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.

[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.

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.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

Dose Escalation in Neoadjuvant Chemoradiotherapy for Rectal Cancer: Short-Term Efficacy and Toxicity of VMAT-SIB vs. 3D-CRT

Background and Objectives: The standard treatment for locally advanced rectal cancer (LARC) includes neoadjuvant chemoradiotherapy (nCRT), followed by surgery with or without adjuvant chemotherapy (CT). This study evaluated the efficacy and safety of dose-escalated radiotherapy (RT) using the volumetric modulated arc therapy-simultaneous integrated boost (VMAT-SIB) technique in patients with LARC compared to 3D conformal radiotherapy (3D-CRT). Materials and Methods: This study prospectively enrolled 75 patients with LARC. All patients received nCRT using VMAT-SIB, delivering a tumor dose (TD) of 54 Gy in 25 fractions, with concomitant CT following the 5-fluorouracil and leucovorin (5-FU-LV) protocol. To compare the treatment outcomes and toxicity associated with the increased RT dose, a retrospective cohort of 62 patients treated with the 3D-CRT technique was analyzed. The 3D-CRT group received a TD of 50.4 Gy in 28 fractions with the same CT. Outcomes, including pathological complete response (pCR), tumor regression grade (TRG), and sphincter preservation rates, were compared. Results: Among operated patients, the group treated with VMAT-SIB demonstrated improved rates of pCR (20.6% vs. 8.9%), with a statistically significant trend (p = 0.06). Sphincter-preserving surgeries were performed in 49 out of 63 operated patients (77.8%) in the VMAT-SIB group, compared to 35 out of 56 (62.5%) in the 3D-CRT group. Analysis of the definitive postoperative stage revealed a significantly higher prevalence of lower T categories (T0-2) (p < 0.01), negative N status (p < 0.05), and lower stages (I + II) (p < 0.05) in patients treated with the intensified RT approach. However, no significant differences in acute toxicity were observed. Conclusions: The implementation of intensified treatment with a higher dose using the VMAT-SIB technique demonstrated significant benefits in downsizing and downstaging compared to the standard treatment approach. These findings support its integration into clinical practice. However, further prospective, multi-center studies are needed to validate these results and assess long-term outcomes.

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.

Real-World Tolerability of Capecitabine and Oxaliplatin in Patients in the United States With Localized Colorectal Cancer Undergoing Curative-Intent Treatment

PURPOSE

The combination of capecitabine and oxaliplatin (CAPOX) is commonly used in patients with localized colorectal cancer (CRC) receiving curative-intent treatment. Our study aimed to assess the real-world tolerability of CAPOX in a single-institution cohort of patients with localized CRC.

METHODS

This is a single-institution retrospective study that included patients with localized CRC receiving neoadjuvant or adjuvant CAPOX. The primary end point was completion rate of intended number (obtained by chart review) of CAPOX cycles irrespective of dose levels. Secondary outcome measures included the rate of grade ≥3 adverse events, hospital admission rate, and dose reductions.

RESULTS

The study included 153 patients with a median age of 61 years; 49% were female and 78.4% had stage III CRC. The proportion of patients (95% CI) who completed all planned CAPOX cycles was 44.4% (36 to 52) in the entire cohort and 34.6% (23 to 45) among female patients. Independent variables associated with treatment completion in multivariable analysis were race, sex, and intended number of cycles. Notably, the therapy completion rates (95% CI) were 55% (43 to 66) and 33% (20 to 45) in patients intended to receive four and eight cycles of CAPOX, respectively. The rate of grade ≥3 adverse events and hospitalization because of CAPOX-related toxicity were 30.7% (95% CI, 23 to 38) and 17.6% (95% CI, 11 to 23), respectively.

CONCLUSION

This study highlights that a substantial number of patients with localized CRC undergoing curative-intent treatment with CAPOX do not complete the planned cycles of chemotherapy because of toxicity. These findings underscore the need for careful patient selection and appropriate supportive care to optimize the therapeutic benefit of CAPOX in this setting.

Integrating Tumor and Organoid DNA Methylation Profiles Reveals Robust Predictors of Chemotherapy Response in Rectal Cancer

Rectal cancer patients display heterogeneous responses to neoadjuvant treatment-including the intensive total neoadjuvant therapy (TNT)-and reliable biomarkers are lacking to guide which tumors will benefit most from these regimens. Here, we profiled DNA methylation in tumor tissue and matched patient-derived organoids (PDOs) from 18 rectal cancer cases (50 total samples), leveraging the Illumina MethylationEPIC array and quality control filters that retained 771,964 CpG sites. Analyses used linear models (for tissue-only or PDO-only) and a joint linear mixed-effects approach (accounting for patient-level random effects) to identify significant CpGs associated with log-transformed FOLFOX IC50. We found that PDOs faithfully recapitulate patient-tumor methylation patterns (Spearman's correlation >0.95 among replicate organoids), and the joint model uncovered 745 CpGs tied to FOLFOX sensitivity, many of which were missed in tissue-only analyses. Differentially methylated regions reinforced that broader epigenetic blocks near TSS or enhancer regions may modulate chemo-resistance, while pathway enrichment pinpointed focal adhesion, ECM-receptor interaction, calcium signaling, and folate metabolism as key processes. A methylation risk score derived from these CpGs significantly predicted progression-free survival in an independent colorectal cancer cohort (p=0.019), outperforming single-sample-based signatures. These findings suggest that combining methylation profiles from both tumors and PDOs can expose robust epigenetic drivers of therapy response, aiding the development of clinically actionable biomarkers for rectal cancer TNT.

Stoma versus no stoma prior to long-course neoadjuvant therapy in rectal cancer

BACKGROUND

Large bowel obstruction is a possible complication in patients undergoing neoadjuvant treatment for rectal cancer; however, it may be prevented by placing a pretreatment defunctioning stoma. The aim of this retrospective study was to investigate complication rates in patients with rectal cancer undergoing long-course neoadjuvant therapy, comparing those with and without a prophylactic stoma.

METHODS

All patients with rectal cancer undergoing neoadjuvant therapy between 2007 and 2022 in Region Västerbotten, Sweden, were identified using the Swedish Colorectal Cancer Registry. Patients not planned for curative long-course neoadjuvant therapy and those requiring a stoma due to urgent bowel-related issues before treatment were excluded. The primary outcome was the incidence of complications between diagnosis and resection surgery or end of follow-up. The secondary outcomes were 30-day complications following resection, time to treatment (neoadjuvant therapy and surgery), and overall survival. Multivariable regression analysis was used, with adjustment for age, sex, American Society of Anesthesiologists fitness grade, and clinical tumour stage.

RESULTS

Of 482 identified patients, 105 were analysed after exclusion. Among these, 22.9% (24 of 105) received a pretreatment stoma, whereas 77.1% (81 of 105) received upfront neoadjuvant therapy. The complication incidence before resection in the group with a defunctioning stoma and in the group without a defunctioning stoma was 75.0% (18 of 24) and 29.6% (24 of 81) respectively. A considerable number of complications were directly caused by the stoma surgery. Patients in the stoma group had an adjusted OR of 6.71 (95% c.i. 2.17 to 20.76) for any complication. However, for 30-day complications following resection, an adjusted non-significant OR of 2.05 (95% c.i. 0.62 to 6.81) was documented for the stoma group, in comparison with the control group. Neoadjuvant treatment was also delayed for the stoma group (adjusted mean time difference: 21 (95% c.i. 14 to 27) days), whereas the difference was not significant for the time to resection surgery. The median survival after diagnosis was 4.7 years in the stoma group and 12.2 years in the control group (P = 0.015); however, adjustment in the multivariable analysis rendered the estimate non-significant (HR 1.71 (95% c.i. 0.93 to 3.14)).

CONCLUSION

Patients with rectal cancer who receive a stoma before long-course neoadjuvant therapy, in the absence of urgent symptoms, experience more complications than those without a stoma and a delay with regard to the start of neoadjuvant treatment.

Cancer-associated fibroblasts in ovarian cancer: research progress

Ovarian cancer, known for its high invasiveness and therapeutic resistance, is one of the leading causes of death from gynecological tumors. The tumor microenvironment (TME) plays a crucial role in the development of ovarian cancer, with cancer-associated fibroblasts (CAFs) being a key non-tumor cell component. They significantly affect the prognosis of ovarian cancer by promoting tumor cell proliferation, invasion, metastasis, immune evasion, and drug resistance. The heterogeneity of CAFs provides a new perspective for targeted therapy in ovarian cancer. This review comprehensively analyzes the mechanisms of action, heterogeneity characteristics, and role in the immune microenvironment of CAFs in ovarian cancer, and discusses targeted therapy strategies for CAFs, aiming to provide new theoretical basis and treatment directions for the treatment of ovarian cancer.

Chemotherapy before or after preoperative chemoradiotherapy and surgery for locally advanced rectal cancer: 5-year results of the CAO/ARO/AIO-12 trial - a general pairwise comparison

BACKGROUND

Total neoadjuvant treatment (TNT) has been increasingly adopted for multimodal rectal cancer treatment. Here, we present the 5-year results of our CAO/ARO/AIO-12 randomized phase II trial that compared two TNT sequences.

PATIENTS AND METHODS

Patients were initially randomized 1 : 1 to arm A (induction chemotherapy followed by chemoradiotherapy) or arm B (chemoradiotherapy followed by consolidation chemotherapy) followed by total mesorectal excision surgery. This report on the 5-year results involved a general pairwise comparison (GPC) of the following parameters, ranked as indicated: overall survival, incidence of locoregional recurrence, incidence of distant metastasis, rate of pathological/clinical complete remission, long-term quality of life (at least 24 months after randomization) based on global health assessed by the European Organisation For Research And Treatment Of Cancer Quality of Life Questionnaire Core 30 questionnaire, and incidence of toxicity, ranked by grade, during follow-up.

RESULTS

A total of 306 patients were eligible for this analysis. After a median follow-up of 60 months (interquartile range 58-62 months), we found that long-term oncological outcome was comparable in both arms [e.g. 5-year overall survival 85.8% (95% confidence interval 80.2% to 91.8%) in arm A and 84.2% (95% confidence interval 78.2% to 90.5%) in arm B], regardless of whether patients received induction chemotherapy and chemoradiotherapy or chemoradiotherapy and consolidation chemotherapy. The GPC showed no clinically meaningful overall treatment benefit (-1.38%) or win ratio difference (0.97) between the two treatment sequences. The incidence of pathological or sustained clinical complete remission remained higher in patients treated with consolidation chemotherapy after adjusting for long-term outcome between both arms (11% versus 6.5%).

CONCLUSIONS

Our 5-year GPC confirmed the 3-year findings that chemoradiotherapy followed by consolidation chemotherapy resulted in higher rates of pathological complete remission without compromising oncological outcome, toxicity, or quality of life. The TNT sequence chemoradiotherapy/chemotherapy may be preferred for organ preservation strategies.

Rectal cancer - French intergroup clinical practice guidelines for diagnosis, treatment, and follow-up (TNCD, SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO, ACHBT, SFP, RENAPE, SNFCP, AFEF, SFR, and GRECCAR)

BACKGROUND

This article summarizes the French intergroup guidelines regarding rectal adenocarcinoma (RA) management published in September 2023, available on the French Society of Gastroenterology website.

METHODS

This work was supervised by French medical and surgical societies involved in RA management. Recommendations were rated from A to C according to the literature until September 2023.

RESULTS

Based on the pretreatment work-up, RA treatment was divided into four groups. T1N0 can be treated by endoscopic or surgical excision alone if there is no risk factor for lymph node involvement. For T2N0, radical surgery with total mesorectal excision is recommended, but rectal conservation is possible for small tumors (<4cm) after complete/subcomplete response following chemoradiotherapy. For T12N+ or T3+any N, total neoadjuvant treatment (TNT) followed by radical surgery is the gold standard, but rectal conservation is possible for small tumors after complete/subcomplete response following TNT. T3N2 or T+any N are an indication for TNT followed by radical surgery. Immunotherapy shows promise for dMMR/MSI RA. For metastatic tumors, recommendations are based on less robust evidence and chemotherapy plays a major role.

CONCLUSION

These guidelines aim at providing a personalized therapeutic strategy and are constantly being optimized. Each case should be discussed by a multidisciplinary team.

Comparison of prognosis for T4b rectal cancer with different pelvic compartment involvement treated using neoadjuvant chemoradiotherapy and implications for refinement of the current T staging system: A retrospective cohort study

PURPOSE

Although classified as one stage, T4b rectal cancer actually represents a group of heterogeneous diseases. Our study aimed to assess the prognosis difference of T4b rectal cancer involving inferior pelvic and other pelvic compartments. This information may be helpful in refinement of the current T staging system.

METHODS

We retrospectively analysed data from 195 patients with magnetic resonance imaging-identified locally advanced T4b rectal cancer who received neoadjuvant chemoradiotherapy between January 2010 and December 2019. 104 patients had only inferior pelvic compartment involvement (group A) while 91 patients had anterior, posterior or lateral pelvic compartment involvement (group B). Short-term and long-term outcomes were compared between the two groups.

RESULTS

After neoadjuvant therapy, 80.8 % patients (84/104) in group A and 92.3 % patients (84/91) in group B underwent surgery. The R0 resection rates were 97.6 % and 89.3 %, respectively. 8.7 % patients (9/104) in group A achieved clinical complete response and adopted watch-and-wait strategy. Patients in group A had significantly superior 5-year progression-free survival (PFS) (67.8 % vs. 55.5 %, P = 0.032) and overall survival (OS) (89.6 % vs. 71.8 %, P = 0.001) than group B. Multivariable Cox regression analysis also identified pelvic compartment involvement classification as an independent predictor of PFS (hazard ratio 1.776, P = 0.046) and OS (hazard ratio 3.477, P = 0.004).

CONCLUSION

T4b rectal cancers with involvement limited to the inferior pelvic compartment had superior prognosis compared to those involving other pelvic compartments. These differences should be investigated further and taken into consideration in refinement of the current T staging system.

Radiation Therapy for Rectal Cancer: An ASTRO Clinical Practice Guideline Focused Update

PURPOSE

With the results of several recently published clinical trials, this guideline focused update provides evidence-based recommendations for the indications and dose-fractionation regimens for neoadjuvant radiation therapy (RT), optimal sequencing of RT and systemic therapy in the context of total neoadjuvant therapy (TNT), and considerations for selective omission of RT and surgery for rectal cancer.

METHODS

The American Society for Radiation Oncology convened a multidisciplinary task force to update 3 key questions that focused on the role of RT for patients with operable rectal cancer. The key questions addressed (1) indications for neoadjuvant RT, (2) selection of neoadjuvant regimens, and (3) indications for consideration of a nonoperative management (NOM) or local excision approach after definitive/preoperative chemoradiation. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for quality of evidence grading and strength of recommendation.

RESULTS

For patients with stage II-III rectal cancer, neoadjuvant RT was strongly recommended; however, among patients deemed at lower risk of locoregional recurrence, consideration of omission of neoadjuvant RT was conditionally recommended in favor of neoadjuvant chemotherapy with a favorable treatment response or upfront surgery. For patients with T3-T4 and node-positive rectal cancer undergoing neoadjuvant RT, a TNT approach was strongly recommended. Among patients with higher risk of locoregional recurrence, TNT with chemotherapy before or after long-course chemoradiation was strongly recommended, whereas TNT with short-course RT followed by chemotherapy was conditionally recommended. For patients with rectal cancer for whom NOM is a priority, concurrent chemoradiation followed by consolidation chemotherapy was strongly recommended. Selection of RT dose-fractionation regimen, sequencing of therapies, and consideration of NOM should be determined by multidisciplinary consensus and based on disease extent, disease location, patient preferences, and quality of life considerations.

CONCLUSIONS

The task force proposed recommendations to inform best clinical practices on the use of RT for rectal cancer with strong emphasis on multidisciplinary care. Future studies should focus on further addressing optimal treatment regimens to allow for more personalized recommendations based on individual risk stratification and patient priorities regarding quality of life.

The Chinese Society of Clinical Oncology (CSCO): Clinical guidelines for the diagnosis and treatment of colorectal cancer, 2024 update

The 2024 updates of the Chinese Society of Clinical Oncology (CSCO) Clinical Guidelines for the diagnosis and treatment of colorectal cancer emphasize standardizing cancer treatment in China, highlighting the latest advancements in evidence-based medicine, healthcare resource access, and precision medicine in oncology. These updates address disparities in epidemiological trends, clinicopathological characteristics, tumor biology, treatment approaches, and drug selection for colorectal cancer patients across diverse regions and backgrounds. Key revisions include adjustments to evidence levels for intensive treatment strategies, updates to regimens for deficient mismatch repair (dMMR)/ microsatellite instability-high (MSI-H) patients, proficient mismatch repair (pMMR)/ microsatellite stability (MSS) patients who have failed standard therapies, and rectal cancer patients with low recurrence risk. Additionally, recommendations for digital rectal examination and DNA polymerase epsilon (POLE)/ DNA polymerase delta 1 (POLD1) gene mutation testing have been strengthened. The 2024 CSCO Guidelines are based on both Chinese and international clinical research, as well as expert consensus, ensuring their relevance and applicability in clinical practice, while maintaining a commitment to scientific rigor, impartiality, and timely updates.

Analysis of patients with locally advanced rectal cancer given neoadjuvant radiochemotherapy with or without RT dose intensification: A multicenter retrospective study - ATLANTIS part I

INTRODUCTION

Preoperative radiochemotherapy (RCHT) is the standard of care for locally advanced rectal cancer (LARC). While there are several data regarding chemotherapy intensification, actually, no reliable data directly comparing different radiotherapy (RT) dose levels are available. The present study aimed to compare intensified RT versus standard dose in patients with LARC.

MATERIALS AND METHODS

Data from 12 centers were collected for the current large retrospective study. The primary end-point evaluated whether RT dose intensification was associated with an increased pathological complete response (pCR). The secondary end-points explored the relation between RT dose and interval to surgery, downstaging, and RT-related toxicity. Subgroup analysis according to primary tumor stage was also performed.

RESULTS

1028 patients were analysed. All patients received combined RCHT with (364) or without (664) a RT boost. Patients underwent surgery after a median 10 weeks (IQ range 5-28). The overall pCR rate was 21.5 %. In the boost and no-boost groups, the pCR was 26.6 % (97) and 17 % (114) (p = 0.00), respectively. As a subgroup analysis, the pCR stratified by interval to surgery was 10 %, 23 %, 26.3 %, and 39.3 % (p < 0.000) in the boost group versus 10.6 %, 20.8 %, 19.3 %, and 20.4 % (p = 0.018) in the no-boost group. cT3 patients operated on ≥ week 11 and cT4 patients, regardless of time to surgery, received a significant benefit by the RT boost in terms of pCR rate. Patients in the boost group had a higher rate of grade ≥ 3 acute gastrointestinal toxicities (6 % vs. 1.7 %; p = 0.003).

CONCLUSION

Our results suggest that RT dose intensification (boost) in LARC might significantly increase the pCR rate, although with a small increase in acute toxicity. While pCR seems only partially improved by prolonged time to surgery in the no-boost group, a progressive and significant pCR improvement in patients treated with boost over time was observed. RT boost seems to be beneficial only in more advanced primary tumors.

Intensity-modulated radiation therapy can reduce acute toxicities in long-course neoadjuvant radiation therapy combined with S-1 for locally advanced rectal cancer

BACKGROUND

The purpose of this study was to compare outcomes and adverse events between three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) in patients undergoing long-course neoadjuvant radiation therapy (NA-RT) for locally advanced rectal adenocarcinoma (LARC).

METHODS

We retrospectively analyzed a total of 47 consecutive patients who received NA-RT for LARC between January 2011 and September 2022. Seven and 40 patients were diagnosed with clinical stages II and III, respectively. The prescribed dose per fraction was 1.8 Gy for total doses of 45 or 50.4 Gy. Seventeen and 30 patients received 3D-CRT and IMRT, respectively. NA-RT was delivered with concurrent chemotherapy of oral administration of S-1.

RESULTS

Planned NA-RT was completed without any treatment interruption in 43 of the 47 patients. Two patients experienced treatment interruption, and two patients discontinued due to grade ≥ 3 toxicities. No significant differences were observed between patients receiving 3D-CRT and IMRT in local control, progression-free survival, and overall survival (P = 0.488, 0.259, and 0.636, respectively). Patients receiving IMRT showed significantly fewer non-hematological grade ≥ 2 acute toxicities than those receiving 3D-CRT (33.3% vs. 70.6%, P = 0.018). In addition, patients who received IMRT tended to have less intestinal toxicity of grade ≥ 2 than those who received 3D-CRT (P = 0.057).

CONCLUSION

IMRT significantly reduced grade ≥ 2 acute toxicities without compromising oncologic outcomes compared to 3D-CRT. Therefore, IMRT may be considered as a current standard treatment in the total neoadjuvant therapy era.

Impact of MRI risk assessment on the survival benefits of neoadjuvant chemoradiotherapy in patients with stage II-III rectal cancer: A retrospective cohort study

PURPOSE

To investigate whether MRI risk factors can be used to predict clinical outcomes and whether MRI risk assessment can be used to select stage II-III rectal cancer patients who may benefit from neoadjuvant chemoradiotherapy (nCRT).

METHODS AND MATERIALS

A total of 947 rectal cancer patients who underwent total mesorectal excision (TME) were retrospectively recruited. An MRI scoring system was established using the cumulative score of three risk factors (mesorectal fascia involvement, extramural venous invasion, and tumour deposits). Patients with mrT3c-T4 stage, N2 stage, or any risk factors were considered MRI high-risk cases of rectal cancer. Cox regression analysis was used to identify independent risk factors for overall survival (OS) and disease-free survival (DFS). Kaplan-Meier curves were generated to show the benefits of nCRT after propensity score matching (PSM).

RESULTS

OS and DFS were more favourable in the MRI low-risk group than in the MRI high-risk group, and the MRI scoring system facilitated prognostic stratification in stage II-III rectal cancer patients. NCRT significantly improved 3-year OS (89.1 % versus 78.8 %, p = 0.001) and 3-year DFS (73.4 % versus 68.0 %, p = 0.030) in the MRI high-risk group. After PSM, OS and DFS were improved in the MRI high-risk group with an MRI score of 1 (OS: HR = 0.432 [95 % CI: 0.214-0.871], p = 0.019; DFS: HR = 0.477 [95 % CI: 0.275-0.825], p = 0.008) and an MRI score of 2 (OS: HR = 0.276 [95 % CI: 0.130-0.586], p = 0.001; DFS: HR = 0.358 [95 % CI: 0.182-0.705], p = 0.003), whereas MRI low-risk patients did not obtain any survival benefit from nCRT.

CONCLUSIONS

MRI-defined high-risk patients with MRI scores of 1 or 2 may benefit from nCRT. Baseline MRI should be given more consideration in nCRT decision-making.

Phase 2, Multicenter, Open-label, Nonrandomized Study of Neoadjuvant Chemotherapy Liposomal Irinotecan With 5-Fluorouracil, Leucovorin, and Oxaliplatin, Followed by Chemoradiotherapy in Patients With Rectal Cancer in a Watch-and-Wait Program

OBJECTIVE

To evaluate the efficacy of neoadjuvant chemotherapy combination with liposomal irinotecan, 5-fluorouracil, leucovorin, and oxaliplatin in patients with locally advanced rectal cancer.

METHODS

This was a phase 2, nonrandomized, multicenter study in adults with stage II or III rectal cancer and an Eastern Cooperative Oncology Group performance status of 0 to 1. Total neoadjuvant therapy (TNT) consisted of neoadjuvant chemotherapy combination with liposomal irinotecan (60 mg/m 2 ), oxaliplatin (60 mg/m 2 ), leucovorin (400 mg/m 2 ), and fluorouracil (2400 mg/m²), followed by chemoradiotherapy [ie, capecitabine (825 mg/m 2 ) and radiotherapy according to the standard of care]. The primary efficacy endpoint was the proportion of patients who achieved clinical complete response (cCR), defined as the normalization of pelvic magnetic resonance imaging, rectoscopy, computed tomography scan, and tumor markers.

RESULTS

The median follow-up was 32.3 months. Of the 30 patients who underwent TNT and were evaluated, 6 (20.0%; 95% CI: 5.2%-34.8%) patients achieved a cCR. There were no deaths. The median disease-free survival (DFS) for patients with cCR was not reached after a follow-up of 32 months; the 1-year DFS rate was 90.0% (95% CI: 71.0%-100%), and the 2-year and 3-year DFS rates were 80.0% (95% CI: 55.0%-100%). No grade ≥4 adverse events (AEs) were observed. Grade 3 AEs occurred in 18 patients (60%), most frequent was diarrhea (n = 9, 30%). Eleven (36.7%) patients experienced serious AEs, with diarrhea being the most frequent (n = 6, 20.0%).

CONCLUSION

TNT with 5-fluorouracil, leucovorin, and oxaliplatin and chemoradiation is a safe and effective therapeutic alternative for the management of locally advanced rectal cancer.

Long-Term Outcomes in Patients With Locally Advanced Rectal Cancer Following R1 Resection After Either Induction Chemotherapy and Chemoradiotherapy or Chemoradiotherapy Alone

INTRODUCTION

Total neoadjuvant treatment (TNT) with induction chemotherapy (ICT) followed by chemoradiotherapy (CRT) has improved long-term outcomes for patients with locally advanced rectal cancer (LARC). However, long-term outcomes have not been investigated for patients with incomplete (R1) resection separately. This study investigates overall survival (OS), disease-free survival (DFS) and local and distant recurrence rates in patients with R1 resection after preoperative treatment with ICT and CRT or CRT.

PATIENTS AND METHODS

From the NORD database 689 patients with LARC who received treatment between 2006 and 2017 were screened for inclusion. All patients with R1 resection were included. ICT consisted of at least 1 cycle of capecitabine and oxaliplatin (CAPOX) and was followed by radiotherapy concomitant with capecitabine.

RESULTS

Among 46 patients with R1 resection, 27 (59%) received both ICT and CRT, and 19 (41%) patients received CRT. The 5-year OS was 44% (95% CI, 26%-63%) (ICT + CRT) versus 37% (95% CI, 15%-59%) (CRT) (P = .25) and 5-year DFS was 44% (95% CI, 26%-63%) (ICT + CRT) versus 32% (95% CI, 11%-53%) (CRT) (P = .22). The local recurrence rates showed a small nonstatistical significant difference in local control in the ICT group: 15% compared to 26% in the CRT group (P = .22). Distant recurrence rates were similar: 41% (ICT + CRT) versus 47% (CRT) (P = .48).

CONCLUSION

There was no significant difference in OS, DFS or local and distant recurrence rates between patients who received ICT + CRT versus patients who received CRT only.

Modern rectal cancer management: A review of total neoadjuvant therapy and current practices

Total Neoadjuvant Therapy (TNT) is a promising strategy for treating locally advanced rectal cancer (LARC) and has started to replace the traditional neoadjuvant chemoradiotherapy (CRT). This review combines findings from pivotal studies that helped TNT to integrate into clinical practice. It emphasizes the efficacy of TNT in improving the disease-free and metastasis-free survival, pathologic complete response and, according to recent studies, a potential improvement in overall survival when compared to standard CRT. In addition, the review analyzes increased organ preservation by TNT and explores the trend towards personalized medicine with the use of TNT. Additionally, it investigates the possibility of excluding radiotherapy in some subgroups. Future directions include integration of immunotherapy, use of TNT in early-stage disease and determining optimal components of TNT, such as type of chemotherapy and type of radiotherapy.