Total Neoadjuvant Therapy (TNT) versus Standard Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer: A Systematic Review and Meta-Analysis

Predictive value of mono-exponential and multiple mathematical models in locally advanced rectal cancer response to neoadjuvant chemoradiotherapy

PURPOSE

This prospective study aimed to assess the predictive value of mono-exponential and multiple mathematical diffusion-weighted imaging (DWI) models in determining the response to neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC).

METHODS

The study included 103 LARC patients scheduled for preoperative chemoradiotherapy between December 2021 and June 2023 Magnetic resonance imaging (MRI) scans were performed using a 3.0-T MR scanner, encompassing sagittal, axial, and oblique coronal T2-weighted images without fat saturation, along with DWI perpendicular to the rectum's long axis. Various DWI parameters, including apparent diffusion coefficient (ADC), stretched exponential model (SEM), continuous-time random-walk model (CTRW), and fractional-order calculus model (FROC), were measured. The pathologic complete response (pCR) rate and tumor downstaging (T-downstage) rate were determined.

RESULTS

After nCRT, SEM-α, SEM-DDC, CTRW-α, CTRW-β, CTRW-D, FROC-β, and ADC values were significantly higher in the pCR group compared to the non-pCR group (all P < 0.05). SEM-DDC, CTRW-α, CTRW-D, FROC-β, FROC-µ, and ADC values were significantly higher in the T-downstage group (ypT0-1) than in the non-T-downstage group (ypT2-4) (P < 0.05). The combination of CTRW (α + β + D) exhibited the best diagnostic performance for assessing pCR after nCRT (AUC = 0.840, P < 0.001). Pre-nCRT CTRW (α + β) demonstrated a predictive AUC of 0.652 (95%CI: 0.552-0.743), 90.3% sensitivity, and 43.1% specificity for pCR. Regarding T-downstage assessment after nCRT, the combination of CTRW (α + D) yielded the best diagnostic performance (AUC = 0.877, P = 0.048).

CONCLUSION

In LARC patients, imaging markers derived from CTRW show promise in predicting tumor response before nCRT and assessing pCR after nCRT.

CMTM4 promotes the motility of colon cancer cells under radiation and is associated with an unfavorable neoadjuvant chemoradiotherapy response and patient survival in rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) is the standard treatment for locally advanced rectal cancer (LARC). Pathological complete regression is closely linked to disease outcomes. However, biomarkers predicting nCRT response and patient survival are lacking for LARC. In the present study, the clinical characteristics and follow-up information of 228 patients with LARC were retrospectively collected. Immunohistochemistry (IHC), reverse transcription-quantitative PCR (RT-qPCR), Kaplan-Meier and multivariate analyses were used to evaluate the expression and predict the role of CKLF-like MARVEL transmembrane domain member 4 (CMTM4) in LARC. Additionally, lentiviral short hairpin (sh)RNA was used to interfere with CMTM4 expression. The phenotype of CMTM4-knockdown LoVo cells was determined by colony formation, migration and invasion assays under irradiation (IR) treatment. RNA-sequencing (RNA-seq) analysis was also used to explore the CMTM4-regulated genes in LoVo-shCMTM4 cells compared with control cells. RT-qPCR was then used to confirm the expression of these CMTM4-regulated genes. CMTM4 expression in pre-nCRT tissues indicated an unfavorable response and a short disease-free survival (DFS) with LARC. The expression of CMTM4 significantly increased following nCRT treatment. Additionally, CMTM4 knockdown increased the proliferation, migration and invasion of colon cancer cells; however, IR disrupted the cell migration and invasion induced by CMTM4 knockdown. RNA-seq analysis, the Tumor Immune Estimation Resource database and RT-qPCR indicated that CMTM4 was involved in different signaling pathways and regulated immune-related genes such as cluster of differentiation 66b, chemokine (CXC motif) ligand 8 (CXCL8) and programmed cell death 1. Furthermore, CXCL8 expression was found to be negatively associated with CMTM4 expression in patients with LARC by IHC and RT-qPCR. CXCL8 expression on invasion margin regions in post-operative tissues was also an inferior predictor of DFS in patients with LARC. In conclusion, CMTM4 may predict the nCRT response and outcomes in patients with LARC.

Comparison of Standard Neoadjuvant Therapy and Total Neoadjuvant Therapy in Terms of Effectiveness in Patients Diagnosed with Locally Advanced Rectal Cancer

Background/Objectives: The study aimed to compare the treatment effectiveness of patients with locally advanced rectal cancer undergoing standard neoadjuvant therapy or total neoadjuvant therapy. It also sought to identify prognostic factors for disease-free survival and overall survival and parameters predictive of pathological complete response. Materials and Methods: A retrospective analysis was conducted on 239 patients diagnosed with locally advanced rectal cancer between 2016 and 2022 at several medical centers in Turkey. Clinical data, including neoadjuvant chemoradiotherapy types, chemotherapy regimens, surgical outcomes, and survival metrics, were collected. Statistical analyses included chi-square tests, Kaplan-Meier survival analysis, and Cox proportional hazard models to evaluate prognostic factors for disease-free survival and overall survival and logistic regression to identify predictors of pathological complete response. Results: Among 239 patients, 46.9% received total neoadjuvant therapy, while 53.1% underwent standard neoadjuvant therapy. Total neoadjuvant therapy was associated with a significantly higher pathological complete response rate (45.5% vs. 14.9% in standard neoadjuvant therapy; p < 0.001) and longer disease-free survival (median 124.2 vs. 72.4 months). The 3-year overall survival rate for all patients was 90.7%, and disease-free survival was 76.8%. Multivariate analysis identified pathological complete response (HR: 2.34), total neoadjuvant therapy (HR: 5.12), and type of surgery (HR: 8.12) as independent prognostic factors for disease-free survival, and pathological complete response and absence of lymphovascular invasion as independent prognostic factors for overall survival. Logistic regression analysis showed that total neoadjuvant therapy (OR: 4.40) and initial neoadjuvant chemotherapy (OR: 2.02) were independent predictors of achieving pathological complete response. Conclusions: Total neoadjuvant therapy significantly improves pathological complete response rates, disease-free survival, and overall survival in patients with locally advanced rectal cancer compared to standard neoadjuvant therapy. Total neoadjuvant therapy and achieving pathological complete response are strong independent prognostic factors for both disease-free survival and overall survival, suggesting that a more intensive neoadjuvant approach may lead to better outcomes in locally advanced rectal cancer. The increased pathological complete responses rate with total neoadjuvant therapy has created an opportunity for the development of new treatment modalities and the advancement of non-surgical management strategies in the future.

Nutritional and inflammatory status dynamics reflect preoperative treatment response and predict prognosis in locally advanced rectal cancer: A retrospective multi-institutional analysis

BACKGROUND

Systemic inflammation, as an important host property, is the most representative tumor-host interactions in cancer, and the development of malignant neoplasms may contribute to impairment on nutritional status. This study aimed to investigate the potential ability of nutritional and inflammatory index in predicting neoadjuvant chemoradiotherapy efficacy and prognosis in locally advanced rectal cancer (LARC).

METHODS

This study was conducted using multi-institutional data. A total of 507 patients (262 in the training and 245 in the validation cohort) with stage IIA-IIIC LARC fit for neoadjuvant chemoradiotherapy were recruited from 2012 to 2014 were included in this study. Advanced lung cancer inflammation index (ALI) reflected nutritional and inflammatory status. The ALI was calculated as body mass index (BMI) × albumin × neutrophil/lymphocyte. Logistic regression model was used to identify predictive factors for preoperative treatment response. Cox multivariate regression models were used to analyze the factors affecting disease-free survival (DFS) and overall survival (OS).

RESULTS

In the training cohort, patients with high pretreatment ALI were observed to be associated with young patients, never smoked, relatively high BMI, and early-stage pathologic TNM staging. The receiver operating characteristic curve indicated that pretreatment ALI and its changing was the single most important factor determining outcomes than other inflammatory indicators. The 10-year DFS and OS rates of the whole group were 63.6% and 74.1% respectively. Patients with low pretreatment ALI and ALI change had significantly poorer 10-year DFS (P < .001 and P = .001) and 10-year OS (P = .002 and P = .025) rates than those with high ALI and ALI change. Similar findings were observed in the validation cohort. Multivariate analysis revealed that pretreatment ALI (P = .047 and P = .006) and ALI change (P = .027 and P = .041) were identified as independent prognostic factors for DFS. Meanwhile, high pretreatment ALI (P = .020 and P = .010), high systemic immune-inflammation index (SII) change (P = .040 and P = .012) and clinical stage T2-T3 were independent protective factors for OS. Furthermore, multivariate logistic regression analyses revealed that pretreatment ALI, ALI change, and SII change could independently predict efficacy of neoadjuvant chemoradiotherapy.

CONCLUSION

Our results suggest that as a feasible indicator of nutritional and inflammatory status, the ALI shows better efficiency than other inflammatory indicators in predicting efficacy of neoadjuvant chemoradiotherapy and prognosis.

A management of patients achieving clinical complete response after neoadjuvant therapy and perspectives: on locally advanced rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) followed by total mesorectal excision (TME) and selective use of adjuvant chemotherapy is currently considered the standard of care for locally advanced rectal cancer (LARC). Despite this, the concept of organ preservation is gradually challenging this approach. The management of complete clinical remission (cCR) lacks international consensus, leading scholars to develop their own perspectives based on well-designed studies and long-term data from large multicenter cohorts. To ensure appropriate treatment, this review focuses on the choice of neoadjuvant therapy, criteria for defining cCR, and treatment strategies for patients who achieve cCR after neoadjuvant therapy. By providing guidance on the accurate management of LARC patients after cCR, this review aims to prevent over- or under-treatment.

Advantages of Robotic Total Mesorectal Excision With Partial Prostatectomy Compared With Open Surgery for Rectal Cancer: A Single-Center Retrospective Cohort Study

AIM

Robotic total mesorectal excision (TME) with resection of adjacent organs has been increasingly used for locally advanced rectal cancer; however, few studies have focused on robotic TME with partial prostatectomy. Therefore, this study aimed to demonstrate the advantages of robotic TME with partial prostatectomy compared with open surgery for rectal cancer.

METHOD

This retrospective cohort study examined consecutive patients with rectal cancer who underwent robotic or open TME with partial prostatectomy at a high-volume center in Japan from April 2003 to March 2022. The patients were divided into robotic (n = 14) and open (n = 11) surgery groups. The short- and long-term outcomes of these patients were compared.

RESULTS

More transabdominal partial prostatectomies were performed in the robotic surgery group than in the open surgery group (71.4% vs. 9.1%, p = 0.001). Moreover, sphincter-preserving surgery was performed in 35.7% of patients in the robotic surgery group. The robotic surgery group had shorter operative times (401 min vs. 435 min, p = 0.047), less blood loss (56 mL vs. 484 mL, p < 0.001), lower complication rates (28.6% vs. 72.7%, p = 0.047), and shorter postoperative hospital stays (8 days vs. 18 days, p < 0.001) than the open surgery group. No significant differences were observed in the positive radial margin rate (7.1% vs. 9.1%, p = 1.000) or long-term outcomes between the two groups.

CONCLUSION

Compared with open surgery, robotic TME with partial prostatectomy facilitates transabdominal partial prostatectomy, resulting in more sphincter-preserving surgeries and better short-term outcomes.

Relationship between clinical features and distant metastases in rectal cancer predicted based on a nomogram: a retrospective cohort study

Rectal cancer is a prevalent global malignancy. Recurrence and metastasis significantly impact patient survival over the long term. This study aims to identify independent risk factors associated with distant metastases in rectal cancer (RC) patients and develop a prognostic columnar-line diagram. This retrospective analysis encompasses data from 1,118 RC patients treated at the Department of Anorectal Surgery, Chifeng Municipal Hospital, between December 2015 and October 2023. These patients were diagnosed with stage I-IV RC. Univariate and multivariate Cox proportional hazard regression models identified risk factors for distant metastases development. The median follow-up duration was 61.3 months (range 2.24-96.33 months). The identified factors linked to distant metastases in RC included hemoglobin levels, body mass index (BMI), leukocyte neutrophil percentage, tumour diameter, pathology type, differentiation degree, number of detected lymph nodes, and T and N stages. These factors are significant risk indicators for distant metastases in RC patients. Incorporating these identified risk factors into a columnar-line diagram effectively predicts the likelihood of distant metastasis in RC patients. This approach aids in devising precise treatment strategies during the initial patient consultation.

Prediction model construction for the occurrence of LARS after neoadjuvant therapy combined with laparoscopic total mesorectal excision in male patients with mid-low rectal cancer

Background

Neoadjuvant chemoradiotherapy for rectal cancer improves surgical outcomes and reduces recurrence but can cause low anterior resection syndrome (LARS), affecting quality of life. This study aims to predict the risk of LARS in male patients with mid-low rectal cancer after laparoscopic total mesorectal excision (TME).

Methods

Clinical data from 203 male patients with mid-low rectal cancer who underwent neoadjuvant therapy and laparoscopic resection were collected. Patients were divided into training (n=143) and validation (n=60) cohorts. LARS risk factors were identified using logistic regression, and a predictive model was constructed and validated using ROC curve, Hosmer-Lemeshow test, calibration curve, and decision curve analysis (DCA).

Results

LARS occurred in 53.6% of the patients in this study. Multivariate logistic regression analysis revealed that BMI ≥ 25 kg/m², tumor distance from the anal margin < 5 cm, radiotherapy, and anastomotic leakage were independent risk factors for postoperative LARS in patients (P < 0.05). The areas under the ROC curves for the training cohort and validation cohort were 0.866 (95% CI: 0.807-0.925) and 0.724 (95% CI: 0.595-0.853), respectively, with both groups showing good goodness-of-fit test results (P > 0.05). The DCA curve indicated that the model had a high clinical utility.

Conclusions

BMI ≥ 25 kg/m², tumor distance from the anal margin < 5 cm, radiotherapy, and anastomotic leakage are independent risk factors for the occurrence of LARS after neoadjuvant therapy combined with laparoscopic TME in male patients with mid-low rectal cancer. These factors should be emphasized in clinical practice, and corresponding preventive measures should be promptly implemented.

Nonoperative management of rectal cancer

The management of locally advanced rectal cancer has changed drastically in the last few decades due to improved surgical techniques, development of multimodal treatment approaches and the introduction of a watch and wait (WW) strategy. For patients with a complete response to neoadjuvant treatment, WW offers an opportunity to avoid the morbidity associated with total mesorectal excision in favor of organ preservation. Despite growing interest in WW, prospective data on the safety and efficacy of nonoperative management are limited. Challenges remain in optimizing multimodal treatment regimens to maximize tumor regression and in improving the accuracy of patient selection for WW. This review summarizes the history of treatment for rectal cancer and the development of a WW strategy. It also provides an overview of clinical considerations for patients interested in nonoperative management, including restaging strategies, WW selection criteria, surveillance protocols and long-term oncologic outcomes.

Perioperative tislelizumab with four cycles of neoadjuvant chemotherapy for resectable locally advanced esophageal squamous cell carcinoma: a phase 2 study

Background

The application of neoadjuvant immunotherapy in the treatment of esophageal cancer needs further exploration. This study aimed to investigate the safety and effectiveness of tislelizumab, an anti-PD-1 antibody, combined with chemotherapy as neoadjuvant treatment for locally advanced esophageal squamous cell carcinoma (LA-ESCC).

Methods

In this phase II study, patients with clinical stages of II-IVA (T3-T4 and/or node positive) potentially resectable LA-ESCC were enrolled. Patients received neoadjuvant tislelizumab and chemotherapy every 3 weeks for 4 cycles before surgery and adjuvant tislelizumab for 9 months. The primary endpoint was pathological complete response (pCR) rate. Secondary endpoints included R0 resection, disease free survival (DFS), adverse events (AE), and biomarkers for predicting efficacy.

Results

The study included 30 patients. 25 patients completed neoadjuvant chemoimmunotherapy and underwent surgery, 96% with R0 resection. The pCR and MPR rate was 44% and 52%. The 6-month and 1-year DFS rate was 100% and 75.3%. 43.3% patients experienced severe (grade 3-4) treatment-related adverse events (TRAEs) and 5 patients developed severe immune-related adverse events (irAEs). Further exploration found that a group of peripheral lymphocyte subsets increased significantly after 2 cycles of neoadjuvant therapy in patients who achieved pCR, suggesting the importance of dynamic monitoring of circulating lymphocyte.

Conclusions

The combination of perioperative tislelizumab and neoadjuvant chemotherapy has achieved an encouraging pCR rate and demonstrated a manageable safety profile in patients with potentially resectable ESCC.

Clinical Trial Registration

https://www.chictr.org.cn/, identifier ChiCTR2100043772.

Oncological Outcomes and Response Rate After Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer: A Network Meta-Analysis Comparing Induction vs. Consolidation Chemotherapy vs. Standard Chemoradiation

TNT is now considered the preferred option for stage II-III locally advanced rectal cancer (LARC). However, the prognostic benefit and optimal sequence of TNT remains unclear. This network meta-analysis (NMA) compared short- and long-term outcomes amongst patients with LARC receiving total neoadjuvant therapy (TNT) as induction (iTNT) or consolidation chemotherapy (cTNT) with those receiving neoadjuvant chemoradiation (nCRT) alone. A systematic literature search was performed between 2012 and 2023. A Bayesian NMA was conducted using a Markov Chain Monte Carlo method with a random-effects model and vague prior distribution to calculate odds ratios (OR) with 95% credible intervals (CrI). The surface under the cumulative ranking (SUCRA) curves were used to rank treatment(s) for each outcome. In total, 11 cohorts involving 8360 patients with LARC were included. There was no significant difference in disease-free survival (DFS) and overall survival (OS) amongst the 3 treatments. Compared with nCRT, both cTNT (OR 2.36; 95% CrI, 1.57-3.66) and iTNT (OR 1.99; 95% CrI, 1.44-2.95) significantly improved complete response (CR) rate. Notably, cTNT ranked as the best treatment for CR (SUCRA 0.90) and iTNT as the best treatment for 3-year DFS and OS (SUCRA 0.72 and 0.87, respectively). Both iTNT and cTNT strategies significantly improved CR rates compared with nCRT. cTNT was ranked highest for CR rates, while iTNT was ranked highest for 3-year survival outcomes. However, no other significant differences in DFS, OS, sphincter-saving surgery, R0 resection and postoperative complications were found amongst the treatment groups.

Omission of Chemoradiation in Locally Advanced Rectal Adenocarcinoma: Evaluation of PROSPECT in a National Database

BACKGROUND AND OBJECTIVES

The PROSPECT trial showed noninferiority of neoadjuvant chemotherapy (NAC) with selective chemoradiation (CRT) versus CRT alone. However, trial results are often difficult to reproduce with real-world data. Pathologic outcomes and overall survival (OS) were evaluated by neoadjuvant strategy in locally advanced rectal adenocarcinoma patients in a national database.

METHODS

The 2012-2020 National Cancer Database was queried for clinical T2N1 and T3N0-1 rectal adenocarcinoma patients with definitive resection. Patients were categorized by neoadjuvant treatment with CRT alone, NAC alone, and NAC with CRT. Outcomes included R0 resection, pathologic complete response (PCR), and OS.

RESULTS

Of 18 892 patients, 16 126 (85.4%) received CRT, 1018 (5.4%) NAC, and 1748 (9.3%) NAC with CRT. Patients with NAC alone or NAC with CRT were more likely to have stage-III disease, private insurance, and academic facility treatment (all p < 0.001). NAC alone had lower adjusted odds of an R0 resection (OR 0.72; 95%CI 0.54-0.95) and PCR (OR 0.77; 95%CI 0.64-0.93). NAC with CRT demonstrated improved OS (HR 0.71; 95%CI 0.61-0.82), with no difference between NAC and CRT alone. Among patients who received adjuvant chemotherapy, no differences in OS were seen.

CONCLUSIONS

Patients who received NAC alone had worse pathologic outcomes. NAC had similar OS to CRT and NAC with CRT showed improved OS.

Neoadjuvant therapy in rectal cancer-one year follow-up results of standard versus total neoadjuvant strategies

BACKGROUND

Locally advanced rectal cancer (LARC) poses a significantly challenge in clinical management, requiring a multimodal treatment approach. Among innovative strategies, Total Neoadjuvant Therapy (TNT) has emerged, delivering all planned chemotherapy before surgery.

OBJECTIVE

Our aim was to evaluate the real-world application and efficacy of TNT and to compare it with the non-TNT standard strategy.

METHODS

This retrospective study compared locally advanced rectal adenocarcinoma patients treated with Total Neoadjuvant Therapy (TNT) in 2022 with those who underwent traditional chemoradiotherapy (CRT) in 2020-2021. The primary endpoints were the pathologic complete response rate and the sustained clinical complete response rate in patients under W&W.

RESULTS

Among 107 patients (54.2% male, mean age 62.48 years), non-TNT (67 patients) and TNT (40 patients) mean follow-ups were 26.7 and 8.2 months, respectively. No differences in gender(p = 0.163), staging (p = 0.707), or location (p = 0.727) were noted. TNT patients received more short-course radiotherapy (42.5% vs1.5%, p < 0.001). Clinical responses favored TNT (p = 0.030) with no significant differences in pathological responses, recurrence rates, or survival. TNT exhibited higher chemotherapy completion (p = 0.007) and lower adverse events (p < 0.001). Post-surgery events showed no significant differences (p = 0.470). Single center with retrospective design and carries limitations that may restrict the generalizability of the findings and the relatively short follow-up duration are our main limitations.

CONCLUSION

Our data add to the body of literature favoring the TNT treatment strategy for locally advanced rectal cancer, aiming to achieve comparable complete response rates with less adverse events.

Assessment of circulating tumor DNA in patients with locally advanced rectal cancer treated with neoadjuvant therapy

Post-neoadjuvant therapy (post-NAT) and post-surgical circulating tumor DNA (ctDNA) risk stratification may enhance the management of patients with locally advanced rectal cancer (LARC). In this study, we assessed the prognostic value of ctDNA-based MRD detection in LARC patients using a personalized, tumor-informed ctDNA assay. Plasma samples from LARC patients (N = 30) were analyzed retrospectively using the Signatera™ assay. The neoadjuvant rectal (NAR) score was calculated and compared to ctDNA status to predict recurrence risk and survival outcomes. ctDNA-positive patients post-NAT and post-surgery had worse Disease Free Survival (DFS) (HR: 7.82; p = 0.001, HR: 19.65; p = 0.001) when compared to ctDNA-negative patients. In the post-NAT setting, patients who responded to NAT had superior DFS compared to patients who did not clear their ctDNA or showed no radiological response (HR: 24.7, p = 0.001 and HR: 5.1, p = 0.054, respectively). When ctDNA status is used alongside the NAR score in the post-NAT setting, patients who were ctDNA-positive with an intermediate or high NAR score showed significantly worse DFS (HR: 47.5, p < 0.001) compared to ctDNA-negative patients with either a low or intermediate/high NAR score (HR: 9.8, p = 0.0301). Post-NAT ctDNA status, whether used alone or in combination with the NAR score, may predict NAT response, and improve risk stratification.

Executive Summary of the American Radium Society on Appropriate Use Criteria for Nonoperative Management of Rectal Adenocarcinoma: Systematic Review and Guidelines

For patients with rectal cancer, the standard approach of chemotherapy, radiation therapy, and surgery (trimodality therapy) is associated with significant long-term toxicity and/or colostomy for most patients. Patient options focused on quality of life (QOL) have dramatically improved, but there remains limited guidance regarding comparative effectiveness. This systematic review and associated guidelines evaluate how various treatment strategies compare to each other in terms of oncologic outcomes and QOL. Cochrane and Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) methodology were used to search for prospective and retrospective trials and meta-analyses of adequate quality within the Ovid Medline database between January 1, 2012, and June 15, 2023. These studies informed the expert panel, which rated the appropriateness of various treatments in 6 clinical scenarios through a well-established consensus methodology (modified Delphi). The search process yielded 197 articles that advised voting. Increasing data have shown that nonoperative management (NOM) and primary surgery result in QOL benefits noted over trimodality therapy without detriment to oncologic outcomes. For patients with rectal cancer for whom total mesorectal excision would result in permanent colostomy or inadequate bowel continence, NOM was strongly recommended as usually appropriate. Restaging with tumor response assessment approximately 8 to 12 weeks after completion of radiation therapy/chemoradiation therapy was deemed a necessary component of NOM. The panel recommended active surveillance in the setting of a near-complete or complete response. In the setting of NOM, 54 to 56 Gy in 27 to 31 fractions concurrent with chemotherapy and followed by consolidation chemotherapy was recommended. The panel strongly recommends primary surgery as usually appropriate for a T3N0 high rectal tumor for which low anterior resection and adequate bowel function is possible, with adjuvant chemotherapy considered if N+. Recent data support NOM and primary surgery as important options that should be offered to eligible patients. Considering the complexity of multidisciplinary management, patients should be discussed in a multidisciplinary setting, and therapy should be tailored to individual patient goals/values.

Evaluation of Volumetric Magnetic Resonance Imaging in Determining the Indication for Total Neoadjuvant Therapy in Rectal Cancer

BACKGROUND

This study aims to evaluate the relationship between volumetric measurements of residual tumor via magnetic resonance imaging (MRI) and pathologic complete response (pCR) in rectal cancer patients undergoing neoadjuvant chemoradiotherapy (nCRT).

METHODS

Patients with locally advanced rectal cancer who had pelvic MRI for clinical staging and completed nCRT followed by radical resection were included. Two experienced radiologists measured tumor volume on MRI obtained before and after nCRT. We compared the pre- and post-CRT tumor volume and measured tumor volume reduction rates.

RESULTS

The median value of tumor volume reduction rate in all patients was 64.7% (min-max - 81.1-98.1%). When the relationship between tumor volume and tumor regression grade (TRG) after nCRT was assessed, it was found that 18 of 21 (86%) patients with a good response (TRG 1) had a post-CRT tumor volume of ≤ 8 cm3 (p = 0.001). While 9 of 10 patients with pCR after nCRT had a tumor volume of ≤ 8 cm3, one patient had pCR despite having a tumor volume greater than 8 cm3 (p = 0.015).

CONCLUSION

The correlation between post-nCRT residual tumor volume and pCR underscores the potential of volumetric MRI as a predictive tool in tailoring rectal cancer treatment. For patients with residual tumor volumes greater than 8 cm3, extending neoadjuvant chemotherapy as part of TNT may enhance the likelihood of achieving pCR. This approach advocates for a more personalized treatment strategy, potentially optimizing outcomes for rectal cancer patients.

Comparative Outcomes of Robotic Versus Open Proctectomy for Rectal Cancer at High Risk of Positive Circumferential Resection Margin

BACKGROUND

Concerns persist regarding the effectiveness of robotic proctectomy compared with open proctectomy for locally advanced rectal cancer with a high risk of circumferential resection margin involvement.

OBJECTIVE

Comparison of surrogate cancer outcomes after robotic versus open proctectomy in this subpopulation.

DESIGN

Retrospective cohort study.

SETTING

Three academic hospitals (Mayo Clinic Arizona, Florida, and Rochester) with data available through the Mayo Data Explorer platform.

PATIENTS

Patients at high risk of circumferential resection margin involvement were selected on the basis of the MRI-based definition from the MERCURY I and II trials.

MAIN OUTCOME MEASURES

Rate of pathologic circumferential resection margin involvement (≤1 mm), mesorectal grading, and rate of distal margin involvement.

RESULTS

Out of 413 patients, 125 (30%) underwent open and 288 (70%) underwent robotic proctectomy. Open proctectomy was significantly associated with a greater proportion of cT4 tumors (39.3% vs 24.8%, p = 0.021), multivisceral/concomitant resections (40.8% vs 18.4%, p < 0.001), and less frequent total neoadjuvant therapy use (17.1% vs 47.1%, p = 0.001). Robotic proctectomy was less commonly associated with pathologic circumferential resection margin involvement (7.3% vs 17.6%, p = 0.002), including after adjustment for cT stage, neoadjuvant therapy, and multivisceral resection (OR 0.326; 95% CI, 0.157-0.670, p = 0.002). Propensity score matching for 66 patients per group and related multivariable analysis no longer indicated any reduction of circumferential positive margin rate associated with robotic surgery ( p = 0.86 and p = 0.18). Mesorectal grading was comparable (incomplete mesorectum in 6% robotic proctectomy patients vs 11.8% open proctectomy patients, p = 0.327). All cases had negative distal resection margins.

LIMITATION

Retrospective design.

CONCLUSIONS

In patients with locally advanced rectal cancer at high risk of circumferential resection margin involvement, robotic proctectomy is an effective approach and could be pursued when technically possible as an alternative to open proctectomy. See Video Abstract .

RESULTADOS COMPARATIVOS ENTRE LA PROCTECTOMA ROBTICA Y LA PROCTECTOMA ABIERTA EN CASOS DE CNCER DE RECTO CON ALTO RIESGO DE MRGEN DE RESECCIN CIRCUNFERENCIAL POSITIVO

ANTECEDENTES:Persisten preocupaciones con respecto a la efectividad de la proctectomía robótica en comparación con la proctectomía abierta en casos de cáncer de recto localmente avanzado con un alto riesgo de margen de resección circunferencial positivo.OBJETIVO:Comparar los resultados en la subpoblación de portadores de cáncer luego de una proctectomía robótica versus una proctectomía abierta.DISEÑO:Estudio retrospectivo de cohortes.AJUSTE:Realizado en tres hospitales académicos (Mayo Clinic de Arizona, Florida y Rochester) a través de la plataforma Mayo Data Explorer.PACIENTES:Fueron seleccionados aquellos pacientes con alto riesgo de compromiso sobre el margen de resección circunferencial, según la definición de los Estudios Mercury I-II basada en la Imágen de Resonancia Magnética.MEDIDAS DE RESULTADO PRINCIPALES Y SECUNDARIAS:La tasa de compromiso patológico sobre el margen de resección circunferencial (≤1 mm), la clasificación mesorrectal y la tasa del compromiso del margen distal.RESULTADOS:De 413 pacientes, 125 (30%) fueron sometidos a una proctectomía abierta y 288 (70%) a proctectomía robótica. La proctectomía abierta se asoció significativamente con una mayor proporción de tumores cT4 (39,3% frente a 24,8%, p = 0,021), las resecciones multiviscerales/concomitantes fueron de 40,8% frente a 18,4%, p < 0,001 y una adminstración menos frecuente de terapia neoadyuvante total (17,1). % vs 47,1%, p = 0,001).La proctectomía robótica se asoció con menos frecuencia con la presencia de una lesión sobre el margen de resección circunferencial patológico (7,3% frente a 17,6%, p = 0,002), incluso después del ajuste por estadio cT, de la terapia neoadyuvante y de resección multivisceral (OR 0,326, IC 95% 0,157-0,670, p = 0,002). El apareado de propensión por puntuación en 66 pacientes por grupo y el análisis multivariable relacionado, no mostraron ninguna reducción en la tasa de margen positivo circunferencial asociado con la cirugía robótica ( p = 0,86 y p = 0,18). La clasificación mesorrectal fue igualmente comparable (mesorrecto incompleto en el 6% de los pacientes con RP frente al 11,8% de los pacientes con OP, p = 0,327). Todos los casos tuvieron márgenes de resección distal negativos.LIMITACIÓN:Diseño retrospectivo.CONCLUSIÓN:En pacientes con cáncer de recto localmente avanzado con alto riesgo de compromiso del margen de resección circunferencial, la proctectomía robótica es un enfoque eficaz y podría realizarse cuando sea técnicamente posible como alternativa a la proctectomía abierta. (Traducción-Dr. Xavier Delgadillo ).

Can yStage Ⅰ/Ⅱ rectal cancer patients be treated in the same way as stage Ⅰ/Ⅱ patients?

Background

Neoadjuvant therapy (NAT) before radical surgery are effective treatments for locally advanced rectal cancer. However, the treatment strategy after NAT and surgery is still unclear. It is difficult to accurately evaluate the stage before NAT, as some cases are downstaged by NAT.

Objective

We investigated the treatment strategies based on the postoperative pathology of patients with yStage Ⅰ or Ⅱ rectal cancer who underwent NAT and radical resection.

Design

They patients were retrospectively evaluated the long-term outcomes. They were divided into patients with yStage I/II receiving NAT and patients with stage I/II patients without NAT (non-NAT). Disease-free survival (DFS) and overall survival (OS) were examined, and the prognosis was compared. Cox proportional hazard model was used to examine the recurrence risk factors in all patients or NAT. We compared the effects of adjuvant therapy in NAT.

Patients

Overall, 521 patients histologically diagnosed with yStage I/II or stage I/II who underwent surgery for rectal cancer between April 2001 and July 2019 were eligible.

Results

The NAT and non-NAT groups included 80 and 441 patients, respectively. DFS was significantly lower in NAT, but there was no difference in OS between the two groups. All patients had several recurrence risk factors, but none of the NAT had such risk factors. No significant difference in DFS and OS was found between NAT with and without adjuvant chemotherapy.

Limitation

This is a single-center retrospective study.

Conclusions

NAT had lower DFS than non-NAT, but no difference in OS was observed. No significant recurrence risk factors were observed in NAT. Adjuvant chemotherapy for NAT may have no benefit.

Total Neoadjuvant Therapy in Locally Advanced Rectal Cancer: Insights from the Western Australian Context

BACKGROUND

Recent studies have associated total neoadjuvant therapy (TNT) with better treatment adherence, decreased toxicity, improved complete clinical response and anal sphincter preservation rates in patients with locally advanced rectal cancer (LARC). However, real-world experience with TNT in the management of LARC remains limited.

AIM

This study aimed to evaluate the efficacy and safety outcomes of TNT for LARC in Western Australia.

METHODS

Patients with LARC (cT2-4 and/or cN1-2) who underwent induction chemotherapy followed by neoadjuvant chemoradiotherapy or neoadjuvant chemoradiotherapy followed by consolidation chemotherapy, followed by surgery were recruited from two hospitals in Western Australia. Efficacy outcomes assessed included clinical response (complete, partial, no response), and pathologic complete response (pCR) rate, R0 resection rate, and R1 resection rate were evaluated. Those patients who achieved clinical complete response following TNT were given the option of active surveillance. The safety and tolerability of TNT were assessed.

RESULTS

32 patients with LARC were treated with TNT. In total, 17 patients (53%) received chemoradiotherapy followed by consolidation chemotherapy and 15 patients (47%) received induction chemotherapy followed by chemoradiotherapy. Nine (28%) of the patients with LARC treated with TNT had a complete clinical response, twenty-one (66%) patients had a partial clinical response, and two (6%) patients had no response to TNT. Of the 32 patients, 27 (84%) underwent surgery. There was a 100% R0 resection rate. The pCR rate was 15%. pCR, clinical response, and the R0 resection rate were similar between the two TNT regimens. TNT was well tolerated, with the majority of patients (88%) completing the chemotherapy course with grade 1 and 2 adverse effects.

CONCLUSIONS

In conclusion, TNT emerges as a promising approach for the management of LARC. However, further research is warranted to refine the optimal TNT protocols, determine its long-term outcomes, and identify patient populations who would benefit the most from this innovative therapeutic strategy.

Node-sparing modified short-course Radiotherapy Combined with CAPOX and Tislelizumab for locally Advanced MSS of Middle and low rectal Cancer (mRCAT): an open-label, single-arm, prospective, multicentre clinical trial

BACKGROUND

Neoadjuvant chemoradiotherapy followed by total mesorectal excision is a standard treatment for locally advanced rectal cancer. Mismatch repair-deficient locally advanced rectal cancer (LARC) was highly sensitive to PD-1 blockade. However, most rectal cancers are microsatellite stable (MSS) or mismatch repair-proficient (pMMR) subtypes for which PD-1 blockade is ineffective. Radiation can trigger the activation of CD8 + T cells, further enhancing the responses of MSS/pMMR rectal cancer to PD-1 blockade. Radioimmunotherapy offers a promising therapeutic modality for rectal cancer. Progenitor T exhausted cells are abundant in tumour-draining lymph nodes and play an important role in immunotherapy. Conventional irradiation fields include the mesorectum and regional lymph nodes, which might cause considerable damage to T lymphocytes and radiation-induced fibrosis, ultimately leading to a poor response to immunotherapy and rectal fibrosis. This study investigated whether node-sparing modified short-course irradiation combined with chemotherapy and PD-1 blockade could be effective in patients with MSS/ pMMR LARC.

METHODS

This was a open-label, single-arm, multicentre, prospective phase II trial. 32 LARC patients with MSS/pMMR will receive node-sparing modified short-course radiotherapy (the irradiated planned target volume only included the primary tumour bed but not the tumour-draining lymph nodes, 25 Gy/5f, 5 Gy/f) followed by CAPOX and tislelizumab. CAPOX and tislelizumab will be started two days after the completion of radiotherapy: oxaliplatin 130 mg/m2 intravenous infusion, day 1; capecitabine 1000 mg/m2 oral administration, days 1-14; and tislelizumab 200 mg, intravenous infusion, day 1. There will be four 21-day cycles. TME will be performed at weeks 14-15. We will collect blood, tumour, and lymphoid specimens; perform flow cytometry and in situ multiplexed immunofluorescence detection; and analyse the changes in various lymphocyte subsets. The primary endpoint is the rate of pathological complete response. The organ preservation rate, tumour regression grade, local recurrence rate, disease-free survival, overall survival, adverse effects, and quality of life will also be analysed.

DISCUSSION

In our research, node-sparing modified radiotherapy combined with immunotherapy probably increased the responsiveness of immunotherapy for MSS/pMMR rectal cancer patients, reduced the occurrence of postoperative rectal fibrosis, and improved survival and quality of life. This is the first clinical trial to utilize a node-sparing radiation strategy combined with chemotherapy and PD-1 blockade in the neoadjuvant treatment of rectal cancer, which may result in a breakthrough in the treatment of MSS/pMMR rectal cancer.

TRIAL REGISTRATION

This study was registered at www.

CLINICALTRIALS

gov .

TRIAL REGISTRATION NUMBER

NCT05972655. Date of registration: 31 July 2023.

Tailoring treatment for locally advanced rectal cancer

The management of locally advanced rectal cancer (LARC) requires personalized treatment to improve outcomes and maintain quality of life. This narrative review examines the recent developments in management, focusing on non-operative management, radiotherapy choices or omission, chemotherapy sequencing, and the role of immunotherapy and brachytherapy boost. Non-operative management can be an option for select patients, and the use of long-course chemoradiation (LCCRT) with consolidation chemotherapy or brachytherapy boost has been shown to enhance rectal preservation rates. For patients requiring surgery, the choice between LCCRT and SCRT depends on the risk of local recurrence and patient preferences. MSI-high LARC patients benefit significantly from single-agent immunotherapy, and early clinical trials show promising results for the application of immunotherapy in MSS tumors. By stratifying patients based on individual and tumor risk factors, clinicians can tailor treatment plans to improve oncologic outcomes and quality of life for patients with LARC.

Preventive efficacy of hydrocortisone enema for radiation proctitis in rectal cancer patients undergoing short-course radiotherapy: a phase II randomized placebo-controlled clinical trial

PURPOSE

This study aimed to investigate the efficacy of hydrocortisone enema in preventing radiation proctitis in patients with rectal cancer undergoing short-course radiotherapy (SCRT).

METHODS

This phase II randomized controlled trial enrolled patients with newly diagnosed locally advanced rectal cancer (clinically staged T3-4 and/or N1-2M0). Participants received a median of 4 cycles of neoadjuvant chemotherapy (capecitabine plus oxaliplatin) followed by 3-dimensional conformal SCRT (25 Gy in 5 fractions). Patients were randomly assigned to receive either a hydrocortisone enema (n=50) or a placebo (n=51) once daily for 5 consecutive days during SCRT. The primary endpoint was the incidence and severity of acute proctitis.

RESULTS

Of the 111 eligible patients, 101 were included in the study. Baseline characteristics, including sex, age, performance status, and tumor location, were comparable across the treatment arms. None of the patients experienced grade 4 acute gastrointestinal toxicity or had to discontinue treatment due to treatment-related adverse effects. Patients in the hydrocortisone arm experienced significantly less severe proctitis (P<0.001), diarrhea (P=0.023), and rectal pain (P<0.001) than those in the placebo arm. Additionally, the duration of acute gastrointestinal toxicity following SCRT was significantly shorter in patients receiving hydrocortisone (P<0.001).

CONCLUSION

Hydrocortisone enema was associated with a significant reduction in the severity of proctitis, diarrhea, and rectal pain compared to placebo. Additionally, patients treated with hydrocortisone experienced shorter durations of gastrointestinal toxicity following SCRT. This study highlights the potential benefits of hydrocortisone enema in managing radiation-induced toxicity in rectal cancer patients undergoing radiotherapy.

Pathologic Outcomes of Short-Course and Long-Course Radiotherapy for Locally Advanced Rectal Cancers Treated With Total Neoadjuvant Therapy

INTRODUCTION

Total neoadjuvant therapy (TNT) for patients with locally advanced rectal cancer (LARC) is now the standard of care. Randomized trials suggest the use of short-course radiotherapy (SCRT) and long-course radiotherapy (LCRT) are oncologically equivalent.

OBJECTIVE

To describe pathologic outcomes after surgical resections of patients receiving SCRT versus LCRT as part of TNT for LARC.

PARTICIPANTS

All patients with LARC treated at a single tertiary hospital who underwent proctectomy after completing TNT were included. Patients were excluded if adequate details of TNT were not available in the electronic medical record.

RESULTS

A total of 53 patients with LARC were included. Thirty-nine patients (73.5%) received LCRT and 14 (26.4%) received SCRT. Forty-nine patients (92.5%) were clinical stage III (cN1-2) prior to treatment. The average lymph node yield after proctectomy was 20.9 for SCRT and 17.0 for LCRT (P = .075). Of the 49 patients with clinically positive nodes before treatment, 76.9% of those who received SCRT and 72.2% of those who received LCRT achieved pN0 disease after TNT. Additionally, there were no significant differences in rates of pathologic complete response between patients who received SCRT and LCRT, 7.1% and 12.8%, respectively (P = .565).

CONCLUSION

Pathologic outcomes of patients with LARC treated with SCRT or LCRT, as part of TNT, may be similar. Further prospective trials are needed to assess long-term clinical outcomes and to determine best treatment protocols.

Effect of neoadjuvant chemoradiotherapy with or without PD-1 antibody sintilimab in pMMR locally advanced rectal cancer: A randomized clinical trial

Neoadjuvant chemoradiotherapy (NACRT) was the standard treatment for patients with locally advanced rectal cancer (LARC) with proficient mismatch repair (pMMR) proteins. In this randomized phase 2 trial (ClinicalTrial.gov: NCT04304209), 134 pMMR LARC patients were randomly (1:1) assigned to receive NACRT or NACRT and the programmed cell death protein 1 (PD-1) antibody sintilimab. As the primary endpoint, the total complete response (CR) rate is 26.9% (18/67, 95% confidence interval [CI] 16.0%-37.8%) and 44.8% (30/67, 95% CI 32.6%-57.0%) in the control and experimental arm, respectively, with significant difference (p = 0.031 for chi-squared test). Response ratio is 1.667 (95% CI 1.035-2.683). Immunohistochemistry shows PD-1 ligand 1 (PD-L1) combined positive score is associated with the synergistic effect. The safety profile is similar between the arms. Adding the PD-1 antibody sintilimab to NACRT significantly increases the CR rate in pMMR LARC, with a manageable safety profile. PD-L1 positivity may help identify patients who might benefit most from the combination therapy.

Effect of radiotherapy on long-term quality of life in recurrence-free rectal cancer survivors (LaTE study): nationwide inverse probability of treatment-weighted registry-based cohort study and survey

BACKGROUND

Radiotherapy reduces local recurrence in locally advanced rectal cancer, but may cause harm in patients who do not experience recurrence. The aim was to investigate the impact of radiotherapy on long-term quality of life after curative treatment for rectal cancer, i.e. in patients without a recurrence during the follow-up.

METHODS

All patients operated on for rectal cancer in Norway under 75 years of age between 30 September 2007 and 1 October 2020 were identified using the Cancer Registry of Norway. Exclusion criteria were distant metastasis, recurrence and dementia. The primary outcome measure was the Gastrointestinal Quality of Life Index. Secondary outcome measures included the 36-item Short Form Survey. Inverse probability weights based on a multiple logistic regression model were used to balance prechosen covariates between the radiotherapy and no radiotherapy groups when assessing differences in outcomes.

RESULTS

Of 5014 invited patients, 2142 (43%) eligible patients answered the questionnaires. Of these 762 (36%) were treated with neoadjuvant radiotherapy plus surgery and 1380 (64%) with surgery alone. The mean follow-up time was 6.4 and 7.4 years respectively. After propensity score matching, the Gastrointestinal Quality of Life Index differed significantly between irradiated and non-irradiated patients ((mean(s.d.), mean score 103.8(19.4) versus 110.8(19.6) respectively, mean difference: -6.96 (95% c.i. -8.72 to -5.19); P < 0.001). Among patients without a stoma the mean difference was -8.1 points, whereas it was -5.7 for patients with a stoma. The radiotherapy group also scored significantly lower in 7 of 8 36-item Short Form Survey domains compared with the surgery alone group.

CONCLUSION

Long-term quality of life was significantly lower in patients without a recurrence during the follow-up who received radiotherapy compared with patients who did not. These findings warrant a critical re-evaluation of the use of radiotherapy both in traditional neoadjuvant treatment and in modern organ-preserving treatment regimens.

Number of lymph nodes retrieved in patients with locally advanced rectal cancer after total neoadjuvant therapy: post-hoc analysis from the STELLAR trial

BACKGROUND

The current gold standard for extraperitoneal locally advanced rectal cancer is total neoadjuvant therapy (TNT) followed by total mesorectal excision. This research explored the number of lymph nodes in patients with locally advanced rectal cancer after TNT and its correlation with survival.

MATERIALS AND METHODS

This is a post-hoc analysis based on the STELLAR trial, including patients with locally advanced rectal cancer from 16 tertiary centres who were randomized for short-term radiotherapy followed by chemotherapy (TNT group) or long-term concurrent chemotherapy group followed by total mesorectal excision between 2015 and 2018. This lymph node-related analysis is based on the TNT group. Subgroups were differentiated based on the lymph node harvest (below the median number: limited lymphadenectomy group, and greater than/equal to the median number: extended lymphadenectomy group). The primary outcomes were overall survival and disease-free survival (DFS). Correlations with clinical/pathological variables, lymphadenectomy categories and use of adjuvant chemotherapy were explored.

RESULTS

Among the 451 patients enrolled in the STELLAR trial, 227 patients (50.3%) were assigned to the TNT group, including 29.5% females. The median number of lymph nodes retrieved in the TNT group was 11.0. Patients in the limited lymphadenectomy subgroup exhibited worse overall survival than those with extended lymphadenectomy (HR 2.95 (95% c.i. 1.47 to 5.92), P = 0.001). The overall survival was similar in the ypN0-limited and ypN1-extended subgroups (HR 0.38 (95% c.i. 0.11 to 1.30), P = 0.109). Adjuvant chemotherapy was associated with better overall survival and DFS than no adjuvant chemotherapy overall (P < 0.001) and in the limited lymphadenectomy subgroup (P < 0.001). However, there was no significant difference in overall survival or DFS with or without adjuvant chemotherapy in the extended lymphadenectomy subgroup (P = 0.887 and P = 0.192, respectively).

CONCLUSION

In the STELLAR trial, the median number of lymph nodes harvested was 11. In patients with limited lymphadenectomy, the use of adjuvant therapy after TNT was beneficial and correlated with better prognosis compared with patients who did not receive adjuvant chemotherapy.

Novel regimens and treatment strategies in neoadjuvant therapy for colorectal cancer: A systematic review

Objective

The objective of this systematic review was to describe novel regimens and treatment strategies in neoadjuvant therapy for colorectal cancer (CRC). The aim was to summarize the current advancements in neoadjuvant chemotherapy (NACT) for CRC, including the use of cytotoxic drugs, targeted treatments, and immunotherapy. The analysis aimed to provide insights into the potential benefits and drawbacks of these novel approaches and highlight the need for further research to optimize NACT use in CRC and improve patient outcomes.

Methods

From October 20, 2023, to December 10, 2023, a comprehensive literature search was conducted across multiple databases, including PubMed, Ovid, Web of Science, the Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, Embase, and Scopus. Studies addressing the use of and treatment strategies for CRC and neoadjuvant therapies were included. Screening was conducted in two steps, initially by title and abstract and then by full-text articles. English-language articles were considered, while preprints, non-English publications, and articles published as grey literature were excluded from the study. A total of 85 studies were selected for further analysis after screening and filtering.

Results

After filtering out duplicates and items that were irrelevant to our research query from the initial database search's 510 results, 397 unique articles were found. Eighty-five studies were chosen for additional analysis after the articles underwent two rounds of screening.

Conclusion

The review concluded that neoadjuvant therapy for CRC has evolved beyond conventional approaches and holds promise for improving patient outcomes. Future prospects for advancing neoadjuvant approaches are promising, with ongoing clinical trials investigating the refinement of strategies, identification of predictive biomarkers, and optimization of patient selection. The adoption of novel regimens, precision medicine, and immunotherapy offers opportunities to redefine treatment paradigms and enhance patient care in CRC.

The benefit of adjuvant chemotherapy in pathological T1-3N0M0 rectal mucinous adenocarcinoma: no improvement survival outcomes based on long-term survival analysis of large population data

Background

Currently, the benefits of the administration of adjuvant chemotherapy (AT) in pathological low-risk rectal mucinous adenocarcinoma (RM) with T1-3N0M0 are unclear. The objective of this study is to retrospectively investigate the clinical significance of AT in terms of survival outcomes for patients with pathological T1-3N0M0 RM using data from a large population.

Methods

The patient data were collected from the Surveillance, Epidemiology, and End Results (SEER) Program. The Chi-squared test was used to analyze categorical variables. The survival curves were compared using the log-rank test and the Kaplan-Meier method. A multivariate proportional hazards regression (Cox) model was applied to identify the independent prognostic factors of survival outcomes. Propensity score matching (PSM) was utilized to eliminate the differences between groups and estimate AT's effect.

Results

The median follow-up duration for the rectal cancer (RC) cohort was 116 months. Multivariate analyses revealed that RM was a significant adverse prognostic factor, correlating with poorer overall survival (OS) and cancer-specific survival (CSS) for RC [hazard ratio (HR): 1.226, 95% confidence interval (CI): 1.094-1.375, P<0.001; HR: 1.446, 95% CI: 1.242-1.683, P<0.001]. Among patients with RM, the rates of 5-year OS and CSS were 68.6% and 79.3% in the AT (-) group, respectively. Additionally, the AT (+) group exhibited similar rates of 65.6% for 5-year OS and 74% for CSS (P=0.80, P=0.26). Subtype analysis according to preoperative therapy status showed that AT also did not significantly affect survival outcomes (P=0.65, P=0.34; P=0.90, P=0.76).

Conclusions

Our study found that RM is a poor prognostic factor in pathological T1-3N0M0 RC. However, AT does not appear necessary to improve survival outcomes of pathological T1-3N0M0 RM.

Particle therapy in gastrointestinal cancer-a narrative review

Background and Objective

Radiation therapy is one of the main pillars in the treatment of gastrointestinal (GI) cancers, especially esophageal and anorectal malignancies. The worldwide standard of care is yet an irradiation with photons. Though not commonly used, charged particles offer some physical advantages with a highly conformal dose distribution, which allows an even better sparing of organs at risk. In addition to dosimetric advantages, heavy-ion beams like carbon ions may offer an additional set of biological advantages. Because particle therapy is not standard of care, data are scarce-especially concerning the use in GI malignancies. The aim of this review is to provide a compact overview of the currently available literature.

Methods

PubMed and Web of Science databases were searched for publications on particle radiotherapy in GI cancer (e.g., proton therapy in esophageal cancer, carbon ion radiotherapy in pancreatic cancer).

Key Content and Findings

Here we present a review of the current data on particle therapy with regard to esophageal, pancreatic, hepatic and anorectal malignancies.

Conclusions

Data on particle therapy in GI cancer are scarce. Nevertheless, the current literature shows some promising results. Further clinical evidence, especially randomized trials, is crucial to augment the role of particle radiotherapy in GI cancer.

A nomogram for predicting the overall survival in rectal cancer patients after total neoadjuvant therapy

BACKGROUND

Total neoadjuvant therapy (TNT) has been recommended by the National Comprehensive Cancer Network for treating locally advanced rectal cancer (LARC), but extremely rare studies have focused on establishing nomograms to predict the prognosis in these patients after TNT. We aimed to develop a nomogram to predict overall survival (OS) in rectal cancer patients who underwent TNT.

METHODS

In retrospective cohort study, we extract the data of the rectal cancer patients from the SEER database between 2010 and 2015, including demographic information and tumor characteristics. The cohort was divided into training set and validation set based on a ratio of 7:3. Univariate logistic regression analysis was utilized for the comparison of variables in training set. Candidate variables with P < 0.1 in training set was entered into the best subset selection, LASSO regression and Boruta feature selection. Finally, the selected variables significantly associated with the 3-year, 5-year, and 8-year OS were used to build a nomogram, followed by validation using receiver operating characteristic (ROC) curve, area under the curve (AUC), and calibration curve.

RESULTS

A total of 3265 rectal cancer patients (training set: 2285; test set: 980) were included in the present study. A nomogram was developed to predict the 3-year, 5-year, and 8-year OS based on age, household income, total number of in situ/malignant tumors, CEA, T stage, N stage and perineural invasion. The nomogram showed good efficiency in predicting the 3-year, 5-year and 8-year OS with good AUC for the training set and test set, respectively.

CONCLUSION

We established a nomogram for predicting the 3-year, 5-year, and 8-year OS of the rectal cancer patients, which showed good prediction efficiency for the OS after TNT.

The Prognostic and Predictive Utility of CDX2 in Colorectal Cancer

Caudal type homeobox transcription factor 2 (CDX2) is a gastrointestinal cancer biomarker that regulates epithelial development and differentiation. Absence or low levels of CDX2 have been associated with poor prognosis and proposed as a chemotherapy response predictor. Tumour tissue samples from 668 patients with stage I-IV colorectal cancer were stained for CDX2 and stratified into two subgroups according to expression levels. Statistical tests were used to evaluate CDX2's relationship with survival and chemotherapy response. Of 646 samples successfully stained, 51 (7.9%) had low CDX2 levels, and 595 (92.1%) had high levels. Low CDX2 staining was associated with poor differentiation and the presence of lymphovascular or perineural invasion and was more common in colon and right-sided tumours. Overall survival (p < 0.001) and disease-free survival (p = 0.009) were reduced in patients with low CDX2 expression. Multivariable analysis validated CDX2 as an independent poor prognostic factor after excluding confounding variables. There was no statistically significant improvement in survival with adjuvant chemotherapy in stage II colon cancer (p = 0.11). In the rectal cohort, there was no relationship between CDX2 levels and therapy response. While confirming the prognostic utility of CDX2 in colorectal cancer, our study highlights that larger studies are required to confirm its utility as a predictive chemotherapy biomarker, especially in left-sided and rectal cancers.

Identification and validation of a machine learning model of complete response to radiation in rectal cancer reveals immune infiltrate and TGFβ as key predictors

BACKGROUND

It is uncertain which biological features underpin the response of rectal cancer (RC) to radiotherapy. No biomarker is currently in clinical use to select patients for treatment modifications.

METHODS

We identified two cohorts of patients (total N = 249) with RC treated with neoadjuvant radiotherapy (45Gy/25) plus fluoropyrimidine. This discovery set included 57 cases with pathological complete response (pCR) to chemoradiotherapy (23%). Pre-treatment cancer biopsies were assessed using transcriptome-wide mRNA expression and targeted DNA sequencing for copy number and driver mutations. Biological candidate and machine learning (ML) approaches were used to identify predictors of pCR to radiotherapy independent of tumour stage. Findings were assessed in 107 cases from an independent validation set (GSE87211).

FINDINGS

Three gene expression sets showed significant independent associations with pCR: Fibroblast-TGFβ Response Signature (F-TBRS) with radioresistance; and cytotoxic lymphocyte (CL) expression signature and consensus molecular subtype CMS1 with radiosensitivity. These associations were replicated in the validation cohort. In parallel, a gradient boosting machine model comprising the expression of 33 genes generated in the discovery cohort showed high performance in GSE87211 with 90% sensitivity, 86% specificity. Biological and ML signatures indicated similar mechanisms underlying radiation response, and showed better AUC and p-values than published transcriptomic signatures of radiation response in RC.

INTERPRETATION

RCs responding completely to chemoradiotherapy (CRT) have biological characteristics of immune response and absence of immune inhibitory TGFβ signalling. These tumours may be identified with a potential biomarker based on a 33 gene expression signature. This could help select patients likely to respond to treatment with a primary radiotherapy approach as for anal cancer. Conversely, those with predicted radioresistance may be candidates for clinical trials evaluating addition of immune-oncology agents and stromal TGFβ signalling inhibition.

FUNDING

The Stratification in Colorectal Cancer Consortium (S:CORT) was funded by the Medical Research Council and Cancer Research UK (MR/M016587/1).

Clinical effects of neoadjuvant chemoradiotherapy versus neoadjuvant chemotherapy on complications and recurrence in patients with advanced gastric cancer

Objective

To compare the clinical effects of neoadjuvant chemoradiotherapy (NCRT) and neoadjuvant chemotherapy (NCT) on complications and recurrence in patients with advanced gastric cancer (AGC).

Method

This was a retrospective study. A total of 83 patients with AGC admitted to Chengde Central Hospital between Jan. 2019 and Jun. 2021 were selected and divided into the observation group(n=41) and the control group(n=42) using a random number table. Patients in the control group received XELOX chemotherapy, and those in the observation group received intensity-modulated radiotherapy (IMRT) with concurrent XELOX chemotherapy. Compared efficacy, pathological complete response rate (pCR), R0 resection rate, adverse reactions, and quality of life (QOL) before and after treatment between the two groups.

Results

The efficacy, pCR, and R0 resection rate of the observation group were significantly increased compared with those of the control group. Comparison of complications showed the number of patients experiencing gastrointestinal (GI) reactions, increased BUN, increased GPT, alopecia, and pigmentation in the observation group was decreased compared with that in the control group, with no statistically significant differences(p>0.05), and the number of patients experiencing myelosuppression was statistically significant between the two groups(p<0.05). There were no significant differences in sub-scores of physical, role, emotional, cognitive, and social functions and the overall score of QOL between the two groups(p>0.05) before treatment.

Conclusion

NCRT is safer and more effective in patients with AGC compared with NCT, and can significantly improve the QOL of patients. It can be widely used in clinical practice.

Neoadjuvant treatment of rectal cancer: Where we are and where we are going

Locally advanced rectal cancer requires a multidisciplinary approach based on total neoadjuvant treatment with radiotherapy (RT) and chemotherapy (ChT), followed by deferred surgery. Currently, alternatives to the standard total neoadjuvant therapy (TNT) are being explored, such as new ChT regimens or the introduction of immunotherapy. With standard TNT, up to a third of patients may achieve a complete pathological response (CPR), potentially avoiding surgery. However, as of now, we lack predictive markers of response that would allow us to define criteria for a conservative organ strategy. The presence of mutations, genes, or new imaging tests is helping to define these criteria. An example of this is the diffusion coefficient in the diffusion-weighted sequence of magnetic resonance imaging and the integration of this imaging technique into RT treatment. This allows for the monitoring of the evolution of this coefficient over successive RT sessions, helping to determine which patients will achieve CPR or those who may require intensification of neoadjuvant therapy.

Effect of neoadjuvant therapy regimens on lymph nodes yield in rectal cancer

BACKGROUND AND OBJECTIVES

Pathological nodal staging is relevant to postoperative decision-making and a prognostic marker of cancer survival. This study aimed to assess the effect of different total neoadjuvant therapy (TNT) regimens on lymph node status following total mesorectal excision (TME) for locally advanced rectal cancer (LARC).

METHODS

A retrospective cohort study of patients treated for node-positive clinical stage 3 LARC with TNT between January 2015 and August 2022. Patients were stratified into induction therapy and consolidation therapy groups. Variables collated included patient demographics, clinical and radiological characteristics of the tumor, and pathology of the resected specimen. Primary outcome was total harvested lymph nodes.

RESULTS

Ninety-seven patients were included (57 [58.8%] males; mean age of 58.5 ± 11.4 years). The induction therapy group included 85 (87.6%) patients while 12 (12.4%) patients received consolidation therapy. A median interquartile range value of 22.00 (5.00-72.00) harvested lymph nodes was recorded for the induction therapy group in comparison to 16.00 (16.00-47.00) in the consolidation therapy arm (p = 0.487). Overall pathological complete response rate was 34%.

CONCLUSION

Total harvested nodes from resected specimens were marginally lower in the consolidation therapy group. Induction therapy may be preferrable to optimize postoperative specimen staging.

Combining immunotherapy and radiation therapy in gastrointestinal cancers: A review

INTRODUCTION AND PURPOSE

With a significant global impact, treatment of gastrointestinal (GI) cancers still presents with challenges, despite current multimodality approaches in advanced stages. Clinical trials are expanding for checkpoint inhibition (ICI) combined with radiation therapy (RT). This review intends to offer a comprehensive image of the current data regarding the effectiveness of this association, and to reflect on possible directions to further optimize the results.

RESULTS

Several early phase studies demonstrated encouraging potential. However, translating preclinical outcomes to clinical settings proves challenging, especially in immunologically "cold" environments. GI cancers exhibit heterogeneity, requiring tailored approaches based on disease stage and patient characteristics. Current results, though promising, lack the power of evidence to influence the general practice.

CONCLUSIONS

Finding biomarkers for identifying or converting resistant cancers is essential for maximizing responses, moreover in this context strategic RT parameters need to be carefully considered. Our review emphasizes the significance of having a thorough grasp of how immunology, tumour biology, and treatment settings interact in order to propose novel research avenues and efficient GI cancer therapy.

Rectal Cancer Survival for Residual Carcinoma In Situ Versus Pathologic Complete Response After Neoadjuvant Therapy

BACKGROUND

Pathologic complete response after neoadjuvant chemoradiotherapy for rectal cancer is associated with improved survival. It is unclear whether residual carcinoma in situ portends a similar outcome.

OBJECTIVE

To compare the survival of patients with locally advanced rectal cancer who received neoadjuvant therapy and achieved pathologic carcinoma in situ versus pathologic complete response.

DESIGN

Retrospective cohort study.

SETTING

National public database.

PATIENTS

A total of 4594 patients in the National Cancer Database from 2006 to 2016 with locally advanced rectal cancer who received neoadjuvant therapy, underwent surgery, and had node-negative ypTis or ypT0 on final pathology were included. Of these, 4321 patients (94.1%) had ypT0 and 273 (5.9%) had ypTis on final pathology.

MAIN OUTCOME MEASURE

Overall survival.

RESULTS

The median age was 60 years, and 1822 patients (39.7%) were women. On initial staging, 54.5% (n = 2503) had stage II disease and 45.5% (n = 2091) had stage III disease. The ypTis group had decreased overall survival compared to the ypT0 group (HR 1.42; 95% CI, 1.04-1.95; p  = 0.028). Other factors associated with decreased overall survival were older age at diagnosis, increasing Charlson-Deyo score, and poorly differentiated tumor grade. Variables associated with improved survival were female sex, private insurance, and receipt of both neoadjuvant and adjuvant chemotherapy. For the total cohort, there was no difference in survival between clinical stage II and stage III.

LIMITATIONS

Standard therapy versus total neoadjuvant therapy could not be abstracted. Overall survival was defined as the time from surgery to death from any cause or last contact, allowing for some erroneously misclassified deaths.

CONCLUSIONS

ypTis is associated with worse overall survival than ypT0 for patients with locally advanced rectal cancer who receive neoadjuvant chemoradiotherapy followed by surgery. For this cohort, clinical stage was not a significant predictor of survival. Prospective trials comparing survival for these pathologic outcomes are needed. See Video Abstract .

SUPERVIVENCIA DEL CNCER DE RECTO PARA EL CARCINOMA RESIDUAL IN SITU VS RESPUESTA PATOLGICA COMPLETA DESPUS DE LA TERAPIA NEOADYUVANTE

ANTECEDENTESLa respuesta patológica completa después de la quimiorradioterapia neoadyuvante para el cáncer de recto se asocia con una mayor supervivencia. No está claro si el carcinoma residual in situ presagia un resultado similar.OBJETIVOComparar la supervivencia de pacientes con cáncer de recto localmente avanzado que recibieron terapia neoadyuvante y lograron un carcinoma patológico in situ versus una respuesta patológica completa.DISEÑOEstudio de cohorte retrospectivo.ESCENARIOBase de datos pública nacional.PACIENTESSe incluyeron 4,594 pacientes de la Base de Datos Nacional de Cáncer de 2006 a 2016 con cáncer de recto localmente avanzado que recibieron terapia neoadyuvante, fueron sometidos a cirugía y tuvieron ganglios negativos, ypTis o ypT0 en el reporte patológico final. 4.321 (94,1%) tuvieron ypT0 y 273 (5,9%) tuvieron ypTis en el reporte final.PRINCIPALES MEDIDAS DE RESULTADOSupervivencia general.RESULTADOSLa mediana de edad fue de 60 años. 1.822 pacientes (39,7%) fueron mujeres. El 54,5% (n = 2.503) tuvo la enfermedad en estadio II y el 45,5% (n = 2.091) tuvo la enfermedad en estadio III según la estadificación inicial. El grupo ypTis tuvo una supervivencia general reducida en comparación con el grupo ypT0 (HR 1,42, IC 95 % 1,04-1,95, p = 0,028). Otros factores asociados con una menor supervivencia general fueron una edad más avanzada al momento del diagnóstico, un aumento de la puntuación de Charlson-Deyo y un grado tumoral poco diferenciado. Las variables asociadas con una mejor supervivencia fueron el sexo femenino, el seguro privado y la recepción de quimioterapia neoadyuvante y adyuvante. Para la cohorte total, no hubo diferencias en la supervivencia entre el estadio clínico 2 y el estadio 3.LIMITACIONESNo se pudo resumir el tratamiento estándar versus el tratamiento neoadyuvante total. La supervivencia general se definió como el tiempo transcurrido desde la cirugía hasta la muerte por cualquier causa o último contacto, lo que permite algunas muertes erróneamente clasificadas.CONCLUSIONESypTis se asocia con una peor supervivencia general que ypT0 en pacientes con cáncer de recto localmente avanzado que reciben quimiorradioterapia neoadyuvante seguida de cirugía. Para esta cohorte, el estadio clínico no fue un predictor significativo de supervivencia. Se necesitan ensayos prospectivos que comparen la supervivencia de estos resultados patológicos. ( Traducción-Dr Osvaldo Gauto ).

Is There any Benefit of Addition of Neo-Adjuvant Chemotherapy (FOLFOX4) to Standard Preoperative Treatment of Rectal Cancer? A Randomized Clinical Trial

BACKGROUND

Total neoadjuvant therapy (TNT) before surgical intervention represents a unique therapeutic approach for the management of locally advanced rectal cancer (LARC) and has witnessed a notable rise in utilization within recent years. However, the efficacy and safety of this treatment remain subjects of ongoing debate and investigation. This randomized controlled trial aimed to evaluate the potential impact of administering induction chemotherapy (IC) before the conventional neoadjuvant concomitant chemoradiotherapy (nCRT) in LARC patients.

MATERIALS & METHODS

patients with resectable stage II-III LARC were randomly allocated to receive either biweekly 6 cycles of FOLFOX4 regimen as IC followed by CRT and total mesorectal excision (TME) (experimental group) or nCRT followed by TME (control group). The primary endpoint was the rate of pathological complete response (pCR). The secondary endpoints encompassed the evaluation of treatment-related adverse events as well as the assessment of survival outcomes.

RESULTS

67 patients were enrolled in this study (32 in the experimental group and 35 in the control group). The median age of the patients was 45 years. Stage IIIB was observed in 46.3% of the patients. The patients who underwent induction chemotherapy demonstrated a notably higher rate of achieving pCR in comparison to the control group (28.1% vs 8.6%; P=0.001). There were no statistically significant differences observed in terms of their toxicity profile and survival outcomes.

CONCLUSIONS

Implementation of induction chemotherapy utilizing the FOLFOX4 regimen has demonstrated a notable enhancement in the rate of pathological complete response. However, this improvement does not appear to translate into significant advancements in overall survival outcomes.

Current Applications and Future Directions of Circulating Tumor Cells in Colorectal Cancer Recurrence

The ability to predict or detect colorectal cancer (CRC) recurrence early after surgery enables physicians to apply appropriate treatment plans and different follow-up strategies to improve patient survival. Overall, 30-50% of CRC patients experience cancer recurrence after radical surgery, but current surveillance tools have limitations in the precise and early detection of cancer recurrence. Circulating tumor cells (CTCs) are cancer cells that detach from the primary tumor and enter the bloodstream. These can provide real-time information on disease status. CTCs might become novel markers for predicting CRC recurrence and, more importantly, for making decisions about additional adjuvant chemotherapy. In this review, the clinical application of CTCs as a therapeutic marker for stage II CRC is described. It then discusses the utility of CTCs for monitoring cancer recurrence in advanced rectal cancer patients who undergo neoadjuvant chemoradiotherapy. Finally, it discusses the roles of CTC subtypes and CTCs combined with clinicopathological factors in establishing a multimarker model for predicting CRC recurrence.

A retrospective cohort study of neoadjuvant chemoradiotherapy combined with immune checkpoint inhibitors in locally advanced rectal cancer

INTRODUCTION

This study aimed to investigate the safety and efficacy of neoadjuvant chemoradiotherapy combined with immune checkpoint inhibitors (ICIs) in patients with locally advanced rectal cancer (LARC). Patients diagnosed with LARC and treated with programmed cell death protein-1 (PD-1) inhibitors were recruited.

METHODS

Four different treatment strategies were employed in this study: plan A [long-course radiotherapy + PD-1 inhibitor/capecitabine + PD-1 inhibitor/XELOX+ total mesorectal excision (TME)], plan B (long-course radiotherapy + capecitabine + PD-1 inhibitor/XELOX + TME), plan C (short-course radiotherapy + PD-1 inhibitor/XELOX + TME), and plan D (PD-1 inhibitor/XELOX + short-course radiotherapy + TME). The basic information about patients, pathological indicators, adverse events, and efficacy indexes of treatment plans were analyzed.

RESULTS

96.8 % of patients were mismatch repair proficient (pMMR) and only 2 patients belonged to mismatch repair deficient (dMMR). The 2 patients with dMMR showed a pathological complete response (pCR) rate of 100 %, while the pCR rate of pMMR patients was 43.3 %. The overall tumor descending rate reached 79 %, and the anus-retained rate was 88.7 % in all LARC patients. Plan A exhibited the highest pCR rate of 60 %, and plan C had the highest tumor descending rate and anal preservation rate. Radiation enteritis was the most common adverse event in LARC patients after neoadjuvant therapy, and its incidence was the highest in Plan A.

CONCLUSION

Neoadjuvant chemoradiotherapy combined with ICIs demonstrated favorable efficacy and safety in treating LARC patients.

The role of total neoadjuvant therapy in locally advanced rectal cancer: a survey of specialists attending the All-Ireland Colorectal Cancer Conference 2022 including lead investigators of OPRA, PRODIGE-23 and RAPIDO

BACKGROUND

The treatment of locally advanced rectal cancer (LARC) has evolved following recent landmark trials of total neoadjuvant therapy (TNT)-the delivery of preoperative chemotherapy sequenced with radiation.

AIM

To assess the preferences of colorectal surgery (CRS), radiation oncology (RO) and medical oncology (MO) specialists attending the All-Ireland Colorectal Cancer Conference (AICCC) 2022 regarding the neoadjuvant management of LARC.

METHODS

A live electronic survey explored the preferred treatment approach and TNT regimen for early-, intermediate-, bad-, and advanced-risk categories of rectal cancer according to the European Society of Medical Oncology (ESMO) guidelines. The survey was preceded by an update from lead investigators of TNT trials (OPRA, PRODIGE-23 and RAPIDO), who then participated in a multidisciplinary panel discussion.

RESULTS

Ten CRS, 7 RO and 15 MO (32 of 45 specialists) participated fully in the survey resulting in a response rate of 71%. Ninety-four percent, 76% and 53% of specialists preferred a TNT approach for patients with advanced, bad, and intermediate-risk rectal cancer, respectively. A consolidation TNT regimen of long-course chemoradiotherapy followed by chemotherapy was the most preferred regimen. Upfront surgery was preferred by 77% for early-risk disease.

CONCLUSION

This survey illustrated the general acceptance of TNT by rectal cancer specialists attending the AICCC as a valuable treatment strategy for higher-risk category LARC. Whilst the treatment of LARC changes, it remains best practice to individualize care, incorporating the selective use of TNT as discussed by an MDT and in keeping with the patient's goals of care.

Robotic surgery after total neoadjuvant therapy for rectal cancer: pitfalls of beyond total mesorectal excision for patients with sidewall invasion

AIM

Total neoadjuvant therapy (TNT) for locally advanced rectal cancer (LARC) is rapidly spreading. The robotic surgical techniques to approach lateral invasion, such as that of the pelvic plexus, have not yet been established. In this technical note, we present a video illustrating a surgical technique for lateral invasion using our novel technique and discuss its pitfalls.

METHOD

We present the case of a 65-year-old man with LARC. Robotic surgery was performed after TNT using the da Vinci Xi Surgical System (Intuitive Surgical Inc., Sunnyvale, CA, USA). The surgical procedure was as follows: (1) D3 lymph node dissection around the inferior mesenteric artery using a medial-to-lateral approach; (2) rectal mobilization; (3) dissection of the ureterohypogastric fascia and ureter; and (4) combined resection of the hypogastric nerve and pelvic plexus. The key surgical point for sidewall invasion is the resection extent. Dividing the resection extent into three areas is important: zone A, which contains the pelvic plexus and is closest to the tumour; zone B, which contains the iliac vessels; and zone C, the most lateral zone, which contains the obturator nerves. This allows organ and function preservation by resecting only the smallest organ that truly requires R0 resection.

RESULTS

The operating time was 333 min, console time was 232 min, and blood loss was 0 mL. The circumferential resection margin was 10 mm, and an R0 resection was achieved.

CONCLUSION

We introduced a novel approach for robotic surgery after TNT for LARC with sidewall invasion. This technique can be performed safely and may help standardize 'beyond total mesorectal excision'.

Total Neoadjuvant Therapy With PD-1 Blockade for High-Risk Proficient Mismatch Repair Rectal Cancer

Importance

Total neoadjuvant therapy (TNT) is the standard treatment for locally advanced rectal cancer, especially for patients with high-risk factors. However, the efficacy of TNT combined with immunotherapy for patients with proficient mismatch repair (pMMR) rectal cancer is unknown.

Objectives

To evaluate the safety and efficacy of TNT with induction chemoimmunotherapy followed by long-course chemoradiation in patients with high-risk, pMMR rectal cancer and to identify potential molecular biomarkers associated with treatment efficacy.

Design, Setting, and Participants

This cohort study was a single-arm phase 2 trial conducted at Gastrointestinal Cancer Center, Peking University Cancer Hospital & Institute, from June 2020 to October 2021. Biopsies and plasma were collected before treatment for whole-exome sequencing and cell-free DNA sequencing, respectively. Data were analyzed from May 2022 to September 2022.

Interventions

Participants received 3 cycles of induction oxaliplatin and capecitabine combined with camrelizumab and radiotherapy (50.6 Gy in 22 fractions) with concurrent capecitabine. Patients without disease progression received 2 cycles of consolidation oxaliplatin/capecitabine.

Main Outcomes and Measures

The primary end point was pathologic complete response rate.

Results

Of 25 patients enrolled (19 men [76%]; 6 women [24%]; median [IQR] age, 58 [48-64] years), 22 patients (88%) completed the TNT schedule. The pathologic complete response rate was 33.3% (7/21). Twelve patients (48%) achieved clinical complete response, and 4 patients (16%) chose to watch and wait. R0 resection was achieved in 21 of 21 patients, and the major pathologic response rate was 38.1% (8/21). The most common adverse event was nausea (80%, 20/25); grade 3 toxic effects occurred in 9 of 25 patients (36%). Patients with tumor shrinkage of 50% or greater after induction oxaliplatin/capecitabine and camrelizumab or clinical complete response had higher percentages of LRP1B mutation. Mutation of LRP1B was associated with high tumor mutation burden and tumor neoantigen burden. Patients with high tumor mutation burden all benefited from therapy.

Conclusions and Relevance

This study found that TNT with induction chemoimmunotherapy followed by long-course chemoradiation was safe and effective for patients with high-risk rectal cancer with pMMR status. Longer follow-up and larger clinical studies are needed to validate this innovative regimen. There is also an urgent need to further validate the predictive value of LRP1B and discover other novel biomarkers with potential predictive value for rectal cancer.

FOXA1-Driven pathways exacerbate Radiotherapy-Induced kidney injury in colorectal cancer

OBJECTIVE

This study aimed to investigate the role of FOXA1 in acute kidney injury (AKI) induced by radiotherapy in colorectal cancer. Although FOXA1 is known to be aberrantly expressed in malignant tumors, its contribution to AKI remains unclear. This study aimed to explore the involvement of FOXA1 in AKI induced by radiotherapy in colorectal cancer and its influence on the regulation of downstream target genes.

METHODS

Firstly, a transcriptome analysis was performed on mice to establish a radiation-induced AKI model, and qPCR was used to determine the expression of FOXA1 in renal cell injury models induced by X-ray irradiation. Additionally, FOXA1 was silenced using lentiviral vectors to investigate its effects on the apoptosis of mice with radiation-induced AKI and HK-2 cells. Next, bioinformatics analysis and various experimental validation methods such as ChIP assays, co-immunoprecipitation, and dual-luciferase reporter assays were employed to explore the relationship between FOXA1 and the downstream regulatory factors ITCH promoter and the ubiquitin ligase-degradable TXNIP. Finally, lentiviral overexpression or knockout techniques were used to investigate the impact of the FOXA1/ITCH/TXNIP axis on oxidative stress and the activation of inflammatory body NLRP3.

RESULTS

This study revealed that FOXA1 was significantly upregulated in the renal tissues of mice with radiation-induced AKI and in the injured HK-2 cells. Furthermore, in vitro cell experiments and animal experiments demonstrated that FOXA1 suppressed the transcription of the E3 ubiquitin ligase ITCH, thereby promoting apoptosis of renal tubular cells and causing renal tissue damage. Further in vivo animal experiments confirmed that TXNIP, a protein degraded by ITCH ubiquitination, could inhibit oxidative stress and the activation of NLRP3 inflammasome in the AKI mouse model.

CONCLUSION

FOXA1 enhances oxidative stress, cell apoptosis, and NLRP3 inflammasome activation by regulating the ITCH/TXNIP axis, thereby exacerbating radiotherapy-induced AKI.

Surgical Outcomes after Radiotherapy in Rectal Cancer

Over the past decade, the treatment of rectal cancer has changed considerably. The implementation of TME surgery has, in addition to decreasing the number of local recurrences, improved surgical morbidity and mortality. At the same time, the optimisation of radiotherapy in the preoperative setting has improved oncological outcomes even further, although higher perineal infection rates have been reported. Radiotherapy regimens have evolved through the adjustment of radiotherapy techniques and fields, increased waiting intervals, and, for more advanced tumours, adding chemotherapy. Concurrently, imaging techniques have significantly improved staging accuracy, facilitating more precise selection of advanced tumours. Although chemoradiotherapy does lead to the downsizing and -staging of these tumours, a very clear effect on sphincter-preserving surgery and the negative resection margin has not been proven. Aiming to decrease distant metastasis and improve overall survival for locally advanced rectal cancer, systemic chemotherapy can be added to radiotherapy, known as total neoadjuvant treatment (TNT). High complete response rates, both pathological (pCR) and clinical (cCR), are reported after TNT. Patients who follow a Watch & Wait program after a cCR can potentially avoid surgical morbidity and colostomy. For both early and more advanced tumours, trials are now investigating optimal regimens in an attempt to offer organ preservation as much as possible. Multidisciplinary deliberation should include patient preference, treatment toxicity, and likelihood of end colostomy, but also the burden of intensive surveillance in a W&W program.

PREX2 contributes to radiation resistance by inhibiting radiotherapy-induced tumor immunogenicity via cGAS/STING/IFNs pathway in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) lacks established biomarkers or molecular targets for predicting or enhancing radiation response. Phosphatidylinositol-3,4,5-triphosphate-dependent Rac exchange factor 2 (PREX2) exhibits intricate implications in tumorigenesis and progression. Nevertheless, the precise role and underlying mechanisms of PREX2 in CRC radioresistance remain unclear.

METHODS

RNA-seq was employed to identify differentially expressed genes between radioresistant CRC cell lines and their parental counterparts. PREX2 expression was scrutinized using Western blotting, real-time PCR, and immunohistochemistry. The radioresistant role of PREX2 was assessed through in vitro colony formation assay, apoptosis assay, comet assay, and in vivo xenograft tumor models. The mechanism of PREX2 was elucidated using RNA-seq and Western blotting. Finally, a PREX2 small-molecule inhibitor, designated PREX-in1, was utilized to enhance the efficacy of ionizing radiation (IR) therapy in CRC mouse models.

RESULTS

PREX2 emerged as the most significantly upregulated gene in radioresistant CRC cells. It augmented the radioresistant capacity of CRC cells and demonstrated potential as a marker for predicting radioresistance efficacy. Mechanistically, PREX2 facilitated DNA repair by upregulating DNA-PKcs, suppressing radiation-induced immunogenic cell death, and impeding CD8+ T cell infiltration through the cGAS/STING/IFNs pathway. In vivo, the blockade of PREX2 heightened the efficacy of IR therapy.

CONCLUSIONS

PREX2 assumes a pivotal role in CRC radiation resistance by inhibiting the cGAS/STING/IFNs pathway, presenting itself as a potential radioresistant biomarker and therapeutic target for effectively overcoming radioresistance in CRC.

Image-based consensus molecular subtyping in rectal cancer biopsies and response to neoadjuvant chemoradiotherapy

The development of deep learning (DL) models to predict the consensus molecular subtypes (CMS) from histopathology images (imCMS) is a promising and cost-effective strategy to support patient stratification. Here, we investigate whether imCMS calls generated from whole slide histopathology images (WSIs) of rectal cancer (RC) pre-treatment biopsies are associated with pathological complete response (pCR) to neoadjuvant long course chemoradiotherapy (LCRT) with single agent fluoropyrimidine. DL models were trained to classify WSIs of colorectal cancers stained with hematoxylin and eosin into one of the four CMS classes using a multi-centric dataset of resection and biopsy specimens (n = 1057 WSIs) with paired transcriptional data. Classifiers were tested on a held out RC biopsy cohort (ARISTOTLE) and correlated with pCR to LCRT in an independent dataset merging two RC cohorts (ARISTOTLE, n = 114 and SALZBURG, n = 55 patients). DL models predicted CMS with high classification performance in multiple comparative analyses. In the independent cohorts (ARISTOTLE, SALZBURG), cases with WSIs classified as imCMS1 had a significantly higher likelihood of achieving pCR (OR = 2.69, 95% CI 1.01-7.17, p = 0.048). Conversely, imCMS4 was associated with lack of pCR (OR = 0.25, 95% CI 0.07-0.88, p = 0.031). Classification maps demonstrated pathologist-interpretable associations with high stromal content in imCMS4 cases, associated with poor outcome. No significant association was found in imCMS2 or imCMS3. imCMS classification of pre-treatment biopsies is a fast and inexpensive solution to identify patient groups that could benefit from neoadjuvant LCRT. The significant associations between imCMS1/imCMS4 with pCR suggest the existence of predictive morphological features that could enhance standard pathological assessment.

Precision Oncology in Gastrointestinal and Colorectal Cancer Surgery

Precision medicine is used to treat gastrointestinal malignancies including esophageal, gastric, small bowel, colorectal, and pancreatic cancers. Cutting-edge assays to detect and treat these cancers are active areas of research and will soon become standard of care. Colorectal cancer is a prime example of precision oncology as disease site is no longer the final determinate of treatment. Here, the authors describe how leveraging an understanding of tumor biology translates to individualized patient care using evidence-based practices.

Development of a Predictive Nomogram for Circumferential Resection Margin in Rectal Cancer Surgery

INTRODUCTION

Circumferential resection margin (CRM) is a key quality metric and predictor of oncologic outcomes and overall survival following surgery for rectal cancer. We aimed to develop a nomogram to identify patients at risk for a positive CRM in the preoperative setting.

METHODS

We performed a retrospective evaluation of the National Cancer Database from 2010 to 2014 for patients with clinical stage I-III rectal cancer who underwent total mesorectal excision. Patients were excluded for emergency operation, resection for cancer recurrence, palliative resection, transanal resection, and missing CRM status. The primary outcome was positive CRM. Secondary outcomes included overall survival.

RESULTS

There were 28,790 patients included. 2245 (7.8%) had a positive CRM. Higher tumor grade, lack of neoadjuvant chemotherapy, mucinous/signet tumor histology, open approach, abdominoperineal resection, higher T stage, lymphovascular invasion, and perineural invasion were all significantly associated with positive CRM (P < 0.05) and were included in the nomogram. The C-statistic was 0.703, suggesting a good predictive model.

CONCLUSIONS

Positive CRM is associated with specific patient demographics and tumor characteristics. These factors can be used along with preoperative MRI to predict CRM positivity in the preoperative period and plan accordingly.

Surgical Outcomes in Total Neoadjuvant Therapy for Rectal Cancer Versus Standard Long-course Chemoradiation: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

This systematic review and meta-analysis seeks to evaluate the impact of total neoadjuvant therapy (TNT) for rectal cancers on surgical complications and surgical pathology when compared with standard long-course chemoradiotherapy (LCRT).

BACKGROUND

The oncological benefits of TNT are well published in previous meta-analyses, but there is little synthesized information on how it affects surgical outcomes. A recent study has suggested an increase in local recurrence and higher rates of breached total mesorectal excision (TME) plane in TNT patients.

METHODS

This study conformed to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A search was performed in Medline (via PubMed), Cochrane databases, EMBASE and CINAHL to identify relevant randomized controlled trials (RCTs) comparing outcomes between TNT and LCRT. Meta-analyses of pooled proportions between TNT and LCRT were performed, comparing primary outcomes of surgical mortality, morbidity and all reported complications; surgical-pathology differences, namely mesorectal quality, R0 resection rates, circumferential resection margin positive rates, and sphincter preservation rates. Death and progression of disease during neoadjuvant treatment period was also compared. Risk of bias of RCTs was performed using the Cochrane risk-of-bias tool by 2 independent reviewers.

RESULTS

A total of 3185 patients with rectal cancer from 11 RCTs were included in the analysis: 1607 received TNT and 1578 received LCRT, of which 1422 (TNT arm) and 1391 (LCRT arm) underwent surgical resection with curative intent. There was no significant difference in mortality [risk ratio (RR)=0.86, 95% CI: 0.13-5.52, P =0.88, I2 =52%] or major complications (RR=1.04, 95% CI: 0.86-1.26, P =0.70, I2 =0%) between TNT and LCRT. There was a significantly higher risk of breached TME in TNT group on pooled analysis (RR=1.49, 95% CI: 1.03-12.16, P =0.03, I2 =0%), and on subgroup analysis there is higher risk of breached TME in those receiving extended duration of neoadjuvant treatment (>17 weeks from start of treatment to surgery) when compared with LCRT (RR=1.61, 95% CI: 1.06-2.44, P =0.03). No difference in R0 resection rates (RR=0.85, 95% CI: 0.66-1.10, P =0.21, I2 =15%), circumferential resection margin positive rates (RR=0.87, 95% CI: 0.65-1.16, P =0.35, I2 =10%) or sphincter preservation rates (RR=1.02, 95% CI: 0.83-1.25, P =0.88, I2 =57%) were observed. There was a significantly lower risk of progression of disease to an unresectable stage during the neoadjuvant treatment period in TNT patients (RR=0.60, 95% CI: 0.39-0.92, P =0.03, I2 =18%). On subgroup analysis, it appears to favor those receiving extended duration of neoadjuvant treatment (RR=0.44, 95% CI: 0.26-0.80, P =0.002), and those receiving induction-type chemotherapy in TNT (RR=0.25, 95% CI: 0.07-0.88, P =0.03).

CONCLUSIONS

TNT increases rates of breached TME which can contribute to higher local recurrence rates. TNT, however, improves systemic control by reducing early progression of disease during neoadjuvant treatment period. Further research is warranted to identify patients that will benefit from this strategy.