Neoadjuvant radiotherapy improves overall survival for T3/4N+M0 rectal cancer patients: a population-based study of 20300 patients

Synbiotics protected radiation-induced tissue damage in rectal cancer patients: A controlled trial

BACKGROUND & AIMS

Colorectal cancer (CRC), particularly rectal cancer, often requires neoadjuvant radiotherapy (RT) as part of its treatment plan. Although effective, RT can cause significant gastrointestinal side effects. Because the onset of RT-induced tissue injury can be anticipated, there is an opportunity to apply preventive measures before the damage occurs. This study aimed to assess whether prebiotic and synbiotic interventions could mitigate RT-induced gut injury by modulating the mucosa-associated microbiota, reducing inflammation, and enhancing gut barrier function in patients undergoing RT for rectal cancer.

METHODS

Thirty patients with rectal adenocarcinoma scheduled for preoperative short-term RT (5 × 5 Gy) were divided into three groups: a control group (Ctrl), a prebiotic group (Fiber) receiving oat bran, and a synbiotic group (Synbiotics) receiving oat bran with L. plantarum HEAL19 and blueberry husks. The study products were administered daily for two weeks, starting one week before RT. Blood, faecal, and biopsy samples were collected before and after RT to evaluate inflammatory markers, intestinal permeability, histopathological changes, and mucosa-associated microbiota.

RESULTS

The Fiber and Synbiotics groups exhibited a significant reduction in white blood cell counts following RT (p = 0.01 for both), whereas the Ctrl group did not demonstrate a significant change. However, there was no significant difference in the magnitude of change in white blood cell counts among the three groups (p = 0.12). Histopathological analysis revealed that the Synbiotics group had reduced inflammation and fibrosis compared to the Fiber and Ctrl groups. Although RT reduced bacterial diversity overall, the Synbiotics group preserved a greater proportion of bacterial species, experiencing only a 25.1 % reduction compared to a 55.4 % reduction in the Fiber group.

CONCLUSION

Synbiotic interventions may protect rectal mucosa by reducing inflammation and modulating mucosa-associated microbiota. The effects were primarily localized to the tissue, reflecting the short-term duration of treatment. While immediate benefits were observed, longer-term interventions should be explored to reduce systemic inflammation.

Predicting pathological response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer with two step feature selection and ensemble learning

Patients with locally advanced rectal cancer (LARC) show substantial individual variability and a pronounced imbalance in response distribution to neoadjuvant chemoradiotherapy (nCRT), posing significant challenges to treatment response prediction. This study aims to identify effective predictive biomarkers and develop an ensemble learning-based prediction model to assess the response of LARC patients to nCRT. A two-step feature selection method was developed to identify predictive biomarkers by deriving stable reversal gene pairs through within-sample relative expression orderings (REOs) from LARC patients undergoing nCRT. Preliminary screening utilized four methods-MDFS, Boruta, MCFS, and VSOLassoBag-to form a candidate feature set. Secondary screening ranked these features by permutation importance, applying Incremental Feature Selection (IFS) with an Extreme Gradient Boosting (XGBoost) to determine final predictive gene pairs. The ensemble model BoostForest, combining boosting and bagging, served as the predictive framework, with SHAP employed for interpretability. Through two-step feature selection, the 32-gene pair signature (32-GPS) was established as the final predictive biomarker. In the test set, the model achieved an area under the precision-recall curve (AUPRC) of 0.983 and an accuracy of 0.988. In the validation cohort, the AUPRC was 0.785, with an accuracy of 0.898, indicating strong model performance. The study further demonstrated that BoostForest achieved superior overall performance compared to Random Forest, Support Vector Machine (SVM), and XGBoost. To evaluate the effectiveness of the 32-GPS, its performance was compared with two alternative feature sets: the lasso-gene pair signature (lasso-GPS), derived through lasso regression, and the 15-shared gene pair signature (15-SGPS), consisting of gene pairs identified by all four feature selection methods. The 32-GPS demonstrated superior performance in both comparisons. The two-step feature selection method identified robust predictive biomarkers, and BoostForest outperformed Random Forest, Support Vector Machine, and XGBoost in classification performance and predictive capability.

Effects of PreOperative radiotherapy in a preclinical glioblastoma model: a paradigm-shift approach

PURPOSE

PreOperative radiotherapy (RT) is commonly used in the treatment of brain metastasis and different cancer types but has never been used in primary glioblastoma (GBM). Here, we aim to establish, describe, and validate the use of PreOperative RT for the treatment of GBM in a preclinical model.

METHODS

Rat brains were locally irradiated with 30-Gy, hypofractionated in five doses 2 weeks before or after the resection of intracranial GBM. Kaplan-Meier analysis determined survival. Hematoxylin-eosin staining was performed, and nuclei size and p21 senescence marker were measured in both resected and recurrent rodent tumors. Immunohistochemistry assessed microglia/macrophage markers, and RNAseq analyzed gene expression changes in recurrent tumors. Akoya Multiplex Staining on two human patients from our ongoing Phase I/IIa trial served as proof of principle.

RESULTS

PreOperative RT group median survival was significantly higher than PostOperative RT (p < 0.05). Radiation enlarged cytoplasm and nuclei in PreOperative RT resected tumors (p < 0.001) and induced senescence in PostOperative RT recurrent tumors (p < 0.05). Gene Set Enrichment Analysis (GSEA) suggested a more proliferative profile in PreOperative RT group. PreOperative RT showed lower macrophage/microglia recruitment in recurrent tumors (p < 0.01) compared to PostOperative RT. Akoya Multiplex results indicated TGF-ß accumulation in the cytoplasm of TAMs and CD4 + lymphocyte predominance in PostOperative group.

CONCLUSIONS

This is the first preclinical study showing feasibility and longer overall survival using neoadjuvant radiotherapy before GBM resection in a mammalian model. This suggests strong superiority for new clinical radiation strategies. Further studies and trials are required to confirm our results.

Clinical development of MRI-based multi-sequence multi-regional radiomics model to predict lymph node metastasis in rectal cancer

OBJECTIVE

We aim to construct a magnetic resonance imaging (MRI)-based multi-sequence multi-regional radiomics model that will improve the preoperative prediction ability of lymph node metastasis (LNM) in T3 rectal cancer.

METHODS

Multi-sequence MRI data from 190 patients with T3 rectal cancer were retrospectively analyzed, with 94 patients in the LNM group and 96 patients in the non-LNM group. The clinical factors, subjective imaging features, and the radiomic features of tumor and peritumoral mesorectum region of patients were extracted from T2WI and ADC images. Spearman's rank correlation coefficient, Mann-Whitney's U test, and the least absolute shrinkage and selection operator were used for feature selection and dimensionality reduction. Logistic regression was used to construct six models. The predictive performance of each model was evaluated by the receiver operating characteristic curve (ROC). The differences of each model were characterized by area under the curve (AUC) via the DeLong test.

RESULTS

The AUCs of T2WI, ADC single-sequence radiomics model and multi-sequence radiomics model were 0.73, 0.75, and 0.78, respectively. The multi-sequence multi-regional radiomics model with improved performance was created by combining the radiomics characteristics of the peritumoral mesorectum region with the multi-sequence radiomics model (AUC, 0.87; p < 0.01). The AUC of the clinical model was 0.68, and the MRI-clinical composite evaluation model was obtained by incorporating the clinical data with the multi-sequence multi-regional radiomics features, with an AUC of 0.89.

CONCLUSION

The MRI-based multi-sequence multi-regional radiomics model significantly improved the prediction ability of LNM for T3 rectal cancer and could be applied to guide surgical decision-making in patients with T3 rectal cancer.

A Propensity Score-Matched Analysis of the Impact of Neoadjuvant Radiation Therapy on the Outcomes of Stage II and III Mucinous Rectal Carcinoma

BACKGROUND

Patients with mucinous rectal carcinoma tend to present in advanced stage with a poor prognosis.

OBJECTIVE

This study aimed to assess the effect of neoadjuvant radiation therapy on outcomes of patients with stage II and III mucinous rectal carcinomas using data from the National Cancer Database.

DESIGN

Retrospective analysis of prospective national databases.

SETTING

National Cancer Database between 2004 and 2019.

PATIENTS

Patients with mucinous rectal carcinoma.

INTERVENTION

Patients who did or did not receive neoadjuvant radiation therapy were matched using the nearest-neighbor propensity score method for age, clinical stage, neoadjuvant systemic treatment, and surgery type.

MAIN OUTCOME MEASURES

Main outcomes of the study were numbers of total harvested and positive lymph nodes, disease downstaging after neoadjuvant radiation, and overall survival. Other outcomes were hospital stay, short-term mortality, and readmission.

RESULTS

A total of 3062 patients (63.5% men) with stage II and III mucinous rectal carcinoma were included, 2378 of whom (77.7%) received neoadjuvant radiation therapy. After 2:1 propensity score matching, 143 patients in the no neoadjuvant group were matched to 286 patients in the neoadjuvant group. The mean overall survival was similar (77.3 vs 81.9 months; p = 0.316). Patients who received neoadjuvant radiation therapy were less often diagnosed with pathologic T3 and 4 disease (72.3% vs 81.3%, p = 0.013) and more often had pathologic stage 0 and 1 disease (16.4% vs 11.2%, p = 0.001), yet with a higher stage III disease (49.7% vs 37.1%, p = 0.001). Neoadjuvant radiation was associated with fewer examined lymph nodes (median: 14 vs 16, p = 0.036) and positive lymph nodes than patients who did not receive neoadjuvant radiation. Short-term mortality, readmission, hospital stay, and positive surgical margins were similar.

LIMITATIONS

Retrospective study and missing data on disease recurrence.

CONCLUSIONS

Patients with mucinous rectal carcinoma who received neoadjuvant radiation therapy had marginal downstaging of disease, fewer examined and fewer positive lymph nodes, and similar overall survival to patients who did not receive neoadjuvant radiation. See Video Abstract .

UN ANLISIS EMPAREJADO POR PUNTUACIN DE PROPENSIN DEL IMPACTO DE LA RADIOTERAPIA NEOADYUVANTE EN LOS RESULTADOS DEL CARCINOMA MUCINOSO DE RECTO EN ESTADIO IIIII

ANTECEDENTES:Los pacientes con carcinoma mucinoso de recto tienden a presentarse en estadio avanzado con mal pronóstico.OBJETIVO:Este estudio tuvo como objetivo evaluar el efecto de la radioterapia neoadyuvante en los resultados de pacientes con carcinomas mucinosos de recto en estadio II-III utilizando datos de la Base de Datos Nacional del Cáncer.DISEÑO:Análisis retrospectivo de bases de datos nacionales prospectivas.PACIENTES:Pacientes con carcinoma mucinoso de recto.AJUSTE:Base de datos nacional sobre el cáncer entre 2004 y 2019.INTERVENCIÓN:Los pacientes que recibieron o no radioterapia neoadyuvante fueron emparejados utilizando el método de puntuación de propensión del vecino más cercano por edad, estadio clínico, tratamiento sistémico neoadyuvante y tipo de cirugía.PRINCIPALES MEDIDAS DE VALORACIÓN:Los principales resultados del estudio fueron el número total de ganglios linfáticos extraídos y positivos, la reducción del estadio de la enfermedad después de la radiación neoadyuvante y la supervivencia general. Otros resultados fueron la estancia hospitalaria, la mortalidad a corto plazo y el reingreso.RESULTADOS:Se incluyeron 3.062 pacientes (63,5% hombres) con carcinoma mucinoso de recto estadio II-III, de los cuales 2.378 (77,7%) recibieron radioterapia neoadyuvante. Después de un emparejamiento por puntuación de propensión 2:1, 143 pacientes del grupo sin neoadyuvancia fueron emparejados con 286 del grupo neoadyuvante. La supervivencia global media fue similar (77,3 vs 81,9 meses; p = 0,316). A los pacientes que recibieron radiación neoadyuvante se les diagnosticó con menos frecuencia enfermedad pT3-4 (72,3% frente a 81,3%, p = 0,013) y con mayor frecuencia tenían enfermedad en estadio patológico 0-1 (16,4% frente a 11,2%, p = 0,001), aunque con una enfermedad en estadio III superior (49,7% vs 37,1%, p = 0,001). La radiación neoadyuvante se asoció con menos ganglios linfáticos examinados (mediana: 14 frente a 16, p = 0,036) y ganglios linfáticos positivos que los pacientes que no recibieron radiación neoadyuvante. La mortalidad a corto plazo, el reingreso, la estancia hospitalaria y los márgenes quirúrgicos positivos fueron similares.LIMITACIONES:Estudio retrospectivo y datos faltantes sobre recurrencia de la enfermedad.CONCLUSIONES:Los pacientes con carcinoma mucinoso de recto que recibieron radioterapia neoadyuvante tuvieron una reducción marginal de la enfermedad, menos ganglios linfáticos examinados y positivos, y una supervivencia general similar a la de los pacientes que no recibieron radiación neoadyuvante. (Traducción- Dr Ingrid Melo ).

Proteomic and metabolomic signatures of rectal tumor discriminate patients with different responses to preoperative radiotherapy

Background

Neoadjuvant radiotherapy (neo-RT) is widely used in locally advanced rectal cancer (LARC) as a component of radical treatment. Despite the advantages of neo-RT, which typically improves outcomes in LARC patients, the lack of reliable biomarkers that predict response and monitor the efficacy of therapy, can result in the application of unnecessary aggressive therapy affecting patients' quality of life. Hence, the search for molecular biomarkers for assessing the radio responsiveness of this cancer represents a relevant issue.

Methods

Here, we combined proteomic and metabolomic approaches to identify molecular signatures, which could discriminate LARC tumors with good and poor responses to neo-RT.

Results

The integration of data on differentially accumulated proteins and metabolites made it possible to identify disrupted metabolic pathways and signaling processes connected with response to irradiation, including ketone bodies synthesis and degradation, purine metabolism, energy metabolism, degradation of fatty acid, amino acid metabolism, and focal adhesion. Moreover, we proposed multi-component panels of proteins and metabolites which could serve as a solid base to develop biomarkers for monitoring and predicting the efficacy of preoperative RT in rectal cancer patients.

Conclusion

We proved that an integrated multi-omic approach presents a valid look at the analysis of the global response to cancer treatment from the perspective of metabolomic reprogramming.

Survival outcomes of different neoadjuvant treatment regimens in patients with locally advanced rectal cancer and MRI-detected extramural venous invasion

PURPOSE

MRI-detected extramural venous invasion (mrEMVI) is associated with poor survival outcomes in patients with locally advanced rectal cancer (LARC). An mrEMVI-positive status is considered a strong indication for neoadjuvant treatment, but the optimal regimen is unknown.

PATIENTS AND METHODS

We retrospectively compared pathological and survival outcomes of 584 patients diagnosed with mrEMVI-positive rectal cancer between January 2013 and October 2021, and receiving either neoadjuvant chemotherapy (NCT) alone, neoadjuvant chemoradiotherapy (nCRT) alone, or nCRT plus NCT, prior to total mesorectal excision. Propensity score matching (PSM) was used to balance clinical bias between groups, which were compared using chi-square testing and Kaplan-Meier curves.

RESULTS

Median follow-up was 33.9 (range, 10.2-100.4) months. The 3-year overall survival (OS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRFS) rates for all patients were 90.4%, 57.5%, 61.1%, and 85.7%, respectively. Of 584 mrEMVI-positive patients at the time of diagnosis, 457 (78.3%) were EMVI-negative on surgical pathology, and they had significantly better 3-year OS, DMFS, DFS, and LRFS rates (all p < 0.001) than patients who remained EMVI-positive. After PSM was applied, patients receiving nCRT alone had significantly better 3-year OS (96.8% vs. 86.5%, p = 0.005) and DMFS (67.1% vs. 53.5%, p = 0.03) rates than those receiving NCT alone. Patients receiving NCT plus nCRT had higher pathological complete response (PCR) (10.8% vs. 2.7%, p = 0.04) and downstaging (33.8% vs. 5.3%, p < 0.001) rates than those receiving nCRT alone, but survival rates did not differ (all p > 0.05).

CONCLUSION

Most EMVI-positive patients with LARC converted to EMVI-negative after neoadjuvant treatment, resulting in improved OS and DFS. Patients receiving nCRT had more favorable survival outcomes than those receiving NCT, suggesting the importance of including neoadjuvant radiotherapy. Patients receiving NCT in addition to nCRT had higher rates of PCR and downstaging, but their survival rates were not better.

Preoperative Radiotherapy Decision-Tree for Rectal Cancer Patients: A Real-World Analysis Based on the Swedish Colorectal Cancer Registry

BACKGROUND

There are 3 widely used preoperative radiotherapy (RT) procedures in rectal cancer treatment including long-course RT (LRT), short-course RT with delayed surgery (SRTW), and short-course RT with immediate surgery (SRT). However, further evidence is required to determine which treatment option results in more optimal patient survival.

METHODS

This Swedish Colorectal Cancer Registry-based retrospective study of real-world data included 7766 stage I-III rectal cancer patients, of which 2982, 1089, 763, and 2932 patients received no RT (NRT), LRT, SRTW, and SRT, respectively. The Kaplan-Meier survival curve and Cox proportional hazard multivariate model were used to identify potential risk factors and to examine the independent association of RT with patient survival after adjusting for baseline confounding factors.

RESULTS

RT effects on survival differed by age and clinical T stage (cT) subgroups. Subsequent survival analysis by age and cT subgroups confirmed that patients ≥70 years old with cT4 benefited from any RT (P < .001, NRT as reference) and equally from any RT (P > .05 pairwise between RTs). In contrast, for cT3 patients ≥70 years, SRT and LRT were associated with better survival than SRTW (P < .001). In patients <70 years, LRT and SRTW had superior survival benefits in cT4 patients but inferior to SRT (P < .001); SRT was the only effective treatment in the cT3N+ subgroup (P = .032); patients with cT3N0 and <70 years did not benefit from any RT.

CONCLUSION

This study suggests that preoperative RT strategies may have varying effects on the survival of rectal cancer patients, depending on their age and clinical stage.

pCR and 2-Year Disease-Free Survival: A Combination of the Two Endpoints as a New Classification for Locally Advanced Rectal Cancer Patients-An Updated Pooled Analysis of Eleven International Randomized Trials

LARC is managed by multimodal treatments whose intensity can be highly modulated. In this context, we need surrogate endpoints to help predict long-term outcomes and better personalize treatments. A previous study identified 2yDFS as a stronger predictor of OS than pCR in LARC patients undergoing neoadjuvant RT. The aim of this pooled analysis was to assess the role of pCR and 2yDFS as surrogate endpoints for OS in a larger cohort. The pooled and subgroup analyses were performed on large rectal cancer randomized trial cohorts who received long-course RT. Our analysis focused on the evaluation of OS in relation to the pCR and 2-year disease status. A total of 4600 patients were analyzed. Four groups were identified according to intermediate outcomes: 12% had both pCR and 2yDFS (the better); 67% achieved 2yDFS but not pCR (the good); 1% had pCR but not 2yDFS; and 20% had neither pCR nor 2yDFS (the bad). The pCR and 2yDFS were favorably associated with OS in the univariate analysis, and 2yDFS maintained a statistically significant association in the multivariate analysis independently of the pCR status. The combination of the pCR and 2yDFS results in a strong predictor of OS, whereas failure to achieve 2yDFS carries a poor prognosis regardless of the pCR status. This new stratification of LARC patients could help design predictive models where the combination of 2yDFS and pCR should be employed as the primary outcome.

Trends in the Characteristics, Treatment, and Outcomes of Rectal Adenocarcinoma in the US From 2004 to 2019: A National Cancer Database Analysis

IMPORTANCE

Rectal cancer management has significantly evolved over the last 2 decades.

OBJECTIVE

This study aimed to evaluate trends in the characteristics, treatment, and outcomes of rectal adenocarcinoma across 16 years.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective, observational case series study used data from the National Cancer Database (NCDB) to evaluate patients diagnosed with rectal adenocarcinoma from 2004 through 2019. Data analysis was performed from March to May 2022.

EXPOSURES

Trends in the treatment and outcomes of rectal adenocarcinoma in the US between 2004 and 2019 were explored. This period was subdivided into 4 equal periods: 2004-2007, 2008-2011, 2012-2015, and 2016-2019.

MAIN OUTCOMES AND MEASURES

Patient and tumor characteristics, treatments, short-term outcomes, and overall survival.

RESULTS

A total of 318 548 patients diagnosed with rectal adenocarcinoma were included in the analysis, 191 369 (60.1%) of whom were males and 127 179 (39.9%%) were females. The mean (SD) age of the patients was 63.5 (13.4) years, and 46 824 patients (14.8%) were younger than 50 years. Among the patients, 10 859 (3.4%) were of Asian race and ethnicity, 28 464 (8.9%) were Black, and 271 236 (85.1%) were White. The percentage of patients younger than 50 years who were diagnosed with rectal cancer increased by 1.5%, from 13.9% in period 1 to 15.4% in period 4. Patients in the last period (2016-2019) presented more often with stages III (36.2% vs 30.2% vs 25.0% vs 23.4%; P < .001) and IV (21.5% vs 19.3% vs 18.1% vs 18.6%; P < .001) disease compared with those in the remaining 3 periods. The use of chemotherapy (36.8% vs 48.1% vs 49.1% vs 47.0%; P < .001) and immunotherapy (0.4% vs 0.2% vs 3.5% vs 6.5%; P < .001) significantly increased across the 4 periods. Although neoadjuvant radiotherapy was used more often across the periods studied (28.6% in period 1 to 34.3% in period 4), the use of adjuvant radiotherapy was reduced by half (12.9% to 6.0%). The median (IQR) time from diagnosis to definitive surgery increased from 95 (15-126) days in period 1 to 128 (47-158) days in period 4. The rate of use of open surgery decreased by half (60.1% in period 2 to 30.1% in period 4), and the use of robotic surgery significantly increased (5.2% in period 2 to 28.4% in period 4). The conversion rate was significantly reduced (11.2% in period 2 to 7.3% in period 4) and the median (IQR) hospital stay decreased by 2 days, from 6 (3-9) days to 4 (2-7) days. The median (IQR) overall survival significantly increased across the periods (from 83.1 months [95% CI, 81.8-84.6 months] in period 1 to 92.1 months [95% CI, 90.2-93.6 months] in period 3; P < .001).

CONCLUSION AND RELEVANCE

The findings of this case series study suggest a treatment trend of increased use of chemotherapy, immunotherapy, sphincter-saving surgery, and minimally invasive surgery. In addition, the time between diagnosis and definitive surgery increased by a median of 33 days. This treatment trend was associated with a significant improvement in the overall survival, reduction in the conversion rate by 3.9%, and a 2-day shorter hospital stay. These findings have major clinical relevance to the management of rectal cancer. The improvements seen in short-term outcomes and survival of patients diagnosed with rectal cancer can probably be attributed to the treatment trends observed. Continued improvement in outcomes warrant further updates in treatments.

NAVIGATOR: an Italian regional imaging biobank to promote precision medicine for oncologic patients

NAVIGATOR is an Italian regional project boosting precision medicine in oncology with the aim of making it more predictive, preventive, and personalised by advancing translational research based on quantitative imaging and integrative omics analyses. The project’s goal is to develop an open imaging biobank for the collection and preservation of a large amount of standardised imaging multimodal datasets, including computed tomography, magnetic resonance imaging, and positron emission tomography data, together with the corresponding patient-related and omics-related relevant information extracted from regional healthcare services using an adapted privacy-preserving model. The project is based on an open-source imaging biobank and an open-science oriented virtual research environment (VRE). Available integrative omics and multi-imaging data of three use cases (prostate cancer, rectal cancer, and gastric cancer) will be collected. All data confined in NAVIGATOR (i.e., standard and novel imaging biomarkers, non-imaging data, health agency data) will be used to create a digital patient model, to support the reliable prediction of the disease phenotype and risk stratification. The VRE that relies on a well-established infrastructure, called D4Science.org, will further provide a multiset infrastructure for processing the integrative omics data, extracting specific radiomic signatures, and for identification and testing of novel imaging biomarkers through big data analytics and artificial intelligence.

Surgery-mediated tumor-promoting effects on the immune microenvironment

Surgical resection continues to be the mainstay treatment for solid cancers even though chemotherapy and immunotherapy have significantly improved patient overall survival and progression-free survival. Numerous studies have shown that surgery induces the dissemination of circulating tumor cells (CTCs) and that the resultant inflammatory response promotes occult tumor growth and the metastatic process by forming a supportive tumor microenvironment (TME). Surgery-induced platelet activation is one of the initial responses to a wound and the formation of fibrin clots can provide the scaffold for recruited inflammatory cells. Activated platelets can also shield CTCs to protect them from blood shear forces and promote CTCs evasion of immune destruction. Similarly, neutrophils are recruited to the fibrin clot and enhance cancer metastatic dissemination and progression by forming neutrophil extracellular traps (NETs). Activated macrophages are also recruited to surgical sites to facilitate the metastatic spread. More importantly, the body's response to surgical insult results in the recruitment and expansion of immunosuppressive cell populations (i.e. myeloid-derived suppressor cells and regulatory T cells) and in the suppression of natural killer (NK) cells that contribute to postoperative cancer recurrence and metastasis. In this review, we seek to provide an overview of the pro-tumorigenic mechanisms resulting from surgery's impact on these cells in the TME. Further understanding of these events will allow for the development of perioperative therapeutic strategies to prevent surgery-associated metastasis.

Protocol: The role of defunctioning stoma prior to neoadjuvant therapy for locally advanced colonic and rectal cancer-A systematic review

Defunctioning stomas (ileostomy and colostomy) may be used prior to commencement of neoadjuvant therapy in patients with locally advanced colon or rectal cancer, in order to prevent clinical large bowel obstruction caused by radiotherapy associated oedema or progression of disease in patients who are not obstructed. However, the exact rate of clinical obstruction in patients undergoing neoadjuvant therapy who do not receive a defunctioning stoma is not known. Furthermore, it is not clear which factors predispose patients to developing clinical large bowel obstruction. Given that defunctioning stomas are associated with post operative and intra-operative risks, it is not currently possible to tailor defunctioning stomas to patients who have the greatest risk of developing obstruction. This systematic review which is in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement (PRISMA), aims to define the role of defunctioning stomas in prevention of obstruction patients with locally advanced colon or rectal cancer while undergoing neoadjuvant therapy. Two researchers will perform the literature search which will include all published and "in process" articles published in the English language between 2002-2022 in the following databases: EMBASE (OVID), MEDLINE (EBSCO), CINHAL complete, Web of Science, Cochrane Central Registry of Controlled Trials, Clinical Trials Registry. The full text of the selected articles will be independently screened by two researchers against the inclusion criteria. Data will be extracted from each article regarding: study design, participants, type of intervention and outcomes. The effect size will be expressed in incidence rates and when appropriate in relative risk with 95% confidence intervals. If possible, we will perform a meta-analysis. Heterogeneity will be assessed using I2 statistics. We will pool the data extracted from the randomised controlled trials to perform a meta-analysis using the Review Manager 5 software (RevMan 5). The Grades of Recommendation, Assessment, Development and Evaluation (GRADE) system will be used to assess the certainty of the evidence.

Radiomics-guided radiation therapy: opportunities and challenges

Radiomics is an advanced image-processing framework, which extracts image features and considers them as biomarkers towards personalized medicine. Applications include disease detection, diagnosis, prognosis, and therapy response assessment/prediction. As radiation therapy aims for further individualized treatments, radiomics could play a critical role in various steps before, during and after treatment. Elucidation of the concept of radiomics-guided radiation therapy (RGRT) is the aim of this review, attempting to highlight opportunities and challenges underlying the use of radiomics to guide clinicians and physicists towards more effective radiation treatments. This work identifies the value of RGRT in various steps of radiotherapy from patient selection to follow-up, and subsequently provides recommendations to improve future radiotherapy using quantitative imaging features.

Histogram analysis of diffusion-weighted magnetic resonance imaging as a biomarker to predict LNM in T3 stage rectal carcinoma

BACKGROUND

Preoperative identification of rectal cancer lymph node status is crucial for patient prognosis and treatment decisions. Rectal magnetic resonance imaging (MRI) plays an essential role in the preoperative staging of rectal cancer, but its ability to predict lymph node metastasis (LNM) is insufficient. This study explored the value of histogram features of primary lesions on multi-parametric MRI for predicting LNM of stage T3 rectal carcinoma.

METHODS

We retrospectively analyzed 175 patients with stage T3 rectal cancer who underwent preoperative MRI, including diffusion-weighted imaging (DWI) before surgery. 62 patients were included in the LNM group, and 113 patients were included in the non-LNM group. Texture features were calculated from histograms derived from T2 weighted imaging (T2WI), DWI, ADC, and T2 maps. Stepwise logistic regression analysis was used to screen independent predictors of LNM from clinical features, imaging features, and histogram features. Predictive performance was evaluated by receiver operating characteristic (ROC) curve analysis. Finally, a nomogram was established for predicting the risk of LNM.

RESULTS

The clinical, imaging and histogram features were analyzed by stepwise logistic regression. Preoperative carbohydrate antigen 199 level (p = 0.009), MRN stage (p < 0.001), _T2WIKurtosis (p = 0.010), _DWIMode (p = 0.038), _DWICV (p = 0.038), and _T2-mapP5 (p = 0.007) were independent predictors of LNM. These factors were combined to form the best predictive model. The model reached an area under the ROC curve (AUC) of 0.860, with a sensitivity of 72.8% and a specificity of 85.5%.

CONCLUSION

The histogram features on multi-parametric MRI of the primary tumor in rectal cancer were related to LN status, which is helpful for improving the ability to predict LNM of stage T3 rectal cancer.

The Correlation Between Survival Benefit of Preoperative Radiotherapy and Pretreatment Carcinoembryonic Antigen Level in Locally Advanced Rectal Cancer

Background

Preoperative radiotherapy followed by radical surgery is the standard treatment for locally advanced rectal cancer; however, its long-term survival benefit remains controversial. This study aimed to determine the relationship between pretreatment carcinoembryonic antigen (CEA) levels and the long-term prognosis of preoperative radiotherapy in locally advanced rectal cancer (LARC) patients.

Methods

Data of LARC patients who underwent surgery between 2011 and 2015 were identified from the Surveillance, Epidemiology, and End Results (SEER) database, and patients were accordingly divided into surgery (S) group and radiotherapy followed by surgery (RT+S) group. The primary outcomes were cancer-specific survival (CSS) and cancer-specific mortality (CSM). CSS was evaluated using Kaplan-Meier analysis, while CSM was evaluated using a competitive risk model. Subgroup analysis was also conducted, which was stratified by pretreatment CEA levels.

Results

A total of 2,760 patients were eligible for this study, including 350 (12.7%) patients in the S group and 2,410 (87.3%) in the RT+S group. There were no significant differences in the CSS and CSM rates at 1, 3, and 4 years between the S and RT+S groups before and after PSM (all p > 0.05). Pretreatment CEA levels were independently associated with CSS and CSM after adjusting for age, sex, stage, pathological factors, and treatment factors (all p < 0.05). Subgroup analysis showed that preoperative radiotherapy would benefit patients with elevated CEA in terms of CSS and CSM (both p < 0.05) but not those patients with normal CEA (both p > 0.05). Further analysis showed that preoperative radiotherapy was an independent protective factor for CSS and CSM in patients with elevated CEA levels (both p < 0.05).

Conclusions

Pretreatment CEA level may be considered a potential biomarker to screen LACR patients who would benefit from preoperative radiotherapy in terms of long-term prognosis.

The Survival Effect of Radiotherapy on Stage II/III Rectal Cancer in Different Age Groups: Formulating Radiotherapy Decision-Making Based on Age

Introduction

Total mesorectal excision (TME), chemotherapy (CT), and radiotherapy (RT) are usually integrated into the comprehensive treatment of stage II/III rectal cancer (RC). Neoadjuvant radiotherapy (nRT) has become the standard treatment for stage II/III RC patients to help reduce the size of a tumor or kill cancer cells that have spread. Adjuvant RT is delivered after the resection to destroy remaining cancer cells and used mainly in stage II/III RC patients who have not received preoperative radiotherapy, such as those who suffered from a bowel obstruction before surgery. It is controversial whether radiotherapy can improve the survival of stage II/III RC patients. An increasing number of studies have reported that rectal cancer exhibited mismatched biology, epidemiology, and therapeutic response to current treatment strategy in different age groups. It is necessary to investigate whether radiotherapy exhibits disparate effects in different age groups of patients with stage II/III RC.

Methods

Data from the Surveillance, Epidemiology, and End Results (SEER) Program was extracted to identify stage II/III RC diagnosed in the periods of 2004-2016. The statistical methods included Pearson's chi-square test, log-rank test, Cox regression model, and propensity score matching.

Results

Neoadjuvant radiotherapy (nRT) cannot improve the prognosis, and postoperative RT may even reduce the survival time for early onset stage II/III RC. Postoperative RT was not able to improve the overall survival (OS), while nRT may provide limited survival improvement for middle-aged stage II/III RC patients. In addition, radiotherapy can significantly improve the prognosis for elderly stage II/III RC.

Conclusions

This study indicated the inconsistent survival effect of radiotherapy on stage II/III rectal cancer patients in different age groups. Hence, we formulated a novel flow chart of radiotherapy decision-making based on age in stage II/III RC patients.

Immunomodulatory nanomedicine for colorectal cancer treatment: a landscape to be explored?

Colorectal cancer (CRC) is one of the deadliest cancers in the world mainly due to metastasis events. Despite improvements, the available treatment modalities for metastatic cases are limited, being generally associated with poor prognosis. As is well known, the immunosuppressive tumor microenvironment (TME) plays a key role in tumorigenesis, promoting cancer cell immune escape and disease progression. In addition, accumulating evidence indicates that the immunosuppressive microenvironment is a critical barrier for antitumor immunity in CRC, being extremely important to modulate the immune microenvironment to inhibit the tumor-promoting immune response. Therefore, new and effective cancer immunotherapeutic approaches demand a better control over the TME to reverse these immunosuppressive conditions. According to the features of different nanomedicines, nanoparticles can constitute a promising strategy, using different materials with the inherent ability to modulate TME and also with the potential to target immunosuppressive cells, to deliver antigens or immunomodulatory agents to eliminate this tumor. In this review, we summarize the importance of the TME in the progression and treatment response of CRC, exploring the potential of the nanotechnology for the development of immunomodulatory therapeutic strategies.

Management of colorectal cancer in the era of COVID-19: Challenges and suggestions

The Coronavirus (COVID-19) pandemic had a huge impact on all sectors around the world. In particular, the healthcare system has been subject to an enormous pressure that has surpassed its ability in many instances. Additionally, the pandemic has called for a review of our daily medical practices, including our approach to colorectal cancer management where treatment puts patients at high risk of virus exposure. Given their higher median age, patients are at an increased risk for severe symptoms and complications in cases of infection, especially in the setting of immunosuppression. Therefore, a review of the routine colorectal cancer practices is needed to minimize risk of exposure. Oncologists should weigh risk of exposure versus the patient's oncologic benefits when approaching management. In addition, treatment protocols should be modified to minimize hospital visits and admissions while maintaining the same treatment efficacy. In this review, we will focus on challenges that colorectal cancer patients face during the pandemic, while highlighting the priority in each case. We will also discuss the evidence for potential modifications to existing treatment plans that could reduce infectious exposure without compromising care. Finally, we will discuss the impact of the socio-economic difficulties faced by Lebanese patients due to a poor economy toppled by an unexpected pandemic.

Pathological Complete Response Following Different Neoadjuvant Treatment Strategies for Locally Advanced Rectal Cancer: A Systematic Review and Meta-analysis

Background

Pathological complete response (pCR) following neoadjuvant treatment for locally advanced rectal cancer (LARC) is associated with better survival, less local recurrence, and less distant failure. Furthermore, pCR indicates that the rectum may have been preserved. This meta-analysis gives an overview of available neoadjuvant treatment strategies for LARC and analyzes how these perform in achieving pCR as compared with the standard of care.

Methods

Pubmed, Embase, and Cochrane Central bibliographic databases were searched. Randomized controlled trials in which patients received neoadjuvant treatment for MRI-staged nonmetastatic resectable LARC were included. The primary outcome was pCR, defined as ypT0N0. A meta-analysis of studies comparing an intervention with standard fluoropyrimidine-based chemoradiation (CRT) was performed.

Results

Of the 17 articles included in the systematic review, 11 were used for the meta-analysis. Addition of oxaliplatin to fluoropyrimidine-based CRT resulted in significantly more pCR compared with fluoropyrimidine-based CRT only (OR 1.46), but at the expense of more ≥ grade 3 toxicity. Other treatment strategies, including consolidation/induction chemotherapy and short-course radiotherapy (SCRT), did not improve pCR rates. None of the included trials reported a benefit in local control or OS. Five-year DFS was significantly worse after SCRT-delay compared with CRT (59% vs. 75.1%, HR 1.93).

Conclusions

All included trials fail to deliver high-level evidence to show an improvement in pCR compared with standard fluoropyrimidine-based CRT. The addition of oxaliplatin might result in more pCR but at the expense of more toxicity. Furthermore, this benefit does not translate into less local recurrence or improved survival.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08615-2) contains supplementary material, which is available to authorized users.

The challenges in colorectal cancer management during COVID-19 epidemic

It has been over 2 months since the start of the Coronavirus disease 2019 (COVID-19) outbreak. The epidemic stage of COVID-19 has brought great challenges to the diagnosis and management of colorectal cancer (CRC) patients. Symptoms, such as fever and cough caused by cancer, and the therapeutic process (including chemotherapy and surgery) should be differentiated from some COVID-19 related characteristics. Besides, clinical workers should not only consider the therapeutic strategy for cancer, but also emphasize COVID-19's prevention. Moreover, the detailed therapeutic regimens of CRC patients may be different from the usual. Also, treatment principles may various for CRC patients with or without severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, as well as patients with or without an emergency presentation. In this paper, we want to discuss the above-mentioned problems based on previous guidelines, the current working status and our experiences, to provide a reference for medical personnel.