Neoadjuvant chemoradiotherapy combined with immunotherapy for locally advanced rectal cancer: A new era for anal preservation

Prognostic Value of LC3A Protein Expression Patterns in Rectal Cancer Tumors

Background/Objectives: Autophagy is a conserved self-degradation process by which cells break down and recycle their cellular constituents. This process is activated by various stressors, including nutrient deprivation and DNA damage, and has also been associated with tumor progression. In the present study, we aimed to determine the expression patterns, clinicopathological significance, and prognostic value of the autophagy marker microtubule-associated protein 1 light chain 3 alpha (LC3A)-an essential component of autophagic vacuoles-in rectal cancer. Methods: LC3A reactivity was measured by immunohistochemistry in tumor samples from 243 patients who underwent surgery for rectal cancer. Results: Three distinct patterns of LC3A expression were identified: diffuse cytoplasmic, perinuclear, and stone-like structures (SLS). In Kaplan-Meier survival analyses, patients positive for the SLS pattern of LC3A staining in the tumor periphery (TP) had worse overall survival (OS; p = 0.001) and disease-free survival (DFS; p = 0.030) than those without SLSs in this region, as determined by the log-rank test. When patients were stratified by tumor stage, this result was significant in those with stage T3-T4 (OS, p < 0.001; DFS, p = 0.001) but not T1-T2 disease. Multivariate Cox regression analysis further showed an association between TP-localized LC3A SLS positivity and reduced OS for the overall cohort (hazard ratio [HR] = 2.6313, 95% confidence interval [CI]: 1.090-6.349, p = 0.031) and specifically those in the T3-T4 subgroup (HR = 3.347, 95% CI: 1.657-6.760, p = 0.001). Conclusions: Our findings suggest that positivity for SLSs in the TP may hold clinical value as a biomarker for survival prognosis in rectal cancer patients.

Tumor budding as an indicator of prognosis in locally advanced rectal cancer after neoadjuvant chemoradiotherapy: a systematic review and meta-analysis

Introduction

Tumor budding (TB) is recognized as a complementary prognostic factor for colorectal cancer. However, data on its impact on the survival of patients undergoing neoadjuvant chemoradiotherapy (nCRT) remain limited. This study aims to investigate the role of TB in disease-free survival (DFS) and overall survival (OS) among patients with locally advanced rectal cancer receiving nCRT.

Methods

In this systematic review and meta-analysis, an exhaustive search of the PubMed, Scopus, Web of Science (WOS), Embase, and Cochrane databases was conducted, ultimately leading to the extraction of eight studies in the qualitative assessment and meta-analysis.

Results

All the included studies were of high quality. The total sample size comprised 1,941 individuals. Although eight studies were included, nine datasets were extracted, as some studies reported multiple outcome measurements. TB positivity was statistically associated with decreased overall survival of 3.24 (95% confidence interval [CI]: 1.71-6.16) and disease-free survival of 2.54 (95% CI: 1.56-4.15) in patients with locally advanced rectal cancer undergoing nCRT.

Discussion

Based on the findings of this study, TB negativity was statistically and directly associated with better OS and DFS in patients with locally advanced rectal cancer undergoing nCRT.

Prediction of pathological complete response to neoadjuvant chemoimmunotherapy in non-small cell lung cancer using 18F-FDG PET radiomics features of primary tumour and lymph nodes

BACKGROUND

Predicting the response to neoadjuvant chemoimmunotherapy in patients with resectable non-small cell lung cancer (NSCLC) facilitates clinical treatment decisions. Our study aimed to establish a machine learning model that accurately predicts the pathological complete response (pCR) using 18F-FDG PET radiomics features.

METHODS

We retrospectively included 210 patients with NSCLC who completed neoadjuvant chemoimmunotherapy and subsequently underwent surgery with pathological results, categorising them into a training set of 147 patients and a test set of 63 patients. Radiomic features were extracted from the primary tumour and lymph nodes. Using 10-fold cross-validation with the least absolute shrinkage and selection operator method, we identified the most impactful radiomic features. The clinical features were screened using univariate and multivariate analyses. Machine learning models were developed using the random forest method, leading to the establishment of one clinical feature model, one primary tumour radiomics model, and two fusion radiomics models. The performance of these models was evaluated based on the area under the curve (AUC).

RESULTS

In the training set, the three radiomic models showed comparable AUC values, ranging from 0.901 to 0.925. The clinical model underperformed, with an AUC of 0.677. In the test set, the Fusion_LN1LN2 model achieved the highest AUC (0.823), closely followed by the Fusion_Lnall model with an AUC of 0.729. The primary tumour model achieved a moderate AUC of 0.666, whereas the clinical model had the lowest AUC at 0.631. Additionally, the Fusion_LN1LN2 model demonstrated positive net reclassification improvement and integrated discrimination improvement values compared with the other models, and we employed the SHapley Additive exPlanations methodology to interpret the results of our optimal model.

CONCLUSIONS

Our fusion radiomics model, based on 18F-FDG-PET, will assist clinicians in predicting pCR before neoadjuvant chemoimmunotherapy for patients with resectable NSCLC.

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.

Synergistic strategies for glioblastoma treatment: CRISPR-based multigene editing combined with immune checkpoint blockade

Glioblastoma (GBM) is a primary brain tumor known for its high levels of aggressiveness and resistance to current treatments such as radiotherapy and chemotherapy. As a result, there is a pressing need for innovative therapeutic approaches to combat GBM. Thus, we have developed an engineered multifunctional extracellular vesicle (EV) delivery system that offers an "all-in-one" strategy for GBM therapy. Our approach involved the use of genetic engineering to the long-lasting production of PD-1 and the brain-specific peptide angiopep-2 on the surface of EVs. These modified EVs were then utilized to rejuvenate exhausted CD8+ T cells blocking PD-L1, resulting in significant therapeutic benefits for GBM treatment. Furthermore, the EVs contained Cas9 protein and sgRNA for precise and minimally invasive gene therapy, which addressing the key barriers associated with in vivo CRISPR‒Cas9 gene editing treatment. The multigene editing of EVs resulted in efficient intratumor multisite gene editing (PLK1: 58.6%, VEGF: 52.7%), leading to the successful apoptosis of tumor cells in vivo and demonstrating an antiangiogenic effect. This research introduces a promising universal platform for combining immune checkpoint blockade therapy with gene editing treatment.

Neoadjuvant immunotherapy for DNA mismatch repair proficient/microsatellite stable non-metastatic rectal cancer: a systematic review and meta-analysis

Background

Neoadjuvant immunotherapy (NIT) has been endorsed by clinical guidelines for the management of DNA mismatch repair deficiency/microsatellite instability-high (dMMR/MSI-H) locally advanced rectal cancer (LARC). Nonetheless, the therapeutic efficacy of NIT in mismatch repair-proficient/microsatellite stable (pMMR/MSS) non-metastatic rectal cancer (RC) remain pending matters. Therefore, a meta-analysis was carried out to assess the efficacy and safety of NIT in patients with non-metastatic pMMR/MSS RC.

Methods

PubMed, Embase, Web of Science, the Cochrane Library, ClinicalTrials.gov, ASCO and ESMO were searched to obtain related studies up to July 2024. Two reviewers independently screened the included articles and extracted the pertinent data. The risk of publication bias was assessed by Begg or Egger tests and in cases of publication bias, the trim and fill method was applied. Heterogeneity was assessed using I 2 statistics.

Results

Thirteen articles including 582 eligible patients were analyzed. The pooled pCR, MPR, cCR and anus preservation rate were 37%, 57%, 26% and 77% separately and the incidence of irAEs≥3 grades and TRAEs≥3 grades were 3% and 29%, respectively. Non-metastatic pMMR/MSS RC receiving the short-course radiotherapy (SCRT) in neoadjuvant setting exhibited superior pooled pCR and MPR than long-course radiotherapy (LCRT) without upregulating the incidence of adverse effects. Furthermore, patients with MSS RC underwent neoadjuvant treatment with anti-PD-1 inhibitors demonstrated higher pooled pCR, MPR, cCR compared to those receiving PD-L1 inhibitors. Additionally, yielded improved pooled MPR and anal preservation rates compared to sequential immuno-radiotherapy (63.4% vs 51.2% and 88.5% vs 69.9%), without raising the incidence of irAEs≥3 grade. Interestingly, RC patients with lymph node metastasis showed a higher pooled pCR than those without lymph node metastasis (43% vs 35%).

Conclusion

NIT was linked to favorable response rates and anal preservation, alongside an acceptable safety profile. Non-metastatic pMMR/MSS RC patients receiving SCRT, PD-1 inhibitors, or concurrent immuno-radiotherapy in the neoadjuvant setting exhibited enhanced outcomes. This meta-analysis provides evidence for further exploration and application of NIT in non-metastatic pMMR/MSS RC and highlights the potential for organ preservation with this approach. The relatively small sample size and the uneven quality of included studies may have had some impact on the generality of the results. Therefore, further analysis with a higher number of high-quality studies is needed to verify the conclusions.

Systematic review registration

https://inplasy.com/, identifier: INPLASY202470110.

Prognostic value of preoperative D-dimer to albumin ratio in patients with locally advanced rectal cancer after neoadjuvant chemoradiotherapy

BACKGROUND

The prognostic value of Albumin and D-dimer has been established for multiple tumor types, indicating their potential for predicting tumor development. Nevertheless, the predictive capability of the DDI-to-albumin ratio (DAR) in locally advanced rectal cancer (LARC) remains uncertain.

PURPOSE

The objective of this study was to investigate the prognostic significance of the DAR in LARC.

METHODS

A total of 513 patients who underwent neoadjuvant chemoradiotherapy (nCRT) prior to total mesorectal excision (TME) between March 2013 to October 2019 were included in this study. Patients were divided into high-level DAR (> 0.016) or low-level DAR (≤ 0.016) groups based on ROC curve analysis optimum cut-off value. The prognostic value of the DAR in LARC was analyzed.

RESULTS

The study enrolled 513 patients. Patients were stratified into high-level DAR (> 0.016) and low-level DAR (≤ 0.016) cohorts according to the optimal cut-off value determined by ROC curve analysis. The 5-year overall survival (OS) rates for patients in the low DAR group (≤ 0.016) and the high DAR group (> 0.016) were 89.4% and 80.9%, respectively (p = 0.013). The 5-year disease-free survival (DFS) rates were 85.7% and 77.4% (p = 0.027). Multivariate analyses demonstrated that DAR were independent prognostic factors for OS (p = 0.02) and DFS (0.025). Predictive nomograms that included the DAR score group (C-index: OS-0.743, DFS-0.705) were superior to those without DAR scores (C-index: OS-0.721, DFS-0.697).

CONCLUSION

The DAR demonstrates high usability and prognostic value in predicting OS and DFS outcomes among patients diagnosed with LARC who undergo nCRT.

Tumor microenvironment remodeling after neoadjuvant chemoradiotherapy in local advanced rectal cancer revealed by single-cell RNA sequencing

BACKGROUND

The use of neoadjuvant chemoradiotherapy (neoCRT) followed by surgery has markedly enhanced the quality of survival in patients suffering from local advanced rectal cancer (LARC). Enhancing this treatment requires a deep understanding of its underlying mechanism. The heterogeneous nature of the tumor microenvironment (TME) significantly impacts therapeutic responses, presenting complex therapeutic challenges.

METHODS

In this comprehensive study, we explored the intricate cellular and molecular shifts within the TME of LARC after neoCRT administration. Using single-cell transcriptomic analysis, we meticulously examined 32,417 cells sourced from six samples, each representing different tumor regression grades (TRG: 0 versus 2). This detailed analysis enabled us to characterize the various cell subpopulations, encompassing epithelial cells, lymphocytes, myeloid cells, endothelial cells, and fibroblasts. Additionally, we identified their marker genes for deconvolution calculation in the READ cohort of the TCGA project. And we obtain their marker genes for deconvolution calculation in the READ cohort of the TCGA project.

RESULTS

Through cluster analysis and pathway comparisons of malignant tumor cells, we discerned that samples with poor tumor regression exhibit enhanced metabolic versatility and adaptability, enabling them to counteract the impacts of both radiotherapy and chemotherapy. Interestingly, within the TRG2 cohort, we observed a predominant immunosuppressive state in the TME, characterized by the activation of CD4 + regulatory T cells, maintained CD8 + T cell functionality, and a heightened M1 to M2 macrophage ratio. Moreover, the differing outcomes of neoCRT were reflected in the varying interaction dynamics between macrophages (M1 and M2) and CD4+/CD8 + T cells. Furthermore, our data reveal that neoCRT intricately modulates fibroblasts and endothelial cells, primarily through the extracellular matrix remodeling pathway, which orchestrates tumor angiogenesis. All changes were validated through immunofluorescence staining on intraoperative samples before and after treatment. To summarize, our investigation presents a comprehensive exploration of the cellular and molecular metamorphoses within the TME post-neoCRT.

CONCLUSIONS

By unveiling the sophisticated interaction between the multifaceted cells within the TME and their respective reactions to neoCRT, we establish a robust platform for ensuing future investigations. This study paves the way for novel therapeutic strategies that leverage these insights to bolster the efficacy of neoCRT in managing LARC.

Conformal proctectomy with sphincter preservation retains acceptable defecation functions in very low rectal cancer male patients

Background

Conformal proctectomy with sphincter preservation (CPSP) is designed to preserve the rectal wall as much as possible in very low rectal cancer patients. Evaluations of anal function and quality of life outcomes are lacking.

Methods

This study included male patients with very low (≤ 5 cm from the anal verge) rectal adenocarcinoma between January 1, 2020, and January 1, 2022. A LARS score questionnaire survey and EORTC-QLQ-CR38 questionnaire survey were administered.

Results

A total of 21 very low rectal cancer patients were enrolled in follow-up. The average age of the patients was 56.7 years, the tumors were 1.9 ± 0.6 cm in size, and the distance from the anal verge was 4.8 ± 0.5 cm. All patients were followed up, and the mean follow-up period was 2.7 ± 0.5 years. The LARS score increased significantly from 4.1 ± 2.8 before surgery to 19.1 ± 6.0 at the 1st year after surgery (P < 0.001) and then decreased to 13.1 ± 4.2 (P < 0.001) at the 2nd year. The quality of life of patients was also lower at the 1st year after surgery (61.1 ± 9.6 vs. 74.2 ± 11.2, P < 0.001) and was restored at the 2nd year after surgery (80.6 ± 11.9 vs. 74.2 ± 11.2, P = 0.029). During standard follow-up at the outpatient department, no rectal tumor relapse was confirmed in these patients, although 2 patients were found to have suspected recurrence of local lymph node metastasis.

Conclusions

These results suggest that the CPSP technique preserves acceptable defecation function and is a safe and feasible option for male patients with very low rectal cancer.

Clinical trial registration

https://www.chictr.org.cn/, identifier ChiCTR2100052094.

A novel high-risk model identified by epithelial-mesenchymal transition predicts prognosis and radioresistance in rectal cancer

Many studies have shown that tumor cells that survive radiotherapy are more likely to metastasize, but the underlying mechanism remains unclear. Here we aimed to identify epithelial-mesenchymal transition (EMT)-related key genes, which associated with prognosis and radiosensitivity in rectal cancer. First, we obtained differentially expressed genes by analyzing the RNA expression profiles of rectal cancer retrieved from The Cancer Genome Atlas database, EMT-related genes, and radiotherapy-related databases, respectively. Then, Lasso and Cox regression analyses were used to establish an EMT-related prognosis model (EMTPM) based on the identified independent protective factor Fibulin5 (FBLN5) and independent risk gene EHMT2. The high-EMTPM group exhibited significantly poorer prognosis. Then, we evaluated the signature in an external clinical validation cohort. Through in vivo experiments, we further demonstrated that EMTPM effectively distinguishes radioresistant from radiosensitive patients with rectal cancer. Moreover, individuals in the high-EMTPM group showed increased expression of immune checkpoints compared to their counterparts. Finally, pan-cancer analysis of the EMTPM model also indicated its potential for predicting the prognosis of lung squamous cell carcinoma and breast cancer patients undergoing radiotherapy. In summary, we established a novel predictive model for rectal cancer prognosis and radioresistance based on FBLN5 and EHMT2 expressions, and suggested that immune microenvironment may be involved in the process of radioresistance. This predictive model could be used to select management strategies for rectal cancer.

Analysis of decision-making factors for defunctioning ileostomy after rectal cancer surgery and their impact on perioperative recovery: a retrospective study of 1082 patients

OBJECTIVE

To explore the decision-making factors for defunctioning ileostomy (DI) after rectal cancer surgery and to analyze the impact of the DI on perioperative outcomes.

METHODS

A retrospective case-control study was conducted that included rectal cancer patients who underwent low anterior resection from January 2013 to December 2023. Among them, 33 patients did not undergo DI but with anastomotic leakage (AL) after surgery, and 1030 patients were without AL. Preoperative, operative and tumor factors between these two groups were compared to explore the decision-making factors for DI. Meanwhile, the differences of perioperative outcomes between the DI group of 381 cases and non-DI group of 701 cases were compared.

RESULTS

For preoperative factors, the proportions of male patients and preoperative chemoradiotherapy (CRT) in the AL with non-DI group were greater than those in the non-AL group (p < 0.05); for operative factors, the proportion of patients in the AL with non-DI group with a surgical time > 180 min were greater (p < 0.05); for tumor factors, the proportion of T3-4 stage was higher in the AL with non-DI group (p < 0.05). Multiple regression analysis revealed that male sex and preoperative CRT were the independent risk factors affecting DI. For perioperative outcomes, the DI did not reduce the incidence of all and symptomatic AL and non-AL postoperative complications (p > 0.05) but with 12.07% stoma-related complications, and increase hospitalization costs (p < 0.05); however, it can shorten the postoperative hospital stay, pelvic drainage tube removal time, and reduce the anal tube placement rate and readmission rate (all p < 0.05).

CONCLUSION

Male patients and preoperative CRT were the independent risk factors affect the decision of DI in our study, and DI can shorten the postoperative hospitalization, pelvic drainage tube removal time, and decrease the anal tube placement rate and readmission rate during the perioperative period but with a higher economic cost.

Lymphopenia Induced by Different Neoadjuvant Chemo-Radiotherapy Schedules in Patients with Rectal Cancer: Bone Marrow as an Organ at Risk

Radiotherapy (RT)-induced lymphopenia may hinder the anti-tumor immune response. Preoperative RT or chemo-RT (CRT) for locally advanced rectal cancer is a standard therapeutic approach, while immunotherapy has been approved for mismatch repair-deficient rectal tumors. We retrospectively analyzed 98 rectal adenocarcinoma patients undergoing neoadjuvant CRT with VMAT (groups A, B, C) or IMRT (group D) techniques, with four different RT schemes: group A (n = 24): 25 Gy/5 Gy/fraction plus a 0.2 Gy/fraction rectal tumor boost; group B (n = 22): 34 Gy/3.4 Gy/fraction, with a 1-week treatment break after the first five RT fractions; group C (n = 20): 46 Gy/2 Gy/fraction plus a 0.2 Gy/fraction rectal tumor boost; group D (n = 32): 45 Gy/1.8 Gy/fraction followed by 5.4 Gy/1.8 Gy/fraction to the rectal tumor. We examined the effect of the time-corrected normalized total dose (NTD-T) to the BM on lymphopenia. Groups A and B (hypofractionated RT) had significantly higher lymphocyte counts (LCs) after RT than groups C and D (p < 0.03). An inverse association between the LCs after RT and NTD-T was demonstrated (p = 0.01). An NTD-T threshold of 30 Gy delivered to 30% of the BM volume emerged as a potential constraint for RT planning, which could be successfully integrated in the RT plan. Hypofractionated and accelerated RT schemes, and BM-sparing techniques may reduce lymphocytic damage and prove critical for immuno-RT clinical trials.

Surgical margins in head and neck squamous cell carcinoma: A narrative review

Head and neck squamous cell carcinoma (HNSCC), a prevalent and frequently recurring malignancy, often necessitates surgical intervention. The surgical margin (SM) plays a pivotal role in determining the postoperative treatment strategy and prognostic evaluation of HNSCC. Nonetheless, the process of clinical appraisal and assessment of the SMs remains a complex and indeterminate endeavor, thereby leading to potential difficulties for surgeons in defining the extent of resection. In this regard, we undertake a comprehensive review of the suggested surgical distance in varying circumstances, diverse methods of margin evaluation, and the delicate balance that must be maintained between tissue resection and preservation in head and neck surgical procedures. This review is intended to provide surgeons with pragmatic guidance in selecting the most suitable resection techniques, and in improving patients' quality of life by achieving optimal functional and aesthetic restoration.

The prognostic role of the change in albumin-derived neutrophil-to-lymphocyte ratio during neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer

The prognosis of patients with locally advanced rectal cancer (LARC) has improved with the adoption of a multidisciplinary treatment approach combining neoadjuvant chemoradiotherapy (nCRT) and total mesorectal excision (TME). Developing real-time, sensitive biomarkers to monitor systemic changes during nCRT is of paramount importance. Although the association between albumin-derived neutrophil-to-lymphocyte ratio (Alb-dNLR) and prognosis in various cancers is established, its prognostic value in LARC patients undergoing nCRT is not well-studied. This study enrolled a cohort of 618 LARC patients, stratifying them into two groups according to their change in Alb-dNLR (∆Alb-dNLR) values, using an optimal cut-off point: a low ∆Alb-dNLR group (≤ 0.90) and a high ∆Alb-dNLR group (> 0.90). The prognostic significance of ∆Alb-dNLR was evaluated using a Cox proportional hazards model. The 5-year overall survival (OS) rates were 75.2% in the low ∆Alb-dNLR group (≤ 0.90) and 85.9% in the high ∆Alb-dNLR group (>0.90) (P < 0.001). The 5-year disease-free survival (DFS) rates were 71.2% and 80.6%, respectively (P = 0.016). Multivariate analyses demonstrated that both ∆Alb-dNLR and pre-Alb-dNLR were independent prognostic factors for OS (P ≤ 0.001), while ∆Alb-dNLR was demonstrated as an independent prognostic factor for DFS (P = 0.016). A predictive nomogram, incorporating the ∆Alb-dNLR subgroup, demonstrated enhanced performance (concordance index [C-index] of 0.720 for OS and 0.690 for DFS) compared to the pre-treatment Alb-dNLR subgroup (C-index of 0.700 for OS and of 0.680 for DFS). Therefore, ∆Alb-dNLR shows significant potential as a usable and prognostic biomarker for predicting OS and DFS in LARC patients undergoing nCRT.

Exploring treatment outcomes in Stage II-III rectal cancer patients undergoing neoadjuvant therapy at a tertiary care center in Pakistan: a comprehensive analysis of pathological outcomes

BACKGROUND

Rectal cancer treatment has transformed in recent years, with neoadjuvant treatment (NT) and total neoadjuvant treatment (TNT) aiming to enhance pathological responses. This pioneering study in our country delves into rectal cancer management, offering crucial insights by examining pathological outcomes in patients treated with the NT and TNT approach, shaping the evolving landscape.

METHODS

In this retrospective-cohort study spanning January 2017 to December 2022 at a tertiary care hospital in Pakistan, ethical approval was obtained to examine outcomes of two treatments. Patients were divided into TNT (chemoradiation and pre-surgery 5 FU-based chemotherapy) and NT (chemoradiation, surgery, and subsequent 5 FU-based chemotherapy). The primary end-point was response rates-no response, pathological complete response (pCR), near complete response (near CR), and partial response (PR). The Chi-Square Test for Independence assessed the association between treatment response and type (TNT or NT). Data analysis used STATA MP 64; significance was set at p < 0.05 for all two-tailed tests.

RESULTS

We analyzed 77 patients, 60 underwent standard neoadjuvant chemoradiation, and 17 followed the total neoadjuvant approach. Predominantly male, most were > 65 with ECOG 0-1. The TNT group showed higher response rates (76% vs 62%, p = 0.039), with 40.38% achieving pCR. In the overall population, pCR and near-CR were similar (27.2% vs 26%), while PR were 14%. Treatment characteristics correlated significantly with chemotherapy type, concurrent chemoradiation, LVI, PNI, and T, N, M staging (p < 0.05). Median overall survival was not reached, and mean survival was 89.1 months (CI: 95.0 to 83.3). Side effects varied, with notable differences in neuropathy, diarrhea, oral mucositis, and thrombocytopenia between NT and TNT groups.

CONCLUSION

Our study adds to evidence favoring neoadjuvant approaches in managing rectal cancer in pakistan. Demonstrating a favorable pcr rate, ongoing research with extended follow-up is essential, given the dynamic landscape of rectal cancer treatment for improved patient outcomes.

Modified FOLFOX6 with Cetuximab versus with Radiotherapy in Neoadjuvant Treatment of Locally Advanced Rectal Cancer: A Single-Center, Prospective, Randomized Controlled Trial

In this trial, the feasibility and efficacy of neoadjuvant chemotherapy with targeted agents in the treatment of patients with locally advanced rectal cancer were evaluated. In this single-center, prospective, randomized controlled trial, we randomly assigned (1 : 1) patients with locally advanced rectal cancer with wild-type RAS/BRAF gene to two groups: 5 cycles of modified leucovorin calcium (folinic acid), fluorouracil, and oxaliplatin combination regimen (modified FOLFOX6, mFOLFOX6) concurrent with 25 times radiotherapy or 5 cycles of mFOLFOX6 plus cetuximab, all with subsequent total mesorectal excision (TME) resection and adjuvant chemotherapy. We performed a random assignment by a computer-generated random number sequence. The primary end point was the R0 resection rate. The secondary end points were rates of pathologic complete response, downstaging, adverse events, postoperative complications, preventive enterostomy and low anterior resection syndrome. From January 6, 2020 to October 28, 2022, 80 patients were assigned and evaluated. In the mFOLFOX6-RT and mFOLFOX6-Cet groups, the rate of R0 resection was 96.7 and 96.9% (p = 1.000); the rate of pathological complete response (pCR) was 23.3 and 21.9% (p = 0.891); and the rate of downstaging (ypStage 0 to 1) was 53.3 and 53.1% (p = 1.000), respectively. No statistical differences between the two groups were observed in the incidence of adverse events and postoperative complications. Additionally, lower rates of preventive enterostomy and low anterior resection syndrome were shown in the mFOLFOX6-Cet group compared to the mFOLFOX6-RT group. The neoadjuvant treatment strategy of mFOLFOX6 with cetuximab is feasible and promising for patients with locally advanced rectal cancer, even superior to mFOLFOX6 with radiotherapy.

Efficacy and safety of radiotherapy combined with anti-angiogenic therapy and immune checkpoint inhibitors in MSS/pMMR metastatic colorectal cancer

PURPOSE

Several studies have demonstrated the effectiveness of anti-angiogenic drugs in combination with immune checkpoint inhibitors (ICIs) in patients with microsatellite stable (MSS) or mismatch repair proficient (pMMR) metastatic colorectal cancer (mCRC). However, whether combination radiotherapy (RT) can further improve the prognosis of mCRC patients after second-line treatment remains to be explored.

METHODS

Retrospective analysis of data from mCRC patients who received anti-angiogenic targeted therapy (TT) and immunotherapy (IT) with or without RT after the failure of standard therapy. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety were evaluated.

RESULTS

A total of 82 patients who received TT + IT were analyzed. For RT group (n = 42) versus NRT group (n = 40), ORR was 21.4% (9/42) versus 5.0% (2/40); DCR was 83.8% (35/42) versus 65.0% (26/40). Compared with NRT group, RT improved PFS (median: 5.0 vs. 3.6 months; p = 0.04) and OS (median: 15.2 vs. 7.2 months; p = 0.01). In addition, in the population receiving RT, the PFS of RT sequential/simultaneous TT + IT was superior to TT + IT sequential RT (median: 7.1 vs. 6.2 vs. 3.5 months, p = 0.004). Multivariate analysis suggested RT was an independent prognostic factor for PFS and OS. No treatment-related deaths were reported.

CONCLUSIONS

Compared with TT + IT, RT combined with TT + IT improved survival outcomes in MSS/pMMR mCRC patients, with manageable toxicity. RT sequential/simultaneous TT + IT treatment is expected to be the optimal strategy for MSS/PMMR mCRC.

Radiotherapy in the preoperative neoadjuvant treatment of locally advanced rectal cancer

Radiotherapy and chemotherapy are effective treatments for patients with locally advanced rectal cancer (LARC) and can significantly improve the likelihood of R0 resection. Radiotherapy can be used as a local treatment to reduce the size of the tumor, improve the success rate of surgery and reduce the residual cancer cells after surgery. Early chemotherapy can also downgrade the tumor and eliminate micrometastases throughout the body, reducing the risk of recurrence and metastasis. The advent of neoadjuvant concurrent radiotherapy (nCRT) and total neoadjuvant treatment (TNT) has brought substantial clinical benefits to patients with LARC. Even so, given increasing demand for organ preservation and quality of life and the disease becoming increasingly younger in its incidence profile, there is a need to further explore new neoadjuvant treatment options to further improve tumor remission rates and provide other opportunities for patients to choose watch-and-wait (W&W) strategies that avoid surgery. Targeted drugs and immunologic agents (ICIs) have shown good efficacy in patients with advanced rectal cancer but have not been commonly used in neoadjuvant therapy for patients with LARC. In this paper, we review several aspects of neoadjuvant therapy, including radiation therapy and chemotherapy drugs, immune drugs and targeted drugs used in combination with neoadjuvant therapy, with the aim of providing direction and thoughtful perspectives for LARC clinical treatment and research trials.

A Modified NAR Scoring Model Incorporating Immune Infiltration Characteristics to Better Predict Long-Term Survival Following Neoadjuvant Radiotherapy in Rectal Cancer

(1) Background: The neoadjuvant rectal (NAR) score has been developed as a prognostic tool for survival in locally advanced rectal cancer (LARC). However, the NAR score only incorporates weighted cT, ypT, and ypN categories. This long-term follow-up study aims to modify a novel prognostic scoring model and identify a short-term endpoint for survival. (2) Methods: The prognostic factors for overall survival (OS) were explored through univariate and multivariate analyses. Based on Cox regression modeling, nomogram plots were constructed. Area under the curve (AUC) and concordance indices were used to evaluate the performance of the nomogram. Receiver operating characteristic (ROC) analysis was conducted to compare the efficiency of the nomogram with other prognostic factors. (3) Results: After a long-term follow-up, the 5-year OS was 67.1%. The mean NAR score was 20.4 ± 16.3. Multivariate analysis indicated that CD8+ T-cell, lymphovascular invasion, and the NAR score were independent predictors of OS. The modified NAR scoring model, incorporating immune infiltration characteristics, exhibited a high C-index of 0.739 for 5-year OS, significantly outperforming any individual factor. Moreover, the predictive value of the nomogram was superior to the AJCC stage and pathological complete regression at 3-year, 5-year, and 10-year time points, respectively. Over time, the model's predictions of long-term survival remained consistent and improved in accuracy. (4) Conclusions: The modified NAR scoring model, incorporating immune infiltration characteristics, demonstrates high accuracy and consistency in predicting OS.

Implications of Rectal Cancer Radiotherapy on the Immune Microenvironment: Allies and Foes to Therapy Resistance and Patients' Outcome

Aside from surgical resection, locally advanced rectal cancer is regularly treated with neoadjuvant chemoradiotherapy. Since the concept of cancer treatment has shifted from only focusing on tumor cells as drivers of disease progression towards a broader understanding including the dynamic tumor microenvironment (TME), the impact of radiotherapy on the TME and specifically the tumor immune microenvironment (TIME) is increasingly recognized. Both promoting as well as suppressing effects on anti-tumor immunity have been reported in response to rectal cancer (chemo-)radiotherapy and various targets for combination therapies are under investigation. A literature review was conducted searching the PubMed database for evidence regarding the pleiotropic effects of (chemo-)radiotherapy on the rectal cancer TIME, including alterations in cytokine levels, immune cell populations and activity as well as changes in immune checkpoint proteins. Radiotherapy can induce immune-stimulating and -suppressive alterations, potentially mediating radioresistance. The response is influenced by treatment modalities, including the dosage administered and the highly individual intrinsic pre-treatment immune status. Directly addressing the main immune cells of the TME, this review aims to highlight therapeutical implications since efficient rectal cancer treatment relies on personalized strategies combining conventional therapies with immune-modulating approaches, such as immune checkpoint inhibitors.

Can neoadjuvant chemoradiotherapy combined with immunotherapy benefit patients with microsatellite stable locally advanced rectal cancer? a pooled and integration analysis

Objective

To assess the clinical efficacy of neoadjuvant chemoradiotherapy combined with immunotherapy for patients with microsatellite stable (MSS) locally advanced rectal cancer and provide evidence to support clinical decision-making.

Methods

A systematic search was conducted on the PubMed, Embase, Cochrane Collaboration databases, conference summaries, and Chinese databases for clinical studies that investigated neoadjuvant chemoradiotherapy combined with immunotherapy for the treatment of locally advanced rectal cancer with MSS status. The search spanned from the inception of each database through July 2023. Data from the identified studies were extracted using a pre-designed table, and efficacy outcomes were analyzed. An integrated analysis was conducted using Stata 12.0 software.

Results

Eight studies were included, comprising 204 patients with locally advanced MSS rectal cancer who received chemoradiotherapy combined with immunotherapy. The integrated analysis revealed a pathologic complete remission rate of 0.33, a sphincter preservation rate of 0.86, an R0 resection rate of 0.83, a major pathologic remission rate of 0.33, and a clinical complete remission rate of 0.30.

Conclusion

Neoadjuvant chemoradiotherapy combined with immunotherapy demonstrates significant short-term efficacy in MSS-type locally advanced rectal cancer, notably enhancing the pathologic complete remission and sphincter preservation rates. This combination is a recommended treatment for patients with MSS-type rectal cancer.

Short-course radiotherapy combined with chemotherapy and PD-1 inhibitor in low-lying early rectal cancer: study protocol for a single-arm, multicentre, prospective, phase II trial (TORCH-E)

INTRODUCTION

Current standard treatment for patients with early rectal cancer is radical surgical resection. Although radical surgery provides effective local tumour control, it also increases the mortality risk and considerable adverse effects, including bowel, bladder, sexual dysfunction and loss of anal function, especially in patients with low-lying rectal cancer. Recent studies have shown promising synergistic effects of the combination of programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) inhibitors and radiotherapy in improving tumour regression. For patients who reach a clinical complete response (cCR) after neoadjuvant therapy, a 'Watch & Wait' (W&W) approach can be adopted to preserve anorectal function and improve quality of life. Thus, this study aims to explore the efficacy and safety of radiotherapy combined with chemotherapy and PD-1 antibody in patients with low early rectal cancer.

METHODS AND ANALYSIS

TORCH-E study is designed as a multicentre, prospective, phase II trial of short-course radiotherapy (SCRT) combined with chemotherapy and PD-1 inhibitor in patients with cT1-3bN0M0 low rectal cancer. The trial was initiated in December 2022 and is currently recruiting patients, with an anticipated completion of participant enrolment by June of the following year. The enrolled 34 patients will receive SCRT (25 Gy/5 Fx), followed by four cycles of capecitabine plus oxaliplatin chemotherapy and PD-1 antibody (toripalimab) and finally receive surgery or the W&W strategy. The primary endpoint is the complete response (CR) rate, that is, the rate of pathological complete response (pCR) plus cCR. The secondary endpoints include organ preservation rate, 3-year local recurrence-free survival rate, 3-year disease-free survival rate, 3-year overall survival rate, grade 3-4 adverse effects rate and patients' quality of life.

ETHICS AND DISSEMINATION

This trial has been approved by the Ethics Committee of Fudan University Shanghai Cancer Center. Trial results will be disseminated via peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05555888 (ClinicalTrials.gov).

Neoadjuvant chemoradiotherapy with capecitabine based regimen in locally advanced rectal cancer: A retrospective study

Capecitabine-based neoadjuvant chemoradiotherapy (nCRT) is the standard treatment for locally advanced rectal cancer. The objective of this study is to analyze overall survival (OS), disease-free survival (DFS) and prognostic factors of patients with stage II to III rectal cancer treated with nCRT in our institution. Between March 2014 to June 2020, 121 locally advanced rectal cancer patients were retrospectively reviewed and analyzed. All of the enrolled patients were treated with capecitabine-based nCRT (pelvic radiotherapy: 45-50.4 Gy, 1.8 Gy/d plus concomitant capecitabine-based chemotherapy), total mesorectal excision surgery (surgery was carried out 8-12 weeks after the end of CRT), and capecitabine-based adjuvant chemotherapy. We examined the pathological complete response rate, 3-year OS, 3-year DFS and the other prognostic factors. Kaplan-Meier method and Log-rank test were used to estimate and compare survival rate. With a median follow-up of 36 months, 3-year DFS and 3-year OS was 74.4% and 83.2%, respectively. Among the 121 patients, 24 achieved pathological complete remission (19.8%). After multivariate analysis, ypTNM stage (TNM stage after neoadjuvant therapy) was significantly associated with DFS. Positive mesorectal fasciae (MRF) status on magnetic resonance imaging and ypTNM stage were significantly related to OS. CRT with capecitabine based regimen provides high rates of survival and sphincter preservation with acceptable toxicity. YpTNM stage was significantly associated with DFS; magnetic resonance imaging MRF status and ypTNM stage were significant factors for OS after multivariate analysis. Distant metastasis is the dominant mode of treatment failure, and it is crucial to optimize systemic treatment for newly diagnosed patients.

New Opportunities for Minimizing Toxicity in Rectal Cancer Management

Advances in multimodal management of locally advanced rectal cancer (LARC), consisting of preoperative chemotherapy and/or radiotherapy followed by surgery with or without adjuvant chemotherapy, have improved local disease control and patient survival but are associated with significant risk for acute and long-term morbidity. Recently published trials, evaluating treatment dose intensification via the addition of preoperative induction or consolidation chemotherapy (total neoadjuvant therapy [TNT]), have demonstrated improved tumor response rates while maintaining acceptable toxicity. In addition, TNT has led to an increased number of patients achieving a clinical complete response and thus eligible to pursue a nonoperative, organ-preserving, watch and wait approach, thereby avoiding toxicities associated with surgery, such as bowel dysfunction and stoma-related complications. Ongoing trials using immune checkpoint inhibitors in patients with mismatch repair-deficient tumors suggest that this subgroup of patients with LARC could potentially be treated with immunotherapy alone, sparing them the toxicity associated with preoperative treatment and surgery. However, the majority of rectal cancers are mismatch repair-proficient and less responsive to immune checkpoint inhibitors and require multimodal management. The synergy noted in preclinical studies between immunotherapy and radiotherapy on immunogenic tumor cell death has led to the design of ongoing clinical trials that explore the benefit of combining radiotherapy, chemotherapy, and immunotherapy (mainly of immune checkpoint inhibitors) and aim to increase the number of patients eligible for organ preservation.

Current Surgical Methods in Local Rectal Excision

Background

The treatment of rectal cancer has evolved with the advancement of surgical techniques. Less invasive approaches are becoming more accepted as the primary treatment method.

Summary

Such methods as transanal excision, transanal endoscopic microsurgery, and transanal minimally invasive surgery can reduce morbidity and mortality rates. However, not all patients are suitable candidates for these procedures, and proper diagnostics are necessary to establish indications. Compared to total mesorectal excision, transanal excision techniques have been shown to have fewer complications and comorbidities while still being able to remove cancerous tissue entirely. Transanal excision is the simplest method, where the operator removes visible rectal lesions. The basic principle of transanal endoscopic microsurgery is to dilate the rectum mechanically and by air insufflation and then use special surgical instruments to remove suspicious lesions under the vision of a telescope. Transanal minimally invasive surgery combines transanal endoscopic microsurgery and single-incision laparoscopic surgery, making the hard-to-reach proximal rectum accessible to classic laparoscopic instruments.

Key Message

Local excision techniques, when used as a monotherapy for treating patients with rectal cancer, have established themselves as a curative and less radical treatment for strictly selected patients with early rectal carcinoma, leading to improved quality of life. When combined with other modalities such as neoadjuvant chemoradiotherapy, total neoadjuvant therapy, and immunotherapy, transanal surgery can be offered to patients with locally advanced rectal cancer as part of the organ preservation strategy. This review will discuss the patient selection and technical aspects of transanal surgery, showcasing its current role in treating rectal carcinoma.

Total neoadjuvant treatment and PD-1/PD-L1 checkpoint inhibitor in locally advanced rectal cancer

For local advanced rectal cancer (LARC), total neoadjuvant treatment (TNT) has shown more complete response (CR), reduced risk of distant metastasis (DM) and increase of the sphincter preservation rate. Now it is the one and only recommendation for high-risk group of LARC according to National Comprehensive Cancer Network (NCCN) rectal cancer guideline, while it is also preferentially recommended for low-risk group of LARC. TNT is also beneficial for distant rectal cancer patients who have need for organ preservation. Even though the prognostic value of programmed cell death-ligand 1 (PD-L1) in the neoadjuvant chemoradiotherapy (NACRT) of LARC patients is undetermined yet, the combination of NACRT and programmed cell death-1 (PD-1)/PD-L1 antibodies seem bring new hope for mismatch repair proficient (pMMR)/microsatellite stable (MSS) LARC patients. Accumulating small sample sized studies have shown that combining NACRT with PD-1/PD-L1 antibody yield better short-term outcomes for pMMR/MSS LARC patients than historic data. However, ideal total dose and fractionation of radiotherapy remains one of unresolved issues in this combination setting. Thorough understanding the impact of radiotherapy on the tumor microenvironment and their interaction is needed for in-depth understanding and exquisite design of treatments combination model.