Management of Rectal Cancer

Stage pT0-T1 rectal cancers: emphasis on submucosal high intensity on high-resolution T2-weighted imaging and other morphological features

BackgroundIdentification and staging of rectal cancer are mainly based on the difference in signal intensity (SI) between the tumor and normal structures of the intestinal wall on T2-weighted imaging. However, differentiating stage pT0-T1 from pT2 rectal tumors is difficult using routine magnetic resonance imaging (MRI) sequences.PurposeTo summarize and explore whether MRI findings from routine imaging can help differentiate pT0-T1 from pT2 rectal tumors.Material and MethodsA total of 110 patients with pT0-T2 rectal cancer underwent preoperative pelvic MRI examinations and tumor resection without preoperative chemoradiotherapy. MRI findings of rectal lesions (including tumor location, shape, longitudinal length, maximum cross-section, submucosal high intensity [SHI], extramural fibrotic scarring, wall shrinkage, lesion-to-wall signal intensity ratio, and presence of lymph node with short axis over 3 mm) and clinical characteristics were analyzed by univariate and multivariate analyses to screen the independent factors associated with pathological results.ResultsOf all the lesions, 32 tumors were proved to be pT0-T1 and 78 tumors were pT2. Univariate and multivariate logistic regression analyses revealed that tumor shape (odds ratio [OR] = 24.607, P < 0.001), SHI (OR = 6.129, P = 0.002), and extramural fibrotic scarring (OR = 0.110, P = 0.007) were independent factors distinguishing pT0-T1 tumors from pT2 tumors. If the rectal lesion has a cauliflower-like shape with SHI and no extramural fibrotic scarring, it is more likely to be a pT0-T1 tumor.ConclusionThe imaging features obtained from the routine MRI sequence showed potential value for differentiating pT0-T1 from pT2 rectal tumors.

Predictive Study of Machine Learning-Based Multiparametric MRI Radiomics Nomogram for Perineural Invasion in Rectal Cancer: A Pilot Study

This study aimed to establish and validate the efficacy of a nomogram model, synthesized through the integration of multi-parametric magnetic resonance radiomics and clinical risk factors, for forecasting perineural invasion in rectal cancer. We retrospectively collected data from 108 patients with pathologically confirmed rectal adenocarcinoma who underwent preoperative multiparametric MRI at the First Affiliated Hospital of Bengbu Medical College between April 2019 and August 2023. This dataset was subsequently divided into training and validation sets following a ratio of 7:3. Both univariate and multivariate logistic regression analyses were implemented to identify independent clinical risk factors associated with perineural invasion (PNI) in rectal cancer. We manually delineated the region of interest (ROI) layer-by-layer on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) sequences and extracted the image features. Five machine learning algorithms were used to construct radiomics model with the features selected by least absolute shrinkage and selection operator (LASSO) method. The optimal radiomics model was then selected and combined with clinical features to formulate a nomogram model. The model performance was evaluated using receiver operating characteristic (ROC) curve analysis, and its clinical value was assessed via decision curve analysis (DCA). Our final selection comprised 10 optimal radiological features and the SVM model showcased superior predictive efficiency and robustness among the five classifiers. The area under the curve (AUC) values of the nomogram model were 0.945 (0.899, 0.991) and 0.846 (0.703, 0.99) for the training and validation sets, respectively. The nomogram model developed in this study exhibited excellent predictive performance in foretelling PNI of rectal cancer, thereby offering valuable guidance for clinical decision-making. The nomogram could predict the perineural invasion status of rectal cancer in early stage.

Comparative efficacy analysis of laparoscopic-assisted transanal total mesorectal excision vs laparoscopic transanal mesorectal excision for low-lying rectal cancer

BACKGROUND

With the continuous development of laparoscopic techniques in recent years, laparoscopic total mesorectal excision (LapTME) and laparoscopic-assisted transanal total mesorectal excision (TaTME) have gradually become important surgical techniques for treating low-lying rectal cancer (LRC). However, there is still controversy over the efficacy and safety of these two surgical modalities in LRC treatment.

AIM

To compare the efficacy of LapTME vs TaTME in patients with LRC.

METHODS

Ninety-four patients with LRC who visited and were treated at the Affiliated Hengyang Hospital of Hunan Normal University & Hengyang Central Hospital between December 2022 and March 2024 were selected and divided into the LapTME (n = 44) and TaTME (n = 50) groups. Clinical operation indexes, postoperative recovery indicators, and postoperative complications were recorded. The anal resting pressure (ARP), anal maximum systolic pressure (MSP), and maximum tolerated volume (MTV) of the anal canal were also measured. The intestinal function of patients was evaluated by the Memorial Sloan Kettering Cancer Center (MSKCC) bowel function questionnaire. Serum norepinephrine (NE), adrenaline (AD), and cortisol (Cor) levels were measured. The Quality of Life Questionnaire Core 30 (QLQ-C30) was used for quality of life assessment.

RESULTS

Compared with the LapTME group, the surgery time in the TaTME group was longer; intraoperative blood loss was low; time of anal exhaust, first postoperative ambulation, intestinal recovery, and hospital stay were shorter; and the distal incisal margin and specimen lengths were longer. The TaTME group also showed higher ARP, MSP, and MTV values and higher MSKCC and QLQ-C30 scores than the LapTME group 3 months postoperatively. Cor, AD, and NE levels were lower in the TaTME group than those in the LapTME group during recovery.

CONCLUSION

We demonstrated that TaTME better improved anal function, reduced postoperative stress, and accelerated postoperative recovery and, hence, was safer for patients with LRC.

Unraveling the complexities of colorectal cancer and its promising therapies - An updated review

Colorectal cancer (CRC) continues to be a global health concern, necessitating further research into its complex biology and innovative treatment approaches. The etiology, pathogenesis, diagnosis, and treatment of colorectal cancer are summarized in this thorough review along with recent developments. The multifactorial nature of colorectal cancer is examined, including genetic predispositions, environmental factors, and lifestyle decisions. The focus is on deciphering the complex interactions between signaling pathways such as Wnt/β-catenin, MAPK, TGF-β as well as PI3K/AKT that participate in the onset, growth, and metastasis of CRC. There is a discussion of various diagnostic modalities that span from traditional colonoscopy to sophisticated molecular techniques like liquid biopsy and radiomics, emphasizing their functions in early identification, prognostication, and treatment stratification. The potential of artificial intelligence as well as machine learning algorithms in improving accuracy as well as efficiency in colorectal cancer diagnosis and management is also explored. Regarding therapy, the review provides a thorough overview of well-known treatments like radiation, chemotherapy, and surgery as well as delves into the newly-emerging areas of targeted therapies as well as immunotherapies. Immune checkpoint inhibitors as well as other molecularly targeted treatments, such as anti-epidermal growth factor receptor (anti-EGFR) as well as anti-vascular endothelial growth factor (anti-VEGF) monoclonal antibodies, show promise in improving the prognosis of colorectal cancer patients, in particular, those suffering from metastatic disease. This review focuses on giving readers a thorough understanding of colorectal cancer by considering its complexities, the present status of treatment, and potential future paths for therapeutic interventions. Through unraveling the intricate web of this disease, we can develop a more tailored and effective approach to treating CRC.

The impact of preoperative treatments on the immune environment of rectal cancer

To improve local disease control, the use of preoperative radiotherapy either alone or combined with chemotherapy has become standard practice in rectal cancer, but it is unclear how these treatments modify the antitumoral immune response. We aimed to evaluate tumor histopathologic features and the prognostic effect of host immune response in rectal cancer with variable treatment modalities. Ninety-five rectal cancers with short-course radiotherapy (SRT), 97 with long-course chemoradiotherapy (CRT), and 154 without preoperative treatments, were evaluated for histopathologic features including Crohn's-like reaction (CLR). CD3+ and CD8+ immunohistochemistry and tumor cells were analyzed from tumor tissue microarray samples to calculate T-cell densities and G-cross function values to estimate cancer cell-T-cell co-localization (proximity score). We found that lymphocyte densities were diminished after SRT, but CLR was scarcer after CRT. Proximity score and CLR density were prognostic for survival in cancer without preoperative treatments and could be combined into an enhanced prognostic score (immune grade). In the irradiated tumors, CLR density remained prognostic while the impact of T-cell infiltration was insufficient alone. In multivariable analysis, the immune grade proved to be an independent prognostic factor for survival. In conclusion, the immune contexture of rectal cancer harbors prognostic significance even after preoperative radiotherapy.

The Role of Frailty in the Treatment of Locally Advanced Rectal Cancer

Owing to the gradual aging of today's population, an increase in the prevalence of frailty syndrome has been noticed. This complex state of health, characterized by decreased resilience and tolerance with concurrent increased vulnerability to stressors and adverse health-related factors, has drawn researchers' attention in recent years. Rectal cancer, which constitutes ~30% of all colorectal cancers, is a disease noticeably related to the elderly. In its locally advanced form, it is conventionally treated with trimodal therapy-neoadjuvant chemoradiotherapy followed by total mesorectal excision and adjuvant chemotherapy. Despite its good clinical outcomes and improvement in rectal cancer local control, as evidenced by clinical trials, it remains unclear if all frail patients benefit from that approach since it may be associated with adverse side effects that cannot be handled by them. As old patients, and frail ones even more noticeably, are poorly represented in the clinical trials describing outcomes of the standard treatment, this article aims to review the current knowledge on the trimodal therapy of rectal cancer with an emphasis on novel approaches to rectal cancer that can be implemented for frail patients.

Development and validation of an MRI and clinicopathological factors prediction model for low anterior resection syndrome in anterior resection of middle and low rectal cancer

Objective

To validate the predictive power of newly developed magnetic resonance (MR) morphological and clinicopathological risk models in predicting low anterior resection syndrome (LARS) 6 months after anterior resection of middle and low rectal cancer (MLRC).

Methods

From May 2018 to January 2021, 236 patients with MLRC admitted to two hospitals (internal and external validation) were included. MR images, clinicopathological data, and LARS scores (LARSS) were collected. Tumor morphology data included longitudinal involvement length, maximum tumor diameter, proportion of tumor to circumference of the intestinal wall, tumor mesorectal infiltration depth, circumferential margin status, and distance between the tumor and anal margins. Pelvic measurements included anorectal angle, mesenterial volume (MRV), and pelvic volume. Univariate and multivariate logistic regression was used to obtain independent risk factors of LARS after anterior resection Then, the prediction model was constructed, expressed as a nomogram, and its internal and external validity was assessed using receiver operating characteristic curves.

Results

The uni- and multivariate analysis revealed distance between the tumor and anal margins, MRV, pelvic volume, and body weight as significant independent risk factors for predicting LARS. From the nomogram, the area under the curve (AUC), sensitivity, and specificity were 0.835, 75.0 %, and 80.4 %, respectively. The AUC, sensitivity, and specificity in the external validation group were 0.874, 83.3 %, and 91.7 %, respectively.

Conclusion

This study shows that MR imaging and clinicopathology presented by a nomogram can strongly predict LARSS, which can then individually predict LARS 6 months after anterior resection in patients with MLRC and facilitate clinical decision-making.

Clinical relevance statement

We believe that our study makes a significant contribution to the literature. This method of predicting postoperative anorectal function by preoperative measurement of MRV provides a new tool for clinicians to study LARS.

The contribution of household income to rectal cancer patient characteristics, treatment, and outcomes from 2010 to 2020

Background

There is a paucity of recent literature investigating the sole effect of income level on the treatment and survival of patients with rectal cancer.

Methods

We analyzed all cases of rectal cancer in the Rectal Cancer PUF of the NCDB from 2010 to 2020. We utilized the Median Income Quartiles 2016-2020 to define our income levels. The two lower quartiles were combined to create a lower income group, with the upper two quartiles creating the higher income group. The total cohort included 201,329 patients, with 116,843 and 84,486 in the higher and lower income groups, respectively.

Results

Lower income patients were more often black (17 % vs 6 %), lived farther from the nearest hospital (33.5 miles vs 25.7 miles) despite being more likely to live in urban areas (25 % vs 7 %), and had lower levels of private insurance (36 % vs 49 %). They underwent more APRs (17 % vs 14 %) and had a 13 % higher chance of undergoing an open operation (OR 1.13, CI 1.09-1.17). Higher income patients had a 12 % reduction in 90-day (OR 0.88, 95 % CI 0.82-0.96) and overall mortality (OR 0.88, 95 % CI 0.86-0.89).

Conclusions

Clinicians should be aware that lower income patients are often faced with unique challenges that may impact care delivery.

Patient management after primary rectal cancer diagnosis. Special focus on surgical treatment for non-metastatic disease

Background: Rectal cancer is a public health priority. Primary objectives of this study were to evaluate the quality of care for non-metastatic rectal cancer using process and outcome indicators. Delay of management, length of stay and readmission rate, sphincter preservation, morbidity, number of examined lymph nodes, mortality, overall and disease-free survivals were evaluated. Secondary objectives were to estimate the relationship between possible predictive parameters for (1) anastomotic leakage (logistic regression), (2) overall or disease-free survivals (cox regression).Methods: We performed a retrospective study on 312 consecutive patients diagnosed with primary rectal cancer between 2016 and 2019. We focused on the 163 patients treated by surgery for non-metastatic cancer.Results: The treatment began within 33 days (range 0-264) after incidence, resection rate was 67%. Digestive continuity rate in lower, middle and upper rectum was 30%, 87% and 96%. Median of 14 lymph nodes (range 1-46) was analyzed. Length of stay and readmission rate were 11 days (range 3-56) and 4%, respectively. Within 90 postoperative days, clinical anastomotic leakage occurred in 9.2% of cases, major morbidity rate was 17%, mortality 1.2%. Multivariate analysis revealed that stoma decreased the risk of anastomotic leakage [hazard ratio: 0.16; 95% confidence intervals: 0.04-0.63; p = 0.008]. The 5-year overall survival after surgery was 85 ± 4%, disease-free survival 83 ± 4%. Patients with major complications, male gender and R1/R2 resection margin had a poorer prognosis.Conclusion: This work showed encouraging results in rectal cancer treatment in our institution, our results were in line with recommendations at the time.

Diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging parameters and serum tumor markers in rectal carcinoma prognosis

BACKGROUND

Rectal carcinoma (RC), one of the most common malignancies globally, presents an increasing incidence and mortality year by year, especially among young people, which seriously affects the prognosis and quality of life of patients. At present, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters and serum carbohydrate antigen 19-9 (CA19-9) and CA125 Levels have been used in clinical practice to evaluate the T stage and differentiation of RC. However, the accuracy of these evaluation modalities still needs further research. This study explores the application and value of these methods in evaluating the T stage and differentiation degree of RC.

AIM

To analyze the diagnostic performance of DCE-MRI parameters combined with serum tumor markers (TMs) in assessing pathological processes and prognosis of RC patients.

METHODS

A retrospective analysis was performed on 104 RC patients treated at Yantai Yuhuangding Hospital from May 2018 to January 2022. Patients were categorized into stages T1, T2, T3, and T4, depending on their T stage and differentiation degree. In addition, they were assigned to low (L group) and moderate-high differentiation (M + H group) groups based on their differentiation degree. The levels of DCE-MRI parameters and serum CA19-9 and CA125 in different groups of patients were compared. In addition, the value of DCE-MRI parameters [volume transfer constant (Ktrans), rate constant (Kep), and extravascular extracellular volume fraction (Ve) in assessing the differentiation and T staging of RC patients was discussed. Furthermore, the usefulness of DCE-MRI parameters combined with serum CA19-9 and CA125 Levels in the evaluation of RC differentiation and T staging was analyzed.

RESULTS

Ktrans, Ve, CA19-9 and CA125 were higher in the high-stage group and L group than in the low-stage group and M + H Group, respectively (P < 0.05). The areas under the curve (AUCs) of the Ktran and Ve parameters were 0.638 and 0.694 in the diagnosis of high and low stages, respectively, and 0.672 and 0.725 in diagnosing moderate-high and low differentiation, respectively. The AUC of DCE-MRI parameters (Ktrans + Ve) in the diagnosis of high and low stages was 0.742, and the AUC in diagnosing moderate-high and low differentiation was 0.769. The AUCs of CA19-9 and CA-125 were 0.773 and 0.802 in the diagnosis of high and low stages, respectively, and 0.834 and 0.796 in diagnosing moderate-high and low differentiation, respectively. Then, we combined DCE-MRI (Ktrans + Ve) parameters with CA19-9 and CA-125 and found that the AUC of DCE-MRI parameters plus serum TMs was 0.836 in the diagnosis of high and low stages and 0.946 in the diagnosis of moderate-high and low differentiation. According to the Delong test, the AUC of DCE-MRI parameters plus serum TMs increased significantly compared with serum TMs alone in the diagnosis of T stage and differentiation degree (P < 0.001).

CONCLUSION

The levels of the DCE-MRI parameters Ktrans and Ve and the serum TMs CA19-9 and CA125 all increase with increasing T stage and decreasing differentiation degree of RC and can be used as indices to evaluate the differentiation degree of RC in clinical practice. Moreover, the combined evaluation of the above indices has a better effect and more obvious clinical value, providing important guiding importance for clinical condition judgment and treatment selection.

PDCD4-induced oxidative stress through FGR/NF-κB axis in rectal cancer radiotherapy-induced AKI

This study aimed to investigate the molecular mechanism of the effect of PDCD4 on radiotherapy-induced acute kidney injury (AKI) in rectal cancer through the regulation of FGR/NF-κB signaling. Differentially expressed genes were identified using Gene Expression Omnibus (GEO) datasets (GSE90627 for rectal cancer and GSE145085 for AKI) and R software. The human renal tubular epithelial cell line, HK-2, was used to establish an in vitro model of radiotherapy-induced AKI. RT-qPCR and western blotting were used to detect gene and protein expression levels, respectively. Cell proliferation and apoptosis were assessed using the CCK-8 assay and flow cytometry, respectively. The malondialdehyde and superoxide dismutase levels in the cell culture supernatants were determined. Additionally, an in vivo AKI model was established using BALB/c mice, and kidney tissue morphology, expression of the renal injury molecule KIM-1, apoptosis of renal tubular cells, and TAS and TOS in serum were evaluated. Bioinformatics analysis revealed the upregulated expression of PDCD4 in AKI. In vitro experiments demonstrated that PDCD4 induced apoptosis in renal tubular cells by promoting FGR expression, which activated the NF-κB signaling pathway and triggered an oxidative stress response. In vivo animal experiments confirmed that PDCD4 promoted oxidative stress response and radiotherapy-induced AKI through the activation of the FGR/NF-κB signaling pathway. Silencing PDCD4 attenuated radiotherapy-induced AKI. Our findings suggest that PDCD4 may induce radiotherapy-induced AKI in rectal cancer by promoting FGR expression, activating the NF-κB signaling pathway, and triggering an oxidative stress response.

Treatment of rectal anastomotic atresia with transurethral prostate resection instrumentation: A report of three cases

Dixon surgery for rectal cancer can lead to severe intestinal narrowing and blockage that is difficult to treat with open surgery or colonoscopy. The aim of the present study was to develop a minimally invasive approach for treating rectal anastomotic atresia based on three cases that were managed with transurethral prostate resection instrumentation. Preoperative imaging determined the distance from the anastomotic closure to the anal margin, the length of the anastomotic closure and the degree of proximal intestinal dilation for all cases. During the procedure, the anastomotic site was visualized, and a circular electrode was used to excavate and open the blockage. Membrane-like closures were directly incised to achieve satisfactory results, with an anastomotic diameter >20 mm. Those cases with tubular atresia required an initial incision using the prostate resectoscope to relieve the obstruction, followed by radial incisions until achieving an anastomotic diameter >20 mm. At 3-6 months post-dilation, two of the patients with anastomotic atresia >20 mm had satisfactory bowel movements, whereas the remaining patient experienced tumor recurrence at the anastomotic site and discontinued treatment. This case series demonstrates the potential of transurethral prostate resection instrumentation as a safe and effective minimally invasive approach for rectal anastomotic atresia. Given that prostate resection instrumentation is readily available in hospitals in China, this approach is widely accessible to most patients. Furthermore, the technique leverages existing surgical technology and practices, requiring only a shift in the surgical site.

Colorectal eversion technique combined with modified single-stapled double-purse-string low colorectal anastomosis

AIM

Total mesorectal excision with adequate free margins is the gold standard for rectal surgery. Applying a linear stapler in a narrow pelvis can be challenging and the proper distal margin difficult to assess. In selected cases the colorectal eversion technique combined with single-stapled double-purse-string anastomosis (SSDP) can be a practical solution.

METHOD

Eleven patients, six men and five women, mean body mass index 27 ± 1.3 kg/m2, underwent total mesorectal excision with the colorectal eversion technique combined with modified SSDP between September 2022 and January 2023.

RESULTS

The mean operative time was 190 min. The mean hospital stay was 4 days. There were no postoperative complications. The final histology showed complete mesorectal resection, circumferential resection margin negative, free distal resection margin, anastomotic doughnuts negative. At 7 ± 3 months follow-up there was no evidence of local recurrence or distant metastasis.

CONCLUSION

The colorectal eversion technique combined with modified SSDP is a reproducible and safe technique in selected patients. Prospective randomized trials with large patient series are needed to confirm our preliminary results.

Predicting the Feasibility of Curative Resection in Low Rectal Cancer: Insights from a Prospective Observational Study on Preoperative Magnetic Resonance Imaging Accuracy

Background and Objectives: A positive pathological circumferential resection margin is a key prognostic factor in rectal cancer surgery. The point of this prospective study was to see how well different MRI parameters could predict a positive pathological circumferential resection margin (pCRM) in people who had been diagnosed with rectal adenocarcinoma, either on their own or when used together. Materials and Methods: Between November 2019 and February 2023, a total of 112 patients were enrolled in this prospective study and followed up for a 36-month period. MRI predictors such as circumferential resection margin (mCRM), presence of extramural venous invasion (mrEMVI), tumor location, and the distance between the tumor and anal verge, taken individually or combined, were evaluated with univariate and sensitivity analyses. Survival estimates in relation to a pCRM status were also determined using Kaplan-Meier analysis. Results: When individually evaluated, the best MRI predictor for the detection of a pCRM in the postsurgical histopathological examination is mrEMVI, which achieved a sensitivity (Se) of 77.78%, a specificity (Sp) of 87.38%, a negative predictive value (NPV) of 97.83%, and an accuracy of 86.61%. Also, the best predictive performance was achieved by a model that comprised all MRI predictors (mCRM+ mrEMVI+ anterior location+ < 4 cm from the anal verge), with an Se of 66.67%, an Sp of 88.46%, an NPV of 96.84%, and an accuracy of 86.73%. The survival rates were significantly higher in the pCRM-negative group (p < 0.001). Conclusions: The use of selective individual imaging predictors or combined models could be useful for the prediction of positive pCRM and risk stratification for local recurrence or distant metastasis.

Pre-operative Neo-adjuvant Chemotherapy Related miRNAs as Key Regulators and Therapeutic Targets in Colorectal Cancer

BACKGROUND

In colorectal cancer, the investigation of cancer pathogenesis and the determination of the relevant gene and gene pathways is particularly important to provide a basis for treatment-oriented studies. miRNAs which affect gene regulation in the molecular pathogenesis of cancer, have an active role in carcinogenesis. In the literature, miRNA expression levels have been associated with metastasis and prognosis in different cancers.

OBJECTIVE

In our study, expression profiling of miRNAs involved in oncogenic and apoptotic pathways in patients with locally advanced colorectal cancer receiving neoadjuvant therapy was performed.

METHODS

miRNAs were isolated from three different FFPE tissue samples taken at different times of the same patient (tumor tissue taken at the time of diagnosis, normal tissue samples, and after neoadjuvant therapy). The expression analysis of 84 miRNAs determined by PCR array (Fluidigm, USA) and mediated meta-analysis was performed comparatively to each study and non-cancerous control group. Evaluations were performed with ΔΔCT calculations.

RESULTS

As a result of the miRNA PCR array study, in addition to differences were observed in miRNA expression between control and study groups. The potential biomarkers which were hsamiR- 215-5p, hsa-miR-9-59, hsa-miR-193a-5p, hsa-miR-206, hsa-miR-1, hsa-miR-96-5p have been detected for possible treatment resistance, prognosis and predispositions to cancers.

CONCLUSION

In patients with colorectal cancer, miRNA expression in the tumoral regions before and after neoadjuvant therapy has represented a variable pattern. It has been shown that miRNA studies can be used to predict the clinical course and response to treatment with differences in expression levels. It has been concluded that specific miRNAs may be candidate biomarkers for colorectal cancer.

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T1 mapping in evaluation of clinicopathologic factors for rectal adenocarcinoma

OBJECTIVE

T1 mapping has been increasingly applied in the study of tumor. The purpose of this study was to evaluate the value of T1 mapping in evaluating clinicopathologic factors for rectal adenocarcinoma.

MATERIALS AND METHODS

Eighty-six patients with rectal adenocarcinoma confirmed by surgical pathology who underwent preoperative pelvic MRI were retrospectively analyzed. High-resolution T2-weighted imaging (T2WI), T1 mapping, and diffusion-weighted imaging (DWI) were performed. T1 and apparent diffusion coefficient (ADC) parameters were compared among different associated tumor markers, tumor grades, stages, and structure invasion statuses. A receiver operating characteristic (ROC) analysis was estimated.

RESULTS

T1 value showed significant difference between high- and low-grade tumors ([1531.5 ± 84.7 ms] vs. [1437.1 ± 80.3 ms], P < 0.001). T1 value was significant higher in positive than in negative perineural invasion ([1495.7 ± 89.2 ms] vs. [1449.4 ± 88.8 ms], P < 0.05). No significant difference of T1 or ADC was observed in different CEA, CA199, T stage, N stage, lymphovascular invasions, extramural vascular invasion (EMVI), and circumferential resection margin (CRM) (P > 0.05). The AUC under ROC curve of T1 value were 0.796 in distinguishing high- from low-grade rectal adenocarcinoma. The AUC of T1 value in distinguishing perineural invasion was 0.637.

CONCLUSION

T1 value was helpful in assessing pathologic grade and perineural invasion correlated with rectal cancer.

Effects of remifentanil combined with propofol on hemodynamics and oxidative stress in patients undergoing resection of rectal carcinoma

BACKGROUND

Rectal carcinoma (RC) treatment primarily involves laparoscopic surgery, which may induce significant hemodynamic changes and weaken immune function. Certain anesthetic approaches using opioid drugs (including remifentanil and sufentanil) pose risks, such as hypotension.

AIM

To determine the effects of remifentanil combined with propofol on hemodynamics and oxidative stress in patients undergoing RC resection.

METHODS

A total of 211 patients one hundred and four patients with RC treated at the First Affiliated Hospital of Dalian Medical University between November 2018 and November 2022 were retrospectively analyzed. Among them, the remifentanil group included 45 patients receiving remifentanil with propofol anesthesia and the sufentanil group included 59 patients receiving sufentanil with propofol anesthesia. Changes in the hemodynamic index, oxidative stress index, general data, consumption of remifentanil, and use of vasoactive drugs were compared. The incidences of adverse reactions were calculated.

RESULTS

The two groups did not significantly differ in terms of operation, anesthesia, and extubation times (P > 0.05). At 1 min after intubation, the sufentanil group showed a notably higher heart rate, systolic blood pressure (SBP), diastolic blood pressure, and mean arterial pressure (MAP) compared with the remifentanil group (P < 0.05), whereas the sufentanil group showed a notably higher SBP and MAP compared with the remifentanil group at 5 min after pneumoperitoneum (P < 0.05). Thirty minutes after surgery, the remifentanil group showed significantly lower plasma cortisol, noradrenaline, and glucose levels than the sufentanil group (P < 0.001). The remifentanil group consumed significantly less remifentanil than the sufentanil group (P < 0.05), and the adoption frequency of ephedrine was lower in the remifentanil group than that in the sufentanil group (P < 0.05). The incidence of hypotension was notably higher in the sufentanil group than that in the remifentanil group (P < 0.05).

CONCLUSION

Remifentanil combined with propofol can improve hemodynamics and relieve oxidative stress in patients undergoing RC resection.

Incidence and associated factors of developing second pelvic malignant neoplasms among prostate cancer patients treated with radiotherapy

Objective

To identify risk factors of secondary pelvic malignant neoplasms (SPMNs) among prostate cancer (PCa) patients treated with radiotherapy. Simultaneously, population-based data were used to validate the high risk of SPMNs in PCa patients with radiotherapy.

Materials and methods

We identified male patients diagnosed with PCa (localized and regional) as the first primary cancer and pelvic malignant neoplasm (including bladder and rectal cancer) as secondary cancer from Surveillance, Epidemiology, and End Results database (1975-2020). An external validation cohort was obtained from the First Affiliated Hospital of Nanchang University. The Fine-Gray competing risk regression and Poisson regression were utilized to evaluate the risk of SPMNs development. Poisson regression was also performed to calculate the standardized incidence ratio (SIR). The Kaplan-Meier method was used to assess the overall survival (OS) of patients with SPMNs.

Results

89397 PCa patients treated with radiotherapy were enrolled. We identified associated factors of SPMNs, including age at diagnosis, race, year of diagnosis, marital status, radiation strategy and latency. In the multivariable competing risk regression model and Poisson regression model, a significantly higher risk of SPMNs development was observed in patients over 50 years(P<0.05), white patients(P<0.001), unmarried patients and treated with brachytherapy combined with external beam radiotherapy or brachytherapy(P<0.05). Patients treated with radiotherapy had a higher bladder and rectal cancer incidence than the general population. Patients who developed SPMNs showed poorer OS.

Conclusion

We identified several risk factors associated with SPMNs and confirmed a relatively higher incidence of bladder and rectal cancer among PCa patients with radiotherapy. These results help tailor treatment and surveillance strategies.

Development and validation of a competitive risk model in patients with rectal cancer: based on SEER database

BACKGROUND

Rectal cancer is one of the most common malignancies. To predict the specific mortality risk of rectal cancer patients, we constructed a predictive nomogram based on a competing risk model.

METHODS

The information on rectal cancer patients was extracted from the SEER database. Traditional survival analysis and specific death analysis were performed separately on the data.

RESULTS

The present study included 23,680 patients, with 16,580 in the training set and 7100 in the validation set. The specific mortality rate calculated by the competing risk model was lower than that of the traditional survival analysis. Age, Marriage, Race, Sex, ICD-O-3Hist/Behav, Grade, AJCC stage, T stage, N stage, Surgery, Examined LN, RX SUMM-SURG OTH, Chemotherapy, CEA, Deposits, Regional nodes positive, Brain, Bone, Liver, Lung, Tumor size, and Malignant were independent influencing factors of specific death. The overall C statistic of the model in the training set was 0.821 (Se = 0.001), and the areas under the ROC curve for cancer-specific survival (CSS) at 1, 3, and 5 years were 0.842, 0.830, and 0.812, respectively. The overall C statistic of the model in the validation set was 0.829 (Se = 0.002), and the areas under the ROC curve for CSS at 1, 3, and 5 years were 0.851, 0.836, and 0.813, respectively.

CONCLUSIONS

The predictive nomogram based on a competing risk model for time-specific mortality in patients with rectal cancer has very desirable accuracy. Thus, the application of the predictive nomogram in clinical practice can help physicians make clinical decisions and follow-up strategies.

MDT-How it is important in rectal cancer

The concept of multidisciplinary team discussion of patient's care has been a part of routine medical practice for several decades [Monson et al. in Bull Am Coll Surg 101:45-46, 2016; NHS. Improving outcomes in colorectal cancer-the manual. (Guidance on commissioning cancer services-improving outcomes). 1997.]. The idea of bringing multiple specialties and ancillary services together to help optimize patient outcomes has been implemented in several clinical arenas from burns to physical medicine and rehabilitation to oncology. In the oncology realm, multidisciplinary tumor boards (MDTs) originated as a broad-based meeting that would permit the review and discussion of cancer patients to optimize treatment strategies [Cancer Co. Optimal Resources for Cancer Care: 2020 Standards. Chicago, IL: 2019.]. Over time, as further specialization occurred and clinical treatment algorithms have become more complex, multidisciplinary tumor boards have become more disease site specific. In this article we will discuss the importance of MDTs, specifically focusing on rectal cancer MDTs including their impact on treatment planning as well as the unique interplay of clinical specialties that provide internal quality control and improvement. Additionally, we will discuss some of the potential benefits of MDTs beyond the direct impact on patient care and review some of the challenges of implementation.

Total neoadjuvant therapy for locally advanced rectal cancer: a narrative review

Locally advanced rectal cancer has traditionally been treated with chemoradiotherapy (CRT) followed by surgery and adjuvant chemotherapy. However, a new strategy, total neoadjuvant therapy, involves the administration of CRT and neoadjuvant chemotherapy with the aim of eradicating micrometastases earlier and achieving greater control of the disease. The use of total neoadjuvant therapy has shown higher rates of pathological complete response and resectability compared with CRT, including improved survival. Nevertheless, distant relapse is the main cause of morbidity and mortality in locally advanced rectal cancer. To address this, new biomarkers are being developed to predict disease response.

Optimal waiting period to surgical treatment after neoadjuvant chemoradiotherapy for locally advanced rectum cancer: a retrospective observational study

BACKGROUND

The optimal waiting period after neoadjuvant treatment in patients with locally advanced rectal cancers is still controversial. The literature has different results regarding the effect of waiting periods on clinical and oncological outcomes. We aimed to investigate the effects of these different waiting periods on clinical, pathological, and oncological outcomes.

METHODS

Between January 2014 and December 2018, a total of 139 consecutive patients with locally advanced rectal adenocarcinoma, who were treated in the Department of General Surgery at the Marmara University Pendik Training and Research Hospital, were enrolled in the study. The patients were split into three groups according to waiting time for surgery after neoadjuvant treatment: group 1 (n = 51) included patients that have 7 weeks and less (≤ 7 weeks) time interval, group 2 (n = 45) 8 to 10 weeks (8-10 weeks), group 3 (n = 43) 11 weeks and above (11 weeks ≤). Their database records, which were entered prospectively, were analyzed retrospectively.

RESULTS

There were 83 (59.7%) males and 56 (40.3%) females. The median age was 60 years, and there was no statistical difference between the groups regarding age, gender, BMI, ASA score, ECOG performance score, tumor location, and preoperative CEA values. Also, we found no significant differences regarding operation times, intraoperative bleeding, length of hospital stay, and postoperative complications. According to the Clavien-Dindo (CD) classification, severe early postoperative complications (CD 3 and above) were observed in 9 patients. The complete pathological response (pCR, ypT0N0) was observed in 21 (15.1%) patients. The groups had no significant difference regarding 3-year disease-free and 3-year overall survival (p = 0.3, p = 0.8, respectively). Local recurrence was observed in 12 of 139 (8.6%) patients and distant metastases occurred in 30 of 139 (21.5%) patients during the follow-up period. There was no significant difference between the groups in terms of both local recurrence and distant metastasis (p = 0.98, p = 0.43, respectively).

CONCLUSION

The optimal time for postoperative complications and sphincter-preserving surgery in patients with locally advanced rectal cancer is 8-10 weeks. The different waiting periods do not affect disease-free and overall survival. While long-term waiting time does not make a difference in pathological complete response rates, it negatively affects the TME quality rate.

Impact of Microscopically Positive (≤1 mm) Distal Margins on Disease Recurrence in Rectal Cancer Treated by Neoadjuvant Chemoradiotherapy

BACKGROUND

The adequate distal resection margin is still controversial in rectal cancer treated by neoadjuvant chemoradiotherapy (nCRT). The aim of this study was to assess the impact of a distal margin of ≤1 mm on locoregional recurrence-free survival (LRRFS).

METHODS

Among 255 patients treated with nCRT and surgery at the National Cancer Institute of Milan, 83 (32.5%) had a distal margin of ≤1 mm and 172 (67.5%) had a distal margin of >1 mm. Survival analyses were performed to assess the impact of distal margin on 5-year LRRFS, as well as Cox survival analysis. The role of distal margin on survival was analyzed according to different tumor regression grades (TRGs).

RESULTS

The overall 5-year LRRFS rate was 77.6% with a distal margin of ≤1 mm vs. 88.3% with a distal margin of >1 mm (Log-rank p = 0.09). Only stage ypT4 was an independent predictor of worse LRRFS (HR 15.14, p = 0.026). The 5-year LRRFS was significantly lower in TRG3-5 patients with a distal margin of ≤1 mm compared to those with a distal margin of >1 mm (68.5% vs. 84.2%, p = 0.027), while no difference was observed in case of TRG1-2 (p = 0.77).

CONCLUSIONS

Low-responder rectal cancers after nCRT still require a distal margin of >1 mm to reduce the high likelihood of local relapse.

Post-Surgical Imaging Assessment in Rectal Cancer: Normal Findings and Complications

Rectal cancer (RC) is one of the deadliest malignancies worldwide. Surgery is the most common treatment for RC, performed in 63.2% of patients. The type of surgical approach chosen aims to achieve maximum residual function with the lowest risk of recurrence. The selection is made by a multidisciplinary team that assesses the characteristics of the patient and the tumor. Total mesorectal excision (TME), including both low anterior resection (LAR) and abdominoperineal resection (APR), is still the standard of care for RC. Radical surgery is burdened by a 31% rate of major complications (Clavien-Dindo grade 3-4), such as anastomotic leaks and a risk of a permanent stoma. In recent years, less-invasive techniques, such as local excision, have been tested. These additional procedures could mitigate the morbidity of rectal resection, while providing acceptable oncologic results. The "watch and wait" approach is not a globally accepted model of care but encouraging results on selected groups of patients make it a promising strategy. In this plethora of treatments, the radiologist is called upon to distinguish a physiological from a pathological postoperative finding. The aim of this narrative review is to identify the main post-surgical complications and the most effective imaging techniques.

Biparametric magnetic resonance imaging-based radiomics features for prediction of lymphovascular invasion in rectal cancer

BACKGROUND

Preoperative assessment of lymphovascular invasion(LVI) of rectal cancer has very important clinical significance. However, accurate preoperative imaging evaluation of LVI is highly challenging because the resolution of MRI is still limited. Relatively few studies have focused on prediction of LVI of rectal cancer with the tool of radiomics, especially in patients with negative statue of MRI-based extramural vascular invasion (mrEMVI).The purpose of this study was to explore the preoperative predictive value of biparametric MRI-based radiomics features for LVI of rectal cancer in patients with the negative statue of mrEMVI.

METHODS

The data of 146 cases of rectal adenocarcinoma confirmed by postoperative pathology were retrospectively collected. In the cases, 38 had positive status of LVI. All patients were examined by MRI before the operation. The biparametric MRI protocols included T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI). We used whole-volume three-dimensional method and two feature selection methods, minimum redundancy maximum relevance (mRMR) and least absolute shrinkage and selection operator (LASSO), to extract and select the features. Logistics regression was used to construct models. The area under the receiver operating characteristic curve (AUC) and DeLong's test were used to evaluate the diagnostic performance of the radiomics based on T2WI and DWI and the combined models.

RESULTS

Radiomics models based on T2WI and DWI had good predictive performance for LVI of rectal cancer in both the training cohort and the validation cohort. The AUCs of the T2WI model were 0.87 and 0.87, and the AUCs of the DWI model were 0.94 and 0.92. The combined model was better than the T2WI model, with AUCs of 0.97 and 0.95. The predictive performance of the DWI model was comparable to that of the combined model.

CONCLUSIONS

The radiomics model based on biparametric MRI, especially DWI, had good predictive value for LVI of rectal cancer. This model has the potential to facilitate the clinical recognition of LVI in rectal cancer preoperatively.

Increased Burden of Second Bladder Cancer and Rectal Cancer in Prostate Cancer Treated With Radiotherapy: Results From Surveillance, Epidemiology, and End Results

BACKGROUND

Previous studies have confirmed the higher risk of bladder cancer (BC) and rectal cancer (RC) development among prostate cancer (PCa) patients receiving radiotherapy. In this study, we intend to explore the long-term trend in second BC and RC incidence among PCa patients undergoing radiotherapy.

METHOD

We identified first primary PCa patients diagnosed between 1975 and 2014 from the Surveillance, Epidemiology, and End Results (SEER)-9 cancer registries. Standardized incidence ratios (SIRs) were calculated by calendar year of diagnosis among PCa patients receiving radiotherapy and not. P trends were evaluated using Poisson regression. 10-year cumulative incidence of BC and RC was calculated utilizing competing risk regression model.

RESULT

Of PCa patients treated with radiotherapy, SIRs of BC increased from .82 (95% CI: .35- 1.61) in 1980-1984 to 1.58 (95% CI: 1.48-1.68) in 2010-2014 (Ptrend=.003). SIRs of RC increased from 1.01 (95% CI: .27-2.58) in 1980-1984 to 1.54 (95% CI: 1.31-1.81) in 2010-2014 (Ptrend=.025). No statistically significant change in both BC and RC incidence was observed. The 10-year cumulative incidence of BC increased from 1975-1984 (.04%) to 2005-2014 (.15%) among PCa treated with radiotherapy. Simultaneously, the 10-year cumulative incidence of RC was demonstrated to range from 1975-1984 (.02%) to 2005-2014 (.11%).

CONCLUSION

we have observed an increasing trend in second BC and RC incidence in PCa patients receiving radiotherapy. There was no significant change in the incidence of second BC and RC in PCa without radiotherapy. These results reflect the increasing clinical burden of second malignant tumors in PCa patients undergoing radiotherapy.

Application of machine learning techniques in real-world research to predict the risk of liver metastasis in rectal cancer

Background

The liver is the most common site of distant metastasis in rectal cancer, and liver metastasis dramatically affects the treatment strategy of patients. This study aimed to develop and validate a clinical prediction model based on machine learning algorithms to predict the risk of liver metastasis in patients with rectal cancer.

Methods

We integrated two rectal cancer cohorts from Surveillance, Epidemiology, and End Results (SEER) and Chinese multicenter hospitals from 2010-2017. We also built and validated liver metastasis prediction models for rectal cancer using six machine learning algorithms, including random forest (RF), light gradient boosting (LGBM), extreme gradient boosting (XGB), multilayer perceptron (MLP), logistic regression (LR), and K-nearest neighbor (KNN). The models were evaluated by combining several metrics, such as the area under the curve (AUC), accuracy score, sensitivity, specificity and F1 score. Finally, we created a network calculator using the best model.

Results

The study cohort consisted of 19,958 patients from the SEER database and 924 patients from two hospitals in China. The AUC values of the six prediction models ranged from 0.70 to 0.95. The XGB model showed the best predictive power, with the following metrics assessed in the internal test set: AUC (0.918), accuracy (0.884), sensitivity (0.721), and specificity (0.787). The XGB model was assessed in the outer test set with the following metrics: AUC (0.926), accuracy (0.919), sensitivity (0.740), and specificity (0.765). The XGB algorithm also shows a good fit on the calibration decision curves for both the internal test set and the external validation set. Finally, we constructed an online web calculator using the XGB model to help generalize the model and to assist physicians in their decision-making better.

Conclusion

We successfully developed an XGB-based machine learning model to predict liver metastasis from rectal cancer, which was also validated with a real-world dataset. Finally, we developed a web-based predictor to guide clinical diagnosis and treatment strategies better.

The effect of Mitomycin-C in neoadjuvant concurrent chemoradiotherapy for rectal cancer

BACKGROUND

Neoadjuvant concurrent chemoradiotherapy (nCCRT) followed by total mesorectal excision has become the standard of care for advanced rectal cancer, but the most effective regimen of chemotherapeutic agents has not yet been determined. The purpose of this study is to determine the effect of Mitomycin-C (MMC) in nCCRT for rectal cancer.

METHODS

From 2000 to 2017, patients with rectal adenocarcinoma who received nCCRT followed by radical surgery were enrolled in our study. The patients were retrospectively separated into two groups according to nCCRT regimens (with or without MMC). Other factors related to cancer down-staging after nCCRT, disease-free survival (DFS) and overall survival (OS) were analyzed.

RESULTS

One hundred ninety-five patients received radiotherapy (RT) + MMC + oral tegafur-uracil (UFUR), and 191 patients received RT + UFUR without MMC as neoadjuvant CCRT. Adding MMC might increase the down-staging rate (odds ratio [OR] = 1.520, p = 0.058), and down-staging had significant effect to improve OS (OR = 1.726, p = 0.002) and DFS (OR = 2.185, p < 0.001). The OS and DFS were improved in patients who received MMC, although this result did not reach a statistically significant difference. There was a higher incidence of low-grade toxicities in the MMC group, especially neutropenia, genitourinary side effects, and dermatological side effects ( p < 0.001).

CONCLUSION

Adding MMC to the regimen of nCCRT for rectal adenocarcinoma is shown to increase tumor down-staging rate and improve disease-free and OS, although these benefits come at the cost of increased low-grade toxicities. Prospective randomized studies are needed to explore the role of MMC in nCCRT for rectal cancer.

The pattern and treatment outcomes for rectal cancer with concurrent locoregional recurrence and distant metastases after total mesorectal excision

Background

To study the pattern and treatment outcome of rectal cancer (RC) with concurrent locoregional recurrence (LR) and distant metastasis (DM) after total mesorectal excision (TME) and to identify patient-, disease-, and treatment-related factors associated with differences in prognosis after concurrent LR and DM.

Methods

RC patients who were diagnosed with concurrent LR and DM after TME from May 2015 to June 2019 were included in our study. All patients received single or multiple treatment modalities under the guidance of multidisciplinary team (MDT) of colorectal cancer in Fudan University Shanghai Cancer Center. The prognostic value of various clinicopathological factors for survival were calculated by Kaplan–Meier curves and Cox regression analyses.

Results

A total of 74 RC patients with concurrent LR and DM who had undergone TME with a median follow-up of 27 months were eligible for analysis. The median survival of the included patients was 34 months, and 30 patients (41%) died. Fifty-nine patients (80%) underwent comprehensive treatments. Patients with oligometastatic disease (OMD) achieved no evidence of disease (NED) status more frequently than those with multiple metastases (P = 0.003). In the univariate analysis, patients achieving NED, diagnosed with OMD and five or less peritoneal metastases tended to have longer survival after LR and DM diagnosis (P < 0.05). In the multivariate analysis, attaining NED status was the only independent factor for survival (hazard ratio (HR), 2.419; P = 0.032). Survival after concurrent LR and DM in the non-NED group was significantly shorter than that in the NED group (median survival, 32 vs. 46 months; HR, 2.7; P = 0.014).

Conclusions

The pattern and treatment outcome of RC with concurrent LR and DM after TME has changed with the development of multiple treatment modalities. Although the prognosis remains poor, pursuing NED status through comprehensive treatments may improve the survival of RC patients with concurrent LR and DM after TME.

Bowel seromuscular flaps used to repair pelvic defects in patients undergoing reoperative surgery

BACKGROUND

Pedicled seromuscular bowel flaps may serve as an alternative for pelvic floor reconstruction when conventional omental and muscular flaps are not an option in patients undergoing reoperative abdominopelvic surgery. The aim of this study was to evaluate a unique series of bowel seromuscular flaps used to obliterate intrapelvic defects.

METHODS

We conducted a retrospective study on all patients in a single tertiary care institutional database who had undergone pelvic reconstruction with a seromuscular bowel flap from January 2006 to December 2018. The primary outcomes measured were the 30-day morbidity and mortality rates.

RESULTS

Twelve patients (6 men 6 women, median age 56.5 years [range 33-77 years]) underwent reoperative abdominopelvic surgery requiring the use of a native small or large seromuscular bowel flap to obliterate pelvic defects. The indications for surgery included chronic infections, fistulizing Crohn's disease, and cancer. In all cases, no residual omentum was available and rectus abdominis muscle flaps were not feasible due to prior operative scars. Thirty-day morbidity occurred in 5 patients (42%), and included urine leak from ureteral injury, anastomotic leak, acute kidney injury, and superficial surgical site infection. No flaps became ischemic or required removal in the postoperative setting. No mortality was recorded.

CONCLUSIONS

Bowel seromuscular flaps are a feasible and safe alternative for covering pelvic defects in patients who are undergoing reoperative surgery without the option to use traditional omental and muscular flaps.

Analysis of Prognostic Factors of Rectal Cancer and Construction of a Prognostic Prediction Model Based on Bayesian Network

Background

The existing prognostic models of rectal cancer after radical resection ignored the relationships among prognostic factors and their mutual effects on prognosis. Thus, a new modeling method is required to remedy this defect. The present study aimed to construct a new prognostic prediction model based on the Bayesian network (BN), a machine learning tool for data mining, clinical decision-making, and prognostic prediction.

Methods

From January 2015 to December 2017, the clinical data of 705 patients with rectal cancer who underwent radical resection were analyzed. The entire cohort was divided into training and testing datasets. A new prognostic prediction model based on BN was constructed and compared with a nomogram.

Results

A univariate analysis showed that age, Carcinoembryonic antigen (CEA), Carbohydrate antigen19-9 (CA19-9), Carbohydrate antigen 125 (CA125), preoperative chemotherapy, macropathology type, tumor size, differentiation status, T stage, N stage, vascular invasion, KRAS mutation, and postoperative chemotherapy were associated with overall survival (OS) of the training dataset. Based on the above-mentioned variables, a 3-year OS prognostic prediction BN model of the training dataset was constructed using the Tree Augmented Naïve Bayes method. In addition, age, CEA, CA19-9, CA125, differentiation status, T stage, N stage, KRAS mutation, and postoperative chemotherapy were identified as independent prognostic factors of the training dataset through multivariate Cox regression and were used to construct a nomogram. Then, based on the testing dataset, the two models were evaluated using the receiver operating characteristic (ROC) curve. The results showed that the area under the curve (AUC) of ROC of the BN model and nomogram was 80.11 and 74.23%, respectively.

Conclusion

The present study established a BN model for prognostic prediction of rectal cancer for the first time, which was demonstrated to be more accurate than a nomogram.

Application of Transurethral Prostate Resection Instrumentation for Treating Low Rectal Anastomotic Leakage: A Pilot Study

PURPOSE

To determine an accurate method of inspecting low anastomotic leakages and application of transurethral prostate resection instrumentation for treating low rectal anastomotic leakage.

PATIENTS AND METHODS

Clinical data of eight patients treated for anastomotic leakage after rectal cancer surgery at Zhangye People's Hospital (affiliated to Hexi University), from August 2019 to November 2021, were retrospectively analyzed. Transanal prostate resection instrumentation was used to assess the leakage and surrounding conditions. Using prostate resection instrumentation, the presacral and perirectal residual cavities were washed and removed, and indwelling suprapubic presacral, transanal presacral, and rectal drainage tubes were placed. Continuous presacral saline irrigation and drainage and open negative-pressure suction in the rectal cavity were performed until the patients' fistula healed.

RESULTS

Of the eight patients with anastomotic leakages, one had grade B and seven had grade C International Study Group of Rectal Cancer anastomotic leakage classifications following Dixon operation. Transanal prostate resection instrumentation showed that the leakage of the one patient with grade B was less than a third of the circumference of the anastomosis. Among the seven patients with grade C, one leakage was less than a third of the anastomotic circumference. One patient had complete separation of the anastomosis and one distal colon necrosis, which necessitated immediate descending colostomy. Conservative treatment was successful in six patients; the conservative overall cure rate was 75%, and the median healing time was 43 (21-68) days.

CONCLUSION

Transanal examination of rectal anastomotic leakage using prostate resection instrumentation is comprehensive, easy to perform, provides clear visualization, accurately guides catheter placement, and can be combined with continuous open negative-pressure drainage, which is a safe, convenient, and effective method for treating low rectal leakage.

Prognostic and clinical significance of subcellular CDC27 for patients with rectal adenocarcinoma treated with adjuvant chemotherapy

Rectal adenocarcinoma (READ) constitutes one-third of newly diagnosed colorectal cancer cases. Surgery, chemotherapy and concurrent chemoradiotherapy are the main treatments to improve patient outcomes for READ. However, patients with READ receiving these treatments eventually relapse, leading to a poor survival outcome. The present study collected surgical specimens from patients with READ and determined that cytoplasmic cell division cycle 27 (CDC27) expression was associated with the risk of lymph node metastasis and distant metastasis. Nuclear CDC27 expression was negatively associated with 5-year disease-free survival (DFS) and 5-year overall survival (OS) rates. Multivariate Cox proportional regression analysis showed that nuclear CDC27 was an independent prognostic factor in the patients with READ, especially in those treated with adjuvant chemotherapy. High nuclear CDC27 expression was significantly associated with poorer 5-year DFS (HR, 2.106; 95% CI, 1.275-3.570; P=0.003) and 5-year OS (HR, 2.369; 95% CI, 1.270-4.6810; P=0.005) rates. The data indicated that cytoplasmic CDC27 expression could affect tumor progression and that it plays an important role in metastasis. Nuclear CDC27 expression was markedly associated with poorer survival outcomes and was an independent prognostic factor in patients with postoperative adjuvant chemotherapy-treated READ. Thus, CDC27 expression serves as a potential prognostic marker for rectal tumor progression and chemotherapy treatment.

Apoptosis-Associated Gene Expression Profiling Is One New Prognosis Risk Predictor of Human Rectal Cancer

Background. Prior research has revealed the predictive significance of a series of genetic markers in the prognosis of rectal cancer (RC), but the roles of apoptosis-associated genes in RC are rarely studied. Methods. The RNA-seq data as well as clinical data about patients with rectum adenocarcinoma (READ) were downloaded from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) project. Additionally, 87 apoptosis-associated genes were downloaded and acquired from Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Comprehensive bioinformatics analysis was carried out for deep exploration of the expression and prognostic significance of these genes. Least absolute shrinkage and selection operator (LASSO) and multivariate Cox regression analysis was performed for the establishment of a risk scoring equation for the prognosis model and construction of a survival prognosis model. ROC curves were drawn for evaluating the accuracy of the model. A real-time quantitative PCR assay was conducted for quantification of apoptosis-associated proteins related to prognosis. Results. Eight genes were identified as hub genes associated with the prognosis of PFS. A risk model of prognosis prediction based on four gene signatures (CYCS, IKBKB, NFKB1, and TRADD) was constructed. According to further analysis of this model, the high-risk group experienced worse overall survival than the other. The prognosis model demonstrated a favorable predictive ability, with areas under the receiver operating characteristic curves (AUC) of 0.720, 0.641, and 0.677 in forecasting the 1-, 2-, and 3-year prognosis, respectively. In addition, CYCS and NFKB1 presented low expression, while IKBKB and TRADD presented high expression in TCGA and clinical tumor samples. Conclusions. A four-gene signature risk model for prognosis forecasting of RC has been constructed, which possesses favorable predictive ability, which offers ideas and breakthrough points to the apoptosis-associated development of RC.

Submucosal resection via a transanal approach for treatment of epithelial rectal tumors - a multicenter study

OBJECTIVE

To report complications and long-term outcomes after submucosal resections of benign and malignant epithelial rectal masses.

STUDY DESIGN

Retrospective multicentric study.

SAMPLE POPULATION

Medical records of 93 dogs at 7 referral hospitals.

METHODS

Records were reviewed for surgical time, diagnosis, margins, complications, and recurrences. Survival of dogs was evaluated based on tumor types, categorized as benign, carcinoma in situ, and carcinoma. The Kaplan-Meier survival curve and Cox proportional hazards analysis were used to determine the association of a range of variables with recurrence and survival time.

RESULTS

Duration of follow up was 708 days (range, 25-4383). Twenty-seven dogs (29%) developed complications. Recurrence was identified in 20/93 (21%), with 12/20 recurrent masses treated with repeat submucosal resection. Median survival was not reached in any group. The 1-,2-, 5-year survival rates for carcinomas were 95%, 89%, and 73% respectively. However, overall survival was longer for benign tumors than carcinomas (P = .001). Recurrence was more likely when complications (P = .032) or incomplete margins (P = .023) were present. Recurrence was associated with an increased risk of death (P = .046).

CONCLUSION

Submucosal resection of both benign and malignant rectal masses was associated with a low rate of severe complications and prolonged survival in the 93 dogs described here.

CLINICAL SIGNIFICANCE

Submucosal resection is a suitable technique for resection of selected rectal masses.

Temporary vs. permanent stoma: factors associated with the development of complications and costs for rectal cancer patients

OBJECTIVE

To compare in-hospital complication rates and treatment costs between rectal cancer patients receiving permanent and temporary stomas. Surgical complications and costs associated with permanent stoma formation are still poorly understood. While choosing between the two stoma options is usually based on clinical and technical factors, disparities exist.

METHODS

Patients with rectal cancer, stoma formation, complications, and cost of care were identified from the Florida Agency for Health Care Administration Discharge Database. Rectal cancer patients who underwent elective surgery and received a permanent or temporary stoma were identified using ICD-10 codes. Patients who underwent colostomy with resection were included in the "Permanent stoma" group, and those who underwent "resection with ileostomy" were included in the "temporary stoma" group. Multivariable models compared patients receiving temporary vs. permanent stomas.

RESULTS

Regression models revealed no difference in the odds of having a complication between patients who obtained permanent versus temporary stoma (OR 0.96, 95% CI: 0.70-1.32). Further, after adjusting for the number of surgeries, demographic variables, socioeconomic and regional factors, comorbidities, and type of surgery, there was a significant difference between permanent and temporary stomas for rectal cancer (ß - 0.05, p = 0.03) in the log cost of creating a permanent stoma.

CONCLUSION

Our findings suggest there are no differences associated with complications, and reduced cost for permanent compared to temporary stomas. Increased costs are also associated with receiving minimally invasive surgery. As a result, disparities associated with receipt of MIS could ultimately influence the type of stoma received.

Magnetic Resonance Image under the Low-Rank Matrix Denoising Algorithm in Evaluating the Efficacy of Neoadjuvant Chemo-Radiotherapy for Rectal Cancer

This study was to explore the application value of magnetic resonance imaging (MRI) images obtained by low-rank matrix recovery algorithm (LRMR algorithm) in evaluating the curative effect of rectal cancer patients receiving the neoadjuvant chemo-radiotherapy (nCRT). In this study, an image denoising model was designed based on the LRMR algorithm, the original low-rank data matrix was recovered from the error, and the low-rank matrix was restored by solving the optimal kernel norm, so as to effectively separate the image data information and the interference noise. In addition, the model was applied to 60 patients with rectal cancer who received nCRT to extract the texture parameters and lesion-related data from the MRI images. The results showed that the MRI images optimized by LRMR algorithm were clearer than the original images, contained less excess noise, and had improved imaging accuracy and image quality. The results of typical cases suggested that the front of the rectal wall membrane of a patient in the T-downstage group was not smooth before treatment, the internal angiography was blurred, and the wall membrane was thickened, but the wall membrane became thinner after treatment, the highest position was reduced from 1.46 cm to 0.38 cm, the average value of the apparent diffusion coefficient (ADC) increased from 0.732 × 10−3 mm2/s to 1.196 × 10−3 mm2/s, and the lesion tissue was thicker. It was found that the height, length, and ADC of the lesion after the nCRT showed statistically great difference in contrast to the values before the treatment $\left(P<0.05\right)$ . Such results indicated that the nCRT showed obvious effects in the clinical treatment of rectal cancer. In short, the LRMR algorithm could remove the interference noise in the MRI image, and from the information about rectal cancer tumor lesions extracted from that, the height value and length value of tumor lesions in patients given neoadjuvant chemo-radiotherapy were reduced compared with those before treatment, and the apparent diffusion coefficient value was increased, indicating that neoadjuvant chemo-radiotherapy has a significant effect in the clinical treatment of rectal cancer.

Minimally Invasive Endoscopic and Surgical Management of Rectal Neoplasia

Rectal cancer demonstrates a characteristic natural history in which benign rectal neoplasia precedes malignancy. The worldwide burden of rectal cancer is significant, with rectal cancer accounting for one-third of colorectal cancer cases annually. The importance of early detection and successful management is essential in decreasing its clinical burden. Minimally invasive treatment of rectal neoplasia has evolved over the past several decades, which has led to reduced local recurrence rates and improved survival outcomes. The approach to diagnosis, staging, and selection of appropriate treatment modalities is a multidisciplinary effort combining interventional endoscopy, surgery, and radiology tools. This review examines the currently available minimally invasive endoscopic and surgical management options of rectal neoplasia.

Amide Proton Transfer Weighted and Intravoxel Incoherent Motion Imaging in Evaluation of Prognostic Factors for Rectal Adenocarcinoma

Objectives

To analyze the value of amide proton transfer (APT) weighted and intravoxel incoherent motion (IVIM) imaging in evaluation of prognostic factors for rectal adenocarcinoma, compared with diffusion weighted imaging (DWI).

Materials and Methods

Preoperative pelvic MRI data of 110 patients with surgical pathologically confirmed diagnosis of rectal adenocarcinoma were retrospectively evaluated. All patients underwent high-resolution T₂-weighted imaging (T₂WI), APT, IVIM, and DWI. Parameters including APT signal intensity (APT SI), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), and apparent diffusion coefficient (ADC) were measured in different histopathologic types, grades, stages, and structure invasion statuses. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic efficacy, and the corresponding area under the curves (AUCs) were calculated.

Results

APT SI, D and ADC values of rectal mucinous adenocarcinoma (MC) were significantly higher than those of rectal common adenocarcinoma (AC) ([3.192 ± 0.661%] vs. [2.333 ± 0.471%], [1.153 ± 0.238×10^-3 mm²/s] vs. [0.792 ± 0.173×10^-3 mm²/s], and [1.535 ± 0.203×10^-3 mm²/s] vs. [0.986 ± 0.124×10^-3 mm²/s], respectively; all P<0.001). In AC group, the APT SI and D values showed significant differences between low- and high-grade tumors ([2.226 ± 0.347%] vs. [2.668 ± 0.638%], and [0.842 ± 0.148×10^-3 mm²/s] vs. [0.777 ± 0.178×10^-3 mm²/s], respectively, both P<0.05). The D value had significant difference between positive and negative extramural vascular invasion (EMVI) tumors ([0.771 ± 0.175×10^-3 mm²/s] vs. [0.858 ± 0.151×10^-3 mm²/s], P<0.05). No significant difference of APT SI, D, D*, f or ADC was observed in different T stages, N stages, perineural and lymphovascular invasions (all P>0.05). The ROC curves showed that the AUCs of APT SI, D and ADC values for distinguishing MC from AC were 0.921, 0.893 and 0.995, respectively. The AUCs of APT SI and D values in distinguishing low- from high-grade AC were 0.737 and 0.663, respectively. The AUC of the D value for evaluating EMVI involvement was 0.646.

Conclusion

APT and IVIM were helpful to assess the prognostic factors related to rectal adenocarcinoma, including histopathological type, tumor grade and the EMVI status.

Brazilian society of surgical oncology: Guidelines for the surgical treatment of mid-low rectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer in North America, Western Europe, and Brazil, and represents an important public health problem. It is estimated that approximately 30% of all the CRC cases correspond to tumors located in the rectum, requiring complex multidisciplinary treatment. In an effort to provide surgeons who treat rectal cancer with the most current information based on the best evidence in the literature, the Brazilian Society of Surgical Oncology (SBCO) has produced the present guidelines for rectal cancer treatment that is focused on the main topics related to daily clinical practice.

OBJECTIVES

The SBCO developed the present guidelines to provide recommendations on the main topics related to the treatment of mid-low rectal cancer based on current scientific evidence.

METHODS

Between May and June 2021, 11 experts in CRC surgery met to develop the guidelines for the treatment of mid-low rectal cancer. A total of 22 relevant topics were disseminated among the participants. The methodological quality of a final list with 221 sources was evaluated, all the evidence was examined and revised, and the treatment guideline was formulated by the 11-expert committee. To reach a final consensus, all the topics were reviewed via a videoconference meeting that was attended by all 11 of the experts.

RESULTS

The prepared guidelines contained 22 topics considered to be highly relevant in the treatment of mid-low rectal cancer, covering subjects related to the tests required for staging, surgical technique-related aspects, recommended measures to reduce surgical complications, neoadjuvant strategies, and nonoperative treatments. In addition, a checklist was proposed to summarize the important information and offer an updated tool to assist surgeons who treat rectal cancer provide the best care to their patients.

CONCLUSION

These guidelines summarize concisely the recommendations based on the most current scientific evidence on the most relevant aspects of the treatment of mid-low rectal cancer and are a practical guide that can help surgeons who treat rectal cancer make the best therapeutic decision.

Efficacy and safety of intraoperative radiotherapy in rectal cancer: A systematic review and meta-analysis

BACKGROUND

In recent years, intraoperative radiotherapy (IORT) has been increasingly used for the treatment of rectal cancer. However, the efficacy and safety of IORT for the treatment of rectal cancer are still controversial.

AIM

To evaluate the value of IORT for patients with rectal cancer.

METHODS

We searched PubMed, Embase, Cochrane Library, Web of Science databases, and conference abstracts and included randomized controlled trials and observational studies on IORT vs non-IORT for rectal cancer. Dichotomous variables were evaluated by odds ratio (OR) and 95% confidence interval (CI), hazard ratio (HR) and 95%CI was used as a summary statistic of survival outcomes. Statistical analyses were performed using Stata V.15.0 and Review Manager 5.3 software.

RESULTS

In this study, 3 randomized controlled studies and 12 observational studies were included with a total of 1460 patients, who are mainly residents of Europe, the United States, and Asia. Our results did not show significant differences in 5-year overall survival (HR = 0.80, 95%CI = 0.60-1.06; P = 0.126); 5-year disease-free survival (HR = 0.94, 95%CI = 0.73-1.22; P = 0.650); abscess (OR = 1.10, 95%CI = 0.67-1.80; P = 0.713), fistulae (OR = 0.79, 95%CI = 0.33-1.89; P = 0.600); wound complication (OR = 1.21, 95%CI = 0.62-2.36; P = 0.575); anastomotic leakage (OR = 1.09, 95%CI = 0.59-2.02; P = 0.775); and neurogenic bladder dysfunction (OR = 0.69, 95%CI = 0.31-1.55; P = 0.369). However, the meta-analysis of 5-year local control was significantly different (OR = 3.07, 95%CI = 1.66-5.66; P = 0.000).

CONCLUSION

The advantage of IORT is mainly reflected in 5-year local control, but it is not statistically significant for 5-year overall survival, 5-year disease-free survival, and complications.