Optimal fractionation of preoperative radiotherapy and timing to surgery for rectal cancer (Stockholm III): a multicentre, randomised, non-blinded, phase 3, non-inferiority trial

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.

Machine Learning for Predicting Postoperative Functional Disability and Mortality Among Older Patients With Cancer: Retrospective Cohort Study

Background

The global cancer burden is rapidly increasing, with 20 million new cases estimated in 2022. The world population aged ≥65 years is also increasing, projected to reach 15.9% by 2050, making cancer control for older patients urgent. Surgical resection is important for cancer treatment; however, predicting postoperative disability and mortality in older patients is crucial for surgical decision-making, considering the quality of life and care burden. Currently, no model directly predicts postoperative functional disability in this population.

Objective

We aimed to develop and validate machine-learning models to predict postoperative functional disability (≥5-point decrease in the Barthel Index) or in-hospital death in patients with cancer aged ≥ 65 years.

Methods

This retrospective cohort study included patients aged ≥65 years who underwent surgery for major cancers (lung, stomach, colorectal, liver, pancreatic, breast, or prostate cancer) between April 2016 and March 2023 in 70 Japanese hospitals across 6 regional groups. One group was randomly selected for external validation, while the remaining 5 groups were randomly divided into training (70%) and internal validation (30%) sets. Predictor variables were selected from 37 routinely available preoperative factors through electronic medical records (age, sex, income, comorbidities, laboratory values, and vital signs) using crude odds ratios (P<.1) and the least absolute shrinkage and selection operator method. We developed 6 machine-learning models, including category boosting (CatBoost), extreme gradient boosting (XGBoost), logistic regression, neural networks, random forest, and support vector machine. Model predictive performance was evaluated using the area under the receiver operating characteristic curve (AUC) with 95% CI. We used the Shapley additive explanations (SHAP) method to evaluate contribution to the predictive performance for each predictor variable.

Results

This study included 33,355 patients in the training, 14,294 in the internal validation, and 6711 in the external validation sets. In the training set, 1406/33,355 (4.2%) patients experienced worse discharge. A total of 24 predictor variables were selected for the final models. CatBoost and XGBoost achieved the largest AUCs among the 6 models: 0.81 (95% CI 0.80-0.82) and 0.81 (95% CI 0.80-0.82), respectively. In the top 15 influential factors based on the mean absolute SHAP value, both models shared the same 14 factors such as dementia, age ≥85 years, and gastrointestinal cancer. The CatBoost model showed the largest AUCs in both internal (0.77, 95% CI 0.75-0.79) and external validation (0.72, 95% CI 0.68-0.75).

Conclusions

The CatBoost model demonstrated good performance in predicting postoperative outcomes for older patients with cancer using routinely available preoperative factors. The robustness of these findings was supported by the identical top influential factors between the CatBoost and XGBoost models. This model could support surgical decision-making while considering postoperative quality of life and care burden, with potential for implementation through electronic health records.

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.

Truly Inevitable-Our Perspective on the Complications After Surgery for Rectal Cancer

Rectal cancer is one of the most common malignancies in the GI tract. Although recent technology and treatments are available today, complications are still there. The focus of this study is to draw attention towards the important complications and their management options in rectal cancer surgeries. Retrospective study of 57 patients diagnosed and operated with rectal cancer between 2012 and 2022 using questionnaire data. 21.05% developed complications following surgery for rectal cancer including SSI, LARS, anastomosis leak, and stomal stenosis. LARS was seen in 26.31% out of the 19 patients involved in the study (LAR + ULAR) of which 80% had minor LARS scores and 20% had major LARS scores. In LARS, 80% had received long-term chemoradiotherapy in a neoadjuvant setting. The study revealed a rising trend of rectal cancer in young individuals (35.08%). Complications are an inevitable part of rectal cancer surgery even with recent technology. Use of long-course radiotherapy in neoadjuvant settings and LAR and ULAR may improve sphincter preservation with the risk of increasing incidence of low anterior resection syndrome, and anastomosis leak should be used cautiously with proper patient selection.

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.

Matched Cohort Analysis of Ultra-hypofractionated Versus Standard Fractionation Preoperative Radiation Therapy for Soft Tissue Sarcoma

OBJECTIVE

This study compares toxicity and oncologic outcomes in a matched cohort of soft tissue sarcoma (STS) patients receiving ultra-hypofractionated preoperative radiation therapy (RT) or standard fractionated RT.

METHODS

This IRB-approved study included patients with STS of the extremity, pelvis, or trunk treated with preoperative RT followed by surgical resection. Patients received either standard RT or ultra-hypofractionated RT (≥30 Gy over 5 fractions) between 2016 and 2023 with intensity-modulated RT at a single institution. Ultra-hypofractionated RT patients proceeded to surgical resection 0 to 7 days after RT and standard fractionated RT group 4 to 6 weeks after completion. The cohorts were matched based on tumor location and type of surgical closure. An inverse propensity weighting (IPW) method was used to balance group covariates.

RESULTS

A total of 74 patients were included in this study. 37 patients treated with ultra-hypofractionated RT were matched with 37 patients treated with standard fractionation RT. Median follow-up time was 21.00 [IQR 11.00, 45.00] months for ultra-hypofractionated RT and 29.00 [IQR 13.00, 43.00] months for standard fractionated RT (P=0.58). Rates of major wound complications (MWC) were 44.4% ultra-hypofractionated RT versus 29.7% standard RT (P=0.289). On logistic regression, MWC (OR 1.9, 95% CI 0.97-3.76, P=0.06) and wound dehiscence (OR 3.91, 95% CI 1.81-8.73, P=0.0006) were more common in the ultra-hypofractionated RT group. Clinically significant late toxicity (grade ≥2 fibrosis, joint stiffness, or edema) did not differ significantly. There was no difference in local control (P=1.00) or distant metastases (P=0.465).

CONCLUSIONS

Ultra-hypofractionated RT for STS results in excellent disease control. To reduce the risk of MWC, we have adopted delayed surgical resection for ultra-hypofractionated RT patients of 4 to 6 weeks.

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.

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.

The Landmark Series: Neoadjuvant Radiotherapy in Extremity Soft Tissue Sarcoma-The Way to Hypofractionation

For patients with nonmetastatic soft tissue sarcoma (STS) who are at high risk of local recurrence, the standard of care for limb-conserving local management is combined radiotherapy and surgery. Radiotherapy for STS entails 5 weeks of conventionally fractionated radiotherapy (25 × 2 Gy) preoperatively or 6 or more weeks postoperatively. There is growing interest in the use of preoperative hypofractionated regimes, viz. shorter courses with higher daily doses, for STS. Recent studies have investigated ultrahypofractionation (UHF, ≥ 5 Gy per fraction) and moderate hypofractionation (MHF, > 2 Gy but < 5 Gy per fraction) for STS. Regimens that are designed to be isoeffective for tumor control indeed result in equivalent local relapse-free survival. However, as the daily dose increases, the impacts to normal tissues and potential for toxicities increase owing to differences in fraction-size sensitivity between STS and normal tissues (e.g., skin, subcutaneous tissue, vascular structures, and bone). This article reviews the key studies informing the debate about hypofractionation for STS. We evaluate the current data that reveal relatively small patient cohorts, short follow-up time, and inconsistent toxicity reporting. A randomized, controlled investigation of conventional fractionation, MHF, and UHF is needed. The current phase 2 data confirm that any such study should have co-primary endpoints of both local relapse-free survival as well as immediate- and long-term toxicities because the fundamental question being investigated with significant increase in daily fraction size while maintaining isoeffective total dose (~ 50 Gy equivalent) is: what are the dose impacts to late-responding normal tissues that may result in decrements to physical functioning for patients?

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.

Short-Course TNT Improves Rectal Tumor Downstaging in a Retrospective Study of the US Rectal Cancer Consortium

BACKGROUND AND OBJECTIVES

The RAPIDO trial showed promising rates of pathologic complete response (pCR) after neoadjuvant short-course radiation with consolidation chemotherapy (total neoadjuvant therapy [SC TNT]) for rectal cancer. Only single-center reviews comparing tumor downstaging between SC TNT and long-course chemoradiation (LCRT) have been published in the United States. We reviewed our multi-institutional experience with both.

METHODS

The US Rectal Cancer Consortium database (2007-2018) including data from six high-volume rectal cancer care centers was reviewed. Patients with nonmetastatic, rectal adenocarcinoma who had neoadjuvant LCRT alone or SC TNT before excision or definitive nonoperative management were included. The primary outcome was the rate of complete response (CR), including pCR or durable (12 month) clinical complete response.

RESULTS

Of 857 included patients, 175 (20%) received SC TNT and 682 (80%) received LCRT. The LCRT group had more low tumors (51.8% vs. 37.1%, p < 0.0001) and more clinically node-negative disease (31.8% vs. 22.3%, p < 0.0001). The CR rate was higher after SC TNT (34.1% vs. 20.3%, p = 0.0001). SC TNT was a predictor of CR (OR: 2.52, CI: 1.68-3.78). SC TNT patients completing 5-6 months of consolidation chemotherapy had a CR rate of 42.9%. There was no difference in 3-year PFS.

CONCLUSIONS

SC TNT increases CR rate when compared to LCRT. For patients seeking nonoperative options or fewer radiation treatments, SC TRT should be preferred over LCRT alone.

Bibliometric analysis of preoperative radiotherapy for locally advanced rectal cancer: evolution and future

Background

Preoperative radiotherapy of rectal cancer has been a hot topic of research in recent years with the introduction of total neoadjuvant therapies and immunotherapeutic agents. We utilized bibliometrics and visualization analysis to examine studies in this field, aiming to identify current hotspots and research trends.

Method

We searched the Web of Science database for all publications related to preoperative radiotherapy of rectal cancer in the past 10 years. Using bibliometric analysis software, such as VOSviewer, CiteSpace and R-studio, we extracted and analyzed the data, summarizing the publication output of countries, institutions, authors, and journals in this field, and analyzing their relationships. We also summarized the keywords, burst words, and most cited articles, and analyzed the relationships among them.

Results

We found 794 publications in the field, sourced from 217 journals or books, involving 5,805 authors from various organizations and countries. Through bibliometric analysis, we observed a growing trend in the number of publications in preoperative radiotherapy of rectal cancer over the past 10 years. China, United States and Italy were the top countries in terms of publication output. Sun Yat-sen University, Fujian University, and Fudan University were the top three medical centers in terms of publication output, while Leiden University from Netherlands led globally in terms of citation impact. Professor Zhen Zhang, Sanjun Cai, and Ji Zhu were the top three authors with the highest publication output. The most highly cited journals in this field includes "The Lancet Oncology," "J Clinical Oncology," and "Annals of Oncology." Journals such as "Radiotherapy and Oncology," "Frontiers in Oncology," and "BMC Cancer" have the highest number of articles published. Based on the analysis of keywords and burst words, we found that "preoperative chemoradiation" and "oral capecitabine" were the research hotspots before 2016, while the focus shifted to "short-course radiotherapy" and "long-term outcomes" after 2017. Currently, the most frequently cited publications mainly summarize multicenter clinical studies and total neoadjuvant treatment models and immunotherapy.

Conclusion

Research on preoperative radiotherapy of rectal cancer is increasing year by year, and attracting attention from high-cited journals such as "The Lancet Oncology," "JCO," and "Annals of Oncology." Based on current data, the total neoadjuvant treatment models and radiation combined with immunotherapy are the research trends.

Selection of rectal cancer patients for organ preservation after neoadjuvant therapy: value of T2W-MRI signal intensity

BackgroundOrgan preservation strategies have been widely implemented for rectal cancer (RC) patients with a good response after neoadjuvant chemoradiation (nCRT). However, to accurately select eligible patients remains one of the key diagnostic challenges.PurposeTo identify eligible candidates for organ preservation after nCRT in RC, by identifying luminal response and lymph node metastases, based on T2W-MRI signal intensities.Material and MethodsA total of 171 RC patients underwent MRI before and after nCRT. The primary tumor (pre-nCRT-MRI) and tumor remnant (post-nCRT-MRI) were manually delineated. Ten signal intensity features were extracted and delta features were calculated by subtraction. Histopathological evaluation classified patients as lymph node negative (ypN0) or positive (ypN+), and as good responders (GR) or partial/poor responders (PR). Five models were constructed based on the timing of imaging.Results42/170 (25%) patients had ypN+, and 72/152 (47%) patients were considered GR. Univariate analysis showed 13/40 signal intensity features were significantly different between luminal response groups and 4/40 between nodal response groups. In multivariate analysis, the Baseline + Restaging-model yielded the best results for both luminal and nodal response with AUCs in the test set of 0.81 (95% CI=0.67-0.95) and 0.74 (95% CI=0.59-0.90), respectively. To identify PR, the Delta-model yielded an AUC of 0.72 (95% CI=0.56-0.89) and the Delta + Restaging-model an AUC of 0.81 (95% CI=0.67-0.95), both were not able to differentiate nodal response. The models including solely baseline or restaging features were not predictive.ConclusionT2W-MRI signal intensities of the primary rectal tumor are related to the luminal and nodal response after nCRT and hold promise to identify patients eligible for organ preservation.

Prognostic Value of Pretreatment Carcinoembryonic Antigen (CEA) in Rectal Cancer Treated with Preoperative Short-Course Radiotherapy with Delayed Surgery or Long-Course Radiotherapy

Purpose

To investigate the prognostic value of the pretreatment serum carcinoembryonic antigen (CEA) level in patients with rectal cancer treated by preoperative short-course radiotherapy (SCRT) followed by chemotherapy and delayed surgery.

Patients and Methods

Two hundred and sixty-six consecutive patients with locally advanced rectal adenocarcinoma without distant metastasis receiving preoperative radiotherapy were enrolled. Group 1 patients (n=144) received long-course radiotherapy (LCRT) with 50.4 Gy in 28 fractions using photon radiotherapy (XRT). Group 2 patients (n=122) received SCRT with 25 Gy in 5 fractions using XRT or proton beam therapy (PBT) followed by chemotherapy and delayed surgery. Pathological complete response (pCR), near pathological complete response (npCR), locoregional recurrence (LRR), distant metastasis (DM), disease-specific survival (DSS) and overall survival (OS) rates were estimated and compared to scrutinize the prognostic significance of factors including CEA level.

Results

In group 1, higher CEA level (≥ 7 ng/mL) was a significant negative prognostic factor of pCR (p = 0.003, OR: 0.133), OS (p = 0.011, HR: 2.999), DM (p = 0.008, HR: 2.569), LRR (p = 0.044, HR: 3.160), and DSS (p = 0.015, HR: 3.273). In group 2, higher CEA level (≥ 7 ng/mL) was a significant negative prognostic factor of pCR (p = 0.002, OR: 0.038), OS (p < 0.001, HR: 44.658), DM (p < 0.001, HR: 8.926), LRR (p = 0.028, HR: 8.570), and DSS (p = 0.001, HR: 43.918). The npCR rates for clinical T4 patients were 6.5% and 22.0% (p = 0.032), in group 1 and group 2, respectively.

Conclusion

This study elucidates the prognostic merit of the pretreatment serum CEA level in patients with rectal cancer treated by either preoperative LCRT or SCRT followed by chemotherapy and delayed surgery.

Longitudinal circulating tumor DNA monitoring in predicting response to short-course radiotherapy followed by neoadjuvant chemotherapy and camrelizumab in locally advanced rectal cancer: data from a Phase Ⅲ clinical trial (UNION)

This study, conducted as part of a multicenter phase III clinical trial, aimed to assess the utility of circulating tumor DNA (ctDNA)-based minimal residual disease (MRD) in comparing the efficacy of short-course and long-course chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC). A total of 244 plasma samples from 79 LARC patients undergoing neoadjuvant therapy (NAT) before surgery were collected at various time points. Targeted deep sequencing using a novel MRD panel was performed. During NAT, ctDNA levels declined significantly. Baseline ctDNA-MRD status did not correlate significantly with treatment response. Notably, compared to long-course radiotherapy, microsatellite instability increased significantly after short-course radiotherapy (shortRT). Additionally, ctDNA negativity or lower levels were significantly associated with pathological complete response (pCR). Clearance of ctDNA and MRD after shortRT correlated significantly with pCR. A predictive model based on ctDNA-MRD, combined with carcinoembryonic antigen (CEA), outperformed models using only MRD or only CEA in predicting pCR/non-pCR. These findings provide insights into NAT for LARC and highlight ctDNA-based MRD assessment's potential in tailoring treatment strategies, emphasizing the need for personalized approaches.

Sciatic Nerve Preservation in Robot-Assisted Surgery for Initially Unresectable Primary Rectal Cancer: A Case Report

Radical surgery for rectal cancer with bulky lateral pelvic lymph node (LPLN) metastasis involving the sciatic nerve presents both technical and oncological challenges. Preoperative multidisciplinary treatments have recently been anticipated to control the disease as well as to preserve organ function. A 51-year-old man, presenting with right buttock pain and impairment of walking, was diagnosed with sciatic nerve impairment due to right LPLN metastasis from rectal cancer. He was initially treated with palliative radiotherapy followed by FOLFOX plus bevacizumab. After 13 cycles of the chemotherapy, his symptoms disappeared and the LPLN shrank. Then, conversion surgery via robot-assisted low anterior resection with right LPLN dissection was performed. Although he had moderate right leg pain postoperatively, there were no motor deficits or other complications. Pathological examination of the specimen revealed microscopic residual disease at the resection margin, but he is currently surviving recurrence-free for 1.5 years. Preoperative multidisciplinary treatment enabled the preservation of the sciatic nerve in the robot-assisted conversion surgery.

Circ_0006174 Upregulates IGF1R to Enhance Radioresistance and Tumorigenesis in Colorectal Cancer via miR-940 Suppression

Colorectal cancer (CRC) is one of the most common malignancies all over the world. Increasing evidence has revealed that circular RNAs (circRNAs) are involved in the progression of CRC. In this study, we aimed to investigate the role and underlying mechanism of circ_0006174 in the development and radiosensitivity of CRC. Circ_0006174, microRNA-940 (miR-940), and insulin-like growth factor 1 receptor (IGF1R) expression levels were evaluated by real-time quantitative polymerase chain reaction (RT-qPCR). The radiosensitivity of cells also was assessed using colony formation assay. Besides, cell proliferation, apoptosis, migration, and invasion were detected by cell counting kit-8 (CCK-8), flow cytometry, and transwell assays. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were performed to verify the relationship between miR-940 and circ_0006174 or IGF1R. IGF1R protein level was examined using western blot. A xenograft tumor model was used to verify the function of circ_0006174 in CRC tumor growth in vivo. Circ_0006174 and IGF1R levels were elevated and miR-940 expression was decreased in CRC tissues and cells. Circ_0006174 knockdown enhanced the radiosensitivity of CRC cells by regulating cell proliferation, apoptosis, migration, and invasion in vitro. In mechanism, circ_0006174 served as a sponge for miR-940 to upregulate IGF1R expression. Moreover, circ_0006174 silencing suppressed CRC growth in vivo. Circ_0006174 boosts radioresistance of CRC cells at least partly through upregulating IGF1R expression by sponging miR-940, providing a novel theoretical basis for CRC therapy.

Total neoadjuvant therapy based on short-course radiotherapy versus standard long-course chemoradiotherapy for locally advanced rectal cancer: a systematic review and meta-analysis of randomized controlled trials

Background

We conducted the meta-analysis to compare the therapeutic effects of total neoadjuvant therapy (TNT) based on short-course radiotherapy followed by consolidation chemotherapy (SCRT/CCT) and long-course chemoradiotherapy (LCCRT) for locally advanced rectal cancer (LARC) according to certain significant randomized controlled trials (RCTs).

Methods

The researchers retrieved several databases, including PubMed, Embase, Web of Science, and the Cochrane Library, to collect all the relevant literature published since the establishment of the databases until July 30, 2024, and then screened to determine the qualified literature and extracted the relevant information. Finally, RevMan 5.4 software was utilized to conduct the meta-analysis for determining the 95% confidence interval (CI) and pooled risk ratio (RR). There were 9 study indicators, including the pathologic complete remission (pCR) rate, tumor downstaging rate, R0 resection rate, sphincter preservation rate, disease-free survival (DFS), overall survival (OS), acute ≥3 grade toxicity rate, surgery complication rate, and distant recurrence rate. When moderate, even severe, heterogeneity was found, a random-effect model was applied; otherwise, a fixed-effect model was used for the analysis.

Results

A total of 6 eligible RCTs and 2259 participants were included in this meta-analysis. Compared with the standard LCCRT, TNT treatment on the basis of SCRT/CCT increased the pCR rate significantly [RR = 1.67, 95% CI (1.36, 2.04), P < 0.00001], especially in ≥ 4 cycles of the CCT arm [RR = 1.77, 95% CI: (1.41-2.23), p < 0.00001], and led to a similar tumor downstaging rate [RR = 0.99, 95% CI (0.85, 1.15), P = 0.92]. Moreover, survival outcomes, distant recurrence rate, and surgical indicators were comparable between the two groups.

Conclusion

For LARC patients, the SCRT/CCT regimen not only has a higher pCR rate, equivalent OS, and comparable additional indicators versus standard LCCRT but also shortens the treatment time, costs less, and improves patients' adherence to the innovative anti-tumor therapy; hence, with the concept of acute toxicity control, it could be further widely and safely utilized, especially in resource-limited settings.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42024600180.

Localized Rectal Cancer: Indian Consensus and Guidelines

The rising incidence of colorectal cancer (CRC) in India, particularly the prevalence of rectal cancer over colon cancer (0.7:1), has been a growing concern in recent decades; especially notable is the trend of increasing cases among young CRC patients. Given the diverse treatment approaches for rectal cancer globally and the varying economic capacities of patients in low to middle-income countries (LMICs) like India, it is essential to establish consensus guidelines that are specifically tailored to meet the needs of these patients. To achieve this, a panel comprising 30 eminent rectal cancer experts convened to conduct a comprehensive and impartial evaluation of existing practices and recent advancements in the field. Through meticulous scrutiny of published literature and a consensus-building process that involved voting on pertinent questions, the panel formulated management strategies. These recommendations are the result of a rigorous, evidence-based process and encapsulate the collective wisdom and judgment of leading authorities in the field.

Is hypofractionated radiotherapy used to treat soft tissue sarcomas? Assessment of practices using the NETSARC network

PURPOSE

Extremity soft-tissue sarcomas are treated by wide surgical resection with normofractionated radiotherapy. Over the past 3years, several phase II trials emerged on perioperative hypofractionated radiotherapy. We aimed to review the current practice in France and Luxembourg of hypofractionated radiotherapy as curative treatment for extremity soft-tissue sarcomas.

MATERIALS AND METHODS

We sent an electronic adaptive survey to sarcoma radiation oncologists at 28 centres in France and the Grand Duchy of Luxembourg belonging to the NETSARC network. The questionnaire was distributed via the NETSARC mailing list in December 2021 and January 2022. It consisted of four to nine questions with closed multiple choice, or open-ended (short or long) answers. Some questions assessed agreement with proposals for pre- or postoperative hypofractionated radiotherapy for extremity soft-tissue sarcomas.

RESULTS

Of the 28 radiation oncologists surveyed, 11 (39.2 %) from nine centres responded. Of these, 55 % used hypofractionated radiotherapy, mainly for elderly and frail patients. The main reason why hypofractionated radiotherapy was not used was the lack of scientific evidence and therapeutic habits.

CONCLUSION

Hypofractionated radiotherapy for extremity soft-tissue sarcomas remains to be investigated in high-powered studies but could be offered in the future for well-selected patients by a multidisciplinary board in a sarcoma referral centre.

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

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

Long-term outcomes and prognostic factors of short-course radiotherapy (SCRT) in rectal cancer: a monocentric retrospective study

PURPOSE

To evaluate efficacy and tolerance of short-course radiotherapy (SCRT) prior to possible chemotherapy (CHT) and surgery in 64 patients with locally advanced rectal cancer, in terms of acute and early late toxicity and survival outcomes with prognostic factors.

METHODS

Sixty-four patients affected by rectal tumor were treated from 2008 to 2023 radiation therapy, with a total dose of 25 Gy in 5 fractions. The Kaplan-Meier method was used to estimate the rates of overall survival (OS), cancer specific survival (CSS), local control (LC), disease free survival (DFS) and metastasis free survival (MFS). Univariate analysis for prognostic factors was performed with the log-rank test, and Cox proportional hazards regression was used to estimate hazard ratios. Toxicity assessment has been considered in acute and in early late for gastrointestinal (GI), genitourinary (GU) districts.

RESULTS

Median follow-up was 49.6 months. The median OS was 65 months with 1-year, 2-year and 5-year OS at 90.6%, 77.7% and 60% respectively. CSS at the 1-year, 2-year and 5-year was 98.3%, 96.2% and 86.2% respectively. LC at 1-year, 2-year and 5-year was 93.4%, 89.4% and 87.2% respectively. DFS at the 1-year, 2-year and 5-year was 93.4%, 89% and 87% respectively. The status of lymph nodes at diagnosis was a prognostic factor in term of LC and DFS. Acute GI toxicity was G1 in 10 (15.6%) patients. Five (7.8%) patients had a G1 acute GU toxicity. Fifteen (23.4%) patients developed chronic GI toxicities.

CONCLUSIONS

SCRT is an effective treatment in patients with rectal cancer and provides good outcomes with very low rates of toxicity profile.

Organ preservation after neoadjuvant long-course chemoradiotherapy versus short-course radiotherapy

BACKGROUND

Potential differences in organ preservation between total neoadjuvant therapy (TNT) regimens integrating long-course chemoradiotherapy (LCCRT) and short-course radiotherapy (SCRT) in rectal cancer remain undefined.

PATIENTS AND METHODS

This natural experiment arose from a policy change in response to the COVID-19 pandemic during which our institution switched from uniformly treating patients with LCCRT to mandating that all patients be treated with SCRT. Our study includes 323 locally advanced rectal adenocarcinoma patients treated with LCCRT-based or SCRT-based TNT from January 2018 to January 2021. Patients who achieved clinical complete response were offered organ preservation with watch-and-wait (WW) management. The primary outcome was 2-year organ preservation. Additional outcomes included local regrowth, distant recurrence, disease-free survival (DFS), and overall survival (OS).

RESULTS

Patient and tumor characteristics were similar between LCCRT (n = 247) and SCRT (n = 76) cohorts. Median follow-up was 31 months. Similar clinical complete response rates were observed following LCCRT and SCRT (44.5% versus 43.4%). Two-year organ preservation was 40% [95% confidence interval (CI) 34% to 46%] and 31% (95% CI 22% to 44%) among all patients treated with LCCRT and SCRT, respectively. In patients managed with WW, LCCRT resulted in higher 2-year organ preservation (89% LCCRT, 95% CI 83% to 95% versus 70% SCRT, 95% CI 55% to 90%; P = 0.005) and lower 2-year local regrowth (19% LCCRT, 95% CI 11% to 26% versus 36% SCRT, 95% CI 16% to 52%; P = 0.072) compared with SCRT. The 2-year distant recurrence (10% versus 6%), DFS (90% versus 90%), and OS (99% versus 100%) were similar between WW patients treated with LCCRT and SCRT, respectively.

CONCLUSIONS

While WW eligibility was similar between cohorts, WW patients treated with LCCRT had higher 2-year organ preservation and lower local regrowth than those treated with SCRT, yet similar DFS and OS. These data support induction LCCRT followed by consolidation chemotherapy as the preferred TNT regimen for patients with locally advanced rectal cancer pursuing organ preservation.

Single pre-operative radiation therapy (SPORT-CK) trial for low-risk breast cancer: Early results of a phase 2 study

BACKGROUND AND PURPOSE

Preoperative partial breast irradiation (PBI) is a novel technique that can be used in patients with early-stage breast cancer with the goal of limiting the irradiated breast volume, toxicity and number of fractions. The aim of this trial is to assess the toxicity, surgical, oncologic and cosmetic outcomes of preoperative PBI.

MATERIALS AND METHODS

In this single-arm phase II trial, we enrolled women ≥ 60 years, with unifocal low-risk breast invasive ductal carcinoma (cT1N0, grade 1-2, ER+, Her2-). Patients were treated with a single fraction of 20 Gy of preoperative PBI using volumetric modulated arc therapy (VMAT). Patients then underwent breast-conserving surgery (BCS) +/- sentinel lymph node biopsy within 72 h of radiation. Primary outcomes were rate of surgical complications and early toxicity. Secondary outcomes were cosmesis at 12 months, chronic toxicity and ipsilateral breast tumor recurrence.

RESULTS

Twenty-five patients were recruited with a median age of 67 years, and a median follow-up of 60 months. Sentinel biopsy was positive in 1 out of 24 patients (4 %). Two patients received adjuvant RT for close margins or positive lymph nodes. Within the first 90 days, none of the patients had surgical complications; almost all had grade 0 to 1 acute and late RTOG skin toxicity. The cosmetic outcome was rated between good and excellent in all cases by physicians and patients, except for one patient who self-rated her cosmesis as fair as of the third year. There were no recurrences.

CONCLUSION

Preoperative single-fraction PBI is a safe and feasible treatment for elderly patients with low-risk early-stage breast cancer, with no surgical complications, very low rates of acute and late radiation toxicity, and excellent cosmetic outcomes. Randomized controlled trials are needed to compare preoperative to adjuvant PBI in this patient population.

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

BACKGROUND

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

METHODS

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

DISCUSSION

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

TRIAL REGISTRATION

This study was registered at www.

CLINICALTRIALS

gov .

TRIAL REGISTRATION NUMBER

NCT05972655. Date of registration: 31 July 2023.

Tailoring treatment for locally advanced rectal cancer

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

The impact of short-course total neoadjuvant therapy, long-course chemoradiotherapy, and upfront surgery on the technical difficulty of total mesorectal excision: an observational study with an intraoperative perspective

PURPOSE

Total neoadjuvant therapy (TNT) is becoming the standard of care for locally advanced rectal cancer. However, surgery is deferred for months after completion, which may lead to fibrosis and increased surgical difficulty. The aim of this study was to assess whether TNT (TNT-RAPIDO) is associated with increased difficulty of total mesorectal excision (TME) compared with long-course chemoradiotherapy (LCRT) and upfront surgery.

METHODS

Twelve laparoscopic videos of low anterior resection with TME for rectal cancer were prospectively collected from January 2020 to October 2021, with 4 videos in each arm. Seven colorectal surgeons assessed the videos independently, graded the difficulty of TME using a visual analog scale and attempted to identify which category the videos belonged to.

RESULTS

The median age was 67 years, and 10 patients were male. The median interval to surgery from radiotherapy was 13 weeks in the LCRT group and 24 weeks in the TNT-RAPIDO group. There was no significant difference in the visual analog scale for difficulty in TME between the 3 groups (LCRT, 3.2; TNT-RAPIDO, 4.6; upfront, 4.1; P=0.12). A subgroup analysis showed similar difficulty between groups (LCRT 3.2 vs. TNT-RAPIDO 4.6, P=0.05; TNT-RAPIDO 4.6 vs. upfront 4.1, P=0.54). During video assessments, surgeons correctly identified the prior treatment modality in 42% of the cases. TNT-RAPIDO videos had the highest recognition rate (71%), significantly outperforming both LCRT (29%) and upfront surgery (25%, P=0.01).

CONCLUSION

TNT does not appear to increase the surgical difficulty of TME.

Neoadjuvant Treatment in Rectal Cancer

A major advance in rectal cancer was the evidence supporting short-course radiotherapy and long-course chemoradiotherapy. Both have been shown to improve local outcomes. Total neoadjuvant therapy (TNT) is the new kid on the block that provides further benefit of improving local responses as well as reducing systemic relapses, thus increasing overall survival. Details of the four key TNT trials are discussed. They pave the way for nonoperative management for patients who achieve clinical complete responses.

Neoadjuvant short-course radiotherapy followed by camrelizumab and chemotherapy in locally advanced rectal cancer (UNION): early outcomes of a multicenter randomized phase III trial

BACKGROUND

Neoadjuvant short-course radiotherapy (SCRT) followed by CAPOX and camrelizumab (a programmed cell death protein 1 monoclonal antibody) has shown potential clinical activity for locally advanced rectal cancer (LARC) in a phase II trial. This study aimed to further confirm the efficacy and safety of SCRT followed by CAPOX and camrelizumab compared to long-course chemoradiotherapy (LCRT) followed by CAPOX alone as neoadjuvant treatment for LARC.

PATIENTS AND METHODS

In this randomized, phase III trial, patients with T3-4/N+ rectal adenocarcinoma were randomly assigned (1 : 1) to receive SCRT or long-course chemoradiotherapy (LCRT), followed by two cycles of camrelizumab and CAPOX or CAPOX alone, respectively. After surgery, each arm underwent either six cycles of camrelizumab and CAPOX, followed by up to 17 doses of camrelizumab, or six cycles of CAPOX. The primary endpoint was pathological complete response (pCR) rate (ypT0N0) assessed by a blinded independent review committee. Key secondary endpoints tested hierarchically were 3-year event-free survival (EFS) rate and overall survival (OS).

RESULTS

Between July 2021 and March 2023, the intention-to-treat population comprised 113 patients in the experimental arm and 118 patients in the control arm, with surgery carried out in 92% and 83.9%, respectively. At data cut-off (11 July 2023), the pCR rates were 39.8% [95% confidence interval (CI) 30.7% to 49.5%] in the experimental arm compared to 15.3% (95% CI 9.3% to 23.0%) in the control arm (difference, 24.6%; odds ratio, 3.7; 95% CI 2.0-6.9; P < 0.001). In each arm, surgical complication rates were 40.0% and 40.8%, and grade ≥3 treatment-related adverse events were 29.2% and 27.2%. Three-year EFS rate and OS continue to mature.

CONCLUSIONS

In LARC patients, neoadjuvant SCRT followed by camrelizumab plus CAPOX demonstrated a significantly higher pCR rate than LCRT followed by CAPOX, with a well-tolerated safety profile. SCRT followed by camrelizumab and chemotherapy can be recommended as a neoadjuvant treatment modality for these patients.

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

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

The risk for rectal cancer recurrence and overall mortality is not increased in men previously diagnosed with prostate cancer: a report from the Swedish colorectal cancer registry

INTRODUCTION

Limited data exists on oncological outcomes following rectal cancer surgery in men who have previously been diagnosed with prostate cancer (PC). This study aimed to assess overall mortality and rectal cancer recurrence in men previously diagnosed with PC who underwent bowel resection.

METHODS

Data from the Swedish Colorectal Cancer Registry identified men who had rectal cancer surgery between 2000 and 2016, and the National Prostate Cancer Registry was used to identify those with a prior PC diagnosis. Cox regression analysis with propensity score matching was employed for data analysis. The primary outcome was overall mortality. Secondary outcome was recurrence for rectal cancer.

RESULTS

Out of 13,299 men undergoing bowel resection for rectal cancer between 2000 and 2016, 1130 had a history of PC. Overall mortality did not significantly differ between men with and without a prior PC diagnosis. Cox regression analyses with propensity score matching revealed that men with previously diagnosed low- or intermediate-risk (HR, 0.79; 95% CI, 0.70-0.90) and high-risk PC (HR, 0.85; 95% CI, 0.74-0.98) had lower overall mortality after rectal cancer surgery compared with men without a PC. There was no significant difference in rectal cancer recurrence between men with a previous low or intermediate-risk PC (HR, 0.92; 95% CI, 0.74-1.14) or high-risk PC (HR, 0.73; 95% CI, 0.52-1.01) compared with those without PC history.

CONCLUSION

Men undergoing rectal cancer surgery with a previous diagnosis of prostate cancer do not experience an increased risk of rectal cancer recurrence or overall mortality compared with men without a previous history of prostate cancer.

Meta-Analysis of 5-Fraction Preoperative Radiotherapy for Soft Tissue Sarcoma

OBJECTIVES

Studies investigating preoperative 5-fraction radiation therapy (RT) for soft tissue sarcoma (STS) are limited. We performed a meta-analysis to determine the efficacy and safety of this treatment paradigm.

METHODS

This study-level meta-analysis was conducted using Bayesian methods. Statistical estimation for risk of outcome rates was conducted by posterior mean and 95% highest posterior density (HPD) intervals. Studies with 2-year local control (LC) and description of major wound complications (MWC) per the CAN-NCIC-SR2 study were included and served as the primary endpoints. Secondary endpoints included rates of acute and late toxicity. A total of 10 studies were identified and 7 met the inclusion criteria. Subgroup analyses were performed for ≥30 Gy vs <30 Gy.

RESULTS

A total of 209 patients from 7 studies were included. Five studies used ≥30 Gy (n=144), and 2 studies <30 Gy (n=64). Median follow-up was 29 months (range: 21 to 57 mo). Primary tumor location was lower extremity in 68% and upper extremity in 22%. Most tumors were intermediate or high grade (95%, 160/169), and 50% (79/158) were >10 cm. The two-year LC for the entire cohort was 96.9%, and the rate of MWC was 30.6%. There was a trend toward improved LC with ≥ 30 Gy (95% HPD: 0.95 to 0.99 vs 0.84 to 0.99). There was no difference in MWC (95% HPD: 0.18 to 0.42 vs 0.17 to 0.55) or late toxicity between the groups.

CONCLUSIONS

Preoperative 5-fraction RT for STS demonstrates excellent 2-year LC with MWC and toxicity similar to standard fractionation preoperative RT. Multi-institutional trials with a universal RT protocol are warranted.

Oncological risks associated with the planned watch-and-wait strategy using total neoadjuvant treatment for rectal cancer: A narrative review

Overall survival benefit of total neoadjuvant treatment (TNT) remains unconfirmed. Thus, in our opinion, the main rationale for using TNT is a planned watch-and-wait (w&w) strategy to improve patients' long-term quality of life through organ preservation. The OPRA randomized trial, which examined a planned w&w strategy using TNT, showed a higher organ preservation rate but also a higher regrowth rate compared to studies on the opportunistic w&w strategy. Higher rates of complete clinical response with TNT did not improve disease-free survival compared to historical controls. Therefore, the gain in organ-sparing capability might not be balanced by the increased oncological risk. The ultimate local failure rate in the intention-to-treat analysis of the OPRA trial was 13% for induction chemotherapy and 16% for consolidation chemotherapy, which seems higher than expected compared to 8% in a meta-analysis of w&w studies or 12% after TNT and surgery in the PRODIGE-23 and RAPIDO trials, which enrolled patients with more advanced cancers than the OPRA trial. Other studies also suggest worse local control when surgery is delayed for radio-chemoresistant cancers. Our review questions the safety of the planned w&w strategy using TNT in unselected patients. To reduce the oncological risk while maintaining high organ preservation rates, we suggest that the planned w&w strategy using TNT requires a two-tier patient selection process: before treatment and after tumor response assessment at the midpoint of consolidation chemotherapy. These robust selections should identify patients who are unlikely to achieve organ preservation with TNT and would be better managed by preoperative chemoradiotherapy (without consolidation chemotherapy) and surgery, or by discontinuing consolidation chemotherapy and proceeding directly to surgery.

A Review of Neoadjuvant Therapy and the Watch-and-Wait Protocol in Rectal Cancer: Current Evidence and Future Directions

The treatment of rectal cancer underwent a significant change with the introduction of total mesorectal excision (TME), which substantially improved recurrence rates. However, TME is associated with complications such as fecal incontinence and poor bladder control, especially in tumors located near the anal verge. The watch-and-wait (WW) protocol has emerged as an alternative for patients achieving a clinical complete response (cCR) following neoadjuvant radiochemotherapy. This narrative review, developed according to the Scale for the Assessment of Narrative Review Articles guidelines, evaluates neoadjuvant treatments and the WW protocol for rectal cancer. Literature was sourced from the PubMed database using specific search terms related to neoadjuvant therapy and the WW protocol, resulting in 63 articles selected for discussion. Neoadjuvant treatment, including chemoradiation and short-course radiotherapy, is indicated for T3 and T4 rectal adenocarcinomas. Studies like the German Rectal Cancer Study Group and the PRODIGE 23 trial have shown the benefits of preoperative treatment, including improved disease-free survival and reduced local recurrence rates. However, challenges in adopting the WW protocol include the risk of local regrowth and distant metastasis. Immune checkpoint inhibitors have shown promise in mismatch repair-deficient patients, yet the data are insufficient to fully endorse WW for these cases. The WW protocol is viable for selected rectal cancer patients, with ongoing debates regarding criteria for inclusion. Key challenges include accurately identifying cCR and managing patients with near-complete responses. MRI and endoscopic evaluation are crucial for assessing treatment response, although achieving a pathological complete response remains uncertain. The WW strategy offers a potential organ-preserving approach in rectal cancer management but requires careful patient selection and comprehensive risk-benefit discussions. Further research is needed to refine criteria for inclusion and optimize treatment protocols, enhancing outcomes while minimizing invasive interventions.

Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer: How to Select the Most Suitable?

Rectal cancer shows specific characteristics in terms of pattern of recurrence, which occurs commonly at both local and distant sites. The standard of care for locally advanced rectal cancer (LARC) including neoadjuvant chemoradiotherapy, followed by surgery based on the total mesorectal excision principles leads to a reduction in the rates of local recurrences to 6-7% at 5 years. However, the outcomes among those with high-risk lesions remain unsatisfactory. On the contrary, neoadjuvant chemoradiotherapy results in long-term morbidities among those with low-risk lesions. Furthermore, the overall survival benefit of neoadjuvant therapy is still a subject to be debated, except for patients with complete or near-complete response to neoadjuvant therapy. Total neoadjuvant therapy (TNT) is a new paradigm of management of high-risk rectal cancer that includes early administration of the most effective systemic therapy either before or after neoadjuvant radiotherapy with or without chemotherapy prior to surgery with or without adjuvant chemotherapy. TNT potentially improves disease-free survival, even though whether it can prolong survival has been debatable. Recently, neoadjuvant chemotherapy only has been proved to be non-inferior to neoadjuvant chemoradiotherapy in patients with low-risk lesions. This review intends to review the current evidences of neoadjuvant therapy and propose a more customized paradigm of management of LARC.

Journey through the Decades: The Evolution in Treatment and Shared Decision Making for Locally Advanced Rectal Cancer

The management of locally advanced rectal cancer has undergone significant transformations over the decades and optimal treatment approaches continue to evolve. There have been numerous advances in surgery, chemotherapy, and radiation therapy from the first description of the abdominoperineal resection in 1908, timing of chemotherapy and radiation therapy in the late 20th and early 21st century, and most recently, the introduction of organ preservation or nonoperative management in 2004. Alongside these advancements, the concept of shared decision making in medicine has evolved, prompting a focus on patient-centered care. This evolution in practice has been fueled by a growing recognition of the importance of patient autonomy and the alignment of treatment options with patients' values and preferences. With the growing number of possible treatment options, variability in patient counseling exists, highlighting the need for a standardized approach to shared decision making in locally advanced rectal cancer. This narrative review will describe the evolution of treatment options of locally advanced rectal cancer as well as the concept of shared decision making and decision aids, and will introduce a decision aid for patients with locally advanced rectal cancer who have achieved a complete clinical response and are eligible for watch and wait.

Clinical Analysis of the Efficacy and Safety of Different Neoadjuvant Strategies in the Treatment of Locally Advanced Rectal Cancer

OBJECTIVE

In this study, we retrospectively analysed the efficacy and safety of three treatment models, namely, short-course radiotherapy sequential XELOX chemotherapy, neoadjuvant mFOLFOX6 concurrent radiotherapy and long-course concurrent radiotherapy with total mesorectal excision (TME) after treatment of locally advanced rectal cancer with high-risk factors.

METHODS

We collected clinical data on 177 patients with locally advanced rectal cancer (cT3-4 and/or cN+) who were treated at the Department of Abdominal Oncology of the Affiliated Cancer Hospital of Guizhou Medical University from December 2017 to December 2022. All patients were associated with 2-3 risk factors [T4b, N2, Extramural Vascular Invasion (EMVI), Mesorectal Fascia (MRF) positivity], positive lateral lymph nodes. Among them, there were 45 cases in the short course radiotherapy sequential XELOX chemotherapy group (RT + XELOX group); 64 cases in the neoadjuvant mFOLFOX6 concurrent radiotherapy group (mFOLFOX6 + CRT group); and 68 cases in the long course concurrent radiotherapy group (CRT group). The RT + XELOX group and mFOLFOX6 + CRT group completed radiotherapy and 4 cycles of neoadjuvant chemotherapy, respectively, and then rested for 1-2 weeks before TME surgery; the CRT group completed concurrent radiotherapy and then rested for 6-8 weeks before TME surgery.Adjuvant chemotherapy was conducted after surgery in each of the three groups: 2 cycles of adjuvant chemotherapy with XELOX regimen in the RT + XELOX group, 4-6 cycles of adjuvant chemotherapy with mFOLFOX6 in the mFOLFOX6 + CRT group, and 8-12 cycles of adjuvant chemotherapy with mFOLFOX6 in the CRT group.The pathological complete response rate (pCR rate), tumour downstage rate, tumour complete resection rate (R0 resection rate), local recurrence rate, distant metastasis rate, overall survival rate, incidence of adverse reactions, surgical complications and completion rate of perioperative systemic chemotherapy were compared among patients in the three groups of cases after TME.

RESULTS

The pCR rate (21.95% vs 17.24% vs 5.00%, p = 0.034) and and tumour downstage rate (78.05% vs 68.97% vs 53.33%, p = 0.029) were higher in the RT + XELOX group and mFOLFOX6 + CRT group compared to the CRT group. The RT + XELOX group had a lower 3-year distant metastasis rate (14.63% vs 36.67%, p = 0.048) and improved 3-year overall survival (76.57% vs 48.56%, p < 0.001) compared to the CRT group. There was no significant reduction in the 3-year distant metastasis rate in the mFOLFOX6 + CRT group versus the CRT group (27.59% vs 36.67%, p = 0.719), and the 3-year overall survival was similar (51.23% vs 48.56%, p = 0.35). Multi-logistic regression analysis and stratified analysis showed that patients in the RT + XELOX group and mFOLFOX6 + CRT group were more likely to achieve pCR than the CRT group (RT + XELOX group: OR 7.3, 95% CI [2.6-20.8], p < 0.001; mFOLFOX6 + CRT group OR 2.9, 95% CI [1.1-7.9], p = 0.036). The completion rates of perioperative systemic chemotherapy in the RT + XELOX, mFOLFOX6 + CRT, and CRT groups were 82.93% vs. 84.48% vs. 61.67% (χ2=9.95, p = 0.007), respectively. And there were significant differences in grade 3-4 leukopenia and thrombocytopenia (incidence of leukopenia: 15.50% vs. 7.81% vs. 1.47%, p = 0.045; incidence of thrombocytopenia: 13.33% vs 7.81% vs 1.47%, p = 0.027). There was no significant difference in the incidence of intraoperative and postoperative complications among the three groups (p > 0.05).

CONCLUSIONS

RT + XELOX group and mFOLFOX6 + CRT group significantly improved the near-term outcome (e.g., pCR rate) in patients with locally advanced rectal cancer with high-risk factors compared with CRT group. The RT + XELOX group also reduced the 3-year distant metastasis rate, increased the 3-year overall survival rate, and did not increase the incidence of perioperative surgical complications. It provides an effective means for the comprehensive treatment of locally advanced rectal cancer and has important clinical guidance and application value.

Cytological Analysis of the Surgical Field During Transanal Total Mesorectal Excision for Rectal Cancer: A Prospective Study

BACKGROUND

An unexpectedly large number of patients experienced local recurrence with transanal total mesorectal excision in Norway. This appears to be associated with cancer cell spillage during surgery.

OBJECTIVE

To investigate the surgical field cytology during transanal total mesorectal excision.

DESIGN

This was a prospective cohort study.

SETTINGS

This study was conducted at a single center between June and December 2020.

PATIENTS

Forty patients with rectal cancer underwent transanal total mesorectal excision. After irrigation of the surgical field, the water specimens were cytologically evaluated at 6 representative steps. The first sample was used as an initial control. The second, third, fourth, fifth, and sixth samples were collected after the first pursestring suture, rectotomy, the second pursestring suture, specimen resection, and anastomosis, respectively. The clinicopathological features and intraoperative complications of the patients were reviewed.

MAIN OUTCOME MEASURES

The primary outcome was to evaluate the presence of cancer cells in washing cytological samples.

RESULTS

Of the 40 consecutive patients enrolled in this study, 18 patients underwent neoadjuvant chemoradiotherapy. Incomplete first pursestring suture and rectal perforation were observed in 4 (10.0%) and 3 (7.5%) cases, respectively. In the first sample, 31 patients (77.5%) had malignant cells. Malignant findings were detected in 2 patients (5.0%) from the second to fifth samples. None of the sixth sample exhibited any malignant findings.

LIMITATIONS

This single-center study had a small sample size.

CONCLUSIONS

Cancer cells were initially detected by cytology, but only a few were observed throughout the procedure; however, cancer cells were not detected in the final surgical field. Further follow-up and novel studies are required to obtain clinically significant findings using cytology during transanal total mesorectal excision. See Video Abstract .

ANLISIS CITOLGICO DEL CAMPO QUIRRGICO DURANTE LA ESCISIN TOTAL DEL MESORRECTO TRANSANAL PARA EL CNCER DE RECTO UN ESTUDIO PROSPECTIVO

ANTECEDENTES:Un número inesperadamente grande de pacientes experimentó recurrencia local con la escisión total del mesorrecto transanal en Noruega. Esto parece estar asociado con el derrame de células cancerosas durante la cirugía.OBJETIVO:Investigar la citología del campo quirúrgico durante la escisión total del mesorrecto transanal.DISEÑO:Este fue un estudio de cohorte prospectivo.ENTORNO CLINICO:Este estudio se realizó en un solo centro entre junio y diciembre de 2020.PACIENTES:Cuarenta pacientes con cáncer de recto se sometieron a escisión total del mesorrecto transanal. Después de la irrigación del campo quirúrgico, las muestras de agua se evaluaron citológicamente en seis pasos representativos. La primera muestra se utilizó como control inicial. La segunda, tercera, cuarta, quinta y sexta muestras se recolectaron después de la primera sutura en bolsa de tabaco, la rectotomía, la segunda sutura en bolsa de tabaco, la resección de la muestra y la anastomosis, respectivamente. Se revisaron las características clínico-patológicas y las complicaciones intraoperatorias de los pacientes.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue evaluar la presencia de células cancerosas en el lavado de muestras citológicas.RESULTADOS:De los 40 pacientes consecutivos inscritos en este estudio, 18 pacientes se sometieron a quimiorradioterapia neoadyuvante. Se observaron la primera sutura en bolsa de tabaco incompleta y perforación rectal en cuatro (10,0%) y tres (7,5%) casos, respectivamente. En la primera muestra, 31 (77,5%) pacientes tenían células malignas. Se detectaron hallazgos malignos en dos pacientes (5,0%) de la segunda a la quinta muestra. Ninguno de la sexta muestra demostraron hallazgos malignos.LIMITACIONES:Este estudio unicéntrico tuvo un tamaño de muestra pequeño.CONCLUSIONES:Inicialmente se detectaron células cancerosas mediante citología, pero solo se observaron unas pocas durante todo el procedimiento; sin embargo, no se detectaron células cancerosas en el campo quirúrgico final. Se requieren más seguimientos y estudios novedosos para obtener hallazgos clínicamente significativos mediante citología durante la escisión total del mesorrecto transanal. (Traducción- Dr. Francisco M. Abarca-Rendon ).

Short-term outcomes of short- and long-course chemoradiotherapy before total mesorectal excision for locally advanced rectal tumors: A single-center study in Taiwan utilizing propensity score matching

BACKGROUND

Locally advanced rectal tumors are typically treated with neoadjuvant chemoradiotherapy. Short-course chemoradiotherapy (SCRT, 2500 cGy in five fractions) is a convenient alternative to concurrent chemoradiotherapy with long-course radiotherapy (CCRT, 4500 cGy in 25 fractions) without sacrificing efficacy. We aimed to compare the short-term outcomes of SCRT and CCRT in patients with mid- and low- rectal tumors who underwent total mesorectal excision using real-world data.

METHODS

We retrospectively reviewed the data of patients with locally advanced rectal cancer who underwent radical resection after neoadjuvant chemoradiotherapy from 2011 to 2022. We analyzed the clinicopathological findings and prognostic factors for disease-free and overall survival in the SCRT and CCRT groups and compared the outcomes using propensity score matching.

RESULTS

Among the 66 patients in the two groups, no disparities were noted in the demographic features, pathological remission, or downstaging rates. Nonetheless, the SCRT group exhibited superior 3-year disease-free survival (81.8% vs 62.1%, p = 0.011), whereas the overall survival did not differ significantly between the two groups. The initial carcinoembryonic antigen (CEA) levels and neoadjuvant SCRT were associated with the recurrence rates [hazard ratio (HR) = 1.13-4.10; HR = 0.19-0.74], but the harvested lymph node count was not (HR = 0.51-1.97).

CONCLUSION

Among patients with locally advanced rectal cancer, SCRT combined with four cycles of FOLFOX was shown to enhance short-term disease-free survival. Factors impacting recurrence include the initial CEA level and SCRT, but not the harvested lymph node count.

Current State of Neoadjuvant Therapy for Locally Advanced Rectal Cancer

ABSTRACT

In locally advanced rectal cancer, neoadjuvant treatment has evolved from no preoperative treatment to the addition of radiation and systemic therapy and ultimately total neoadjuvant therapy. Total neoadjuvant therapy is the completion of preoperative radiation or chemoradiation and chemotherapy before surgery in order to maximize tumor response and improve survival outcomes. This review summarizes the literature of the neoadjuvant approaches related to locally advanced rectal cancer and highlights the nuances of selecting the appropriate treatment.

Modern Multidisciplinary Management of Soft Tissue Sarcoma of the Extremity and Trunk

Soft tissue sarcomas (STS) of the extremity and trunk are heterogeneous and rare tumors that require coordinated multidisciplinary management. Surgical resection remains the backbone of treatment for localized tumors, with the addition of radiotherapy to surgery to achieve high rates of local control. Despite this, overall survival is limited because of significant distant metastatic risk and a lack of efficacious systemic therapies. Clinical trials have produced conflicting results on the impact of systemic therapy in the neoadjuvant and adjuvant settings for patients with localized disease, leaving systemic treatment decisions largely guided by shared decision making and prognostic prediction tools such as nomograms. This article will review the foundational data as well as latest developments in surgical, radiotherapy, and systemic management supporting current practice guidelines for localized STS of the extremity and trunk.

Radiotherapy for Rectal Cancer: How Much is Enough?

Though resection has been the mainstay of treatment for nonmetastatic rectal cancer over the past century, radiation has become an increasingly integral component of care for locally advanced disease. Today, two predominant radiotherapy approaches-hyperfractionated chemoradiotherapy and "short-course" radiation-are widely utilized to reduce local recurrence and, in some cases, cure disease. Both have been incorporated into total neoadjuvant therapy (TNT) regimens and achieved excellent local control and superior complete response rates compared to chemoradiation alone. Additionally, initial results of "watch and wait" protocols utilizing either radiation modality have been promising. Yet, differences do exist; though short course is cheaper and more convenient for patients, recently published data may show superior complete response and local recurrence rates with chemoradiation. Ultimately, direct comparisons of short-course radiotherapy against chemoradiation within the TNT framework are needed to identify optimal radiation regimens in the treatment of locally advanced rectal cancer.

Nonoperative Management for Rectal Cancer

ABSTRACT

The treatment paradigm for rectal cancer has been shifting toward de-escalated approaches to preserve patient quality of life. Historically, the standard treatment in the United States for locally advanced rectal cancer has standardly comprised preoperative chemoradiotherapy coupled with total mesorectal excision. Recent data challenge this "one-size-fits-all" strategy, supporting the possibility of omitting surgery for certain patients who achieve a clinical complete response to neoadjuvant therapy. Consequently, patients and their physicians must navigate diverse neoadjuvant options, often in the context of pursuing organ preservation. Total neoadjuvant therapy, involving the administration of all chemotherapy and radiation before total mesorectal excision, is associated with the highest rates of clinical complete response. However, questions persist regarding the optimal sequencing of radiation and chemotherapy and the choice between short-course and long-course radiation. Additionally, meticulous response assessment and surveillance are critical for selecting patients for nonoperative management without compromising the excellent cure rates associated with trimodality therapy. As nonoperative management becomes increasingly recognized as a standard-of-care treatment option for patients with rectal cancer, ongoing research in patient selection and monitoring as well as patient-reported outcomes is critical to guide personalized rectal cancer management within a patient-centered framework.

Circulating tumor DNA in patients with locally advanced rectal cancer treated with multimodal treatment

Background

The management of locally advanced rectal cancer (LARC) relies on a multimodal approach. Neither instrumental work-up nor molecular biomarkers are currently available to identify a risk-adapted strategy.

Objectives

We aim to investigate the role of circulating tumor DNA (ctDNA) and its clearance at different timepoints during chemo-radiotherapy (CRT) and correlate them with clinical outcomes.

Design

Between November 2014 and November 2019, we conducted a monocentric prospective observational study enrolling consecutive patients with LARC managed with neoadjuvant standard CRT (capecitabine and concomitant pelvic long-course radiotherapy), followed by consolidation capecitabine in selected cases and surgery.

Methods

Blood samples for ctDNA were obtained at pre-planned timepoints. We evaluated the correlation of baseline variant allele frequency (VAF) with pathologic complete response (pCR) down-staging, node regression (pN0), event-free survival (EFS), and overall survival (OS).

Results

Among 112 screened patients, 61 were enrolled. In all, 38 (62%) had a positive ctDNA at baseline with VAF > 0 and 23 had negative ctDNA (VAF = 0). Among patients with negative ctDNA, 30% had a complete response, while only 13% of positive ctDNA patients had pCR [odds ratio (OR) 0.35 (95% confidence interval (CI): 0.10-1.26), p = 0.11]. Similarly, 96% and 74% of pN0 were observed among negative and positive ctDNA patients, respectively [OR 0.13 (95% CI: 0.02-1.07), p = 0.058]. The presence of a baseline VAF > 0 was associated with a trend toward a lower EFS compared with VAF = 0 patients [hazard ratio (HR) = 2.30, 95% CI: 0.63-8.36, p = 0.21]. Within the limitations of small sample size, no difference in OS was observed according to the baseline ctDNA status (HR = 1.18, 95% CI: 0.35-4.06, p = 0.79).

Conclusion

Within the limitations of a reduced number of patients, patients with baseline negative ctDNA seem to show a higher probability of pN0 status and a trend toward improved EFS. Prospective translational studies are required to define the role of ctDNA analysis in the multimodal treatment of LARC.

Quantification of the environmental impact of radiotherapy and associated secondary human health effects: a multi-institutional retrospective analysis and simulation

BACKGROUND

The health-care industry is a substantial contributor to global greenhouse gas emissions, yet the specific environmental impact of radiotherapy, a cornerstone of cancer treatment, remains under-explored. We aimed to quantify the emissions associated with the delivery of radiotherapy in the USA and propose a framework for reducing the environmental impact of oncology care.

METHODS

In this multi-institutional retrospective analysis and simulation study, we conducted a lifecycle assessment of external beam radiotherapy (EBRT) for ten anatomical disease sites, adhering to the International Organization for Standardization's standards ISO 14040 and ISO 14044. We analysed retrospective data from Jan 1, 2017, to Oct 1, 2023, encompassing patient and staff travel, medical supplies, and equipment and building energy use associated with the use of EBRT at four academic institutions in the USA. The primary objective was to measure the environmental impacts across ten categories: greenhouse gases (expressed as kg of carbon dioxide equivalents [CO2e]), ozone depletion, smog formation, acidification, eutrophication, carcinogenic and non-carcinogenic potential, respiratory effects, fossil fuel depletion, and ecotoxicity. Human health effects secondary to these environmental impacts were also estimated as disability-adjusted life years. We also assessed the potential benefits of hypofractionated regimens for breast and genitourinary (ie, prostate and bladder) cancers on US greenhouse gas emissions using an analytic model based on the 2014 US National Cancer Database for fractionation patterns and patient commute distances.

FINDINGS

We estimated that the mean greenhouse gas emissions associated with a standard 25-fraction EBRT course were 4310 kg CO2e (SD 2910), which corresponded to 0·0035 disability-adjusted life years per treatment course. Transit and building energy usage accounted for 25·73% (1110 kg CO2e) and 73·95% of (3190 kg CO2e) of total greenhouse gas emissions, respectively, whereas supplies contributed only 0·32% (14 kg CO2e). Across the other environmental impact categories, most of the environmental impact also stemmed from patient transit and energy use within facilities, with little environmental impact contributed by supplies used. Hypofractionated treatment simulations suggested a substantial reduction in greenhouse gas emissions-by up to 42% for breast and 77% for genitourinary cancer-and environmental impacts more broadly.

INTERPRETATION

This comprehensive lifecycle assessment of EBRT delineates the environmental and secondary health impacts of radiotherapy, and underscores the urgent need for sustainable practices in oncology. The findings serve as a reference for future decarbonisation efforts in cancer care and show the potential environmental benefits of modifying treatment protocols (when clinical equipoise exists). They also highlight strategic opportunities to mitigate the ecological footprint in an era of escalating climate change and increasing cancer prevalence.

FUNDING

Mount Zion Health Fund.

Total Neoadjuvant Therapy for Rectal Cancer

The treatment of locally advanced rectal cancer has traditionally included sequenced multimodal therapy including radiation, chemotherapy, and surgery. The relative contribution of each and the order of treatments have evolved over the years. By the early twenty-first century, there was widespread use of the German Rectal Cancer Trial approach: preoperative chemoradiation, followed by standardized surgery including total mesorectal excision, and finally adjuvant chemotherapy. Recent advances have defined the superiority of moving the chemotherapy into the preoperative setting. This approach, termed total neoadjuvant therapy promises better systemic control and overall survival and expaned options for omitting surgery in selected patients.