excellent segmentation performance (Dice similarity coefficients > 0.9 per tissue). Internal testing on unseen scans was performed for only four of seven algorithms, whilst only three were tested externally. Trained DL algorithms achieved full CT segmentation in 12 to 75 s versus 25 min for non-DL techniques. DL enables opportunistic, rapid and automated volumetric BC analysis of CT performed for clinical indications. However, most CT scans do not cover head-to-fingertip-to-toe; further research must validate using common CT regions to estimate true whole-body BC, with direct comparison to single lumbar slice. Due to successes of DL, we expect progressive numbers of algorithms to materialize in addition to the seven discussed in this paper. Researchers and clinicians in the field of BC must therefore be aware of pitfalls. High Dice similarity coefficients do not inform the degree to which BC tissues may be under- or overestimated and nor does it inform on algorithm precision. Consensus is needed to define accuracy and precision standards for ground-truth labelling. Creation of a large international, multicentre common CT dataset with BC ground-truth labels from multiple experts could be a robust solution.

Key clinical trials in rectal cancer shaping the current treatment paradigms: reference guide for radiologists

Total neoadjuvant therapy (TNT), which includes chemotherapy and radiation prior to surgical resection, has been recently accepted as the new standard of care for patients with locally advanced low and mid rectal cancers. Multiple clinical trials have evaluated this approach in the last several decades and demonstrated improvement in, local control and reduced risk of recurrence. In addition, in the course of these investigations, it has been shown that between a third and a half of patients experience a clinical complete response (cCR) after being treated with the TNT approach, leading to the development of new organ preservation protocol, now known as watch-and-wait (W&W). On this protocol, cCR patients are not referred for surgery after total neoadjuvant treatment. Instead, they remain on close surveillance and, thus, avoid potential complications associated with surgical resection. Multiple clinical trials are ongoing, investigating the long-term outcomes of these new approaches and the development of less toxic and more effective TNT regimens for LARC. Improvements in technology and rectal MRI protocols position radiologists as vital members of multidisciplinary rectal cancer management teams. Rectal MRI has become a critical tool for rectal cancer initial staging, treatment response assessment, and surveillance on W&W protocols. In this review, we summarize the findings of the pivotal clinical trials that contributed to establishing the current treatment paradigms in locally advanced rectal cancer (LARC) management, with the intention of helping radiologists play more effective roles in their multidisciplinary teams.

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.

Fibroblast Activation Protein Inhibitor-PET Imaging in Colorectal Cancer

Fibroblast activation protein inhibitor (FAPI)-PET imaging holds great promise for improving the clinical management of colorectal cancer. High fibroblast activation protein expression is particularly observed in lymph node metastases, in the aggressive Consensus Molecular Subtype 4, in peritoneal metastases, and in tumors that respond poorly to immunotherapy. We have defined six clinical dilemmas in the diagnosis and treatment of colorectal cancer, which FAPI-PET may help solve. Future clinical trials should include patients undergoing tumor resection, allowing correlation of FAPI-PET signals with in-depth histopathological, cellular, and molecular tissue analyses.

CT is unreliable in locoregional staging of early colon cancer: A nationwide registry-based study

BACKGROUND AND OBJECTIVE

The option to treat early colon cancer (CC) with local resection, as well as trials investigating neoadjuvant treatment, has increased the importance of identifying early-stage disease in the workup. Most CC patients are T- and N-staged preoperatively with CT, although its reliability in staging early CC remains elusive. The aim of this study was to investigate CT-staging accuracy in early CC by evaluating pT and pN stages in patients staged as cT1-2, and cT and cN stages in patients with pT1 tumors.

METHODS

Retrospective population-based cohort study on data from the nationwide Swedish colorectal cancer registry on all CC patients staged as cT1-2 and all patients with pT1 undergoing surgical resection 2009-2018. CT-acquired T- and N-stages were compared with final histopathology. Factors potentially influencing accuracy were analyzed with uni- and multivariate logistic regression.

RESULTS

Computed tomography (CT) staged 4849 patients as cT1-2, whereas 2445 (50%) were pT3 and 453 (9%) pT4. Positive predictive value of the cT1-2 stage was 40%. Of 1401 pT1 patients, 624 (45%) were staged as cT1-2, 139 (10%) as cT3, 15 (1%) as cT4 and 623 (44%) as cTx. In all, 1474 (30%) of the cT1-2 patients were pN+, whereas CT staged 1062 (72%) as cN0. A total of 771 patients were staged as cN+, whereas 403 (52%) were pN0. Overall accuracy in determining N+ was 67%, with 26% sensitivity and 88% specificity. Positive and negative predictive values in determining N+ were 48% and 73%, respectively.

CONCLUSIONS

This nationwide population-based study shows that CT-staging carries a substantial risk of understaging locally advanced tumors as cT1-2 and pT1 tumors as cTx, in addition to poor N-staging. Thus, CT obtained T- and N-staging should not be used for deciding treatment strategies in early CC.

The ability of magnetic resonance imaging to predict lymph node metastases and the risk of recurrence in rectal cancer

AIM

This study aimed to examine the diagnostic accuracy and prognostic value of magnetic resonance imaging (MRI) detected lymph nodes in rectal cancer.

METHOD

We evaluated 806 rectal cancer patients consecutively operated on between 2015 and 2018 at Helsinki University Hospital. In total, 485 patients met the inclusion criteria of presenting with stage I-III disease and were intended for curative treatment at the time of diagnosis. The effect of MRI-detected clinical lymph node status (cN) on cumulative overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS) was calculated using the Kaplan-Meier analysis.

RESULTS

Negative predictive value (NPV) of MRI-lymphnode negativity was 74.8%. Positive predictive value of lymph node metastasis was only 48.6%. In the Kaplan-Meier survival analysis, OS (p = 0.989), DSS (p = 0.911), and DFS (p = 0.109) did not significantly differ according to MRI nodal status. However, cumulative disease-free survival significantly (p < 0.001) differed according to the histopathological lymph node metastasis status (pN).

CONCLUSIONS

MRI detected lymph node positivity appears insufficiently precise and cannot predict disease recurrence or survival. Therefore, it should not serve as an independent risk factor when considering neoadjuvant treatment options for rectal cancer patients.

Determinants of Pre-Surgical Treatment in Primary Rectal Cancer: A Population-Based Study

When preoperative radiotherapy (RT) is best used in rectal cancer is subject to discussions and guidelines differ. To understand the selection mechanisms, we analysed treatment decisions in all patients diagnosed between 2010-2020 in two Swedish regions (Uppsala with a RT department and Dalarna without). Information on staging and treatment (direct surgery, short-course RT, or combinations of RT/chemotherapy) in the Swedish Colorectal Cancer Registry were used. Staging magnetic resonance imaging (MRI) permitted a division into risk groups, according to national guidelines. Logistic regression explored associations between baseline characteristics and treatment, while Cohen's kappa tested congruence between clinical and pathologic stages. A total of 1150 patients without synchronous metastases were analysed. Patients from Dalarna were older, had less advanced tumours and were pre-treated less often (52% vs. 63%, p < 0.001). All MRI characteristics (T-/N-stage, MRF, EMVI) and tumour levels were important for treatment choice. Age affected if chemotherapy was added. The correlation between clinical and pathological T-stage was fair/moderate and poor for N-stage. The MRI-based risk grouping influenced treatment choice the most. Since the risk grouping was modified to diminish the pre-treated proportion, fewer patients were irradiated with time. MRI staging is far from optimal. A stronger wish to decrease irradiation may explain why fewer patients from Dalarna were irradiated, but inequality in health care cannot be ruled out.

Preoperative MR radiomics based on high-resolution T2-weighted images and amide proton transfer-weighted imaging for predicting lymph node metastasis in rectal adenocarcinoma

OBJECTIVES

Lymph node (LN) metastasis is an important prognostic factor in rectal cancer (RC). However, accurate identification of LN metastasis can be challenged for radiologists. The aim of our study was to assess the utility of MRI radiomics based on T2-weighted images (T2WI) and amide proton transfer-weighted (APTw) images for predicting LN metastasis in RC preoperatively.

METHODS

A total of 125 patients with pathologically confirmed rectal adenocarcinoma (RA) from January 2019 to June 2021 who underwent preoperative MR were enrolled in this retrospective study. Radiomics features were extracted from high-resolution T2WI and APTw images of primary tumor. The most relevant radiomics and clinical features were selected using correlation and multivariate logistic analysis. Radiomics models were built using five machine learning algorithms including support vector machine (SVM), logical regression (LR), k- nearest neighbor (KNN), naive bayes (NB), and random forest (RF). The best algorithm was selected for further establish the clinical- radiomics model. The receiver operating characteristic curve (ROC) analysis was used to assess the performance of radiomics and clinical-radiomics model for predicting LN metastasis.

RESULTS

The LR classifier had the best prediction performance, with AUCs of 0.983 (95% CI 0.957-1.000), 0.864 (95% CI 0.729-0.972), 0.851 (95% CI 0.713-0.940) on the training set, validation, and test sets, respectively. In terms of prediction, the clinical-radiomics combined model outperformed the radiomics model. The AUCs of the clinical-radiomics combined model in the validation and test sets were 0.900 (95% CI 0.785-0.986), and 0.929 (95% CI 0.721-0.943), respectively.

CONCLUSION

The radiomics model based on high-resolution T2WI and APTw images can predict LN metastasis accurately in patients with RA.

MRI-based multiregional radiomics for predicting lymph nodes status and prognosis in patients with resectable rectal cancer

Purpose

To establish and evaluate multiregional T2-weighted imaging (T2WI)-based clinical-radiomics model for predicting lymph node metastasis (LNM) and prognosis in patients with resectable rectal cancer.

Methods

A total of 346 patients with pathologically confirmed rectal cancer from two hospitals between January 2019 and December 2021 were prospectively enrolled. Intra- and peritumoral features were extracted separately, and least absolute shrinkage and selection operator regression was applied for feature selection. Radiomics signatures were built using the selected features from different regions. The clinical-radiomic nomogram was developed by combining the intratumoral and peritumoral radiomics signatures score (radscore) and the most predictive clinical parameters. The diagnostic performances of the nomogram and clinical model were evaluated using the area under the receiver operating characteristic curve (AUC). The prognostic model for 3-year recurrence-free survival (RFS) was constructed using univariate and multivariate Cox analysis.

Results

The intratumoral radscore (radscore 1) included four features, the peritumoral radscore (radscore 2) included five features, and the combined intratumoral and peritumoural radscore (radscore 3) included ten features. The AUCs for radscore 3 were higher than that of radscore 1 in training cohort (0.77 vs. 0.71, P=0.182) and internal validation cohort (0.76 vs. 0.64, P=0.041). The AUCs for radscore 3 were higher than that of radscore 2 in training cohort (0.77 vs. 0.74, P=0.215) and internal validation cohort (0.76 vs. 0.68, P=0.083). A clinical-radiomic nomogram showed a higher AUC compared with the clinical model in training cohort (0.84 vs. 0.67, P<0.001) and internal validation cohort (0.78 vs. 0.64, P=0.038) but not in external validation (0.72 vs. 0.76, P=0.164). Multivariate Cox analysis showed MRI-reported extramural vascular invasion (EMVI) (HR=1.099, 95%CI: 0.462-2.616; P=0.031) and clinical-radiomic nomogram-based LNM (HR=2.232, 95%CI:1.238-7.439; P=0.017) were independent risk factors for assessing 3-year RFS. Combined clinical-radiomic nomogram based LNM and MRI-reported EMVI showed good performance in training cohort (AUC=0.748), internal validation cohort (AUC=0.706) and external validation (AUC=0.688) for predicting 3-year RFS.

Conclusion

A clinical-radiomics nomogram exhibits good performance for predicting preoperative LNM. Combined clinical-radiomic nomogram based LNM and MRI-reported EMVI showed clinical potential for assessing 3-year RFS.

Preoperative prediction of lymph node status in patients with colorectal cancer. Developing a predictive model using machine learning

PURPOSE

Develop a prediction model to determine the probability of no lymph node metastasis (pN0) in patients with colorectal cancer.

METHODS

We used data from four Danish health databases on patients with colorectal cancer diagnosed between 2001 and 2019. The registries were harmonized into one common data model (CDM). Patients with clinical T4 tumors, undergoing palliative or acute surgery, and patients undergoing neoadjuvant therapy were excluded. Preoperative data was used to train the model. A postoperative model including tumor-specific variables potentially available after local tumor resection was also developed. Additionally, both models were compared with a model based on age, sex, and clinical N stage to resemble current standards. A Least Absolute Shrinkage and Selection Operator (LASSO) logistic regression analysis for prediction was used.

RESULTS

In total, 35,812 patients with 16,802 variables were identified in the CDM, and 194 variables affected the probability of pN0 preoperative. The area under the receiver operating characteristic curve (AUROC) was 0.64 (95% CI 0.63-0.66), and the area under the precision-recall curve (AUPRC) was 0.75 (95% CI 0.74-0.76). The mean predicted risk was 0.649, observed risk was 0.650, and calibration-in-large was 0.998. Adding histopathological data from the tumor improved the model slightly by increasing AUROC to 0.69. In comparison, the AUROC of the current standard clinical staging model was 0.57.

CONCLUSION

Using Danish National Patient Registry data in a machine learning-based predictive model showed acceptable results and outperforms current tools for clinical staging in predicting pN0 status in patients scheduled for CRC surgery.

Construction of Nomogram-Based Prediction Model for Clinical Prognosis of Patients with Stage II and III Colon Cancer Who Underwent Xelox Chemotherapy after Laparoscopic Radical Resection

Objective

To construct a nomogram-based prediction model for the clinical prognosis of patients with stage II and III colon cancer who underwent Xelox chemotherapy after laparoscopic radical resection based on large data sets.

Methods

A total of 7,832 patients with colorectal cancer who received postoperative Xelox-based chemotherapy were screened from the Surveillance, Epidemiology, and End Results database (USA) as the training data set. In addition, 348 domestic patients were screened as the validation data set. Multivariate Cox regression analysis was performed to identify variables for inclusion in the nomogram-based prediction model. The predictive accuracy of the model was assessed using C-index and calibration curve.

Results

Age, cell differentiation, nerve invasion, T and N stages of tumours, number of dissected lymph nodes, and carcinoembryonic antigen (CEA) level were found to influence the efficacy of postoperative chemotherapy. The nomogram-based prediction model was successfully constructed. The C-index of both the training set and validation set were higher than those of the 7th edition of TNM staging system published by the American Joint Commission on Cancer (C − index of training data set = 0.728, C − index of validation data set = 0.734). The prediction results of the model in the calibration curve showed a good fit with the actual situation.

Conclusion

We successfully constructed a nomogram-based model to predict the clinical prognosis of patients with colorectal cancer receiving postoperative Xelox-based chemotherapy after laparoscopic radical resection, which showed good clinical application value for predicting the efficacy of postoperative Xelox-based chemotherapy in patients with colorectal cancer.

Multimodal Treatment of Rectal Cancer

BACKGROUND

Colorectal cancer is one of the three most common types of cancer in Germany. Approximately 30% of these cancers are located in the rectum, corresponding to about 18 000 new cases per year.

METHODS

This review is based on publications retrieved by a selective search in the PubMed database, including current guidelines and recommendations.

RESULTS

Specialized imaging, particularly magnetic resonance imaging, is essential for treatment planning. In very early stages of this disease, tumors without risk factors can be excised locally. Otherwise, radical surgical resection with lymphadenectomy remains the standard treatment, and can be performed either minimally invasive or open. At present, neoadjuvant treatment plans are evolving in the direction of total neoadjuvant therapy. In addition, recent studies investigate whether the improved efficacy of neoadjuvant therapy might now enable patients with a complete clinical remission to be spared from surgical resection (organ-preserving watch-and-wait strategy).

CONCLUSION

The treatment of rectal cancer is a prime example of an interdisciplinary, multimodal approach. In the past, the focus was mainly on improving oncologic outcomes; at present, increasing attention is being devoted to the patients' quality of life as well and the functional aspects of the various modes of treatment.

Microsatellite instability in rectal cancer: what does it mean? A study of two randomized trials and a systematic review of the literature

Currently, compelling evidence illustrates the significance of determining microsatellite instability (MSI) in colorectal cancer (CRC). The association of MSI with proximal CRC is well established, however, its implications in patients with rectal cancer remain undefined. We therefore aimed to determine the role of MSI with respect to incidence and outcome in patients with rectal cancer, by the examination of patients from two prospective phase III trials: TME trial and PROCTOR-SCRIPT trial (n=1250). No differences in terms of overall survival (HR 1.00, 95%CI 0.69-1.47) and disease-free survival (HR 1.00, 95%CI 0.68-1.45) were observed in patients with MSI compared to microsatellite stable (MSS) rectal cancer. In addition, we performed a literature review to evaluate the overall prevalence, the effect on survival and the response to neo-adjuvant treatment in patients with MSI rectal cancer compared with MSS rectal cancer. The total number of MSI cases in the included studies (including our own) was 1220 (out of 16526 rectal cancer patients), with an overall prevalence of 6.7% (SE 1.19%). Both for overall survival as for disease-free survival there was no impact of MSI status on prognosis (HR 1.00, 95%CI 0.77-1.29 and HR 0.86, 95% CI 0.60-1.22, respectively). The risk ratio for downstaging and pCR showed also no impact of MSI status (RR 1.15, 95% CI 0.86-1.55 and RR 0.81, 95% CI 0.54-1.22 respectively). In conclusion, rectal cancer patients with MSI form a distinct and rare subcategory, however, there is no prognostic effect of MSI in rectal cancer patients.

Assessment of the 2020 NICE criteria for preoperative radiotherapy in patients with rectal cancer treated by surgery alone in comparison with proven MRI prognostic factors: a retrospective cohort study

BACKGROUND

Selection of patients for preoperative treatment in rectal cancer is controversial. The new 2020 National Institute for Health and Care Excellence (NICE) guidelines, consistent with the National Comprehensive Cancer Network guidelines, recommend preoperative radiotherapy for all patients except for those with radiologically staged T1-T2, N0 tumours. We aimed to assess outcomes in non-irradiated patients with rectal cancer and to stratify results on the basis of NICE criteria, compared with known MRI prognostic factors now omitted by NICE.

METHODS

For this retrospective cohort study, we identified patients undergoing primary resectional surgery for rectal cancer, without preoperative radiotherapy, at Basingstoke Hospital (Basingstoke, UK) between Jan 1, 2011, and Dec 31, 2016, and at St Marks Hospital (London, UK) between Jan 1, 2007, and Dec 31, 2017. Patients with MRI-detected extramural venous invasion, MRI-detected tumour deposits, and MRI-detected circumferential resection margin involvement were categorised as MRI high-risk for recurrence (local or distant), and their outcomes (disease-free survival, overall survival, and recurrence) were compared with patients defined as high-risk according to NICE criteria (MRI-detected T3+ or MRI-detected N+ status). Kaplan-Meier and Cox proportional hazards analyses were used to compare the groups.

FINDINGS

378 patients were evaluated, with a median of 66 months (IQR 44-95) of follow up. 22 (6%) of 378 patients had local recurrence and 68 (18%) of 378 patients had distant recurrence. 248 (66%) of 378 were classified as high-risk according to NICE criteria, compared with 121 (32%) of 378 according to MRI criteria. On Kaplan-Meier analysis, NICE high-risk patients had poorer 5-year disease-free survival compared with NICE low-risk patients (76% [95% CI 70-81] vs 87% [80-92]; hazard ratio [HR] 1·91 [95% CI 1·20-3·03]; p=0·0051) but not 5-year overall survival (80% [74-84] vs 88% [81-92]; 1·55 [0·94-2·53]; p=0·077). MRI criteria separated patients into high-risk versus low-risk groups that predicted 5-year disease-free survival (66% [95% CI 57-74] vs 88% [83-91]; HR 3·01 [95% CI 2·02-4·47]; p<0·0001) and 5-year overall survival (71% [62-78] vs 89% [84-92]; 2·59 [1·62-3·88]; p<0·0001). On multivariable analysis, NICE risk assessment was not associated with either disease-free survival or overall survival, whereas MRI criteria predicted disease-free survival (HR 2·74 [95% CI 1·80-4·17]; p<0·0001) and overall survival (HR 2·44 [95% CI 1·51-3·95]; p=0·00027). 139 NICE high-risk patients who were defined as low-risk based on MRI criteria had similar disease-free survival as 118 NICE low-risk patients; therefore, 37% (139 of 378) of patients in this study cohort would have been overtreated with NICE 2020 guidelines. Of the 130 patients defined as low-risk by NICE guidelines, 12 were defined as high-risk on MRI risk stratification and would have potentially been missed for treatment.

INTERPRETATION

Compared to previous guidelines, implementation of the 2020 NICE guidelines will result in significantly more patients receiving preoperative radiotherapy. High-quality MRI selects patients with good outcomes (particularly low local recurrence) without radiotherapy, with little margin for improvement. Overuse of radiotherapy could occur with this unselective approach. The high-risk group, with the most chance of benefiting from preoperative radiotherapy, is not well selected on the basis of NICE 2020 criteria and is better identified with proven MRI prognostic factors (extramural venous invasion, tumour deposits, and circumferential resection margin).

FUNDING

None.

Multimodal CEA-targeted fluorescence and radioguided cytoreductive surgery for peritoneal metastases of colorectal origin

In patients with colorectal peritoneal metastases scheduled for cytoreductive surgery, accurate preoperative estimation of tumor burden and subsequent intraoperative detection of all tumor deposits remains challenging. In this study (ClinicalTrials.gov NCT03699332) we describe the results of a phase I clinical trial evaluating [¹¹¹In]In-DOTA-labetuzumab-IRDye800CW, a dual-labeled anti-carcinoembryonic antigen (anti-CEA) antibody conjugate that enables both preoperative imaging and intraoperative radioguidance and fluorescence imaging. Primary study outcomes are safety and feasibility of this multimodal imaging approach. Secondary outcomes are determination of the optimal dose, correlation between tracer uptake and histopathology and effects on clinical strategy. Administration of [¹¹¹In]In-DOTA-labetuzumab-IRDye800CW is well-tolerated and enables sensitive pre- and intraoperative imaging in patients who receive 10 or 50 mg of the tracer. Preoperative imaging revealed previously undetected lymph node metastases in one patient, and intraoperative fluorescence imaging revealed four previously undetected metastases in two patients. Alteration of clinical strategy based on multimodal imaging occurred in three patients. Thus, multimodal image-guided surgery after administration of this dual-labeled tracer is a promising approach that may aid in decision making before and during cytoreductive surgical procedures.

Characteristics of tumour stroma in regional lymph node metastases in colorectal cancer patients: a theoretical framework for future diagnostic imaging with FAPI PET/CT

Purpose

The recently developed fibroblast activation protein inhibitor (FAPI) tracer for PET/CT, binding tumour-stromal cancer-associated fibroblasts, is a promising tool for detection of positive lymph nodes. This study provides an overview of features, including sizes and tumour-stromal content, of lymph nodes and their respective lymph node metastases (LNM) in colorectal cancer (CRC), since literature lacks on whether LNMs contain sufficient stroma to potentially allow FAPI-based tumour detection.

Methods

Haematoxylin and eosin-stained tissue slides from 73 stage III colon cancer patients were included. Diameters and areas of all lymph nodes and their LNMs were assessed, the amount of stroma by measuring the stromal compartment area, the conventional and total tumour-stroma ratios (TSR-c and TSR-t, respectively), as well as correlations between these parameters. Also, subgroup analysis using a minimal diameter cut off of 5.0 mm was performed.

Results

In total, 126 lymph nodes were analysed. Although positive correlations were observed between node and LNM for diameter and area (r = 0.852, p < 0.001 and r = 0.960, p < 0.001, respectively), and also between the LNM stromal compartment area and nodal diameter (r = 0.612, p < 0.001), nodal area (r = 0.747, p < 0.001) and LNM area (r = 0.746, p < 0.001), novel insight was that nearly all (98%) LNMs contained stroma, with median TSR-c scores of 35% (IQR 20–60%) and TSR-t of 20% (IQR 10–30%). Moreover, a total of 32 (25%) positive lymph nodes had a diameter of < 5.0 mm.

Conclusion

In LNMs, stroma is abundantly present, independent of size, suggesting a role for FAPI PET/CT in improved lymph node detection in CRC.

A model of multiple tumor marker for lymph node metastasis assessment in colorectal cancer: a retrospective study

Background

Assessment of colorectal cancer (CRC) lymph node metastasis (LNM) is critical to the decision of surgery, prognosis, and therapy strategy. In this study, we aimed to develop and validate a multiple tumor marker nomogram for predicting LNM in CRC patients.

Methods

A total of 674 patients who met the inclusion criteria were collected and randomly divided into primary cohort and internal test cohort at a ratio of 7:3. An external test cohort enrolled 178 CRC patients from the West China Hospital. Clinicopathologic variables were obtained from electronic medical records. The least absolute shrinkage and selection operator (LASSO) and interquartile range analysis were carried out for variable dimensionality reduction and feature selection. Multivariate logistic regression analysis was conducted to develop predictive models of LNM. The performance of the established models was evaluated by the receiver operating characteristic (ROC) curve, calibration belt, and clinical usefulness.

Results

Based on minimum criteria, 18 potential features were reduced to six predictors by LASSO and interquartile range in the primary cohort. The model demonstrated good discrimination and ROC curve (AUC = 0.721 in the internal test cohort, AUC = 0.758 in the external test cohort) in LNM assessment. Good calibration was shown for the probability of CRC LNM in the internal and external test cohorts. Decision curve analysis illustrated that multi-tumor markers nomogram was clinically useful.

Conclusions

The study proposed a reliable nomogram that could be efficiently and conveniently utilized to facilitate the assessment of individually-tailored LNM in patients with CRC, complementing imaging and biopsy tests.

Diagnostic Efficiency of Diffusion Sequences and a Clinical Nomogram for Detecting Lymph Node Metastases from Rectal Cancer

RATIONALE AND OBJECTIVES

First, to evaluate and compare three different diffusion sequences (i.e., standard DWI, IVIM, and DKI) for nodal staging. Second, to combine the DWI, and anatomic information to assess metastatic lymph node (LN).

MATERIALS AND METHODS

We retrospectively identified 136 patients of rectal adenocarcinoma who met the inclusion criteria. Three diffusion sequences (i.e., standard DWI, IVIM, and DKI) were performed, and quantitative parameters were evaluated. Univariate and multivariate analyses were used to assess the associations between the anatomic and DWI information and LN pathology. Multivariate logistic regression was used to identify independent risk factors. A nomogram model was established, and the model performance was evaluated by the concordance index (c-index) and calibration curve.

RESULTS

There was a statistical difference in variables (LN long diameter, LN short diameter, LN boundary, LN signal, peri-LN signal intensity, ADC_-1000, ADC_-1400, ADC_-2000, K_app and D) between metastatic and non-metastatic LN for training and validation cohorts (p < 0.05). The ADC value derived from b = 1000 mm/s (ADC_-1000) showed the relative higher AUC (AUC = 0.780) than the ADC value derived from b = 1400 mm/s (ADC_-1400) (AUC = 0.703). The predictive accuracy of the nomogram measured by the c-index was 0.854 and 0.812 in the training and validation cohort, respectively.

CONCLUSION

The IVIM and DKI model's diagnostic efficiency was not significantly improved compared to conventional DWI. The diagnostic accuracy of metastatic LN can be enhanced using the nomogram model, leading to a rational therapeutic choice.

The Association Between Modifiable Lifestyle Factors and Postoperative Complications of Elective Surgery in Patients With Colorectal Cancer

BACKGROUND

Research has demonstrated a possible relation between patients' preoperative lifestyle and postoperative complications.

OBJECTIVE

This study aimed to assess associations between modifiable preoperative lifestyle factors and postoperative complications in patients undergoing elective surgery for colorectal cancer.

DESIGN

This is a retrospective study of a prospectively maintained database.

SETTING

At diagnosis, data on smoking habits, alcohol consumption, BMI, and physical activity were collected by using questionnaires. Postoperative data were gathered from the nationwide database of the Dutch ColoRectal Audit.

PATIENTS

Patients (n = 1564) with newly diagnosed stage I to IV colorectal cancer from 11 Dutch hospitals were included in a prospective observational cohort study (COLON) between 2010 and 2018.

MAIN OUTCOME MEASURES

Multivariable logistic regression models were used to identify which preoperative lifestyle factors were associated with postoperative complications.

RESULTS

Postoperative complications occurred in 28.5%, resulting in a substantially prolonged hospital stay (12 vs 5 days, p < 0.001). Independently associated with higher postoperative complication rates were ASA class II (OR, 1.46; 95% CI, 1.05-2.04; p = 0.03) and III to IV (OR, 3.17; 95% CI, 1.96-5.12; p < 0.001), current smoking (OR, 1.62; 95% CI, 1.02-2.56; p = 0.04), and rectal tumors (OR, 1.81; 95%CI, 1.28-2.55; p = 0.001). Body mass index, alcohol consumption, and physical activity did not show an association with postoperative complications. However, in a subgroup analysis of 200 patients with ASA III to IV, preoperative high physical activity was associated with fewer postoperative complications (OR, 0.17; 95% CI, 0.03-0.87; p = 0.04).

LIMITATIONS

Compared with most studied colorectal cancer populations, this study describes a relatively healthy study population with 87.2% of the included patients classified as ASA I to II.

CONCLUSIONS

Modifiable lifestyle factors such as current smoking and physical activity are associated with postoperative complications after colorectal cancer surgery. Current smoking is associated with an increased risk of postoperative complications in the overall study population, whereas preoperative high physical activity is only associated with a reduced risk of postoperative complications in patients with ASA III to IV. See Video Abstract at http://links.lww.com/DCR/B632.

LA ASOCIACIN ENTRE FACTORES MODIFICABLES DEL ESTILO DE VIDA Y COMPLICACIONES POSOPERATORIAS EN CIRUGA ELECTIVA EN PACIENTES CON CNCER COLORECTAL

ANTECEDENTES:Estudios han demostrado una posible relación entre el estilo de vida preoperatorio de los pacientes y las complicaciones posoperatorias.OBJETIVO:Evaluar las asociaciones entre los factores de estilo de vida preoperatorios modificables y las complicaciones posoperatorias en pacientes llevados a cirugía electiva por cáncer colorrectal.DISEÑO:Estudio retrospectivo de una base de datos continua de forma prospectiva.ESCENARIO:En el momento del diagnóstico se recopilaron mediante cuestionarios datos sobre tabaquismo, consumo de alcohol, el IMC y la actividad física. Los datos posoperatorios se obtuvieron de la base de datos nacional de la Auditoría Colorectal Holandesa.PACIENTES:Se incluyeron pacientes (n = 1564) de once hospitales holandeses con cáncer colorrectal en estadio I-IV recién diagnosticado incluidos en un estudio de cohorte observacional prospectivo (COLON) entre 2010 y 2018.PRINCIPALES VARIABLES ANALIZADAS:Se utilizaron modelos de regresión logística multivariable para identificar qué factores de estilo de vida preoperatorios y se asociaron con complicaciones posoperatorias.RESULTADOS:Las complicaciones posoperatorias se presentaron en el 28,5%, lo que resultó en una estancia hospitalaria considerablemente mayor (12 contra 5 días, p <0,001). De manera independiente se asociaron con mayores tasas de complicaciones posoperatorias la clasificación ASA II (OR 1,46; 95% IC 1,05-2,04, p = 0,03) y III-IV (OR 3,17; 95% IC 1,96-5,12, p <0,001), tabaquismo presente (OR 1,62; IC 95% 1,02-2,56, p = 0,04) y tumores rectales (OR 1,81; IC 95% 1,28-2,55, p = 0,001). El IMC, el consumo de alcohol y la actividad física no mostraron asociación con complicaciones posoperatorias. Sin embargo, en un análisis de subgrupos de 200 pacientes ASA III-IV, la actividad física íntensa preoperatoria se asoció con menos complicaciones posoperatorias (OR 0,17; IC del 95%: 0,03-0,87, p = 0,04).LIMITACIONES:En comparación con las poblaciones de cáncer colorrectal más estudiadas, este estudio incluyó una población relativamente sana con el 87,2% de los pacientes incluidos clasificados como ASA I-II.CONCLUSIONES:Los factores modificables del estilo de vida, como son el encontrarse fumando y la actividad física, se asocian con complicaciones posoperatorias después de la cirugía de cáncer colorrectal. El encontrarse fumando se asocia con un mayor riesgo de complicaciones posoperatorias en la población general del estudio, mientras que la actividad física íntensa preoperatoria se asocia con un menor riesgo de complicaciones posoperatorias únicamente en pacientes ASA III-IV. Consulte Video Resumen en http://links.lww.com/DCR/B632.

Clinical TNM staging for esophageal, gastric, and colorectal cancers in the era of neoadjuvant therapy: A systematic review of the literature

AIM

Clinical staging is vital for selecting appropriate candidates and designing neoadjuvant treatment strategies for advanced tumors. The aim of this review was to evaluate diagnostic abilities of clinical TNM staging for gastrointestinal, gastrointestinal cancers.

METHODS

We conducted a systematic review of recent publications to evaluate the accuracy of diagnostic modalities on gastrointestinal cancers. A systematic literature search was performed in PubMed/MEDLINE using the keywords "TNM staging," "T4 staging," "distant metastases," "esophageal cancer," "gastric cancer," and "colorectal cancer," and the search terms used in Cochrane Reviews between January 2005 to July 2020. Articles focusing on preoperative diagnosis of: (a) depth of invasion; (b) lymph node metastases; and (c) distant metastases were selected.

RESULTS

After a full-text search, a final set of 55 studies (17 esophageal cancer studies, 26 gastric cancer studies, and 12 colorectal cancer studies) were used to evaluate the accuracy of clinical TNM staging. Positron emission tomography-computed tomography (PET-CT) and/or magnetic resonance imaging (MRI) were the best modalities to assess distant metastases. Fat and fiber mode of CT may be useful for T4 staging of esophageal cancer, CT was a partially reliable modality for lymph node staging in gastric cancer, and CT combined with MRI was the most reliable modality for liver metastases from colorectal cancer.

CONCLUSION

The most reliable diagnostic modality differed among gastrointestinal cancers depending on the type of cancer. Therefore, we propose diagnostic algorithms for clinical staging for each type of cancer.