The watch-and-wait strategy versus surgical resection for rectal cancer patients with a clinical complete response after neoadjuvant chemoradiotherapy

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.

Local resection in rectal cancer: When, who and how?

Local resection (LR) in rectal cancer is indicated in stage T1N0M0 without unfavorable pathological factors, achieving oncologically satisfactory outcomes through transanal endoscopic surgery techniques. However, the initial step involves accurate staging and selection of these tumors through specific tests conducted in specialized colorectal units. For T2N0M0 tumors and T1 tumors with poor prognostic factors, the standard treatment is total mesorectal excision (TME), a procedure associated with high postoperative morbidity and mortality, functional impairments, and reduced quality of life. Therefore, new organ-preservation strategies are being explored as alternatives to TME. These include neoadjuvant therapy combined with LR, which has shown promising results, and neoadjuvant therapy followed by a "Watch and Wait" approach -where patients with complete clinical response are selected for strict surveillance- as an ideal future treatment, although there are still current challenges to be addressed.

Effectiveness of Organ Preservation for Locally Advanced Rectal Cancer With Complete Clinical Response After Neoadjuvant Chemoradiotherapy: Bayesian Network Meta-analysis

BACKGROUND

Neoadjuvant chemoradiotherapy followed by radical surgery is the common treatment for patients with locally advanced rectal cancer. Presently, for patients with complete clinical response after neoadjuvant chemoradiotherapy, organ preservation ("watch-and-wait" and local excision strategies) has been increasingly favored. However, the optimal treatment for patients with complete clinical response remains unclear.

OBJECTIVE

This study aimed to use Bayesian meta-analysis to determine the best treatment for patients with locally advanced rectal cancer with complete clinical response among radical surgery, local excision, and watch-and-wait strategies.

DATA SOURCES

PubMed, Web of Science, Cochrane Library, and Embase (Ovid) databases were searched for literature published through December 31, 2023.

STUDY SELECTION

Studies that compared 2 or more treatments for patients with complete clinical response were included.

INTERVENTION

The analysis was completed via Bayesian meta-analysis using a random-effects model.

MAIN OUTCOME MEASURES

Surgery-related complications, local recurrence, distant metastasis, and 5-year overall and disease-free survival rates.

RESULTS

Eleven articles met the inclusion criteria. The watch-and-wait group and local excision group exhibited a higher rate of tumor recurrence compared to the radical surgery group (watch-and-wait vs radical surgery: OR, 9.10 [95% CI, 3.30-32.3]; local excision vs radical surgery: OR, 2.93 [95% CI, 1.05-9.95]). The distant metastasis, overall survival, and disease-free survival rates of the 3 treatments were not statistically different. The radical surgery group had the most number of stomas and had the greatest risk of morbidity than the watch-and-wait group (watch-and-wait vs radical surgery: OR, 0.00 [95% CI, 0.00-0.12]).

LIMITATIONS

The study included only 1 randomized controlled trial compared to 10 observational studies, which could affect overall quality. Funnel plots of disease-free survival rates and stoma suggest significant publication bias among studies that compared radical surgery with the watch-and-wait strategy.

CONCLUSIONS

The watch-and-wait strategy could be optimal for patients with locally advanced rectal cancer with complete clinical response after neoadjuvant chemoradiotherapy.

Active surveillance in patients with a complete clinical response after neoadjuvant chemoradiotherapy for esophageal- and gastroesophageal junction cancer

Neoadjuvant chemoradiotherapy in patients with esophageal- and gastroesophageal junction cancer induces tumor regression. In approximately one fourth of patients, this leads to a pathological complete response in the resection specimen. Hence, active surveillance may be an alternative strategy in patients without residual disease after neoadjuvant chemoradiotherapy. Previous studies have shown that the combination of esophagogastroduodenoscopy with bite-on-bite biopsies, endoscopic ultrasound with fine needle aspiration of suspected lymph nodes, and a PET-CT-scan can be considered adequate for the detection of residual disease. So far, it has been unclear whether active surveillance with surgery as needed is a safe treatment option and leads to non-inferior overall survival compared to standard esophagectomy after neoadjuvant chemoradiotherapy. This review will discuss the current status of active surveillance for esophageal and junctional cancer.

ACCORD study: a national multi-centre study of the watch and wait approach in patients with rectal cancer in Aotearoa New Zealand

AIM

The adoption of a watch and wait (W&W) approach in patients with rectal cancer, and a complete clinical response (cCR) following neoadjuvant therapy, is increasing worldwide. Despite this, pragmatic unbiased outcome data is limited. This study aimed to investigate national outcomes associated with W&W in Aotearoa New Zealand (AoNZ).

METHODS

A national retrospective study of patients with adenocarcinoma of the rectum managed with a W&W approach between January 2015 and December 2022 in AoNZ was performed by STRATA, a student and trainee led collaborative network. The Cancer Registry and the New Zealand Ministry of Health National Minimum Data Set were linked to identify patients who had rectal cancer and who were treated with neoadjuvant therapy but not rectal resection. Research teams across 17 AoNZ hospitals then screened these patients for inclusion and data collection.

RESULTS

One thousand five hundred and eighteen patients were screened across 17 hospitals, 133 met inclusion criteria. Median age was 71 years. Median follow-up was 2.2 years. The 2-year cumulative incidence of local regrowth was 18.2% (95% CI 10.7%-25.1%), of which 92% was present in the bowel wall, and 68% underwent surgery, all with curative intent. The 2-year cumulative distant metastasis rate was 8.8% (95% CI 3.0%-14.2%) and the 2-year overall survival was 94.8% (95% CI 90.4%-99.4%).

CONCLUSION

This nationwide study of a W&W approach has clinical outcomes similar to the international literature. This data will help guide further implementation of a W&W approach in the management of patients with rectal cancer and inform both clinicians and patients.

Deep learning algorithms for predicting pathological complete response in MRI of rectal cancer patients undergoing neoadjuvant chemoradiotherapy: a systematic review

PURPOSE

This systematic review examines the utility of deep learning algorithms in predicting pathological complete response (pCR) in rectal cancer patients undergoing neoadjuvant chemoradiotherapy (nCRT). The primary goal is to evaluate the performance of MRI-based artificial intelligence (AI) models and explore factors affecting their diagnostic accuracy.

METHODS

The review followed PRISMA guidelines and is registered with PROSPERO (CRD42024628017). Literature searches were conducted in PubMed, Embase, and Cochrane Library using keywords such as "artificial intelligence," "rectal cancer," "MRI," and "pathological complete response." Articles involving deep learning models applied to MRI for predicting pCR were included, excluding non-MRI data and studies without AI applications. Data on study characteristics, MRI sequences, AI model details, and performance metrics were extracted. Quality assessment was performed using the PROBAST tool.

RESULTS

Out of 512 initial records, 26 studies met the inclusion criteria. Most studies demonstrated promising diagnostic performance, with AUC values for external validation typically exceeding 0.8. The use of T2W and diffusion-weighted imaging (DWI) MRI phases enhanced model accuracy compared to T2W alone. Larger datasets generally correlated with improved model performance. However, heterogeneity in model designs, MRI protocols, and the limited integration of clinical data were noted as challenges.

CONCLUSION

AI-enhanced MRI demonstrates significant potential in predicting pCR in rectal cancer, particularly with T2W + DWI sequences and larger datasets. While integrating clinical data remains controversial, standardizing methodologies and expanding datasets will further enhance model robustness and clinical utility.

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.

Imaging Assessment of the Response to Neoadjuvant Treatment in Rectal Cancer in Relation to Postoperative Pathological Outcomes

BACKGROUND AND OBJECTIVE

Rectal cancer remains a global health challenge with significant morbidity and mortality. Neoadjuvant therapy (NAT) is critical for downstaging tumors and improving surgical outcomes. This study aimed to compare the performance of magnetic resonance imaging (MRI) and computed tomography (CT) in evaluating tumor response to NAT in rectal cancer patients, focusing on imaging accuracy and correlation with histopathological findings.

MATERIALS AND METHODS

This retrospective study analyzed 201 patients diagnosed with rectal cancer who underwent NAT followed by surgery. Imaging evaluations were conducted pre-NAT and post-NAT using MRI or CT. Tumor responses were categorized into complete response, downstaging, stable disease, and upstaging. Statistical analyses included Chi-square, Mann-Whitney U, and Z-tests to assess differences in imaging performance and concordance with pathological outcomes.

RESULTS

Both imaging modalities identified significant downstaging post-NAT, with CT demonstrating a higher sensitivity for detecting complete responses (12.5% vs. 6.61% for MRI) and better local staging accuracy. CT showed superior performance in systemic metastasis detection but had limitations in distinguishing fibrosis from residual tumors. Overall diagnostic accuracy was 42.29%, with MRI having a statistically significant edge in detecting favorable tumor responses (p=0.043). The combined use of CT and MRI provided complementary insights, enhancing clinical decision making.

CONCLUSIONS

MRI excels in local tumor evaluation post-NAT, offering detailed imaging crucial for surgical planning and conservative strategies like "watch-and-wait" in complete responders. CT remains indispensable for systemic staging and metastasis detection. Integrating both modalities within a standardized protocol can optimize staging accuracy and treatment outcomes in rectal cancer.

Great Debates: Surgery or Watch and Wait After Total Neoadjuvant Therapy for Rectal Cancer

Locally advanced rectal cancer has traditionally been treated with multimodal therapy including neoadjuvant chemoradiotherapy followed by surgical resection. More recent data suggests that in appropriate patients, total neoadjuvant treatment (TNT) makes it possible to adopt a "watch and wait" approach. Advocates for watch and wait argue that patients with a complete or near-complete clinical response to TNT have comparable overall and disease-free survival to their counterparts who undergo surgical resection, and also have a better quality of life, fewer complications, and potentially avoid a stoma. The dogma of surgery as regional curative intent therapy has been challenged by similar recurrence rates among those treated with total mesorectal excision (TME) and those treated with watch and wait. Furthermore, those who develop local recurrence in the watch and wait groups are equally salvageable, either by surgery, brachytherapy, or chemotherapy. While watch and wait is not appropriate in all patients, this manuscript highlights the benefits and drawbacks of both therapeutic modalities.

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

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

Identification of circulating tumor DNA as a biomarker for diagnosis and response to therapies in cancer patients

The sampling of circulating biomarkers provides an opportunity for non-invasive evaluation and monitoring of cancer activity. In modern day practice, this has typically been in the form of circulating tumor DNA (ctDNA) detected in plasma. The field of ctDNA has been a burgeoning technology, with prominent applications for blood-based cancer screening and in disease status assessment, especially after curative-intent surgery to evaluate for minimal residual disease (MRD). Clinical applications for the latter show an incredibly high sensitivity in certain cancer types with a need for additional studies to determine how much clinical decision-making should be adapted based on ctDNA results and which cancer types, stages, and treatments are best informed by ctDNA results. This chapter provides an overview of ctDNA detection as tool for cancer screening, detecting MRD, and/or molecularly characterizing a cancer, highlighting the rapidly amassing research as a prognostic biomarker and emerging data on ctDNA as a predictive biomarker.

Can Pretreatment MRI and Planning CT Radiomics Improve Prediction of Complete Pathological Response in Locally Advanced Rectal Cancer Following Neoadjuvant Treatment?

OBJECTIVE(S)

The treatment response to neoadjuvant chemoradiation (nCRT) differs largely in individuals treated for rectal cancer. In this study, we investigated the role of radiomics to predict the pathological response in locally advanced rectal cancers at different treatment time points: (1) before the start of any treatment using baseline T2-weighted MRI (T2W-MR) and (2) at the start of radiation treatment using planning CT.

METHODS

Patients on nCRT followed by surgery between June 2017 to December 2019 were included in the study. Histopathological tumour response grading (TRG) was used for classification, and gross tumour volume was defined by the radiation oncologists. Following resampling, 100 and 103 pyradiomic features were extracted from T2W-MR and planning CT images, respectively. Synthetic minority oversampling technique (SMOTE) was used to address class imbalance. Four machine learning classifiers built clinical, radiomic, and merged models. Model performances were evaluated on a held-out test dataset following 3-fold cross-validation using area under the receiver operator characteristic curves (AUC) with bootstrap 95% confidence intervals.

RESULTS

One hundred and fifty patients were included; 58/150 with TRG 1 were classified as complete responders, and rest were incomplete responders (IR). Clinical models performed better (AUC = 0.68) compared to radiomics models (AUC = 0.62). Overall, the clinical + T2W-MR model showed best performance (AUC = 0.72) in predicting the pathological response prior to therapy. Clinical + Planning CT-merged models could only achieve the highest AUC of 0.66.

CONCLUSION

Merging clinical and baseline T2W-MR radiomics enhances predicting pathological response in rectal cancer. Validation in larger cohorts is warranted, especially for watch and wait strategies.

Outcomes of Watch-and-Wait Versus Abdominoperineal Resection in Lower Rectal Adenocarcinoma Post Neoadjuvant Therapy: An Iraqi Cohort Study

BACKGROUND

Rectal malignancy ranks among the most prevalent malignancies in humans. Neoadjuvant chemoradiotherapy (nCRT) is advocated as the standard treatment for locally advanced rectal cancer. In patients who achieve complete clinical response (cCR), successive surgical intervention may result in favorable immediate and long-lasting results; however, it may be associated with decreased quality of life. This study aims to evaluate the incidence of local recurrence in rectal adenocarcinoma between patients who underwent a watch-and-wait approach and those who underwent abdominoperineal resection following the achievement of a cCR after nCRT.

METHODS

This is an analytic cohort study that included 68 patients and was conducted in Baghdad Teaching Hospital/Medical City, Baghdad. The data were collected from the 1st of April 2021 to the 1st of October 2023. All patients with stage II and III rectal adenocarcinoma who achieved cCR after receiving nCRT were included in the study.

RESULTS

There was no statistically significant difference between the two study groups regarding non-regrowth disease-free survival (p-value = 0.708). Cox-regression multivariate analysis revealed that baseline T stage and serum carcinoembryonic antigen (CEA) were significantly associated with locoregional failure.

CONCLUSION

The present study reveals that implementing the watch-and-wait strategy had the benefit of avoiding major surgery, stoma, and their complications without coming at the cost of reduced locoregional recurrence.

Comparing outcomes and cost in surgery versus watch & wait surveillance of patients with rectal cancer post neoadjuvant long course chemoradiotherapy

BACKGROUND

Watch and wait (W&W) in complete clinical responders after neoadjuvant chemoradiotherapy has increasingly robust data supporting its oncological safety. Recently, studies have assessed the real-world costs of this strategy compared to surgical resection. Our aim was to compare our oncological safety and costs associated with operative and surveillance strategies to international literature.

METHODS

Data were retrospectively collected and analysed via electronic health records from March 2014 to March 2021 in Christchurch, New Zealand. Two cohorts were created based on intention to treat. All hospital events were recorded and costed, as well as oncologic outcomes. Our primary endpoints were the cumulative cost of both strategies, 3-year survival rate, and disease-free survival.

RESULTS

Forty-eight patients were identified who had rectal cancers resected (OT) with a yPT0N0 pathology, and 42 who were on the wait-and-watch (W&W) audit after having a clinical complete response. After exclusions, we identified 38 OT and 23 W&W patients; the W&W group were more co-morbid (P = 0.05), had worse functional status (P = 0.008), higher BMI (P = 0.34) and more favourable clinical tumour staging (P = 0.01). The operative treatment (OT) group (n = 38) had more acute admissions (34% versus 13% in W&W, P = 0.08, OR 0.29). There was a 35.7% (n = 8 of 23) local recurrence in W&W and none in the OT group (P ≤ 0.001), with successful salvage in the W&W with local recurrence in 71.5% (n = 5 of 7). Three-year distant metastasis-free rate was 97.3% in the OT group and 90.9% in W&W (p = 0.05). Overall survival was 100% (W&W) and 94.7% (OT); (P = 0.019). Care in the OT group cost more than W&W, accounting for local regrowth management; $NZ70,759.56 versus $NZ47,905.52 (P = 0.014).

CONCLUSION

This study found better oncological outcomes in the OT group, whilst the W&W group had reduced morbidity and acute bed days. The cost of wait and watch was approximately two-thirds that of operative treatment, even accounting for salvage procedures for local regrowth.

MRI-defined T3, clear mesorectal fascia mid-low rectal cancer: is neoadjuvant treatment necessary?

AIM

Neoadjuvant treatments (nCRT) are becoming the standard treatment for patients with stage II or III mid-low rectal cancer. Recently, some studies have shown that surgery alone may be sufficient for patients with T3 rectal cancer. This raises the question of whether nCRT is necessary for all patients with T3 rectal cancer. Therefore, this study compared the clinical outcomes of patients with MRI-defined T3, clear MRF mid-low rectal cancer treated with surgery alone (TME group) or nCRT followed by surgery (nCRT + TME group).

METHODS

A total of 1509 patients were enrolled in this study. After a 1:1 propensity score matching analysis, 480 patients were included in each group. The primary endpoint was 3-year disease-free survival (DFS). The secondary endpoints included the perioperative outcomes, histopathologic outcomes, and other follow-up outcomes.

RESULTS

nCRT had advantages in rates of sphincter-preserving surgery and tumor downstaging, but it was accompanied by a higher rate of enterostomies. At 3 years after surgery, local recurrence occurred in 3.3% of patients in the TME group and in 3.5% of patients in the nCRT + TME group (P = 0.914), the DFS rates were 78.3% in the TME group and 75.3% in the nCRT + TME group (P = 0.188), and the overall survival rates were 90.3% in the TME group and 89.9% in the nCRT + TME group (P = 0.776).

CONCLUSIONS

Surgery alone versus nCRT followed by surgery may provide similar long-term oncological outcomes for patients with MRI-defined T3, clear MRF, and mid-low rectal cancer. nCRT may cause overtreatment in some patients.

Advancing Personalized Medicine in the Treatment of Locally Advanced Rectal Cancer

Rectal cancer presents a significant burden globally, often requiring multimodal therapy for locally advanced cases. Long-course chemoradiotherapy (LCRT) and short-course radiotherapy (SCRT) followed by surgery have been conventional neoadjuvant approaches. Recent trials favor LCRT due to improved local control. However, distant tumor recurrence remains a concern, prompting the exploration of total neoadjuvant therapy (TNT) as a comprehensive treatment strategy. Immune checkpoint inhibitors (ICIs) show promise, particularly in mismatch repair-deficient (dMMR) or microsatellite instability-high (MSI-H) tumors, potentially revolutionizing neoadjuvant regimens. Nonoperative management (NOM) represents a viable alternative post-neoadjuvant therapy for selected patients achieving complete clinical response (cCR). Additionally, monitoring minimal residual disease (MRD) using circulating tumor DNA (ctDNA) emerges as a non-invasive method for the assessment of treatment response. This review synthesizes current evidence on TNT, ICIs, NOM, and ctDNA, elucidating their implications for rectal cancer management and highlighting avenues for future research and clinical application.

Can rectal MRI and endorectal ultrasound accurately predict the complete response to neoadjuvant immunotherapy for rectal cancer?

Background

Standardized assessments of clinical complete response (cCR) to neoadjuvant chemoradiotherapy (nCRT) for rectal cancer have been established, but their utility and accuracy remain unclear. This study aimed to evaluate the clinical diagnostic value of rectal magnetic resonance imaging (MRI) and endorectal ultrasonography (ERUS) for the determination of cCRs after neoadjuvant immunotherapy and to investigate the concordance between cCR and pathological complete response (pCR).

Methods

Ninety-four patients with rectal cancer treated with neoadjuvant radiotherapy with or without immunotherapy were included. The sensitivity, specificity, and accuracy of each evaluation method were calculated.

Results

Combined MRI and ERUS assessments found cCR in seven of the 94 patients in our cohort. In the non-immunotherapy group, the sensitivity, specificity, and accuracy of MRI for diagnosing cCR were 50.0%, 85.2%, and 77.1%, respectively, whereas those of ERUS were 50.0%, 92.6%, and 82.9%, respectively; those of combined MRI and ERUS were 25.0%, 96.3%, and 87.5%, respectively. In the immunotherapy group, the sensitivity, specificity, and accuracy with which MRI identified CR were 51.7%, 76.7%, and 64.4%, respectively; those of ERUS were 13.8%, 90.0%, and 52.5%, respectively, and those of combined MRI and ERUS were 10.3%, 96.7%, and 54.2%, respectively. We also found that 32 of 37 patients with pCR did not meet the cCR evaluation criteria. Of these pCR patients, 78.4% (29/37) received immunotherapy. In the entire cohort, there were five pCRs among the seven cCRs. Of the four cCRs that occurred in the immunotherapy group, three were pCRs.

Conclusions

Rectal MRI and/or ERUS did not provide sufficiently accurate assessments of cCR in patients with rectal cancer receiving neoadjuvant therapy, especially immunotherapy, and cCR did not predict pCR.

Immunotherapy and radiotherapy for older patients with locally advanced rectal cancer unfit for surgery or decline surgery: a practical proposal by the International Geriatric Radiotherapy Group

The standard of care for locally advanced rectal cancer is total neoadjuvant therapy followed by surgical resection. Current evidence suggests that selected patients may be able to delay or avoid surgery without affecting survival rates if they achieve a complete clinical response (CCR). However, for older cancer patients who are too frail for surgery or decline the surgical procedure, local recurrence may lead to a deterioration of patient quality of life. Thus, for clinicians, a treatment algorithm which is well tolerated and may improve CCR in older and frail patients with rectal cancer may improve the potential for prolonged remission and potential cure. Recently, immunotherapy with check point inhibitors (CPI) is a promising treatment in selected patients with high expression of program death ligands receptor 1 (PD- L1). Radiotherapy may enhance PD-L1 expression in rectal cancer and may improve response rate to immunotherapy. We propose an algorithm combining immunotherapy and radiotherapy for older patients with locally advanced rectal cancer who are too frail for surgery or who decline surgery.

Whether the watch-and-wait strategy has application value for rectal cancer with clinical complete response after neoadjuvant chemoradiotherapy? A network meta-analysis

The aim was to evaluate the efficacy and safety between the watch-and-wait strategy (WW), radical surgery (RS), and local excision (LE) for rectal cancer with clinical complete response (cCR) after neoadjuvant radiotherapy (nCRT). We searched MEDLINE, EMBASE, the Cochrane Library, and clinical trials to compare WW with RS and LE for patients with cCR until March 2023 and collected the following data: local recurrence (LR), distant metastasis (DM), cancer-related death (CRD), overall survival (OS), and disease-free survival (DFS). In total, 2240 patients from 21 studies were included. Pairwise meta-analysis revealed no statistically significant differences between the three groups in terms of CRD and 2-, 3-, and 5-year OS (P < 0.05). The RS group was significantly better than the WW group in terms of the LR rate (odds ratio [OR] = 0.12, 95 % confidence interval [CI]: 0.06-0.21, P < 0.001, I2 = 0 %], 3-year DFS (OR = 1.56, 95 % CI: 1.10-2.21, P = 0.01, I2 = 38 %), and 5-year DFS (OR = 2.30, 95 % CI: 1.53-3.46, P < 0.001, I2 = 34 %). The results of network meta-analysis were also similar. After sensitivity analysis, the 5-year OS of the RS group was significantly better than that of the WW group (OR = 2.77, 95 % CI: 1.28-6.00, P = 0.009, I2 = 33 %). Nevertheless, neither regression analysis nor subgroup analysis provided meaningful results. However, the cumulative meta-analysis of LR, DM, and 3- and 5-year DFS revealed significant turning points (P < 0.05). Our meta-analysis recommends using the WW strategy for patients with cCR having poor underlying conditions and high surgical risk; however, there is a risk of higher LR and worse survival after 3 years.

Increased Pathologic Downstaging with Induction versus Consolidation Chemotherapy in Patients with Locally Advanced Rectal Cancer Treated with Total Neoadjuvant Therapy-A National Cancer Database Analysis

Total neoadjuvant therapy (TNT) is the recommended treatment for locally advanced rectal cancer. The optimal sequence of TNT is debated: induction (chemotherapy first) or consolidation (chemoradiation first)? We aim to evaluate the practice patterns and clinical outcomes of total neoadjuvant therapy with either induction or consolidation regiments in the United States for patients with locally advanced rectal cancer.

METHODS

This is a retrospective analysis of the National Cancer Database for patients with clinical stage II or stage III rectal cancer, diagnosed between 2006 and 2017, who underwent total neoadjuvant therapy followed by surgery.

RESULTS

From 2006 to 2017, we identified 8999 patients and found that the utilization of induction chemotherapy increased from 2.0% to 35.0%. TNT resulted in pathologic downstaging 46.7% of the time and a pathologic complete response 11.6% of the time. Induction chemotherapy lead to higher pathologic downstaging (58% vs. 44.7%, p < 0.001) and pathologic complete responses (16.8% vs. 10.7%, p < 0.001). Similar trends held true in a multivariate analysis and subset analysis of stage II and III disease.

CONCLUSIONS

These findings suggest that induction chemotherapy may be preferred over consolidation chemotherapy when downstaging prior to oncologic resection is desired. The optimal treatment plan for total neoadjuvant therapy is multi-factorial and requires further elucidation.

Clinical Complete Response After Conversion Therapy for Unresectable Hepatocellular Carcinoma: Is Salvage Hepatectomy Necessary?

BACKGROUND

This study aimed to determine whether salvage hepatectomy offers prognostic advantages for unresectable hepatocellular carcinoma (uHCC) patients with clinical complete response (cCR) after conversion therapy.

METHODS

A total of 74 consecutive uHCC patients with cCR after conversion therapy at seven major cancer centers in China between October 2018 and December 2021 were included. One-to-one propensity score matching (PSM) was performed to minimize the influence of potential confounders. Disease-free survival (DFS) and overall survival (OS) rates were compared between the surgical group and the non-surgical group.

RESULTS

Before PSM, 45 patients received salvage hepatectomy, and 29 patients received nonsurgical treatment. The 1-, 2-, and 3-year DFS rates were 77.8%, 61.5%, and 61.5% in the surgical group and 81.2%, 60.9%, and 60.9% in the non-surgical group, respectively. The 1-, 2-, and 3-year OS rates were 92.9%, 92.9%, and 69.7% in the surgical group and 100%, 70%, and 70% in the non-surgical group, respectively. There were no statistical differences in DFS and OS between groups [hazard ratio (HR)=0.715, 95% confidence interval (CI): 0.250-2.043, p=0.531; HR=0.980, 95% CI: 0.177-5.418, p=0.982, respectively]. After PSM, 26 pairs of patents were selected; there remained no significant differences in DFS and OS between these two groups (HR=1.547, 95% CI: 0.512-4.669, p=0.439; HR=1.024, 95% CI: 0.168-6.242, p=0.979, respectively).

CONCLUSION

Through the study, it tend to show that salvage hepatectomy may be not essential for uHCC patients with cCR, especially for patients with a high risk of surgical complications. Prospective trials with long term follow-up are warranted to evaluate this treatment option.

Should informed consent and information related to patient recruitment in clinical trials be available to the reader of scientific articles? A case study in dentistry

Ethical aspects in research should be transparently reported. This study aimed to investigate whether informed consent and information related to patient recruitment in clinical studies are well reported in the scientific literature. Randomized clinical trials (RCTs) on root coverage procedures published between November 2016 and November 2021 were selected from the PubMed database. Items/questions were used to guide the extraction of data related to patient recruitment, with a focus on the detailed report of informed consent used to clarify the research to the patient. Data were extracted from the published article and the respective research protocol published in a public registry. Information related to potential selective outcome reporting (SOR) was also extracted. In total, 187 documents were initially screened and 74 reports of RCTs were included. No informed consent was published in the article. Only one research protocol provided a link to the informed consent. Deviations from reporting in the research protocol and published article were found, suggesting SOR. Informed consent and information related to patient recruitment in RCTs on root covering procedures are severely underreported. The present findings may stimulate further discussion and debate on the need for making this information publicly available.

Survival outcomes of salvage surgery in the watch-and-wait approach for rectal cancer with clinical complete response after neoadjuvant chemoradiotherapy: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis compared the outcomes of the watch-and-wait (WW) approach versus radical surgery (RS) in rectal cancers with clinical complete response (cCR) after neoadjuvant chemoradiotherapy.

METHODS

This study followed the PRISMA guidelines. Major databases were searched to identify relevant articles. WW and RS were compared through meta-analyses of pooled proportions. Primary outcomes included overall survival (OS), disease-free survival (DFS), local recurrence, and distant metastasis rates. Pooled salvage surgery rates and outcomes were also collected. The Newcastle-Ottawa scale was employed to assess the risk of bias.

RESULTS

Eleven studies including 1,112 rectal cancer patients showing cCR after neoadjuvant chemoradiation were included. Of these patients, 378 were treated nonoperatively with WW, 663 underwent RS, and 71 underwent local excision. The 2-year OS (risk ratio [RR], 0.95; P = 0.94), 5-year OS (RR, 2.59; P = 0.25), and distant metastasis rates (RR, 1.05; P = 0.80) showed no significant differences between WW and RS. Local recurrence was more frequent in the WW group (RR, 6.93; P < 0.001), and 78.4% of patients later underwent salvage surgery (R0 resection rate, 97.5%). The 2-year DFS (RR, 1.58; P = 0.05) and 5-year DFS (RR, 2.07; P = 0.02) were higher among RS cases. However, after adjustment for R0 salvage surgery, DFS showed no significant between-group difference (RR, 0.82; P = 0.41).

CONCLUSION

Local recurrence rates are higher for WW than RS, but complete salvage surgery is often possible with similar long-term outcomes. WW is a viable strategy for rectal cancer with cCR after neoadjuvant chemoradiation, but further research is required to improve patient selection.

Endoscopic ultrasound-guided injection of carbon nanoparticles suspension to label rectal cancer before neoadjuvant chemoradiotherapy: a retrospective cohort study

Background

Localization of the primary tumor and ensuring safe distal surgical margins (DSMs) following neoadjuvant chemoradiotherapy (nCRT) are challenging in locally advanced rectal cancers (LARCs). This study investigated the effectiveness of carbon nanoparticles suspension (CNS) for labeling the primary tumor and allowing precise tumor resection after nCRT.

Methods

Clinicopathological data of LARC patients who underwent nCRT followed by laparoscopic radical anal preservation surgery at our center between January 2018 and February 2023 were prospectively collected. The patients were divided into the CNS tattooed (CNS) and non-tattooed (control) groups. In the CNS group, CNS was injected in four quadrants on the anal side 1 cm away from the lower tumor margin. DSMs were determined through intraoperative distal rectal examination in the control group and observation of CNS tattoos in the CNS group. DSM lengths and positive DSM rates were compared between the two groups to analyse the feasibility and effectiveness of CNS for labeling LARCs before nCRT.

Results

There was no statistically significant difference in the basic demographic data, effectiveness of nCRT, or post-operative recovery rates between the two groups (all P > 0.05). In the CNS group, CNS tattoos were observed on the outside of the rectal wall, with an overall efficiency of 87.1% (27/31). The CNS group had fewer positive DSMs and safer DSM lengths (2.73 ± 0.88 vs 2.12 ± 1.15 cm, P = 0.012) than the control group (P < 0.05).

Conclusions

Endoscopic ultrasound-guided injection of CNS tattoos before nCRT could effectively label the LARCs, ensuring safe DSMs during anus-preserving surgeries (Chictr.org.cn No.: ChiCTR2300068991).

Oncologic outcomes of watch-and-wait strategy or surgery for low to intermediate rectal cancer in clinical complete remission after adjuvant chemotherapy: a systematic review and meta-analysis

BACKGROUND

A watch-and-wait (WW) strategy or surgery for low to intermediate rectal cancer that has reached clinical complete remission (cCR) after neoadjuvant chemotherapy (nCRT) or total neoadjuvant therapy (TNT) has been widely used in the clinic, but both treatment strategies are controversial.

OBJECTIVE

The aim of this study was to compare the oncologic outcomes of a watch-and-wait strategy or a surgical approach to treat rectal cancer in complete remission and to report the evidence-based clinical advantages of the two treatment strategies.

METHODS

Seven national and international databases were searched for clinical trials comparing the watch-and-wait strategy with surgical treatment for oncological outcomes in patients with rectal cancer in clinical complete remission.

RESULTS

In terms of oncological outcomes, there was no significant difference between the watch-and-wait strategy and surgical treatment in terms of overall survival (OS) (HR = 0.92, 95% CI (0.52, 1.64), P = 0.777), and subgroup analysis showed no significant difference in 5-year disease-free survival (5-year DFS) between WW and both local excision (LE) and radical surgery (RS) (HR = 1.76, 95% CI (0.97, 3.19), P = 0.279; HR = 1.98, 95% CI (0.95, 4.13), P = 0.164), in distant metastasis rate (RR = 1.12, 95% CI (0.73, 1.72), P = 0.593), mortality rate (RR = 1.62, 95% CI (0.93, 2.84), P = 0.09), and organ preservation rate (RR = 1.05, 95% CI (0.94, 1.17), P = 0.394) which were not statistically significant and on the outcome indicators of local recurrence rate (RR = 2.09, 95% CI (1.44, 3.03), P < 0.001) and stoma rate (RR = 0.35, 95% CI (0.20, 0.61), P < 0.001). There were significant differences between the WW group and the surgical treatment group.

CONCLUSION

There were no differences in OS, 5-year DFS, distant metastasis, and mortality between the WW strategy group and the surgical treatment group. The WW strategy did not increase the risk of local recurrence compared with local resection but may be at greater risk of local recurrence compared with radical surgery, and the WW group was significantly better than the surgical group in terms of stoma rate; the WW strategy was evidently superior in preserving organ integrity compared to radical excision. Consequently, for patients who exhibit a profound inclination towards organ preservation and the evasion of stoma formation in the scenario of clinically complete remission of rectal cancer, the WW strategy can be contemplated as a pragmatic alternative to surgical interventions. It is, however, paramount to emphasize that the deployment of such a strategy should be meticulously undertaken within the ambit of a multidisciplinary team's management and within specialized centers dedicated to rectal cancer management.

Clinical trials of neoadjuvant immune checkpoint inhibitors for early-stage operable colon and rectal cancer

BACKGROUND

Immune checkpoint inhibitors (ICI) have become first-line treatment for metastatic colorectal cancer (CRC) with deficient mismatch repair (dMMR). Despite the remarkable response reported in preliminary trials, the role of ICI in patients with early-stage, operable CRC remains unclear. The aim of this study was to investigate trials on neoadjuvant ICI in operable CRC.

MATERIALS AND METHODS

Scoping review of clinical trial registries (Clinicaltrials.gov and EU clinical trial registers) and PubMed/Medline database of trials on neoadjuvant ICI for operable CRC was done up to December 2022.

RESULTS

Some 40 trials investigating neoadjuvant ICI for early-stage, operable CRC were identified, including five published trials and three conference abstracts. Preclinical phase I/II trial predominated with only three clinical phase III trials. Few trials investigated neoadjuvant ICI as the only intervention (monotherapy). Trials in rectal cancer were designed for combined ICI with chemo(radio)therapy, only 8 trials stating an MSI/dMMR status for inclusion, one designed for MSS/pMMR only and, the rest agnostic for MMR status. Thirty-eight (95%) trials investigated programmed cell death protein 1 (PD-1) or programmed cell death ligand 1 (PD-L1) inhibitors. PD-1/PD-L1 inhibitors were combined with vascular endothelial growth factor (VEGF) inhibitor or with cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) inhibitor, in two trials each, respectively. Pathological complete response as primary outcome after surgery was the most frequently used study endpoint. In rectal cancer, six trials included a "watch and wait" strategy for patients with complete clinical response. No "watch and wait" study design for colon cancer after neoadjuvant ICI were identified.

CONCLUSION

High response rates from neoadjuvant ICI in early-stage colon and rectal cancer are reported in phase I/II studies. Contemporary trial designs are heterogeneous, with few comparable inclusion criteria, use of several drug combinations and durations and, wide variation of endpoints reported. Harmonizing clinical and translational aspects including survival data is needed for improved future trial designs with clinical impact.

The ultimate local failure rate after the watch-and-wait strategy for rectal cancer: a systematic review of literature and meta-analysis

BACKGROUND

We hypothesise that a high rate of tumour regrowth after the watch-and-wait (w&w) strategy may lead, despite salvage surgery, to a significant impairment of ultimate local control compared with immediate surgery.

MATERIALS AND METHODS

To test this hypothesis, we conducted meta-analyses of studies on the w&w strategy (both opportunistic and planned) with an ultimate local failure rate as an endpoint in three patient groups: (1) in all starting radio(chemo)therapy as potential w&w candidates, (2) in a subgroup starting w&w, and (3) in a subgroup with regrowth.

RESULTS

We identified eight studies for evaluation of local failure in group 1 (N = 837) and 36 studies in group 2 (N = 1914) and in group 3 (N = 439). The meta-analysis revealed an ultimate local failure rate of 8.0% (95% CI 4.8%-12.1%) in group 1 and 5.4% (95% CI 3.9%-7.1) in group 2. These rates are similar to those reported in the literature following preoperative chemoradiation and surgery. However, in the most unfavourable group 3 (with regrowth), the rate of ultimate local failure was 24.1% (95% CI 17.9%-30.9%), with the most common causes being patients' refusal of salvage total mesorectal excision (TME) (9.1%), recurrence after salvage TME (7.8%), distant metastases (4.1%), frailty (2.4%), and pelvic tumour unresectability (1.7%).

CONCLUSION

Nearly 25% of patients with regrowth (unfavourable subgroup) experienced ultimate local failure, primarily due to refusing salvage TME. The risk of ultimate local failure in patients initiating radio(chemo)therapy as potential w&w candidates, or in patients starting w&w, appears comparable to that reported after preoperative chemoradiation and surgery. However, this comparison may be biased, because w&w studies included more early tumours compared with surgical studies.

Practical recommendations for using ctDNA in clinical decision making

The continuous improvement in cancer care over the past decade has led to a gradual decrease in cancer-related deaths. This is largely attributed to improved treatment and disease management strategies. Early detection of recurrence using blood-based biomarkers such as circulating tumour DNA (ctDNA) is being increasingly used in clinical practice. Emerging real-world data shows the utility of ctDNA in detecting molecular residual disease and in treatment-response monitoring, helping clinicians to optimize treatment and surveillance strategies. Many studies have indicated ctDNA to be a sensitive and specific biomarker for recurrence. However, most of these studies are largely observational or anecdotal in nature, and peer-reviewed data regarding the use of ctDNA are mainly indication-specific. Here we provide general recommendations on the clinical utility of ctDNA and how to interpret ctDNA analysis in different treatment settings, especially in patients with solid tumours. Specifically, we provide an understanding around the implications, strengths and limitations of this novel biomarker and how to best apply the results in clinical practice.

Total neoadjuvant treatment to increase the clinical complete response rate for distal locally advanced rectal cancer (TESS): A study protocol of a prospective, open-label, multicenter, single-arm, phase 2 trial

BACKGROUND

Standard treatment of locally advanced rectal cancer (LARC) was neoadjuvant chemoradiotherapy (CRT), followed by total mesorectal excision (TME). Total neoadjuvant treatment (TNT), a new concept, attempts to deliver both systemic chemotherapy and neoadjuvant CRT prior to surgery. Patients treated with neoadjuvant chemotherapy were more likely to show higher tumor regression. The objective of this trial was to increase complete clinical rate (cCR) for LARC patients by optimizing tumor response, using TNT regimen as compared to conventional chemoradiotherapy. TESS, a prospective, open-label, multicenter, single-arm, phase 2 study, is underway.

METHODS

Main inclusion criteria include cT3-4aNany or cT1-4aN+ rectal adenocarcinoma aged 18-70y; Eastern Cooperative Oncology Group (ECOG) performance 0-1; location ≤5 cm from anal verge. Ninety-eight patients will receive 2 cycles of neoadjuvant chemotherapy Capeox (capecitabine + oxaliplatin) before, during, and after radiotherapy 50Gy/25 fractions, before TME (or other treatment decisions, such as Watch and Wait strategy) and adjuvant chemotherapy capecitabine 2 cycles. Primary endpoint is the cCR rate. Secondary endpoints include ratio of sphincter preservation strategy; pathological complete response rate and tumor regression grade distribution; local recurrence or metastasis; disease-free survival; locoregional recurrence-free survival; acute toxicity; surgical complications; long-term anal function; late toxicity; adverse effect, ECOG standard score, and quality of life. Adverse events are graded per Common Terminology Criteria for Adverse Events V5.0. Acute toxicity will be monitored during antitumor treatment, and late toxicity will be monitored for 3 years from the end of the first course of antitumor treatment.

DISCUSSION

The TESS trial aims to explore a new TNT strategy, which is expected to increase the rate of cCR and sphincter preservation rate. This study will provide new options and evidence for a new sandwich TNT strategy in patients with distal LARC.

Outcomes after the watch-and-wait strategy and local excision treatment for rectal cancer: a meta-analysis

BACKGROUND

The watch-and-wait (W&W) strategy and local excision (LE) have been used in patients with clinical complete response (cCR) for rectal cancer, but the comparative outcomes of the two strategies are controversial. We compared the efficacy of the W&W strategy with LE for rectal cancer patients after neoadjuvant chemoradiotherapy (nCRT) or total neoadjuvant therapy (TNT).

RESEARCH DESIGN AND METHODS

Several domestic and foreign databases were searched for the relevant literature on comparative trials of the W&W strategy and LE surgery for rectal cancer after neoadjuvant therapy with the following outcomes; differences in local recurrence (LR), distant metastasis (DM/DM+LR), 3-year disease-free survival (DFS), 3-year local recurrence-free survival (LRFS) and 3-year overall survival (OS).

RESULTS

Nine articles, were analyzed. Overall, 442 patients were included, with 267 and 175 patients in the W&W and LE groups, respectively. Meta-analysis results showed no significant differences the between W&W and LE groups with respect to LR, DM/DM+LR, 3-year DFS, 3-year LRFS, and 3-year OS. This study has been registered in PROSPERO (registration number: CRD42022331208).

CONCLUSION

The W&W strategy may be preferred for some rectal cancer patients who select LE and reach cCR or near cCR after nCRT or TNT.

Correlation of Presacral Tumour Recurrence with Tumour Metastasis and Long-Term Tumour Recurrence Risk in Patients with Rectal Cancer

Objective

To explore the risk factors that affect long-term presacral tumour recurrence in patients with rectal cancer (RC) after radical rectal cancer resection.

Methods

In our study, a total of 50 patients with presacral tumour recurrence after radical resection of RC in our hospital between May 2017 and May 2018 were enrolled in the observation group, and the other 50 patients without presacral tumour recurrence after the resection over the same span were enrolled in the control group. The two groups were compared in distant metastatic rate and long-term recurrence, and corresponding K-M curves were drawn. Additionally, the quality of life of the two groups was also compared. Patients in both groups were assigned to a long-term recurrence group or a non-long-term recurrence group based on their long-term recurrence, and a multivariate logistic regression analysis was carried out for analysis of risk factors of long-term recurrence.

Results

The two groups were not greatly different in clinical data (P > 0.05). The observation group was higher than the control group in terms of distant metastasis and long-term recurrence (P < 0.05). In addition, the MOS 36-Item Short-Form Health Survey (SF-36) scores of the observation group were all lower than those of the control group in the eight dimensions (P < 0.05). Moreover, tumour diameter (OR: 0.315, 95% CI: 0.118–0.835), differentiation (OR: 2.652, 95% CI: 1.086–6.852), and presacral recurrence (OR: 2.370, 95% CI: 1.263–4.447) were all independent risk factors for long-term recurrence of patients undergoing radical resection of RC.

Conclusions

Patients undergoing radical resection of RC face greatly higher risks of presacral tumour distant metastasis and long-term tumour recurrence, and tumour diameter ≥ 5 cm, low-differentiation degree, and presacral recurrence are independent risk factors for long-term recurrence of patients undergoing radical resection of RC. In the future, when performing radical resection of rectal cancer, it is necessary to pay attention to the changes in the above indicators in patients so as to prevent tumour recurrence.

Laparoscopic versus open surgery for elderly patients with colorectal cancer: a systematic review and meta-analysis of matched studies

BACKGROUND

To compare clinical and survival outcomes between laparoscopic versus open surgery in elderly colorectal cancer patients.

METHODS

PubMed, Embase and Scopus databases were systematically searched. The review included studies that were either randomized controlled trials (RCTs) or observational in design. STATA was used for statistical analysis.

RESULTS

The meta-analysis was conducted with 24 studies. Compared with elderly subjects with open surgery, those undergoing laparoscopic surgery had a lower risk of mortality (within 3 months postoperatively) (RR 0.70, 95% CI: 0.53, 0.94). The long-term overall survival (HR 0.96, 95% CI: 0.89, 1.04), disease-free survival (HR 1.02, 95% CI: 0.93, 1.13), risk of recurrence (RR 1.44, 95% CI: 0.90, 2.30) and readmission (RR 1.11, 95% CI: 0.88, 1.40) rates were statistically similar in both the groups. The operative time (in minutes) was higher (WMD 30.37, 95% CI: 17.75, 43.0) and the blood loss (in ml) was lower (WMD -78.85, 95% CI: -101.96, -55.75) in those undergoing laparoscopic surgery. The length of hospital stay (in days) (WMD -2.53, 95% CI: -3.11, -1.95) and the time of return of bowel movements (in days) (WMD -1.06, 95% CI: -1.20, -0.93) was lower in those with laparoscopic surgery. The pooled risk of complications was lower in those with laparoscopic surgery (RR 0.66, 95% CI: 0.60, 0.74), compared with open surgery.

CONCLUSIONS

Findings suggest that in elderly subjects with colorectal cancer, laparoscopic surgery appears to be more beneficial than open surgery and should be prioritized, subject to the availability of required technical skills and facilities.

Quantitative analysis of diffusion weighted imaging in rectal cancer during radiotherapy using a magnetic resonance imaging integrated linear accelerator

Background and purpose

Magnetic resonance imaging integrated linear accelerator (MR-Linac) platforms enable acquisition of diffusion weighted imaging (DWI) during treatment providing potential information about treatment response. Obtaining DWI on these platforms is technically different from diagnostic magnetic resonance imaging (MRI) scanners. The aim of this project was to determine feasibility of obtaining DWI and calculating apparent diffusion coefficient (ADC) parameters longitudinally in rectal cancer patients on the MR-Linac.

Materials and methods

Nine patients undergoing treatment on MR-Linac had DWI acquired using b-values 0, 30, 150, 500 s/mm2. Gross tumour volume (GTV) and normal tissue was delineated on DWI throughout treatment and median ADC was calculated using an in-house tool (pyOsirix ®).

Results

Seven out of nine patients were included in the analysis; all demonstrated downstaging at follow-up. A total of 63 out of 70 DWI were analysed (7 excluded due to poor image quality). An increasing trend of ADC median for GTV (1.15 × 10-3 mm2/s interquartile range (IQ): 1.05-1.17 vs 1.59 × 10-3 mm2/s IQ: 1.37 - 1.64; p = 0.0156), correlating to treatment response. In comparison ADC median for normal tissue remained the same between first and last fraction (1.61 × 10-3 mm2/s IQ: 1.56-1.71 vs 1.67 × 10-3 mm2/s IQ: 1.37-2.00; p = 0.9375).

Conclusions

DWI assessment in rectal cancer patients on MR-Linac is feasible. Initial results provide foundations for further studies to determine DWI use for treatment adaptation in rectal cancer.

BRIDGE -1 TRIAL: BReak Interval Delayed surgery for Gastrointestinal Extraperitoneal rectal cancer, a multicentric phase III randomized trial

Design

Neoadjuvant chemoradiotherapy (nCRT) followed by surgery is the standard of care for locally advanced rectal cancer (LARC).Several studies have shown a correlation between a longer interval between the end of nCRT and surgery (surgical interval - SI) and an increased pathological complete response (pCR) rate, with a maximum obtained between 10 and 13 weeks.The primary endpoint of this multicenter, 2-arm randomised trial is to investigate SI lengthening, evaluating the difference in terms of complete response (CR) and Tumor Regression Grade (TRG)1 rate in the two arms. Secondly, the impact of SI lengthening on survival outcomes and quality of life (QoL) will be investigated.

Methods

Intermediate-risk LARC patients undergoing nCRT will be prospectively included in the study. nCRT will be administered with a total dose of 55 Gy in 25 fractions on Gross Tumor Volume (GTV) plus the corresponding mesorectum of 45 Gy in 25 fractions on the whole pelvis. Chemotherapy with oral capecitabine will be administered continuously.The patients achieving a clinical major or complete response assessed at clinical-instrumental re-evaluation at 7-8 weeks after treatment completion, will be randomized into two groups, to undergo surgery or local excision at 9-11 weeks (control arm) or at 13-16 weeks (experimental arm). Pathological response will be assessed on the surgical specimen using the AJCC TNM v.7 and the TRG according to Mandard. Patients will be followed up to evaluate toxicity and QoL.The promoter center of the trial will conduct the randomization process through an automated procedure to prevent any possible bias.For sample size calculation, using CR difference of 20% as endpoint, 74 patients per arm will be enrolled.

Conclusions

The results of this study may prospectively provide a new time frame for the clinical re-evaluation for complete/major responders patients in order to increase the CR rate to nCRT.Trial registration:ClinicalTrials.gov Identifier: NCT03581344.

Propensity score analysis of radical proctectomy versus organ preservation using contact X-ray brachytherapy for rectal cancer

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Key objective: the goal provides data to evaluate the oncological risk of performing a planned- conservative strategy in selected patients presenting early T2-T3 rectal adenocarcinoma.

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Knowledge generated: This propensity score analysis on 72 patients, comparing neoadjuvant chemoradiotherapy followed by radical surgery with planned organ preservation using combined chemoradiotherapy and contact X-ray brachytherapy boost, showed no detrimental oncological safety results after 5 year follow-up.

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Relevance: This study supplies additional arguments in favor of organ preservation for selected early rectal T2-T3.

Introduction

Radical proctectomy (RP-TME) with neo adjuvant chemoradiotherapy (nCRT) remains the standard treatment for T2-T3 rectal cancer. Organ preservation (OP) using CRT and a “watch and wait” strategy (W&W) is a field of research. Planned organ preservation can be proposed for early T1-T3 using contact X-ray brachytherapy (CXB). We compared the oncological outcomes of both approaches using a propensity score matched-cohort analysis.

Material and methods

For comparative analyses between patients with nCRT + RP-TME and patients with CXB + CRT, propensity scores were calculated with logistic regression and multiple imputations for missing data. The variables included in the propensity score model were PS status, T-N stage and rectal circumference extension. Patients were matched 1:1 using the nearest neighbor method with a 0.1 caliper restriction. The 5-year Cancer Specific survival was the primary end point.

Results

The Accord 12 phase III trial included 584 patients who treated with nCRT + RP-TME. The CXB cohort included 71 patients with a planned OP. To select OP patient candidate, T4, tumor with extension >66% circumference were eliminated and only patients treated with CXB + CRT were analyzed in the CXB cohort resulting in a total of 374 patients. A one to one paired cohort with 36 patients in each group was derived. These two cohorts were well matched for all confounding factors except for age. The 5-year cancer specific rate showed no significant difference between the two groups (89% in Accord 12 vs 82% in CXB; p = 0.84). At 5 years, rate of metastasis (15% vs 22%, p = 0.54) showed no significant difference. In the CXB group 33/36 patients preserved their rectum.

Conclusion

The organ preservation strategy using CXB boost yielded a 5-year cancer specific survival rate similar to patients treated with RP-TME. In selected early T2-3 rectal adenocarcinoma an organ preservation strategy could be offered as a reasonable option.

Neoadjuvant chemotherapy and radiotherapy followed by resection/ablation in stage IV rectal cancer patients with potentially resectable metastases

Background

The optimal treatment of stage IV rectal cancer remains controversial. The purpose of this study was to assess the treatment outcomes and toxicity of neoadjuvant chemotherapy and radiotherapy followed by local treatment of all tumor sites and subsequent adjuvant chemotherapy in stage IV rectal cancer patients with potentially resectable metastases.

Methods

Adult patients diagnosed with locally advanced rectal adenocarcinoma with potentially resectable metastases, who received neoadjuvant chemotherapy and radiotherapy from July 2013 and September 2019 at Sun Yat-sen University cancer center, were included. Completion of the whole treatment schedule, pathological response, treatment-related toxicity and survival were evaluated.

Results

A total of 228 patients were analyzed with a median follow-up of 33 (range 3.3 to 93.4) months. Eventually, 112 (49.1%) patients finished the whole treatment schedule, of which complete response of all tumor sites and pathological downstaging of the rectal tumor were observed in three (2.7%) and 90 (80.4%) patients. The three-year overall survival (OS) and progression-free survival (PFS) of all patients were 56.6% (50.2 to 63.9%) and 38.6% (95% CI 32.5 to 45.8%), respectively. For patients who finished the treatment schedule, 3-year OS (74.4% vs 39.2%, P < 0.001) and 3-year PFS (45.5% vs 30.5%, P = 0.004) were significantly improved compared those who did not finish the treatment. Grade 3–4 chem-radiotherapy treatment toxicities were observed in 51 (22.4%) of all patients and surgical complications occurred in 22 (9.6%) of 142 patients who underwent surgery, respectively.

Conclusions

Neoadjuvant chemotherapy and radiotherapy followed by resection/ablation and subsequent adjuvant chemotherapy offered chances of long-term survival with tolerable toxicities for selected patients with potentially resectable stage IV rectal cancer, and could be considered as an option in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09089-5.

Neoadjuvant immunotherapy in primary and metastatic colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the second most common solid organ cancer. Traditional treatment is with surgery and chemotherapy. Immunotherapy has recently emerged as a neoadjuvant therapy that could change treatment strategy in both primary resectable and metastatic CRC.

METHODS

A literature review of PubMed with a focus on studies exploring upfront immunotherapy in operable CRC, either for primary resectable stage I-III cancers or for (potentially) operable liver metastasis.

RESULTS

Immune checkpoint blockade by the programmed cell death 1 (PD-1) receptor inhibitors nivolumab and pembrolizumab and the cytotoxic T cell-associated protein 4 (CTLA-4) inhibitor ipilimumab has shown good results in both early-stage and advanced CRC. The effects of immune checkpoint inhibitors have so far been demonstrated in small phase I/II studies and predominantly in treatment-refractory stage IV disease with defect Mismatch repair (dMMR). However, recent data from phase I/II (NICHE-1) studies suggest an upfront role for immunotherapy in operable stage I-III disease. By blocking crucial immune checkpoints, cytotoxic T cells are activated and release cytotoxic signals that initiate cancer cell destruction. The very high complete response rate in dMMR operable CRC with neoadjuvant immunotherapy with nivolumab and ipilimumab, and even partial pathological response in some patients with proficient MMR (pMMR) CRC, calls for further attention to patient selection for neoadjuvant treatment, beyond MMR status alone.

CONCLUSION

Early data on the effect of immunotherapy in CRC provide new strategic thinking of treatment options in CRC for both early-stage and advanced disease, with prospects for new trials.

A meta-analysis of the watch-and-wait strategy versus total mesorectal excision for rectal cancer exhibiting complete clinical response after neoadjuvant chemoradiotherapy

Background

Some clinical researchers have reported that patients with cCR (clinical complete response) status after neoadjuvant chemoradiotherapy (nCRT) could adopt the watch-and-wait (W&W) strategy. Compared with total mesorectal excision (TME) surgery, the W&W strategy could achieve a similar overall survival. Could the W&W strategy replace TME surgery as the main treatment option for the cCR patients? By using the meta-analysis method, we evaluated the safety and efficacy of the W&W strategy and TME surgery for rectal cancer exhibiting cCR after nCRT.

Methods

We evaluated two treatment strategies for rectal cancer with cCR after nCRT up to July 2021 by searching the Cochrane Library, PubMed, Wanfang, and China National Knowledge Infrastructure (CNKI) databases. Clinical data for primary outcomes (local recurrence, cancer-related death and distant metastasis), and secondary outcomes (disease-free survival (DFS) and overall survival (OS)) were collected to evaluate the efficacy and safety in the two groups.

Results

We included nine studies with 818 patients in the meta-analysis, and there were five moderate-quality studies and four high-quality studies. A total of 339 patients were in the W&W group and 479 patients were in the TME group. The local recurrence rate in the W&W group was greater than that in the TME group in the fixed-effects model (OR 8.54, 95% CI 3.52 to 20.71, P < 0.001). The results of other outcomes were similar in the two groups.

Conclusion

The local recurrence rate of the W&W group was greater than that in the TME group, but other results were similar in the two groups. With the help of physical examination and salvage therapy, the W&W strategy could achieve similar treatment effects with the TME approach.

Trial registration

Protocol registration number: CRD42021244032.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02415-y.

Watch and Wait Approach for Rectal Cancer Following Neoadjuvant Treatment: The Experience of a High Volume Cancer Center

Multimodal treatments for rectal cancer, along with significant research on predictors to response to therapy, have led to more conservative surgical strategies. We describe our experience of the rectal sparing approach in rectal cancer patients with clinical complete response (cCR) after neoadjuvant treatment. We also specifically highlight our clinical and imaging criteria to select patients for the watch and wait strategy (w&w). Data came from 39 out of 670 patients treated for locally advanced rectal cancer between January 2016 until February 2020. The selection criteria were a clinical complete response after neoadjuvant chemotherapy managed with a watch and wait (w&w) strategy. A strict follow-up period was adopted in these selected patients and follow-ups were performed every three months during the first two years and every six months after that. The median follow-up time was 28 months. Six patients had a local recurrence (15.3%); all were salvageable by total mesorectal excision (TME). Five patients had a distant metastasis (12.8%). There was no local unsalvageable disease after w&w strategy. The rectal sparing approach in patients with clinical complete response after neoadjuvant treatment is the best possible treatment and is appropriate to analyze from this perspective. The watch and wait approach after neoadjuvant treatment for rectal cancer can be successfully explored after inflexible and strict patient selection.

Re-staging and follow-up of rectal cancer patients with MR imaging when "Watch-and-Wait" is an option: a practical guide

In the past nearly 20 years, organ-sparing when no apparent viable tumour is present after neoadjuvant therapy has taken an increasingly relevant role in the therapeutic management of locally-advanced rectal cancer patients. The decision to include a patient or not in a “Watch-and-Wait” program relies mainly on endoscopic assessment by skilled surgeons, and MR imaging by experienced radiologists. Strict surveillance using the same modalities is required, given the chance of a local regrowth is of approximately 25–30%, almost always surgically salvageable if caught early. Local regrowths occur at the endoluminal aspect of the primary tumour bed in almost 90% of patients, but the rest are deep within it or outside the rectal wall, in which case detection relies solely on MR Imaging. In this educational review, we provide a practical guide for radiologists who are, or intend to be, involved in the re-staging and follow-up of rectal cancer patients in institutions with an established “Watch-and-Wait” program. First, we discuss patient preparation and MR imaging acquisition technique. Second, we focus on the re-staging MR imaging examination and review the imaging findings that allow us to assess response. Third, we focus on follow-up assessments of patients who defer surgery and confer about the early signs that may indicate a sustained/non-sustained complete response, a rectal/extra-rectal regrowth, and the particular prognosis of the “near-complete” responders. Finally, we discuss our proposed report template.