Short-course radiotherapy followed by chemotherapy before total mesorectal excision (TME) versus preoperative chemoradiotherapy, TME, and optional adjuvant chemotherapy in locally advanced rectal cancer (RAPIDO): a randomised, open-label, phase 3 trial

Combined tumor-associated microbiome and immune gene expression profiling predict response to neoadjuvant chemo-radiotherapy in locally advanced rectal cancer

Locally advanced rectal cancer (LARC) is treated with neoadjuvant chemo-radiotherapy (nCRT) followed by surgery. A minority of patients show complete response (CR) to nCRT and may avoid surgery and its functional consequences. Instead, most patients show non-complete response (non-CR) and may benefit from additional treatments to increase CR rates. Reliable predictive markers are lacking. Aim of this study was to identify novel signatures predicting nCRT responsiveness. We performed a combined analysis of tumor-associated microbiome and immune gene expression profiling of diagnostic biopsies from 70 patients undergoing nCRT followed by rectal resection, including 16 with CR and 54 with non-CR. Findings were validated by an independent cohort of 49 patients, including 7 with CR and 42 with non-CR. Intratumoral microbiota significantly differed between CR and non-CR groups at genus and species level. Colonization by bacterial species of Ruminococcus genera was consistently associated with CR, whereas abundance of Fusobacterium, Porhpyromonas, and Oscillibacter species predicted non-CR. Immune gene profiling revealed a panel of 59 differentially expressed genes and significant upregulation of IFN-gamma and -alpha response in patients with CR. Integrated microbiome and immune gene profiling analysis unraveled clustering of microbial taxa with each other and with immune cell-related genes and allowed the identification of a combined signature correctly identifying non-CRS in both cohorts. Thus, combined intratumoral microbiome-immune profiling improves the prediction of response to nCRT. Correct identification of unresponsive patients and of bacteria promoting responsiveness might lead to innovative therapeutic approaches based on gut microbiota pre-conditioning to increase nCRT effectiveness in LARC.

MRI-based radiomic nomogram for predicting disease-free survival in patients with locally advanced rectal cancer

PURPOSE

Individual prognosis assessment is of paramount importance for treatment decision-making and active surveillance in cancer patients. We aimed to propose a radiomic model based on pre- and post-therapy MRI features for predicting disease-free survival (DFS) in locally advanced rectal cancer (LARC) following neoadjuvant chemoradiotherapy (nCRT) and subsequent surgical resection.

METHODS

This retrospective study included a total of 126 LARC patients, which were randomly assigned to a training set (n = 84) and a validation set (n = 42). All patients underwent pre- and post-nCRT MRI scans. Radiomic features were extracted from higher resolution T2-weighted images. Pearson correlation analysis and ANOVA or Relief were utilized for identifying radiomic features associated with DFS. Pre-treatment, post-treatment, and delta radscores were constructed by machine learning algorithms. An individualized nomogram was developed based on significant radscores and clinical variables using multivariate Cox regression analysis. Predictive performance was evaluated by the C-index, calibration curve, and decision curve analysis.

RESULTS

The results demonstrated that in the validation set, the clinical model including pre-surgery carcinoembryonic antigen (CEA), chemotherapy after radiotherapy, and pathological stage yielded a C-index of 0.755 (95% confidence interval [CI]: 0.739-0.771). While the optimal pre-, post-, and delta-radscores achieved C-indices of 0.724 (95%CI: 0.701-0.747), 0.701 (95%CI: 0.671-0.731), and 0.625 (95%CI: 0.589-0.661), respectively. The nomogram integrating pre-surgery CEA, pathological stage, alongside pre- and post-nCRT radscore, obtained the highest C-index of 0.833 (95%CI: 0.815-0.851). The calibration curve and decision curves exhibited good calibration and clinical usefulness of the nomogram. Furthermore, the nomogram categorized patients into high- and low-risk groups exhibiting distinct DFS (both P < 0.0001).

CONCLUSIONS

The nomogram incorporating pre- and post-therapy radscores and clinical factors could predict DFS in patients with LARC, which helps clinicians in optimizing decision-making and surveillance in real-world settings.

Phase II trial of organ preservation program using short-course radiation and FOLFOXIRI for rectal cancer (SHORT-FOX): Two-Year primary outcome analysis

BACKGROUND AND PURPOSE

As patients with rectal cancer with clinical complete response (cCR) after neoadjuvant therapy may be safely spared Total Mesorectal Excision (TME), strategies to maximize cCR are needed.

MATERIALS AND METHODS

We conducted a single-arm phase II study to determine whether dose-escalated short-course radiotherapy (25 Gy/5 fractions + 5 Gy/1 fraction boost) followed by eight cycles of FOLFOXIRI increased cCR rates among adult patients with > T2N0M0 or low T2N0 rectal cancer.

RESULTS

Between 2020 and 2023, we enrolled 37 patients, of whom 27 (73 %) had at least one high-risk feature (cT4, extramural vascular invasion [EMVI], N2, threatened circumferential resection margin, positive lateral node). At primary endpoint assessment, nine (24 %) patients had cCR on both endoscopy and MRI, and pursued organ preservation (OP). Fourteen (38 %) patients had cCR only on endoscopy, nine of whom pursued OP. Of the 18 patients who pursued OP, nine had local regrowth at two years from radiotherapy start, with two-year TME-free survival of 26 %. Baseline factors significantly associated with not achieving OP included age < 50 years and T4 disease. At mid-treatment restaging, patients who achieved OP were significantly less likely to have persistent node positivity, EMVI, and endoscopically visible tumor. Grade 3+ adverse events at least possibly attributed to chemotherapy and radiotherapy occured in 51% and 43% of patients, respectively.

CONCLUSION

Short-course radiotherapy with a boost followed by FOLFIXIRI results in OP in one-quarter of patients with high-risk rectal cancer, with poorer response among younger patients and T4 disease. Mid-treatment response may help guide timely decision-making regarding treatment.

Total neoadjuvant therapy for locally advanced rectal cancer

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the effectiveness and safety of total neoadjuvant therapy versus standard therapy in individuals with locally advanced rectal cancer.

Short-course versus long-course neoadjuvant chemoradiotherapy in patients with rectal cancer: long-term results of a randomized controlled trial

BACKGROUND AND PURPOSE

Short-course radiotherapy (SCRT) and long-course radiotherapy (LCRT) are the primary neoadjuvant radiotherapy schedules for locally advanced rectal cancer. Recent research has questioned the efficacy of SCRT. This study presents an updated analysis of our previous research, extending the follow-up to evaluate 5-year outcomes by comparing the long-term results of these two strategies.

MATERIALS AND METHODS

This randomized controlled trial compared SCRT and LCRT in locally advanced middle or high rectal adenocarcinoma. The SCRT group received 25 Gy/5 fractions over 1 week plus CAPOX, while the LCRT group received 50-50.4 Gy/25-28 fractions over 5-5.5 weeks plus capecitabine. All patients received consolidation chemotherapy and then underwent delayed surgery after 8 weeks or more post-radiotherapy. The endpoints of this updated analysis include overall survival (OS),disease-free survival (DFS), locoregional recurrence (LR) and distant metastasis (DM).

RESULTS

Ninety-nine cases (45 LCRT, 54 SCRT) were followed for a median of 4.7 years. Five-year OS rates were 77.3% for LCRT vs. 65.6% for SCRT group (P = 0.4). The 5-year DFS rates were 69.6% for LCRT vs. 54.9% for SCRT (P = 0.07). Cox regression indicated no prominent difference between the two groups regarding OS, LR, or DM. Subgroup analysis demonstrated a significantly better DFS with LCRT compared to SCRT in male patients ([HR] = 2.48, 95%CI: 1.04-5.93, P = 0.03), patients under the age of 60 (HR = 3.19, 95%CI: 1.03-9.92, P = 0.04), and cT4 patients (HR not calculated: no events in LCRT group, P = 0.004).

CONCLUSION

DFS showed a trend in favor of the LCRT group, with LCRT being significantly superior among men, patients under 60, and cT4 stage. Despite being intensified, SCRT failed to achieve long-term outcomes comparable to LCRT. Further research is needed to compare these two approaches in the context of total neoadjuvant treatment.

TRIAL REGISTRATION DATA

IRCT2017110424266N3 (Registration date: 2017-11-12).  https://irct.behdasht.gov.ir/trial/20526 .

They Not Like Us: Evaluating the Diverse Strategies in Locally Advanced Rectal Cancer Treatment

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Total neoadjuvant therapy in high-risk rectal cancer: organ preservation and survival outcomes in a single-center retrospective cohort

Background

Rectal cancer poses a significant global health burden. Conventional neoadjuvant chemoradiotherapy (nCRT) demonstrates limited efficacy in achieving disease-free survival (DFS) and organ preservation. Total neoadjuvant therapy (TNT), an emerging paradigm integrating systemic chemotherapy with radiotherapy, aims to address these limitations.

Objectives

To evaluate the short- and long-term oncological outcomes and organ preservation feasibility of TNT in high-risk locally advanced rectal cancer (LARC) patients.

Designs

A retrospective study was conducted to analyze the short-term and long-term results after total nCRT.

Methods

This retrospective study involved 110 rectal cancer patients with high-risk features treated at the Fudan University Shanghai Cancer Center from 2008 to 2022. Patients underwent comprehensive staging and received nCRT followed by either total mesorectal excision (TME) or a watch and wait (W&W) strategy. The regimen included concurrent chemoradiotherapy with 50 Gy/25 fractions and at least six cycles of induction or consolidation chemotherapy. Both short-term and long-term outcomes were collected and analyzed.

Results

Among the LARC patients, 73.6% were stage III, and 47.3% opted for the W&W strategy. The combined rate of clinical complete response or confirmed pathological complete response (pCR) reached 49.1%. During follow-up, 10% of patients experienced local regrowth. The 3-year DFS and overall survival (OS) rates were 75.7% and 92.4%, respectively. The W&W strategy could achieve superior outcomes than patients without pCR in DFS (p = 0.021) and OS (p = 0.006).

Conclusion

TNT demonstrates durable survival outcomes and facilitates organ preservation in over 50% of high-risk LARC patients. Intensive surveillance is critical for the early detection of local regrowth.

Trial registration

Our study is retrospective in nature, rather than a prospective clinical trial. Therefore, registration was not conducted, and the Clinical Trial Number is not applicable.

Neoadjuvant short-course radiotherapy followed by camrelizumab and chemotherapy for locally advanced rectal cancer: 3-year survival from a phase 2 study

BACKGROUND

Neoadjuvant short-course radiotherapy (SCRT) followed by camrelizumab and chemotherapy has shown an encouraging pathological complete response rate (48.1%, primary endpoint) in patients with locally advanced rectal cancer (LARC). Here, we present the 3-year survival outcomes.

METHODS

In this phase 2 trial, patients with previously untreated T3-4N0M0 or T1-4N + M0 rectal adenocarcinoma received 5 × 5 Gy SCRT over 5 days, followed by two cycles of camrelizumab (200 mg) and CAPOX regimen every 3 weeks after 1 week. Total mesorectal excision (TME) was scheduled 1 week after the completion of neoadjuvant treatment. The 3-year disease-free survival (DFS) and overall survival (OS) were evaluated in this analysis.

RESULTS

A total of 30 patients were enrolled, of whom 28 (93.3%) had microsatellite stable status (MSS) and 27 (90.0%) underwent TME. With a median follow-up of 40.8 months, the median DFS and OS were both not reached, with the 3-year DFS and OS rates of 80.2% (95% CI 58.6-91.3) and 93.3% (95% CI 75.9-98.3), respectively. Additionally, there was a trend toward improved 3-year DFS and OS in patients with pCR, postoperative pathological node-negative status (pN0), baseline negative circumferential resection margin as assessed by MRI, baseline negative extramural venous invasion and a PD-L1 combined positive score of 1 or higher, as compared with those without these characteristics.

CONCLUSIONS

Our data support the potential efficacy of neoadjuvant SCRT followed by camrelizumab and CAPOX regimen in LARC, as indicated by 3-year survival outcomes, suggesting that this may be an alternative therapeutic strategy, especially with the potential to address an unmet need for MSS patients.

TRIAL REGISTRATION

www.

CLINICALTRIALS

gov . NCT04231552.

Sustained Organ Preservation in Patients With Rectal Cancer After Sequential Short-Course Radiation Therapy and Chemotherapy

BackgroundNonoperative management in patients with rectal cancer with complete response to radiation therapy and chemotherapy is of increasing interest. Most of the data on nonoperative management have centered around patients treated with long-course chemoradiotherapy. The ability of short-course radiation-based treatment courses to achieve durable complete responses with sustained organ preservation is less defined. This study updates our institution's long-term experience with nonoperative management following upfront short-course radiation therapy and sequential/consolidation chemotherapy.MethodsWe retrospectively reviewed patients with nonmetastatic rectal cancer treated with sequential short-course radiation therapy and chemotherapy who reached complete response and were subsequently followed with nonoperative management. We report on disease control outcomes, including rates of regrowth and results of salvage surgery. We investigated characteristics associated with local tumor regrowth.ResultsOur study included 52 patients. The 2-year freedom from local regrowth for the entire cohort was 75%. Notably, patients with high-risk disease characteristics at diagnosis exhibited a trend toward a higher rate of local tumor regrowth. No patient with sustained clinical complete response developed metastatic disease. Of the twelve patients undergoing surgical salvage for regrowth of disease, ten were resected with complete/near-complete total mesorectal surgical specimens with negative margins.ConclusionsThe optimal approach to achieving sustained organ preservation through the use of radiation therapy and chemotherapy is not well defined. Our findings show the viability of neoadjuvant therapy incorporating short-course radiation therapy to achieve durable complete responses.

Impact of mSWI/SNF epigenetic complexes on ionizing radiotherapy resistance in malignant diseases: A comprehensive view in oncology

The mSWI/SNF chromatin remodeling complexes are critical regulators of genomic stability, particularly in their role in orchestrating DNA repair and modulating cellular responses to ionizing radiation therapy. Their involvement has positioned these molecular complexes as key factors in determining radiosensitivity in human malignant diseases. The present review delves into the biomedical contributions of specific mSWI/SNF subunits, including ARID1A, SMARCB1, SMARCA4, PBRM1, and BRD9, highlighting their pivotal roles in influencing tumor responses to radiotherapy. Evidence suggests that the loss of function in these subunits, often due to mutations, disrupts DNA repair pathways, thereby compromising genomic integrity and enhancing susceptibility to radiation-induced damage. Emerging preclinical studies have underscored the potential of exploiting these vulnerabilities through pharmacological targeting of mSWI/SNF complexes. Inhibition of these complexes can impair DNA damage repair mechanisms, creating a synthetic lethality effect by using a combined epigenetic therapy with ionizing radiation protocols. This dual approach not only amplifies the therapeutic efficacy of radiotherapy but also broadens the spectrum of potential strategies for oncological therapy. However, further investigation into the molecular mechanisms underlying these epigenetic interactions is essential for optimizing oncological therapies and paving the way for clinical applications aimed at enhancing radiotherapy outcomes in cancer patients.

Compliance and Toxicity of Total Neoadjuvant Therapy in Locally Advanced Rectal Cancer: A Systematic Review and Network Meta-analysis

PURPOSE

The individual chemotherapy- and radiotherapy-related toxicities between induction (iTNT) and consolidation total neoadjuvant therapy (cTNT) remain unclear. This network meta-analysis (NMA) comparing iTNT, cTNT, and traditional neoadjuvant chemoradiation (nCRT) evaluated the comparative treatment-related toxicities and compliance of the TNT schemas.

METHODS

A systematic review of randomized clinical trials and nonrandomized studies of interventions was performed as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-NMA guidelines. A Bayesian NMA was conducted, and odds ratios (OR) with 95% credible intervals (CrI) are reported for all outcomes.

RESULTS

Eighteen studies including 5730 patients were identified. iTNT ranked highest on rate of rectal bleeding (cTNT: OR 0.23 95% CrI 0.05-0.93; nCRT: OR 0.33, 95% CrI 0.09-0.96), proctitis (cTNT: OR 0.2, 95% CrI 0.06-0.55; nCRT: OR 0.2, 95% CrI 0.06-0.51), and postoperative diarrhea (cTNT: OR 0.37, 95% CrI 0.18-0.73; nCRT: OR 0.33, 95% CrI 0.15-0.71); cTNT ranked highest on rate of vomiting (iTNT: OR 0.24, 95% CrI 0.05-0.96; nCRT: OR 0.29, 95% CrI 0.06-0.89) and a higher rate of lymphopenia than iTNT (iTNT: OR 0.56, 95% CrI 0.34-0.99). Radiotherapy compliance was highest in cTNT (iTNT: OR 0.23, 95% CrI 0.05-0.72; nCRT: OR 0.18, 95% CrI 0.04-0.58). There was no difference in overall toxicity and mortality, chemotherapy compliance, and remaining individual system-based toxicities and postoperative complications.

CONCLUSIONS

Across all treatment strategies, iTNT had higher radiation-related gastrointestinal toxicities and postoperative diarrhea; cTNT had higher vomiting and lymphopenia rates. While no treatment strategy was superior in chemotherapy compliance, radiotherapy compliance was ranked highest in cTNT.

[Intraoperative frozen section diagnostics for low rectal cancer-Primary surgery vs. neoadjuvant pretreatment]

Depending on the extent of the tumor, the treatment strategies for rectal cancer include primary surgical resection or, in the case of locally advanced carcinoma, neoadjuvant chemo(radio)therapy (C[R]Tx) or total neoadjuvant therapy (TNT), usually followed by surgical treatment. During resection, it is important to find a balance between radicality and preservation of function. Current data show that shorter safety margins are possible for patients who received neoadjuvant treatment without compromising the oncological outcome. This enables continence-preserving surgery in many patients with low rectal cancer. In these cases in particular, intraoperative frozen section diagnostics play a central role in confirming tumor-free margins. However, frozen section diagnostics also play an important role in the transanal resection of early carcinomas or in the therapy of recurrent rectal cancer. It should not be performed routinely, but rather in a targeted maner for specific questions and the corresponding therapeutic consequences. The informative value of frozen section diagnostics in neoadjuvant treated rectal cancer may be limited, so that the final assessment of the resection status and thus the determination of further therapy must be based on paraffin-embedded sections.

Neoadjuvant Treatment of Rectal Cancer: A Repeat UK-wide Survey After Implementation of National Intensity Modulated Radiotherapy Guidance

AIMS

Rectal cancer management has changed significantly in the last decade with the introduction of total neoadjuvant therapy (TNT), minimally invasive surgery, brachytherapy, and organ preservation. A national survey of intensity modulated radiotherapy (IMRT) was carried out in 2020 to support the development of national Royal College of Radiologists (RCR) guidance, published in 2021. We performed a repeat survey in collaboration with the RCR, to inform iterations of the RCR Guidance and establish treatment patterns across the UK to facilitate future research and development.

MATERIALS AND METHODS

A web-based survey was developed and tested by the authors prior to dissemination by the RCR to all UK radiotherapy centres. The repeat survey requested details and strategies of current radiotherapy techniques, including details on setup, doses, organs at risk, peer review, and verification, and asked for the standard management of 5 clinical cases within each multidisciplinary team (MDT) serving that radiotherapy centre. Descriptive statistical analysis was carried out.

RESULTS

In total, 42 of 60 (70%) of the NHS centres across the UK answered the repeat IMRT rectal survey, which reflected 70 MDTs answering the clinical scenarios questions. 100% of centres that responded are routinely using IMRT, with 95% of centres using it in all patients. Variation in treatment delivery has reduced since the previous survey. The greatest difference is still in the use of simultaneous integrated boost and definition of organs at risk. The management for the clinical cases was widely different, with answers generally equally distributed between 2-4 options. The highest-scoring treatment strategies ranged from 24% to 57%.

CONCLUSION

RCR guidance has helped standardise the delivery of radiotherapy to treat rectal cancer in the UK. The variation in neoadjuvant treatment represents an exciting, evolving time in rectal cancer management. Clinical trials are needed to further homogenise treatment, but a degree of national variation is likely to continue.

Neoadjuvant chemotherapy and chemoradiotherapy versus chemoradiotherapy alone in high-risk locally advanced rectal cancer: A retrospective comparison of two Dutch tertiary referral centres

INTRODUCTION

The effect of neoadjuvant chemotherapy and chemoradiotherapy in patients with locally advanced rectal cancer, at increased risk of failing current treatment regimens, is unknown. This study compared the complete response rate and long-term survival of these patients treated with or without neoadjuvant chemotherapy prior to chemoradiotherapy.

MATERIALS AND METHODS

Patients with high-risk locally advanced rectal cancer, who were surgically treated or entered a watch and wait approach after neoadjuvant chemoradiotherapy with or without neoadjuvant chemotherapy in Erasmus Medical Centre or Catharina Hospital between 2016 and 2020, were retrospectively identified. High-risk was defined as the presence of tumour invasion into the mesorectal fascia, grade 4 extramural venous invasion, enlarged lateral lymph nodes, or tumour deposits. The primary endpoint was complete response rate, which was defined as a histopathological complete response or a sustained (during 12 months) clinical complete response. Long-term oncological outcomes were evaluated based on Kaplan-Meier and Cox regression survival analyses.

RESULTS

The neoadjuvant chemotherapy group consisted of 64 patients, of whom 61 (95.3 %) were treated with chemotherapy prior to chemoradiotherapy, the chemoradiotherapy group of 194 patients. The complete response rates were 25.0 % and 9.8 %, respectively (P = 0.002). The estimated 3-year overall survival was 92.2 % in the neoadjuvant chemotherapy group versus 66.9 % in the chemoradiotherapy group.

CONCLUSION

Excellent oncological outcomes were observed in patients with high-risk locally advanced rectal cancer selected during a multidisciplinary team (MDT) meeting for neoadjuvant chemotherapy and chemoradiotherapy. The actual difference with patients treated with chemoradiotherapy alone should be investigated in prospective trials. Pretreatment referral to expert MDTs is encouraged.

Quality of Life and Functional Outcomes in Patients With Locally Advanced Rectal Cancer Receiving Total Neoadjuvant Therapy Versus Concurrent Chemoradiation Therapy: An Analysis of the STELLAR Trial

PURPOSE

To explore differences in the effects of total neoadjuvant therapy (TNT) and preoperative concurrent chemoradiation therapy (CRT) on quality of life and functional outcomes in patients with locally advanced rectal cancer.

METHODS AND MATERIALS

In the study, 591 patients with distal or middle-third, clinical primary tumor stage cT3 to 4 and/or regional lymph node-positive rectal cancer were randomly assigned (1:1) to receive short-term radiation therapy (25 Gy in 5 fractions) followed by 4 cycles of CAPOX (TNT group, n = 297) or standard CRT (50 Gy in 25 fractions concurrently with oral capecitabine) (CRT group, n = 294) before surgery. After a 6-year follow-up, the surviving patients were sent surveys, including the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30, EORTC QLQ-CR29, and Wexner incontinence score questionnaires. Differences between the 2 groups were compared, and baseline data from the general population who completed the EORTC QLQ-C30 were also compared.

RESULTS

The median follow-up was 77.38 (59.07-103.20) months, with 196 out of 414 surviving patients (47.3%) completing the questionnaire. Patients in the TNT group had better emotional function (94.16 ± 10.19 vs 90.17 ± 14.63, P = .031) but more severe diarrhea (12.46 ± 21.73 vs 6.74 ± 16.03, P = .036) than did those in the CRT group. However, the mean differences between the 2 groups were <5 points, which is not clinically significant, and there were no significant differences in other quality of life items. The Wexner incontinence scores were 5 (0-6) and 3 (0-6) for the TNT and CRT groups, respectively, with no significant difference between the groups (P = .357). Compared to the general population data from the completed EORTC QLQ-C30 assessment, the patients did not exhibit differences >5 points in terms of worse function or more severe symptoms.

CONCLUSIONS

There were no significant differences in quality of life or anal function between patients receiving TNT and those receiving CRT. After 6 years, patients were able to maintain stability.

Extent-based tailored strategy for rectal cancer with resectable synchronous liver metastases: Long-term oncologic results of a multicentric cohort study

BACKGROUND

There is no standard surgical management for rectal cancer with synchronous resectable liver metastases. The aim of this study was to assess the oncologic outcomes of an adaptative and individualized strategy considering the extension of both tumoral sites in the management of rectal cancer with synchronous resectable liver metastases.

METHODS

From 2011 to 2020, all consecutive patients treated for low/midrectal cancer with resectable synchronous resectable liver metastases in 4 French centers were included. The choice of strategy was not systematic but tailored on a case-by-case basis to the extension of rectal cancer and liver metastases, prioritizing the most advanced site. The success of the strategy was defined as complete resection of both tumor sites.

RESULTS

Among 83 included patients, most had locally advanced rectal cancer (cT3T4 = 96%) and a median of 3 liver metastases. Forty patients underwent a rectum-first strategy, 31 a liver-first strategy, and 12 a simultaneous resection strategy. Complete resection rate of both sites was 82%. After a 43-month follow-up, median overall survival was 58 months. One- and 3-year survival rates were 94% and 73%, with no difference between strategies (P = .650). In multivariate analysis, the only prognostic factor for overall survival was complete resection of both sites (P = .011, hazard ratio, 0.321; 95% confidence interval, 0.135-0.768), with a median overall survival of 72 months in these patients.

CONCLUSION

Extent-based tailored strategy for rectal cancer with synchronous resectable liver metastases, on the basis of disease extension, allows high rates of complete resection and favorable long-term survival outcomes. This individualized approach maximizes potential for curative outcomes in patients with metastatic rectal cancer.

Mucosal Microbiome Markers of Complete Pathologic Response to Neoadjuvant Therapy in Rectal Carcinoma

Abstract

The intestinal microbiome contributes to colorectal carcinogenesis, disease progression, and response to therapy. Pathologic complete response is the therapeutic goal of neoadjuvant chemoradiation in rectal carcinoma. Nonoperative management has become an accepted strategy, and markers of complete treatment response are needed. Intestinal commensal bacteria contribute to treatment response and radiation colitis, and microbiome-targeted therapies have shown promise in clinical trials. We investigated the relationship among mucosa-associated bacteria, neoadjuvant therapy response, and radiation colitis symptoms in 57 patients who received neoadjuvant regimens with no therapy, chemotherapy only, or chemoradiation. The design was a retrospective cohort study. Microbiome profiling was performed by 16S rDNA sequencing of formalin-fixed, paraffin-embedded tissue at the proximal margin of resection. Global β diversity differed according to neoadjuvant therapy modality and was associated with radiation colitis. Taxonomic differences were detectable at phylum and lower classification levels, and radiation-induced colitis was associated with enrichment of the Bacillaceae family. Taxonomic features, including reduced Streptococcus, Lachnospiraceae, and Bacillaceae, were enriched in complete histopathologic responders to neoadjuvant therapy. Taxon-based prediction of metabolic pathways identified enrichment of prokaryotic NAD+ biosynthesis and salvage pathways in complete responders. Mucosal microbiome responses to multimodal neoadjuvant therapy reflect symptomatic radiation colitis, histopathologic evidence of radiation injury, and pathologic treatment response. Posttreatment microbiome β diversity markers of complete pathologic response may be useful in decisions to manage rectal carcinoma nonoperatively.

Significance

Posttreatment markers of the complete response of rectal carcinoma to neoadjuvant chemoradiation are needed to guide decisions about surgical resection. We found that mucosal microbiome β diversity, bacterial metabolic capacities, and specific taxonomic groups distinguished between complete and incomplete responders. The mucosal microbiome provides markers for complete pathologic response.

Risk score model for predicting local control and survival in patients with rectal cancer treated with neoadjuvant chemoradiotherapy

The present study aimed to investigate clinicopathological factors affecting local recurrence and survival in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (nCRT) and to create a risk-scoring model predicting local control (LC) and survival. The clinical and pathological data of 115 patients who received nCRT for LARC between February 2010 and December 2020 were reviewed retrospectively. A risk-scoring model was developed to predict LC and survival using statistically significant prognostic factors in univariate and multivariate analyses. In the multivariate analysis, the LC rate was improved in patients with a good pathological response to nCRT. By contrast, the disease-free survival (DFS) rate was significantly worse in patients with perineural invasion (PNI). The overall survival (OS) rate was significantly worse in patients who were >60 years of age, who had tumors ≥5 cm, who were PNI-positive and who had pathological N2 stage disease. Patients were grouped to analyze the ability of the scoring system to predict LC and survival. The total score was derived by assigning points to the prognostic factors in univariate and multivariate analyses and was subsequently divided into three groups according to tertile. The median LC times in groups 1-3 were significantly different at 143.6, 97.2 and 93.6 months, respectively. The median DFS times in groups 1-3 were significantly different at 136.1, 108.5 and 67.2 months, respectively, while the median OS times in groups 1-3 were significantly different at 138.3, 87.2 and 64.6 months, respectively. In conclusion, risk score modeling with prognostic factors effectively determined the difference in LC and survival between the groups. Adding effective systemic therapy to nCRT may improve results, especially in patients with multiple poor prognostic factors, including larger tumors, PNI and multiple nodal involvement.

Patterns of care and surgical outcomes for early-stage rectal cancer in the United States

BACKGROUND

Although limited trials have demonstrated the feasibility of rectal-preserving approaches in clinical T1-3N0 adenocarcinoma, local excision after neoadjuvant therapy has been associated with high rates of morbidity. We hypothesized that this strategy would be comparable to the standard, total mesorectal excision. The aim of this study was to describe trends of early-stage rectal cancer management.

METHODS

cT1-3N0 rectal cancers in the National Cancer Database (2006-2018) were grouped into 5 treatments: total mesorectal excision, total neoadjuvant therapy + local excision, neoadjuvant chemoradiotherapy + local excision, total neoadjuvant therapy + total mesorectal excision, and neoadjuvant chemoradiotherapy + total mesorectal excision. Morbidity was defined as a combination of readmissions and 30- and 90-day mortality.

RESULTS

We identified 22,793 patients. Neoadjuvant chemoradiotherapy + local excision had the highest proportion of patients ≥70 years (41%) and those with comorbidities (Charlson-Deyo score ≥2, 9%). Median stay was 1 day for local excision and 5 days for total mesorectal excision. Overall composite morbidity was 9%, which, after adjustment, was not statistically different between local excision and total mesorectal excision (odds ratio = 0.45, 95% confidence interval: 0.17-1.19). Among local excision patients, 56% had pathologic complete response, 33% were pStage I, and 12% pStage II-III. In multivariable analysis, all strategies had similar overall survival compared with total mesorectal excision, except for neoadjuvant chemoradiotherapy + local excision, which was associated with worse prognosis (hazard ratio = 1.57, 95% confidence interval: 1.21-2.03).

CONCLUSION

Although infrequent, neoadjuvant chemoradiotherapy/total neoadjuvant therapy + local excision were associated with high rates of tumor downstaging, suggesting that rectal-preserving strategies are feasible. However, 1 in 8 patients had more advanced disease, which may have compromised future total mesorectal excision planes. Together with the similar morbidity and relatively worse prognosis of neoadjuvant chemoradiotherapy + local excision, these observations should prompt careful patient selection for this approach, while cautioning against its widespread use.

Quantitative analysis of rectal cancer biopsies with the digital pathology segmentation algorithm QuantCRC associates with therapy response and recurrence

We examined whether QuantCRC, a digital pathology segmentation algorithm, on pre-therapy rectal cancer biopsies is associated with pathologic complete response (pCR) to neoadjuvant therapy, recurrence-free survival (RFS), and transcriptomic spatial profiling. QuantCRC was evaluated in an observational cohort of 288 pre-therapy biopsies and a separate validation cohort of 37 pre-therapy biopsies of rectal adenocarcinoma from patients undergoing neoadjuvant therapy. Associations between QuantCRC features and clinical outcomes, pCR, and RFS were analyzed using multivariable logistic regression and Cox proportional hazards modeling, respectively. QuantCRC variables were also correlated with transcriptomic digital spatial profiling of 37 pre-treatment biopsies of cT3N+ rectal cancer. QuantCRC-derived lymphocytes per mm2 of tumor epithelium (TILs) was significantly associated with pCR (multivariate OR 1.05, 95% CI 1.02-1.10, P=0.038). QuantCRC-derived TILs were significantly higher in pre-therapy biopsies with pCR (91.3 vs. 55.9 lymphocytes per mm2, P=0.004). The validation cohort confirmed that only QuantCRC-derived TILs in pre-therapy biopsies of rectal cancer were significantly associated with complete response to neoadjuvant therapy. QuantCRC %high tumor grade was independently associated with worse RFS (multivariate HR 1.27, 95% CI 1.09-1.47, P=0.002). Patients with ≥10.1% high tumor grade identified by QuantCRC had significantly reduced RFS (5-year RFS 69% vs 83%, log-rank p=0.007). Transcriptomic profiling identified high IL-6/JAK/STAT3 signaling within immune cells to be associated with worse RFS (adjusted P=0.01). Tumors with low IL-6/JAK/STAT3 expression within immune cells had significantly higher TILs compared to tumors with high expression (median 152 vs. 97 TILs per mm2, P=0.039). Biopsy-adapted QuantCRC in pre-therapy rectal cancer may be helpful in identifying patients who achieve pCR and are at risk for recurrence.

MRI radiomics prediction modelling for pathological complete response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer: a systematic review and meta-analysis

PURPOSE

Predicting response to neoadjuvant therapy in locally advanced rectal cancer (LARC) is challenging. Organ preservation strategies can be offered to patients with complete clinical response. We aim to evaluate MRI-derived radiomics models in predicting complete pathological response (pCR).

METHODS

Search included MEDLINE, Embase and Cochrane Central Register of Controlled Trials (CENTRAL) and Cochrane Database of Systematic Reviews (CDSR) for studies published before 1st February 2024. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) and Radiomics Quality Score (RQS) tools were used to assess quality of included study. The research protocol was registered in PROSPERO (CRD42024512865). We calculated pooled area under the receiver operating characteristic curve (AUC) using a random-effects model. To compare AUC between subgroups the Hanley & McNeil test was performed.

RESULTS

Forty-four eligible studies (12,714 patients) were identified for inclusion in the systematic review. We selected thirty-five studies including 10,543 patients for meta-analysis. The pooled AUC for MRI radiomics predicted pCR in LARC was 0.87 (95% CI 0.84-0.89). In the subgroup analysis 3 T MRI field intensity had higher pooled AUC 0.9 (95% CI 0.87-0.94) than 1.5 T pooled AUC 0.82 (95% CI 0.80-0.83) p < 0.001. Asian ethnicity had higher pooled AUC 0.9 (95% CI 0.87-0.93) than non-Asian pooled AUC 0.8 (95% CI 0.75-0.84) p < 0.001.

CONCLUSION

We have demonstrated that 3 T MRI field intensity provides a superior predictive performance. The role of ethnicity on radiomics features needs to be explored in future studies. Further research in the field of MRI radiomics is important as accurate prediction for pCR can lead to organ preservation strategy in LARC.

The Landmark Series: Neoadjuvant Therapy for Locally Advanced Rectal Cancer

The management of locally advanced rectal cancer (LARC) has seen much development over recent decades. Neoadjuvant radiotherapy combined with high-quality total mesorectal excision saw improvements in locoregional control. With the advent of several key trials, neoadjuvant therapy for LARC has seen a shift toward total neoadjuvant therapy, with corresponding improvements in tumor response and survival outcomes. The collective pool of evidence has allowed for increasingly personalized treatment of LARC, with organ-preservation now an option for many. The aims of the review are to summarize the evolution of neoadjuvant therapy for LARC, highlight key studies informing contemporary best practices, navigate the complexity of options available, and present areas of ongoing development.

Short-course radiation followed by mFOLFOX-6 plus avelumab for locally-advanced microsatellite stable rectal adenocarcinoma: The Averectal study

BACKGROUND

Total neoadjuvant therapy(TNT) has improved complete pathologic response (pCR) rate and disease-free survival (DFS) in locally advanced rectal cancer (LARC), though an increased local recurrence rate (LRR) with short-course radiotherapy (SCRT) is concerning. Synergism between immunotherapy and radiotherapy may improve outcomes in LARC, even where microsatellite stable (MSS) tumours exist. The Averectal trial evaluated SCRT, followed by chemotherapy and immunotherapy with avelumab and total mesorectal excision (TME) in these patients.

METHODS

Patients with LARC received SCRT (5 Gy x5 fractions), 6 cycles of mFOLFOX-6 plus avelumab every 2 weeks, followed by TME in an investigator-initiated, open-label, single-arm, multicentre, phase II study. The primary outcome was pCR vs. historical control. Secondary outcomes were 3-year DFS, local recurrence rate (LR) and the association of the ImmunoScore (IS) with outcomes including pCR, safety, and quality of life (QoL).

RESULTS

Out Of 44 MSS patients enrolled from 3 centres (July 2018 -October 2020), 40 completed treatment and analysed (65 % male, median age 58.5 [31.0, 74.0] years). Median follow-up was 44 months (11.4, 51.4). Fifteen patients (37.5 %) achieved pCR; and 67.5 % had a major pathologic response. Mean DFS was 42 months (37.9, 46.1). Mean OS was 46.3 months (44.4, 48.2). Median DFS and OS were not reached. Three-year DFS was 85 %. LRR was 2.5 %. Patients with vs. without pCR had higher mean IS (68 vs. 52, p = 0.036). Serious adverse events occurred in 23.5 % (one was related to avelumab). Three patients died (7.5 %), due to disease progression. QOL was similar between baseline and last follow-up.

CONCLUSION

Adding avelumab to neoadjuvant chemotherapy mFOLFOX6 after SCRT, followed by TME, improved pCR without increasing LRR, with acceptable toxicity and QOL.

Targeting the phosphatidylinositol-3-kinase (PI3K) and mitogen activated protein kinase (MAPK) signalling pathways to enhance chemoradiotherapy in locally advanced rectal cancer

Responses to neoadjuvant chemoradiotherapy for locally advanced rectal cancer are not uniform. The phosphatidylinositol-3 kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways are involved in tumorigenesis and treatment resistance in many cancers; therefore, targeting these pathways could enhance response to chemoradiotherapy. A panel of colorectal cancer (CRC) cell lines (n = 10) with varying PI3K and MAPK mutational backgrounds were treated with combinations of 5-Flourouracil (5-FU), radiation, the PI3K inhibitor copanlisib, and/or the MEK inhibitor refametinib, and their effects on proliferation in vitro were measured. BALB/c SCID mice were implanted with CRC cell lines representative of each mutational background, treated with copanlisib and/or chemoradiotherapy, and monitored for tumor growth. In vitro, PIK3CA mutated cell lines were most sensitive to copanlisib (IC50=28 nM) and KRAS mutated cell lines were most sensitive to refametinib (IC50 = 36 nM), while the combination of copanlisib and refametinib was synergistic in 9/10 cell lines tested. The addition of copanlisib to 5-FU chemoradiotherapy inhibited cell growth compared to 5-FU chemoradiotherapy alone, an effect that was most notable in LS-1034 (KRAS mutated) and Caco-2 (PIK3CA/KRAS wild-type) cell lines. In vivo copanlisib and 5-FU chemoradiotherapy reduced tumor growth in all xenograft models and increased overall survival in LS-1034 and Caco-2 xenografts. Our results suggest that activation of the kinase signalling pathway may modulate PI3K/MEK inhibitor responsiveness in colorectal cancer. Furthermore, the addition of copanlisib to 5-FU chemoradiotherapy resulted in an enhanced anti-proliferative cytotoxic effect compared to 5-FU chemoradiotherapy alone, regardless of the background mutational status, and supports further clinical development of this regimen.

Comparison of immunotherapy based total neoadjuvant therapy or standard neoadjuvant chemoradiation for locally advanced rectal cancer: a multi-institutional retrospective study

Background

Combining radiation therapy with immunotherapy produces a synergistic effect in patients with microsatellite stable/mismatch repair-proficient (MSS/pMMR) locally advanced rectal cancer (LARC). This study aimed to evaluate the long-term outcomes and safety of immunotherapy combined with long-course chemoradiotherapy (ICIs + nCRT) versus immunotherapy combined with total neoadjuvant therapy (ICIs + TNT).

Methods

This retrospective study collected clinical data of adult patients with clinical T3-4 and/or N1 rectal adenocarcinoma who underwent ICIs + TNT or ICIs + nCRT followed by curative surgery at four medical centers between March 2020 and August 2021. The study compared clinical efficacy, disease-free survival (DFS), overall survival (OS) at 3 years postoperatively, and adverse event.

Results

Among 211 enrolled patients, 89 (42%) received ICIs + TNT, while 122 (58%) underwent ICIs + nCRT, with a median age of 56.0 years (range, 20.0-75.0 years). The ICIs + TNT group had a higher median number of resected lymph nodes (15.0 [range, 4.0-37.0] vs. 13.0 [range, 3.0-33.0], P=0.028) compared to the ICIs+nCRT group. However, the groups had no substantial difference in median operative time. The pathological complete response (pCR) rate was 49.4% (44/89, 95% confidence interval [CI] 39.8%-61.3%) in the ICIs + TNT group compared to 35.3% (43/122, 95% CI 26.8%-44.4%) in the ICIs + nCRT group, respectively, with significant difference (P=0.039). After adjusting for potential confounders, the 3-year DFS rates were comparable between the two groups (84.3% vs. 81.9%; P=0.620), as were the OS rates (94.0% vs. 91.1%; P=0.634). Factors independently associated with poorer DFS included age ≤50 years (P=0.044) and a neoadjuvant rectal (NAR) score ≥8 (P=0.008). Similarly, patients aged ≤50 years (P=0.025) exhibited a trend toward worse OS than those older than 50 years. The safety profiles of the two treatment groups were similar.

Conclusions

Overall, ICIs + TNT demonstrated therapeutic efficacy and a safety profile comparable to ICIs + nCRT in patients with LARC and MSS/pMMR status. Although ICIs + TNT achieved numerically higher downstaging rates, it was not associated with improved survival outcomes. These findings underscore the importance of refining patient selection criteria and making judicious treatment decisions to enhance the prognosis of individuals with rectal cancer.

Network meta-analysis of RTCs for efficacy of neoadjuvant treatment in rectal cancer

BACKGROUND

This network meta-analysis examined the efficacy of different types of neoadjuvant therapy (NAT) for rectal cancer in improving clinical and pathologic outcomes.

METHODS

PRISMA-compliant systematic review of PubMed and Scopus including only randomized clinical trials comparing two or more NAT regimens for rectal cancer. A network meta-analysis was undertaken for the main outcomes, including pathological complete response (pCR), disease downstaging, R0 resection, permanent stoma, and major adverse effects. Risk of bias was assessed using the ROB-2 tool.

RESULTS

19 randomized controlled trials incorporating 7037 patients (62 % males) were included in the analysis. Compared to standard neoadjuvant chemoradiation (NCRT), consolidation total neoadjuvant therapy (TNT) (OR: 1.82, 95 % CI: 1.46-2.27; p < 0.001) and induction TNT (OR: 1.72, 95 % CI: 1.31-2.26; p < 0.001) had higher odds of achieving pCR. Induction TNT was also significantly associated with higher odds of major adverse effects than was NCRT (OR: 3.14, 95 % CI: 2.50-3.94; p < 0.0001). Compared to NCRT, long course chemotherapy significantly increased the odds of R0 resection (OR: 1.42, 95 % CI: 1.13-1.78; p = 0.002), while consolidation TNT significantly increased organ preservation rates (OR: 2.82, 95 % CI: 1.58-5.05; p < 0.001). Short course radiotherapy doubled the odds of positive circumferential resection margins (CRM) compared to NCRT (OR: 1.99, 95 % CI: 1.11-3.55; p = 0.02).

CONCLUSIONS

Consolidation and induction TNT were superior in achieving better pathological outcomes in rectal cancer, offering significant benefits over standard NCRT. However, they were associated with a higher risk of adverse effects. Conversely, short course radiotherapy was linked to higher rates of positive CRM.

Neoadjuvant FOLF(IRIN)OX Chemotherapy for Resectable Pancreatic Adenocarcinoma: A Multicenter Randomized Noncomparative Phase II Trial (PANACHE01 FRENCH08 PRODIGE48 study)

PURPOSE

Despite limited RCTs, neoadjuvant chemotherapy (NAC) shows promise for resectable pancreatic adenocarcinoma (rPAC). Few prospective results are available on completing the full therapeutic sequence and oncologic outcomes with NAC.

METHODS

The PANACHE01-PRODIGE48 phase II trial randomly assigned 153 patients with rPAC (2:2:1) to four cycles of NAC (modified leucovorin, fluorouracil, irinotecan, and oxaliplatin [mFOLFIRINOX], arm 1; leucovorin, fluorouracil, and oxaliplatin [FOLFOX], arm 2) or up-front surgery (control) across 28 French centers (February 2017-July 2020). The primary objective was to evaluate the feasibility and efficacy of these NAC regimens. Two binary primary end points included 1-year overall survival (OS) postrandomization and the rate of patients completing the full therapeutic sequence. Event-free survival (EFS) assessed time to failure, defined as progression before surgery, unresectable/metastatic disease at surgery, recurrence, or death.

RESULTS

The primary objective was achieved for arm 1. In the intention-to-treat population, 70.8% (90% CI, 60.8 to 79.6) and 68% (90% CI, 55.5 to 78.8) completed the therapeutic sequence in arm 1 and arm 2, respectively. Within 12 months postrandomization, 84.3% (90% CI, 75.3 to 90.9) and 71.4% (90% CI, 59.0 to 81.8) of the patients were alive in arm 1 and arm 2, respectively. Treatment was safe and well-tolerated in both NAC arms. Arm 2 was stopped after interim analysis for lack of efficacy (H0 rejection for 1-year OS). One-year EFS rates were 51.4% (95% CI, 41.0 to 64.3), 43.1% (95% CI, 31.3 to 59.5), and 38.7% (95% CI, 24.1 to 62.0) in arm 1, arm 2, and control arm, respectively.

CONCLUSION

The feasibility and efficacy of mFOLFIRINOX in the perioperative setting are confirmed concerning therapeutic sequence completion and oncologic outcomes, supporting ongoing trials (PREOPANC3, Alliance AO21806). Further research is needed to identify patients who benefit from NAC (ClinicalTrials.gov identifier: NCT02959879; EudraCT: 2015-001851-65).

Real-World Data on the Practice of Chemoradiation with Select Cohort Consolidation Chemotherapy in High-Risk Locally Advanced Rectal Cancers (SOLAR study)

Chemoradiation with capecitabine radiotherapy (Cape–RT) has been the standard of care as neoadjuvant treatment in locally advanced rectal cancer (LARC) for more than a decade. However, total neoadjuvant therapy has recently emerged as an alternative with the potential to impact survival outcomes; baseline outcomes with Cape–RT in real-world practice in the Indian context are not well known.

Treatment-naive patients with adenocarcinoma on histology and clinical-radiologically diagnosed LARC who received Cape–RT from June 2014 to December 2021 after multidisciplinary discussion were included. Patients received a long course of conventionally fractionated external beam RT (45–50 Gy in 25#) with concurrent oral capecitabine at a dose of 1650 mg/m2/day. Post approximately 6 to 8 weeks of completion of Cape–RT, patients were evaluated clinically and by magnetic resonance imaging pelvis for total mesorectal excision (TME) in the multidisciplinary team meetings. The primary endpoint of the study was event-free survival (EFS), and the secondary endpoint was overall survival (OS) and pathological complete response (PCR) rates. EFS and OS were calculated using the Kaplan–Meier method.

A total of 1,189 patients with a median age of 49 years (range: 15–95) were identified and included. A significant proportion of patients had high-risk characteristics, such as T3/T4 disease (94%) and node positivity (90%), and they involved circumferential resection margin (CRM) (51%) at baseline. Signet ring and mucinous histology were seen in 13 and 11% of patients. Two hundred and seventy-six patients (23%) required further consolidation chemotherapy (commonly CAPOX [capecitabine-oxaliplatin] or modified FOLFIRINOX [5-fluorouracil-leucovorin-irinotecan-oxaliplatin]) post-Cape–RT prior to attempting surgery due to either persistent CRM positivity, clinical T4 disease, prostate abutment, sphincter involvement (248 patients, 21%), or extensive bulky disease with poor response (12 patients, 1%). Overall, 14 patients (6%) had an interruption in RT and 22 (8%) in chemotherapy. Post-Cape–RT, with or without chemotherapy, 945 patients (79%) underwent TME. Chemotherapy post-TME was administered in 808 patients (78%). With a median follow-up of 54 months (range: 51.2–57.2), the 3- and 5-year EFS for the entire cohort was 73.2% (95% confidence interval [CI]: 70.6–75.8) and 64.3% (95% CI: 61.1–67.5), respectively, while the estimated 3- and 5-year OS was 81.3% (95% CI: 78.9–83.7) and 73% (95% CI: 70–76), respectively. On multivariate analysis, the presence of higher T stage (p < 0.001) and signet ring histology (p = 0.004) predicted inferior OS.

Real-world data in a less-resourced setting concurs with published prospective and Western real-world data. This provides confidence in implementing consolidation chemotherapy in total neoadjuvant settings in countries with fewer resources.

Short- and long-term outcomes of minimally invasive vs. open pelvic exenteration in rectal tumours: a focused meta-analysis

PURPOSE

Pelvic exenteration (PE) is a complex surgical procedure used to treat patients with recurrent or locally advanced rectal cancer (LARC) as a final recourse. Thus, minimally invasive surgery (MIS) has emerged as an alternative to the traditional open PE as it may reduce surgical trauma and improve recovery. This meta-analysis compared the clinical outcomes between MIS and open PE in patients with LARC.

METHODS

A systematic review and meta-analysis were conducted following PRISMA and AMSTAR guidelines. Six retrospective studies comprising 368 patients (179 MIS patients; 189 open patients) were included. Data on operative parameters along with short-term and long-term outcomes, including the 3-year overall (OS) and disease-free survival (DFS), were extracted. Risk ratios (RRs) and odds ratios (ORs) were calculated for binary outcomes, while standardised mean differences (SMDs) were calculated for continuous outcomes. All measures were reported with 95% confidence intervals (CIs) using random-effects models.

RESULTS

MIS was associated with significantly reduced blood loss (standardised mean difference (SMD), - 1.57; 95% CI, - 2.27 to - 0.88; p < 0.00001), shorter hospital stays (SMD, - 6.46; 95% CI, - 12.21 to - 0.71; p = 0.03), and quicker diet resumption (SMD: - 0.79; 95% CI, - 1.36 to - 0.21; p = 0.008) than open PE. MIS was associated with a borderline reduction in total complications (OR, 0.45; 95% CI, 0.20-1.00; p = 0.05) and lower rates of abdominal wound complications (OR, 0.22; 95% CI, 0.11 to 0.45; p < 0.0001). No significant differences were observed in R0 resection rates, major complications, or mortality. For long-term outcomes, MIS demonstrated significantly improved 3-year OS (RR, 1.19; 95% CI, 1.01 to 1.41; p = 0.04), whereas 3-year DFS showed no significant difference (RR, 1.02; 95% CI, 0.79 to 1.41; p = 0.87).

CONCLUSION

MIS offers significant short-term advantages over open PE, including reduced blood loss, faster recovery, and fewer complications while demonstrating improved 3-year OS. These findings support MIS PE as a safe, effective, and viable option for patients with recurrent or LARC.

Neoadjuvant therapy for colorectal cancer from 2015 to 2024: a visual analysis and bibliometric analysis

Background

Colorectal cancer (CRC) imposes a substantial burden on global health., but research trends and hotspots in this field are still not clear. The purpose of this research is to create a visual knowledge map based on bibliometric analysis, identify research hotspots and predict future research trends.

Method

Utilizing the Web of Science Core Collection (WoSCC) as data source and integrating the visualization capabilities of the Bibliometrix R software package, CiteSpace, and VOSviewer, analyze the authors, research institutions, countries, cited documents, publishing journals, abstracts, and keyword information of literature pertaining to neoadjuvant therapy for colorectal cancer spanning from January 2015 to December 2024.

Result

The analysis included 1,587 articles from 1,464 institutions, 385 journals, and 61 countries or regions. China has the largest number of publications (449) and the largest number of citations (5,035). The United States occupies the leading position with an average of 21.6. "Annals of Surgical Oncology" is the most published journal with 51 articles, and "Journal of Clinical Oncology" is the journal with the most references (4,465 references). Highly cited references focus on clinical trials and guidelines for neoadjuvant therapy for colorectal cancer. In recent years, the most important keywords in the research on colorectal cancer and neoadjuvant therapy have been "artificial intelligence", "total neoadjuvant therapy" and "immunotherapy".

Conclusion

This article provided a review of the research on neoadjuvant therapy for colorectal cancer, can provide reference for subsequent research on neoadjuvant therapy for colorectal cancer. The results offered valuable insights and data that informed the direction of future advancements.

Investigation of changes in planning target volume and regression probability of rectal boost using in-silico cone-beam computed tomography-guided online-adaptive radiotherapy

Background and purpose

Radiotherapy boost to the primary tumour may enable organ preservation in locally advanced rectal cancer (LARC). This study evaluated cone-beam computed tomography (CBCT)-guided online-adaptive radiotherapy (ART) to reduce rectal boost planning target volume (PTVBoost) margins and allow dose escalation.

Materials and methods

Eleven LARC patients were included in this in silico study. Population-based PTVBoost margins were computed for non-adaptive and online-ART using van Herk's formalism. Dose/volume results were compared between: non-adaptive RT with a 25 x 2.16 Gy boost (Non-ART54Gy), ART with a 25 x 2.16 Gy boost (ART54Gy), and ART with an escalated boost of 25 x 2.4 Gy (ART60Gy). Tumour regression probability was compared between each plan using a dose-response model.

Results

PTVBoost margins for non-adaptive vs. online-ART were 14.2 vs. 3.3 mm in the antero-posterior, 5.0 vs. 3.2 mm in the left-right, and 12.3 vs. 8.7 mm in the supero-inferior axes. PTVBoost and pelvic lymph node PTV coverage (V95%) were significantly improved with ART54Gy and ART60Gy compared to Non-ART54Gy (p < 0.001). High-priority organ-at-risk constraints (priority 1&2) were violated in 26.8 % of cases for Non-ART54Gy, 21.2 % of cases for ART54Gy, and 20.8 % of cases for ART60Gy. Tumour regression probability was superior for ART60Gy (20.8 %) compared to ART54Gy (17.0 %, p < 0.001) and Non-ART54Gy (16.9 %, p < 0.001).

Conclusions

Online-ART significantly reduce rectal boost PTV margin. It allows better target volume coverage with a similar risk of radiation-induced toxicities, even when escalating the dose. Therefore, online-ART should be considered to perform dose-escalation in LARC patients with the objective of organ preservation.

Therapeutic potential of flavonoids in gastrointestinal cancer: Focus on signaling pathways and improvement strategies (Review)

Flavonoids are a group of polyphenolic compounds distributed in vegetables, fruits and other plants, which have considerable antioxidant, anti‑tumor and anti‑inflammatory activities. Several types of gastrointestinal (GI) cancer are the most common malignant tumors in the world. A large number of studies have shown that flavonoids have inhibitory effects on cancer, and they are recognized as a class of potential anti‑tumor drugs. Therefore, the present review investigated the molecular mechanisms of flavonoids in the treatment of different types of GI cancer and summarized the drug delivery systems commonly used to improve their bioavailability. First, the classification of flavonoids and the therapeutic effects of various flavonoids on human diseases were briefly introduced. Then, to clarify the mechanism of action of flavonoids on different types of GI cancer in the human body, the metabolic process of flavonoids in the human body and the associated signaling pathways causing five common types of GI cancer were discussed, as well as the corresponding therapeutic targets of flavonoids. Finally, in clinical settings, flavonoids have poor water solubility, low permeability and inferior stability, which lead to low absorption efficiency in vivo. Therefore, the three most widely used drug delivery systems were summarized. Suggestions for improving the bioavailability of flavonoids and the focus of the next stage of research were also put forward.

Rectal cancer approach strategies after neoadjuvant treatment - a systematic review and network meta-analysis

BACKGROUND AND AIMS

An increasing number of patients with rectal cancer who respond well to neoadjuvant chemoradiotherapy (nCRT) are being considered for organ preservation programs. However, due to the lack of high-level evidence, the survival outcomes of the organ preservation programs are still full of controversy and uncertainty.

METHODS

To assess the effects of total mesorectal excision (TME) surgery, watch-and-wait (W&W), and local excision (LE) on long-term outcomes after nCRT, we searched PubMed, Embase, and Web of Science for articles published between 1 January 2010, and 31 December 2023.

RESULTS

We found 7029 pieces of literature, of which 26 studies met the inclusion criteria, and recruited 2778 participants in the network meta-analysis. Risk of bias assessment showed that most included studies had a low risk of bias. Low-certainty evidence suggests that the TME group was significantly superior to all other interventions for the 2-year local regrowth rate. (W&W group [OR, 0.20; 95% CI, 0.12-0.35], LE group compared with TME group [3.00; 1.60-5.80]). There was no significant difference in the 2-year local regrowth rate between W&W and LE group (OR, 0.60; 95% CI, 0.32-1.20). There was high to moderate certainty evidence that at 3 years, the W&W group had a significant advantage in overall survival compared with the TME group (OR, 0.37; 95% CI, 0.09-0.95). After 5 years, no significant difference in overall survival was found between the 3 treatment modalities.

CONCLUSIONS

We concluded that TME achieved the most significant reduction in 2-year local regrowth rates. However, the W&W strategy and LE demonstrated noninferiority to TME in long-term survival outcomes.

Colon and rectal peritoneal carcinomatosis: are we mixing apples with oranges? A propensity score-matched analysis

Rectal cancer is universally considered a different disease entity as compared to colon cancer, except when dealing with colorectal peritoneal carcinomatosis (PC), in which the two cancers are deemed as the same one. The present study aims to investigate the influence of primary tumor location (colon vs. rectum) on oncologic outcomes in patients undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal peritoneal metastases. Data from three referral centers undergoing CRS plus HIPEC for PC of colorectal origin were prospectively collected. The primary outcomes were overall survival (OS) and disease-free survival (DFS) according to primary tumor location (colic vs. rectal). Univariate and multivariate analyses were performed using the Cox proportional hazard model first on the total number of patients. Then, a propensity score matching using the nearest-neighbour method with a 1:1 ratio was performed. The study included 167 patients: 126 colic and 41 rectal PC. After propensity score matching, rectal primary tumor location was independently predictive of a lower DFS (HR 1.91; 95%CI 1.06-3.45; p = 0.031) but not of a lower OS (HR 1.12; 95%CI 0.57-2.21; p = 0.73). Post-matching 3-year DFS rates were 49.2% (95%CI 34,3-70,5%) and 19.4% (95%CI 9,4-40,2%) for colic and rectal PC, respectively. The present study shows a significantly worse DFS for rectal cancer PC undergoing CRS and HIPEC compared to colon cancer PC, suggesting a possible need for dedicated pathways for rectal PC patients and posing a question for rectal PC to be considered as a unique disease entity.

[For Whom, How and to What End - Neoadjuvant Therapy for Rectal Cancer?]

Over the past few decades, considerable progress has been made in the treatment of rectal cancer, leading to a reduction in local recurrence rates and an improvement in prognosis. The current German S3 guideline on colorectal cancer recommends neoadjuvant therapy for UICC stage II and III tumours of the middle and lower rectum. Primary surgery is still recommended for UICC I tumours, although exceptions are being discussed for certain subgroups, such as cT1/2 tumours with questionable nodal involvement. Current trials are focusing on multimodality treatment concepts, in particular total neoadjuvant therapy (TNT), which has been examined in several phase II and phase III trials. Therapies with selective omission of neoadjuvant radiotherapy and organ-preserving approaches are also being investigated. This review provides a comprehensive overview of the current evidence on neoadjuvant treatment of rectal cancer, highlights new multimodal treatment approaches, and discusses future challenges and opportunities to optimise treatment according to stage and to provide patients with the best possible individualised treatment.

Shared Decision Making in the Treatment of Rectal Cancer

Background/Objectives: The management of locally advanced rectal cancer has evolved significantly, shaped by advances in multimodal neoadjuvant therapy and a growing emphasis on organ preservation through the watch-and-wait approach. These advancements, however, introduce complex treatment decisions that require careful consideration by both patients and clinicians. Methods: This narrative review explores the evolution of the management of locally advanced rectal cancer and the role of shared decision-making in guiding treatment decisions, particularly for patients facing decisions between surgical resection and watch-and-wait. Additionally, it discusses the development of tools to aid in shared-decision making, current challenges in implementing shared decision-making and future directions for improvement patient centered care in locally advanced rectal cancer management. Results: Considerations for decision making include anatomical considerations that influence surgical options, the potential benefits and risks of watch-and-wait versus surgical resection of the rectum, and the impact of treatment on bowel, urinary, and sexual function. Additionally, patients must weigh the long-term implications of their choices on quality of life. Conclusions: Shared decision-making has emerged as a critical component of patient-centered care and ensures that treatment decisions align with patients' values and priorities. Given the preference-sensitive nature of the management of locally advanced rectal cancer, shared decision-making plays an important role in helping patients navigate these decisions.

MRI is more accurate than FDG-PET in assessing complete response in rectal cancer patients after neoadjuvant therapy

PURPOSE

The role of FDG-PET in the restaging rectal cancer following neoadjuvant therapy (NAT) is not clear. We compared the accuracy of FDG-PET and MRI in the assessment of rectal cancer response to NAT.

METHODS

Data of patients treated between January 2015 and September 2022 were captured from a rectal tumor registry. Restaging FDG-PET and MRI were evaluated for the presence of viable tumor. Imaging was compared to the reference standard of pathological results for patients that underwent surgery, and sustained clinical complete response for patients that entered watch and wait. Sensitivity was defined as correctly identifying patients with a complete response.

RESULTS

Eighty-two patients met the inclusion criteria. Of these, 60 patients underwent restaging MRI and 54 underwent restaging FDG-PET. Thirty-two were evaluated by both modalities. Mean age and distance from anal verge were 59.9 ± 12.7 years and 5.9 ± 3.2 cm. Baseline staging was cT1-2, cT3 and cT4 for 7 (8.5%), 62 (75.6%) and 13 (15.9%) of the patients, respectively. Baseline nodal staging was cN0 and cN + for 32 (39%) and 50 (61%) of the patients, respectively. All patients were treated with radiation with the majority 73 (89%) receiving chemoradiotherapy. There were 17 patients (21%) that had a pathological or sustained clinical complete response. All baseline characteristics were not meaningfully different between groups. MRI was more accurate than FDG-PET in all parameters including sensitivity, specificity, positive and negative predictive value and overall accuracy.

CONCLUSION

MRI outperforms FDG-PET in the identification of complete response in rectal cancer patients after NAT.

Results of radical treatment of locally advanced rectal cancer in geriatric and non-geriatric patients

BACKGROUND

It is estimated that 60% of new rectal cancer cases will be diagnosed in patients ≥ 65 years old. The geriatric patient is heterogeneous and underrepresented in clinical trials, and oncologic therapies are often tailored with little evidence. We describe a cohort of patients diagnosed with locally advanced rectal cancer in geriatric and non-geriatric patients.

MATERIALS AND METHODS

Retrospective and descriptive analysis of 137 patients, 44 (32.1%) ≥ 75 years old and 93 (67.9%) ≤ 75 years old, with diagnosis of locally advanced rectal cancer. All patients received neoadjuvant chemoradiotherapy (nCRT), followed by total mesorectal excision (TME) and adjuvant chemotherapy.

RESULTS

Mean age was 79.5 for ≥ 75 years and 62.7 for ≤ 75 years, tumor location was: upper rectum (16.1% and 11.3%), middle rectum (60.2% and 47.7%) and lower rectum (23.7% and 41%), using the Eastern Cooperative Oncology Group (ECOG) 0: 74.1% and 81.8%, ECOG 1: 25.9% and 18.2%. Pathological complete response was 21.5% and 22.7%, partial response, 57% and 59% and no response, 21.5% and 18.3%, respectively. Tumor shrinkage in both groups after neoadjuvant treatment was 34.5% and 35.46%. Local recurrence was 2.2% and 3.2% and distance recurrence, 11.3% and 8.6%, respectively.

CONCLUSION

The study shows similar outcomes in both groups following radical treatment, with similar rates of pathological complete response. However, it has notable limitations, including a small sample size and the absence of a comprehensive geriatric assessment. To enhance these findings, future research should involve larger patient cohorts with comparative analysis and clinical trials specifically focused on the geriatric population.

Short-term outcomes of transanal endoscopic intersphincteric resection for locally advanced rectal cancer after neoadjuvant chemoradiotherapy: A single-center retrospective cohort study

OBJECTIVE

To compare the perioperative safety and specimen characteristics after transanal endoscopic intersphincteric resection (taE-ISR) versus classical intersphincteric resection (cISR) in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (nCRT).

METHODS

Clinicopathological data of 145 patients (75 undergoing taE-ISR and 70 undergoing cISR after nCRT) were retrospectively analyzed. Baseline characteristics, perioperative details, and pathological specimen quality of the two groups were compared.

RESULTS

Intraoperative blood loss was lower in the taE-ISR group compared to cISR (50.0 (40.0-100.0) ml vs. 70.0 (50.0-100.0) ml, P = 0.034). Two patients (2.6 %) in the taE-ISR group and eight patients (11.4 %) in the cISR group sustained adjacent organ injury (P = 0.037). There was no statistically significant difference in the prevalence of postoperative complications between the two groups (17.3 % vs. 30.0 %, P = 0.072). However, pelvic abscess (1.3 % vs. 8.6 %, P = 0.042) and rectovaginal fistula (0.0 % vs. 5.7 %, P = 0.036) occurred less often in taE-ISR compared to cISR. The complete resection rate was higher in taE-ISR compared to cISR (98.7 % vs. 91.4 %, P = 0.042). No patients in taE-ISR had positive distal resection margins (DRM), while four patients in cISR had positive DRM (0.0 % vs. 5.7 %, P = 0.036).

CONCLUSION

taE-ISR after nCRT was associated with higher-quality specimens, reduced intraoperative blood loss, and fewer perioperative complications, attesting to the feasibility and safety of taE-ISR In low-LARC patients.

Contact X-ray brachytherapy in rectal cancer: A systematic review and meta-analysis

Rectal cancer is a highly prevalent disease. Evidence presented in the 2025 phase-III OPERA randomised trial suggests that Contact X-ray Brachytherapy (CXB), with external beam chemoradiotherapy, is a viable organ-preserving alternative to radical surgery. We conducted a systematic review and meta-analysis to assess the clinical effectiveness of CXB in the treatment of rectal cancer. This systematic review was prospectively registered (CRD42021284969) and reported following PRISMA guidelines. Multiple electronic databases were interrogated using the search terms "Rectal cancer", "Contact Brachytherapy", and synonym terms. Clinical complete response (cCR) was the primary outcome. Proportional meta-analyses were conducted and presented as forest plots with summary proportions and 95 % confidence intervals. The literature search identified 973 studies, of which 52 studies encompassing 5447 patients met the inclusion and exclusion criteria and were included in the meta-analysis. Pooled estimates of outcomes were as follows: cCR rate = 82 % (95 % CI 76-88 %), Local Regrowth rate = 20 % (95 % CI 15-25 %), regional metastasis rate = 3 % (95 % CI 2-4 %), salvage surgery rate = 14 % (95 % CI 11-18 %), long-term disease control post-salvage surgery rate = 88 % (95 % CI 78-96 %) and organ preservation = 81 % (95 % CI 74-88 %). CXB in the appropriately selected patient population can achieve long-term disease control and organ preservation whilst avoiding major surgery. Salvage surgery remains a viable option for patients who experience disease regrowth with excellent long-term disease control. Clinicians should discuss CXB with rectal cancer patients, presenting it as a viable and safe alternative to radical surgery. This is particularly pertinent for patients who are stoma-averse or older patients in frail health.

A randomized phase II/III trial of rosuvastatin with neoadjuvant chemo-radiation in patients with locally advanced rectal cancer

Aim

Statins have been shown to improve the possibility of a pathological complete response (pCR) in patients with locally advanced rectal cancer when given in combination with neo-adjuvant chemo-radiation (NACTRT) in observational studies. The primary objective of this phase II randomized controlled trial (RCT) is to determine the impact of rosuvastatin in improving pCR rates in patients with locally advanced rectal cancer who are undergoing NACTRT. The secondary objectives are to compare adverse events, postoperative morbidity and mortality, disease-free survival (DFS), and overall survival in the two arms and to identify potential prognostic and predictive factors determining outcomes. If the study is positive, we plan to proceed to a phase III RCT with 3-year DFS as the primary endpoint.

Methods

This is a prospective, randomized, open-label phase II/III study. The phase II study has a sample size of 316 patients (158 in each arm) to be accrued over 3 years to have 288 evaluable patients. The standard arm will receive NACTRT while the intervention group will receive 20 mg rosuvastatin orally once daily along with NACTRT for 6 weeks followed by rosuvastatin alone for 6-10 weeks until surgery. All patients will be reviewed after repeat imaging by a multidisciplinary tumor board at 12-16 weeks after starting NACTRT and operable patients will be planned for surgery. The pathological response rate, tumor regression grade (TRG), and post-surgical complications will be recorded.

Conclusion

The addition of rosuvastatin to NACTRT may improve the oncological outcomes by increasing the likelihood of pCR in patients with locally advanced rectal cancer undergoing NACTRT. This would be a low-cost, low-risk intervention that could potentially lead to the refinement of strategies, such as "watch and wait", in a select subgroup of patients.

Clinical trial registration

Clinical Trials Registry of India, identifier CTRI/2018/11/016459.

No operation after short-course radiotherapy followed by consolidation chemotherapy in locally advanced rectal cancer (NOAHS-ARC): study protocol for a prospective, phase II trial

PURPOSE

Organ preservation through a watch-and-wait (W&W) strategy has become a viable option for select rectal cancer patients with clinical complete responses (cCR) to total neoadjuvant therapy (TNT). This approach limits the morbidity associated with multimodal treatment. However, the optimal treatment strategy and predictors of treatment response are still unresolved. Rectal cancer incidence is rising, particularly in developing countries, and the disease is a major public health concern in Chile. Prior to the no operation after short-course radiotherapy followed by consolidation chemotherapy in locally advanced rectal cancer (NOAHS-ARC) trial, TNT-based treatments and W&W programs had not been implemented in Chile.

METHODS/DESIGN

This single-arm, multicenter, phase II prospective trial, conducted in Santiago, Chile, will enroll patients with stage II/III rectal adenocarcinoma. Treatment involves induction short-course radiotherapy (25 Gy in 5 fractions) followed by consolidation chemotherapy (FOLFOX × 9 or CAPOX × 6 cycles). The response will be assessed 4-8 weeks after chemotherapy completion. Patients achieving cCR will be offered W&W, while those with incomplete responses will undergo total mesorectal excision. The primary endpoint is the rate of complete tumor response, combining pathologic complete responses (pCR) and sustained cCR (> 1 year), compared to a matched cohort treated with neoadjuvant chemoradiation alone. The trial aims to recruit 48 patients, assuming a combined pCR/sustained cCR rate of 12%. Quality of life measures will be assessed, and a biorepository of tissue and plasma samples will be established for future research, alongside serial endoscopic and MRI images.

DISCUSSION

NOAHS-ARC seeks to advance organ preservation strategies in rectal cancer while pioneering TNT and W&W protocols in Chile. The study will also focus on functional outcomes and provide valuable data for improving patient care both locally and globally.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT04864067. Registered on April 28, 2021.

Eastern Canadian Gastrointestinal Cancer Consensus Conference 2024

The Eastern Canadian Gastrointestinal Cancer Consensus Conference was an annual meeting that was held in St. John's, Newfoundland and Labrador, from 26 to 28 September 2024. This included experts in medical oncology, radiation oncology, surgical oncology, nuclear medicine, and general practitioners in oncology (GPO) from across the eastern Canadian provinces who are involved in the management of patients with gastrointestinal malignancies. This consensus statement generated by the conference addresses multiple topics, including the management of localized rectal cancer, liver-limited colorectal cancer, systemic therapy for advanced biliary tract cancers, radioligand therapy for gastroenteropancreatic neuroendocrine tumors (GEP-NETs), systemic therapy for pancreatic and midgut well-differentiated NETs, and systemic therapy for HER2-positive gastroesophageal cancers.

Complete pathological response to neoadjuvant chemoradiotherapy is associated with improved long-term survival after surgical treatment for rectal cancer

BACKGROUND

Tumor regression after neoadjuvant chemoradiotherapy can improve the long-term outcomes of rectal cancer. However, it is unclear how the tumor regression grade (TRG) relates to long-term outcomes. We evaluated how the TRG affects overall survival in patients with rectal cancer who underwent neoadjuvant chemoradiotherapy prior to radical surgery.

METHODS

All patients who underwent low anterior resection for rectal cancer after chemoradiotherapy over a 13-year period were included in this study. Perioperative and histopathological data of patients, including the TRG (categorized as no regression, minimal regression, moderate regression, near complete regression and complete regression) were evaluated. The correlation of TRG with overall survival was assessed using the log-rank test and Cox proportional hazards regression analysis.

RESULTS

During the study period,193 patients underwent low anterior rectal resection after neoadjuvant chemoradiotherapy. The 90-day mortality rate was 1.5 % and the median follow up was 69.5 months. The 5-year and 10-year overall survival rates were 85.0 % and 69.8 %, respectively. Patients with complete regression had a significantly higher 10-year overall survival rate than other patients (87.3 % vs. 66.5 %, p = 0.031). Multivariate analysis revealed that older age (hazard ratio [HR] = 2.4,95 % confidence interval [95 % CI] = 1.3-4.6, p = 0.007) and complete pathological response (HR = 0.23, 95 % CI = 0.06-0.96, p = 0.044) were independent predictors of overall survival.

CONCLUSION

Complete pathological response after neoadjuvant therapy for rectal cancer improves overall survival after surgery. Further studies are needed to determine the factors that predict complete TRG to identify patients who would benefit most from neoadjuvant chemoradiotherapy.

Total neoadjuvant treatment, non-operative management and radiotherapy-free strategies: New approaches for the management of proficient mismatch repair/microsatellite stable locally advanced rectal cancer. A narrative review and evidence-based algorithm

In recent years, new therapeutic approaches have emerged in addition to classical neoadjuvant (chemo)radiotherapy for the treatment of locally advanced rectal cancer (LARC): total neoadjuvant treatment, non-operative management, and radiotherapy-free strategy. While the introduction of these approaches in a relatively short timeframe has quickly increased our therapeutic armamentarium, on the other hand it has complicated the decision-making process regarding the choice of the most appropriate treatment strategy for each patient with LARC. Therefore, a tool to interpret the evidence from clinical trials and to translate them into daily practice is highly demanded. In the present review, we address how these new developments are changing the multimodal treatment of LARC and offer an algorithm to integrate them into clinical practice.