Effect of Interval (7 or 11 weeks) Between Neoadjuvant Radiochemotherapy and Surgery on Complete Pathologic Response in Rectal Cancer: A Multicenter, Randomized, Controlled Trial (GRECCAR-6)

Local tumor regrowth after clinical complete response following neoadjuvant therapy for rectal cancer: what happens when organ preservation falls short

Organ preservation strategies, especially watch and wait, after neoadjuvant treatment in locally advanced rectal cancer, have become topics that generate significant interest, for both patients and clinicians. The obvious advantage of these strategies is the avoidance of surgery with its associated risks and functional consequences. Over time, it has become evident that these strategies offer acceptable safety in oncological terms and, in most patients, allows preservation of the rectum without harming patients in terms of distant metastasis or survival. However, there is a small group of patients in whom the tumor returns after an initially diagnosed clinical complete response; patients with local tumor regrowth. The main threat in these patients is not simply local disease, which can be successfully managed in most cases, but the possible effects it may have on distant metastases. The pathophysiology of the phenomenon of local tumor regrowth is not well known and, therefore, strategies to minimize possible impact on survival are not well defined. Our aim is to review key issues in this subgroup that pose a substantial threat to the safety and viability of organ-preserving and watch-and-wait strategies. We also explore possible pathophysiologic explanations and future directions and perspectives that may improve both local and systemic disease control.

Vasculitis, CA19-9, and Perineural Invasion Differentially Predict Response and Surgical Outcome in Pancreatic Ductal Adenocarcinoma

PURPOSE

Curative intent treatment of pancreatic adenocarcinoma (PDAC) relies on surgical resection. Modern treatment protocols focus on optimizing neoadjuvant therapy to increase resectability and improve oncologic outcomes. To elucidate differences in outcomes, we investigated the relationship between neoadjuvant chemotherapy (NAC), either with or without stereotactic body radiation therapy (SBRT), and vascular inflammation, surgical outcomes, and the resultant transcriptomic changes.

METHODS AND MATERIALS

Clinical data were collected from patients with borderline resectable PDAC (clinical T3-T4N0-1) who underwent NAC or NAC-SBRT followed by curative intent resection between 2014 and 2019. Vascular structures on surgical specimens were histologically evaluated for vasculitis. RNA sequencing was used to evaluate differential gene expression and to generate enrichment maps. Multivariate analysis was used to analyze the relationship between patient characteristics and oncological outcome.

RESULTS

In total, 46 patients met inclusion criteria (n = 12 NAC, n = 34 NAC-SBRT) with a median follow-up of 20.1 months. All patients underwent curative resection, with 91.3% achieving R0. There was no significant difference in patterns of failure, overall survival, or progression-free survival between NAC and NAC-SBRT groups. Patients with vasculitis had a lower median overall survival compared with those without (14.5 vs 28.3 months; hazard ratio, 12.96; 95% confidence interval, 3.55-47.28; P < .001). There was no significant correlation between inflammation and surgical complications or pathologic response. Neoadjuvant therapy did not have a significant effect on development of vasculitis (odds radio, 1.64 for NAC-SBRT; 95% confidence interval, 0.40-8.43; P = .52). Predictors of poor survival included perineural invasion and high baseline carbohydrate antigen 19-9 (CA19-9) (>191 U/mL). Patients with robust CA19-9 (>20% decrease) responses to neoadjuvant therapy had enrichment in immune response, chemotaxis, and cytotoxic T-cell and natural killer-cell proliferation.

CONCLUSIONS

Vasculitis predicts for poor survival outcomes in patients with PDAC; NAC-SBRT did not increase the rate of vasculitis compared with NAC. Perineural invasion and CA19-9 remain strong prognosticators. Understanding and optimizing immune interactions remain a crucial hurdle in achieving response in pancreatic cancer.

Changing patterns of neoadjuvant therapy for locally advanced rectal cancer: A narrative review

Standard treatment for patients with locally advanced rectal cancer has been the multidisciplinary approach of neoadjuvant chemoradiotherapy, followed by total mesorectal excision (TME) and postoperative adjuvant chemotherapy. This reduces the local recurrence rate, but the challenge of distant metastasis still persists. The improvement in treatment approach has always been the focus of clinical research and studies have been conducted worldwide in recent years. On one hand, evidence suggests that increasing the intensity of treatment can result in better tumor regression, for example by adding a second drug to the neoadjuvant chemoradiotherapy, or extending the interval between neoadjuvant therapy and surgery, or incorporating chemotherapy and chemoradiotherapy in the neoadjuvant setting. On the other hand, neoadjuvant immunotherapy and selective omission of neoadjuvant radiotherapy may improve the quality of life of patients. In this article, we review the key clinical research progresses in neoadjuvant therapy for locally advanced rectal cancer, hoping to provide some valuable views on the individualized treatment for rectal cancer.

Trends of sphincter-preserving surgeries for low lying rectal cancer: A 20-year experience in China

Background

Over the last 2 decades, patients with low rectal cancer have had better outcomes from improvements in surgical techniques in sphincter preservation. We aimed to quantify the trends in sphincter-preserving surgeries for low rectal cancer over 20 years in a top tertiary hospital in China.

Methods

Between 1999 and 2021, a cohort of patients with primary malignant rectal tumor ≤5cm from the anal verge and who received elective surgeries at Changhai Hospital, Shanghai, China, was identified. Data were extracted from electronic medical records. A Joinpoint Regression Model was used to analyze trends in surgical procedures by average annual percentage change (AAPC). Adjusted Cox proportional hazards regression model was used to assess overall survival.

Results

Among a total of 4,172 patients during the study period, 3,111 (74.6%) underwent a sphincter-preserving surgery and 1,061 (25.4%) received APR. Sphincter-preserving surgery increased 3.6% per year (95%CI, 2.3-4.9). Low anterior resection was the most performed procedure (86.3%) and maintained a steady trend, while intersphincteric resection increased 49.4% annually (95%CI, 19.5-86.7) after initiation. Laparoscopic techniques increased 15.1% per year (95%CI, 8.4-43.4) after initiation. Sphincter-preserving surgery increased annually for tumors ≤2cm, 2-≤3cm and 3-≤4cm from the anal verge (AAPC 7.1, 4.5-9.8; 4.7, 3.1-6.3; 2.7, 1.7-3.6, respectively). Furthermore, patients with sphincter-preserving surgery had a better overall survival than abdominoperineal resection (APR) patients (adjusted HR 0.78, 95% CI, 0.65-0.93, p=.01).

Conclusions

Utilization of sphincter-preserving surgeries increased significantly over the last 20 years. Patients with low rectal cancer who underwent sphincter preservation had better survival than similar patients who underwent APR.

Determination of biomarkers associated with neoadjuvant treatment response focusing on colibactin-producing Escherichia coli in patients with mid or low rectal cancer: a prospective clinical study protocol (MICARE)

INTRODUCTION

The management of mid and low rectal cancer is based on neoadjuvant chemoradiotherapy (CRT) followed by standardised surgery. There is no biomarker in rectal cancer to aid clinicians in foreseeing treatment response. The determination of factors associated with treatment response might allow the identification of patients who require tailored strategies (eg, therapeutic de-escalation or intensification). Colibactin-producing Escherichia coli (CoPEC) has been associated with aggressive colorectal cancer and could be a poor prognostic factor. Currently, no study has evaluated the potential association between intestinal microbiota composition and tumour response to CRT in mid and low rectal cancer. The aim of this study is to assess the association between response to neoadjuvant CRT and faecal intestinal microbiota composition and/or CoPEC prevalence in patients with mid or low rectal cancer.

METHODS AND ANALYSIS

This is a non-randomised bicentric prospective clinical study with a recruitment capacity of 200 patients. Three stool samples will be collected from participants with histological-proven adenocarcinome of mid or low rectum who meet eligibility criteria of the study protocol: one before neoadjuvant treatment start, one in the period between CRT end and surgery and one the day before surgery. In each sample, CoPEC will be detected by culture in special media and molecular (PCR) approaches. The global microbiota composition will be also assessed by the bacterial 16S rRNA gene sequencing. Neoadjuvant CRT response and tumour regression grade will be described using the Dworak system at pathological examination. Clinical data and survival outcomes will also be collected and investigated.

ETHICS AND DISSEMINATION

MICARE was approved by the local ethics committee (Comité de Protection des Personnes Sud-Est II, 18 December 2019. Reference number 2019-A02493-54 and the institutional review board. Patients will be required to provide written informed consent. Results will be published in a peer reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04103567.

How We Treat Localized Rectal Cancer-An Institutional Paradigm for Total Neoadjuvant Therapy

Total neoadjuvant therapy (TNT)-the neoadjuvant employment of radiotherapy (RT) or chemoradiation (CRT) as well as chemotherapy (CHT) before surgery-may lead to increased pathological complete response (pCR) rates as well as a reduction in the risk of distant metastases in locally advanced rectal cancer. Furthermore, increased response rates may allow organ-sparing strategies in a growing number of patients with low rectal cancer and upfront immunotherapy has shown very promising early results in patients with microsatellite instability (MSI)-high/mismatch-repair-deficient (dMMR) tumors. Despite the lack of a generally accepted treatment standard, we strongly believe that existing data is sufficient to adopt the concept of TNT and immunotherapy in clinical practice. The treatment algorithm presented in the following is based on our interpretation of the current data and should serve as a practical guide for treating physicians-without any claim to general validity.

Effect of interval between neoadjuvant chemoradiotherapy and surgery on disease recurrence and survival in rectal cancer: long-term results of a randomized clinical trial

BACKGROUND

The optimal timing of surgery following chemoradiotherapy (CRT) is controversial. This trial aimed to assess disease recurrence and survival rates between patients with locally advanced rectal adenocarcinoma (LARC) who underwent total mesorectal excision (TME) after a waiting interval of 8 weeks or less (classic interval; CI) versus more than 8 weeks (long interval; LI) following preoperative CRT.

METHODS

This was a phase III, single-centre, randomized clinical trial. Patients with LARC situated within 12 cm of the anal verge (T3-T4 or N+ disease) were randomized to undergo TME within or after 8 weeks after CRT.

RESULTS

Between January 2006 and January 2017, 350 patients were randomized, 175 to each group. As of February 2022, the median follow-up time was 80 (6-174) months. Among the 322 included patients (CI, 159; LI, 163) the cumulative incidence of locoregional recurrence at 5 years was 10.1 per cent in the CI group and 6.9 per cent in the LI group (P = 0.143). The cumulative incidence of distant metastasis at 5 years was 30.8 per cent in the CI group and 18.6 per cent in the LI group (sub-HR = 1.78; 95 per cent c.i. 1.14 to 2.78, P = 0.010). The disease-free survival (DFS) in each group was 59.7 and 69.9 per cent respectively (P = 0.157), and overall survival (OS) rates at 5 years were 73.6 versus 77.9 per cent (P = 0.476).

CONCLUSION

Incidence of distant metastasis decreased with an interval between CRT and surgery exceeding 8 weeks, but this did not impact on DFS or OS.

REGISTRATION NUMBER

NCT03287843 (http://www.clinicaltrials.gov).

Predicting Factors of Complete Pathological Response in Locally Advanced Rectal Cancer

Background: Current treatment of choice for locally advanced rectal cancer is neoadjuvant chemoradiotherapy (neo-CRT) followed by surgical resection and adjuvant chemotherapy. Some patients may experience complete pathological response (cPR) after the neoadjuvant treatment. However, the predicting factors are still debated. Methods: In this registry-based retrospective cohort study, 258 patients with locally advanced rectal cancer were included. Patients were categorized into two groups with or without cPR. Logistic regression analysis was recruited to investigate the odds ratio for all independent variables, and those with significant results were included in multivariate regression analysis. Results: Achievement of cPR was 21.3%. The odds ratio of cPR was significantly lower when the tumor distance from the anal verge was>10 centimeters (OR=0.24, P=0.040). Also, the odds of cPR with N1 involvement in comparison with N0 involvement decreased for 0.41 (P=0.043). It was also true for patients with N2 involvement in comparison with N0 involvement (OR=0.31, P=0.031). Higher odds ratio of cPR was observed in patients who underwent surgery in>12 weeks after neo-CRT (OR=2.9, P=0.022). Furthermore, the odds of cPR decreased for 0.9 with increasing in carcinoembryonic antigen (CEA) level (P=0.044). Conclusion: Patients with rectal cancer in clinical stage II or lower, without the involvement of the lymphatic system at diagnosis, and with tumors located in the lower parts of the rectum, with lower levels of CEA, and longer duration between neo-CRT and surgery were more likely to achieve cPR after neo-CRT. With the current knowledge, the "wait and watch policy" is still debated and needs to be defined more precisely by upcoming studies.

Standard versus longer interval of radical resection after neoadjuvant chemoradiotherapy in locally advanced rectal cancer: A 20-year single-center experience & propensity-score matching

BACKGROUND AND OBJECTIVES

Despite the standard interval of 6-8 weeks between neoadjuvant chemoradiotherapy (nCRT) and surgery, it is debated whether an interval of >8 weeks increases the pathologic complete response (pCR) rate. We investigated the interval between nCRT and surgery, and its impact on oncological outcomes and postoperative complications in patients with locally advanced rectal cancer.

METHODS

We retrospectively reviewed patients with rectal cancer who underwent total mesorectal excision after long-course nCRT between 2000 and 2020. They were divided into two groups-those who underwent surgery at 6-8 and >8 weeks after nCRT. Surgical outcomes (stoma rate and postoperative complications), pCR, tumor regression grade (TRG), recurrence-free survival (RFS), and overall survival (OS) were compared.

RESULTS

We selected 770/1153 patients with rectal cancer, including 502 and 268 patients surgically treated at 6-8 and >8 weeks after nCRT, respectively. The pCR rates were similar between the two groups (14.7% vs. 15.3%, p = 0.836), while the TRG was significantly better in the >8 weeks group (p = 0.267). Additionally, the postoperative complications, recurrence, 5-year RFS, and OS rates were not significantly different between the two groups.

CONCLUSIONS

Although tumor regression increased in the >8 weeks group, the oncological benefits of surgery >8 weeks after nCRT remain uncertain.

Three perspectives: the approach to neoadjuvant treatment of rectal cancer according to medical oncologists, radiation oncologists, and surgeons

Background: Two treatment options considered for radiotherapy are short-course radiotherapy and immediate surgery, or chemoradiation with 5-Fluorouracil based chemotherapy and delayed surgery. Aim of the study: Evaluate the real-life treatment approaches of medical, radiation, and surgical oncologists, to neoadjuvant treatment of rectal cancers. Material and methods: An online survey was established via Google Forms. The survey was taken voluntarily by medical oncologists, radiation oncologists, surgical oncologists, and general surgeons. Results: Of those who participated, 183 were medical oncologists, 36 were radiotherapists, and 36 were surgeons. Most of the study population preferred long-course radiation therapy and chemotherapy (85%). Meanwhile, two-thirds of the participants preferred chemotherapy prior to operating. The most frequent chemotherapy cycles for the pre-operative setting were ‘three’ and ‘four-or-more’ (27.8% and 25.1%, respectively). Medical oncologists had a significantly higher tendency to offer chemotherapy between radiation therapy and surgery compared to the other groups. Optimal time of surgery was different between groups, but there was no difference among groups between surgery and the ‘watch & wait’ strategy. Neoadjuvant chemotherapy regimens were significantly different between groups. Conclusions: We found that the new pre-operative chemotherapy regimen with short-course radiotherapy was slowly adopted into current practice. Also, medical oncologists tended to prefer pre-operative chemotherapy in comparison to the other groups.

Predictors and histological effects of preoperative chemoradiotherapy for rectal cancer and control of lateral lymph node metastasis

Introduction

Standard treatment strategy for low rectal cancer in Japan is different from Western countries. Total mesorectum excision (TME) + lateral lymph node dissection (LLND) is mainly carried out in Japan, whereas neoadjuvant chemoradiotherapy (nCRT) + TME is selected in Western countries. There is no clear definition of preoperative diagnosis of lateral lymph node metastasis. If we can predict lateral lymph node swelling that can be managed by nCRT from lateral lymph node swelling that require surgical resection, clinical benefit is significant. In the current study we assessed characteristics of the lateral lymph node recurrence (LLNR) and LLND that can be managed by nCRT.

Patients and Methods

Patients with low rectal cancer (n = 168) underwent nCRT between 2009 and 2016. We evaluated CEA, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and lateral lymph node short axis pre and post nCRT, respectively, and also evaluated tumor shrinkage rate, tumor regression grade (TRG). We evaluated the relationship between each and LLNR.

Results

LLND was not carried out all patients. Factors associated with LLNR were PLR and lymph node short axis pre and post nCRT. (p = 0.0269, 0.0278, p < 0.0001, p < 0.0001, respectively). Positive recurrence cut-off values of lateral lymph node short-axis calculated were 11.6 mm pre nCRT and 5.5 mm post nCRT.

Conclusion

Results suggest that PLR before and after CRT was associated with control of LLNR, and LLND should be performed on lateral lymph nodes with short-axis of 5 mm and 11 mm pre and post nCRT.

Total neoadjuvant therapy for the treatment of locally advanced rectal cancer: a systematic minireview

Colorectal carcinoma is the second leading cause of cancer-related deaths, and indeed, rectal cancer accounting for approximately one third of newly diagnosed patients. Gold standard in the treatment of rectal cancer is a multimodality approach, aiming at a good control of the local disease. Distant recurrences are the major cause of mortality. Currently, Locally Advanced Rectal Cancer (LARC) patients undergo a combined treatment of chemotherapy and radiotherapy, followed by surgery. Eventually, more chemotherapy, namely adjuvant chemotherapy (aCT), may be necessary. Total Neoadjuvant Therapy (TNT) is an emerging approach aimed to reduce distant metastases and improve local control. Several ongoing studies are analyzing whether this new approach could improve oncological outcomes. Published results were encouraging, but the heterogeneity of protocols in use, makes the comparison and interpretation of data rather complex. One of the major concerns regarding TNT administration is related to its effect on larger and more advanced cancers that might not undergo similar down-staging as smaller, early-stage tumors. This minireview, based on a systematic literature search of randomized clinical trials and meta-analysis, summarizes current knowledge on TNT. The aim was to confirm or refute whether or not current practice of TNT is based on relevant evidence, to establish the quality of that evidence, and to address any uncertainty or variation in practice that may be occurring. A tentative grouping of general study characteristics, clinical features and treatments characteristics has been undertaken to evaluate if the reported studies are sufficiently homogeneous in terms of subjects involved, interventions, and outcomes to provide a meaningful idea of which patients are more likely to gain from this treatment.

The Multimodal Management of Locally Advanced Rectal Cancer: Making Sense of the New Data

In the past 40 years, the treatment of locally advanced rectal cancer has evolved with the addition of radiotherapy or chemoradiotherapy and providing (neo)adjuvant systemic chemotherapy to major surgery. However, recent trends have focused on improving our ability to risk-stratify patients and tailoring treatment to achieve the best oncologic outcome while limiting the impact on long-term quality of life. Therefore, there has been increasing interest in pursuing a watch-and-wait approach to achieve organ preservation. Several retro- and prospective studies suggest safety of the watch-and-wait approach, though it is still considered controversial due to limited clinical evidence, concerns about tumor regrowth, and subsequent distant progression. To further reduce treatment, MRI risk stratification, together with patient characteristics and patient preferences, can guide personalized treatment and reserve radiation and chemotherapy for a select patient population. Ultimately, improved options for reassessment during neoadjuvant treatment may allow for more adaptive therapy options based on treatment response. This article provides an overview of some major developments in the multimodal treatment of locally advanced rectal cancer. It reviews some relevant, controversial issues of the watch-and-wait approach and opportunities to personally tailor and reduce treatment. It also reviews the overall neoadjuvant treatment, including total neoadjuvant therapy trials, and how to best optimize for a potential complete response. Finally, it provides an algorithm as an example of how such a personalized, tailored, adaptive, and reduced treatment could look like in the future.

Is it safe to perform an anastomosis for rectal cancer after prostate cancer? A multicentre study of 126 patients from the GRECCAR group

AIM

To determine the safety of performing an anastomosis after rectal cancer (RC) resection in patients with a previously treated prostate cancer (PC).

METHODS

Patients with a previously treated PC who underwent rectal resection from 2008 to 2018 were retrospectively included. Outcomes were compared between patients who underwent rectal resection with anastomosis (restorative surgery, RS+ group) and those with a definitive stoma (RS- group). In the RS+ group, anastomotic leak (AL) rates were assessed according to the type of reconstruction.

RESULTS

A total of 126 patients underwent rectal surgery for mid-low RC after a previous PC treated by radiotherapy (RT) and/or radical prostatectomy. Overall, 80 patients (63%) underwent a RS and 46 patients (37%) underwent rectal surgery with a definitive stoma. There was no statistical difference between the two groups in terms of intraoperative data, except for the type of resection with more multivisceral resection in the RS- group (p < 0.01). In the RS+group, a diverting stoma was performed in 74% of cases. No difference between the two groups in terms of overall morbidity was found. In the RS+group (n = 80), 17 patients (21%) experienced AL. Of these, none was observed when delayed coloanal anastomosis was performed (p = 0.16). Long-term permanent stoma in the RS+ group was 16% (n = 13).

CONCLUSION

Restorative surgery after resection for RC in patients with a previous history of RT and/or radical prostatectomy for PC is safe without additional morbidity. In selected patients for restorative surgery, performing delayed coloanal anastomosis may represent a promising option.

More Is Not Better When It Comes to Treating Rectal Cancer With Multimodal Chemoradiation Beyond the Standard Radiation Dose of 5040 cGy

BACKGROUND

Radiation dose schedules for neoadjuvant chemoradiation for rectal cancers differ, with the most common dose schedule using 5040 cGy in 28 fractions.

OBJECTIVES

The aim of this retrospective study was to assess the benefit of higher radiation doses beyond 5040 cGy in the context of pathological response and follow-up events.

SETTING

The database from a provincial tertiary cancer center in Canada was the source of information for this study.

PATIENTS

Included in this study were 508 consecutive patients with rectal cancer with locally advanced disease (clinical T3/T4 or N1/N2) who received neoadjuvant chemoradiation followed by surgery. Of the 508 patients, 281 received the standard radiation dose of 4500 to 5040 cGy and 227 received a dose >5040 cGy.

MAIN OUTCOME MEASURE

The postsurgical pathology, late toxicities, and follow-up outcomes were analyzed. The outcomes were evaluated in relation to the dose of radiation received.

RESULTS

Data regarding the clinical outcomes were comparable between the 4500 to 5040 cGy and >5040 cGy radiation groups with pathological complete response rates of 20.9% and 15.4% (p = 0.104); distant recurrence rates of 17.4% and 19.4% (p = 0.36); local recurrence rates of 3.2% and 3.5% (p = 0.36); and the median overall survival rates of 61 and 60.5 months (p = 0.8). No statistically significant correlation of improvement in outcomes was noted with radiation doses beyond 5040 cGy.

LIMITATIONS

This is a retrospective study.

CONCLUSION

Our study showed that dose escalation beyond the standard dose of 4500 to 5040cGy failed to achieve meaningful clinical outcomes. See Video Abstract at http://links.lww.com/DCR/B633.

MS NO ES MEJOR CUANDO SE TRATA DE TRATAR EL CNCER DE RECTO CON QUIMIORRADIACIN MULTIMODAL MS ALL DE LA DOSIS DE RADIACIN ESTNDAR DE CGY

ANTECEDENTES:En neoadyuvancia de cáncer rectal es posible encontrar muchas variaciones, en radioterapia la dosis más común que usa 5040 cGy en 28 fracciones.OBJETIVOS:El objetivo de este estudio retrospectivo fue evaluar el beneficio de dosis de radiación más altas más allá de 5040cGy en el contexto de la respuesta patológica y en su seguimiento.AJUSTE:Base de datos de un centro de cáncer terciario provincial en Canadá.PACIENTES:Se incluyeron en este estudio quinientos ocho pacientes consecutivos con cáncer de recto y enfermedad localmente avanzada (clínica T3 / T4 o N1 / N2) que recibieron quimiorradiación neoadyuvante seguida de cirugía. De los 508 pacientes, 281 recibieron la dosis de radiación estándar de 4500-5040 cGy y 227 recibieron una dosis > 5040 cGy.PRINCIPAL MEDIDA DE RESULTADO:Se analizo evolucion posquirúrgica, toxicidad tardía y seguimiento. Los resultados se evaluaron en relación con la dosis de radiación recibida.RESULTADOS:Los datos con respecto a los resultados clínicos fueron comparables entre los grupos de radiación de 4500-5040 cGy y> 5040 cGy con tasas de respuesta patológica completa de 20,9% y 15,4% respectivamente (p = 0,104); tasas de recurrencia a distancia de 17,4% y 19,4%, respectivamente (p = 0,36); tasas de recurrencia local de 3,2% y 3,5%, respectivamente (p = 0,36); y la mediana de las tasas de supervivencia global de 61 y 60,5 meses, respectivamente (p = 0,8). No se observó una correlación estadísticamente significativa de mejoría en los resultados con dosis de radiación superiores a 5040 cGy.LIMITACIONES:Este es un estudio retrospectivo.CONCLUSIONES:Nuestro estudio mostró que el aumento de la dosis más allá de la dosis estándar de 4500-5040cGy no logró resultados clínicos significativos. Consulte Video Resumen en http://links.lww.com/DCR/B633. (Traducción-Dr. Gunther Bocic).

Simulation CT-based radiomics for prediction of response after neoadjuvant chemo-radiotherapy in patients with locally advanced rectal cancer

Background

To report on the discriminative ability of a simulation Computed Tomography (CT)-based radiomics signature for predicting response to treatment in patients undergoing neoadjuvant chemo-radiation for locally advanced adenocarcinoma of the rectum.

Methods

Consecutive patients treated at the Universities of Tübingen (from 1/1/07 to 31/12/10, explorative cohort) and Florence (from 1/1/11 to 31/12/17, external validation cohort) were considered in our dual-institution, retrospective analysis. Long-course neoadjuvant chemo-radiation was performed according to local policy. On simulation CT, the rectal Gross Tumor Volume was manually segmented. A feature selection process was performed yielding mineable data through an in-house developed software (written in Python 3.6). Model selection and hyper-parametrization of the model was performed using a fivefold cross validation approach. The main outcome measure of the study was the rate of pathologic good response, defined as the sum of Tumor regression grade (TRG) 3 and 4 according to Dworak’s classification.

Results

Two-hundred and one patients were included in our analysis, of whom 126 (62.7%) and 75 (37.3%) cases represented the explorative and external validation cohorts, respectively. Patient characteristics were well balanced between the two groups. A similar rate of good response to neoadjuvant treatment was obtained in in both cohorts (46% and 54.7%, respectively; p = 0.247). A total of 1150 features were extracted from the planning scans. A 5-metafeature complex consisting of Principal component analysis (PCA)-clusters (whose main components are LHL Grey-Level-Size-Zone: Large Zone Emphasis, Elongation, HHH Intensity Histogram Mean, HLL Run-Length: Run Level Variance and HHH Co-occurence: Cluster Tendency) in combination with 5-nearest neighbour model was the most robust signature. When applied to the explorative cohort, the prediction of good response corresponded to an average Area under the curve (AUC) value of 0.65 ± 0.02. When the model was tested on the external validation cohort, it ensured a similar accuracy, with a slightly lower predictive ability (AUC of 0.63).

Conclusions

Radiomics-based, data-mining from simulation CT scans was shown to be feasible and reproducible in two independent cohorts, yielding fair accuracy in the prediction of response to neoadjuvant chemo-radiation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-022-02053-y.

Redo-surgery after failed colorectal or coloanal anastomosis: Morbidity, mortality and factors predictive of success. A retrospective study of 200 patients

AIM

In cases of anastomotic failure after colorectal (CRA) or coloanal anastomosis (CAA), revision of the anastomosis is an ambitious surgical option that can be proposed in order to maintain bowel continuity. Our aim was to assess postoperative morbidity, risk of failure and risk factor for failure in patients after CRA or CAA.

METHODS

All consecutive patients who underwent redo-CRA/CAA in our institution between 2007-2018 were retrospectively included. The success of redo-CRA/CAA was defined by the restoration of bowel continuity 12 months after the surgery.

RESULTS

Two hundred patients (114 male: 57%) were analyzed. The indication for redo-CRA/CAA was chronic pelvic infection in 74 patients (37%), recto-vaginal or urinary fistula in 59 patients (30%), anastomotic stenosis in 36 patients (18%) and redo anastomosis after previous anastomosis takedown in 31 patients (15%). Twenty-three percent of the patients developed a severe postoperative complication. Anastomotic leakage was diagnosed in 39 patients (20%). One-year-success of the redo-CRA/CAA was obtained in 80% of patients. In multivariate analysis, only obesity was associated with redo-CRA/CAA failure (p = 0.042). We elaborated a pre-operative predictive score of success using the four variables: male sex, age > 60 years, obesity and history of pelvic radiotherapy. The success of redo-CRA/CAA was 92%, 86%, 80% and 62% for a preoperative predictive score value of 0, 1, 2 and ≥3, respectively (p = 0.010).

CONCLUSIONS

In case of failure of primary CRA/CAA, bowel continuity can be saved in 4 out of 5 patients by redo-CRA/CAA despite 23% suffering severe postoperative morbidity.

Does a long interval between neoadjuvant chemoradiotherapy and surgery benefit the clinical outcomes of locally advanced rectal cancer? A systematic review and meta analyses

PURPOSE

The study aims to systematically evaluate the clinical efficacy after 8 weeks (long interval, LI) between neoadjuvant chemoradiotherapy and surgery for locally advanced rectal cancer.

METHODS

The PubMed database, EMBASE database, and the Cochrane Library (deadline: September 25, 2021) were searched to select clinical studies that compared two intervals between neoadjuvant chemoradiotherapy and surgery for locally advanced rectal cancer: after 8 weeks (long interval, LI) and within 8 weeks (short interval, SI). The included studies were screened and evaluated according to the inclusion and exclusion criteria, and meta-analysis was performed by RevMan 5.3 software.

RESULTS

Eighteen studies were included, with 9070 cases in the LI group and 14,207 cases in the SI group. The analysis results showed that the pathologic complete response (PCR) rate in the LI group was higher than that in the SI group (P < 0.00001). There was no significant difference in the R0 resection rate (P = 0.85), anal preservation rate (P = 0.89), morbidity rate (P = 0.60), anastomotic leakage rate (P = 0.06), operation time (P = 0.58), local recurrence rate (P = 0.56), distant metastasis rate (P = 0.32), or overall survival (OS) rate (P = 0.17) between the two groups.

CONCLUSION

A longer interval between neoadjuvant chemoradiotherapy and surgery can improve the PCR rate; however, it has no significant impact on the clinical efficacy or long-term prognosis. Due to some limitations in the number and quality of the studies, these findings still need to be further verified by multicenter, large-sample high-quality RCTs in the future.

Preoperative Chemoradiotherapy plus Nivolumab before Surgery in Patients with Microsatellite Stable and Microsatellite Instability-High Locally Advanced Rectal Cancer

PURPOSE

Preoperative chemoradiotherapy (CRT) and surgical resection are the standard treatment for locally advanced rectal cancer (LARC). Combining immune checkpoint inhibitors with radiation suggests a promising approach for enhancing efficacy. We investigated the efficacy of CRT followed by nivolumab and surgery in patients with LARC.

PATIENTS AND METHODS

In phase I, we investigated the feasibility of sequentially combined CRT, 5 cycles of nivolumab, and radical surgery. In phase II, patients with microsatellite stable (MSS) and microsatellite instability-high (MSI-H) LARC were evaluated.

RESULTS

Three patients in phase I received full courses of CRT and nivolumab without dose modification; the schedule was recommended for phase II. A pathologic complete response (pCR) was centrally confirmed in 30% [11/37; 90% confidence interval (CI), 18%-44%] and 60% (3/5) of the MSS and exploratory MSI-H cohorts, respectively. While immune-related severe adverse events were observed in 3 patients, no treatment-related deaths were observed. In 38 patients with MSS who underwent surgery, pCR rates of 75% (6/8) and 17% (5/30; P = 0.004, Fisher exact test) were observed in those with programmed cell death ligand 1 (PD-L1) tumor proportion score ≥1% and <1%, respectively; IHC staining was performed using pre-CRT samples. In 24 patients with MSS, pre-CRT samples were analyzed by flow cytometry; pCR rates of 78% (7/9) and 13% (2/15; P = 0.003, Fisher exact test) were observed for CD8+ T cell/effector regulatory T cell (CD8/eTreg) ratios of ≥2.5 and <2.5, respectively, in tumor-infiltrating lymphocytes.

CONCLUSIONS

CRT followed by consolidation nivolumab could increase pCR. PD-L1 expression and an elevated CD8/eTreg ratio were positive predictors in patients with MSS LARC.

Perioperative Complications After Proctectomy for Rectal Cancer: Does Neoadjuvant Regimen Matter?

OBJECTIVE

Investigate the association between neoadjuvant treatment strategy and perioperative complications in patients undergoing proctectomy for nonmetastatic rectal cancer.

SUMMARY OF BACKGROUND DATA

Neoadjuvant SC-TNT is an alternative to neoadjuvant CRT for rectal cancer. Some have argued that short-course radiation and extended radiation-to-surgery intervals increase operative difficulty and complication risk. However, the association between SC-TNT and surgical complications has not been previously investigated.

METHODS

This single-center retrospective cohort study included patients undergoing total mesorectal excision for nonmetastatic rectal cancer after SC-TNT or CRT between 2010 and 2018. Univariate analysis of severe POM and multiple secondary outcomes, including overall POM, intraoperative complications, and resection margins, was performed. Logistic regression of severe POM was also performed.

RESULTS

Of 415 included patients, 156 (38%) received SC-TNT and 259 (62%) received CRT. The cohorts were largely similar, though patients with higher tumors (69.9% vs 47.5%, P < 0.0001) or node-positive disease (76.9% vs 62.6%, P = 0.004) were more likely to receive SC-TNT. We found no difference in incidence of severe POM (9.6% SC-TNT vs 12.0% CRT, P = 0.46) or overall POM (39.7% SC-TNT vs 37.5% CRT, P = 0.64) between cohorts. Neoadjuvant regimen was also not associated with a difference in severe POM (odds ratio 0.42, 95% confidence interval 0.04-4.70, P = 0.48) in multivariate analysis. There was no significant association between neoadjuvant regimen and any secondary outcome.

CONCLUSION

In rectal cancer patients treated with SC-TNT and proctectomy, we found no significant association with POM compared to patients undergoing CRT. SC-TNT does not significantly increase the risk of POM compared to CRT.

Nonmetastatic ypt0 rectal cancer after neoadjuvant treatment and total mesorectal excision: Lessons from a retrospective multicentric cohort of 383 patients

BACKGROUND

A better understanding of pathological features and oncological survival in ypT0 rectal cancer after neoadjuvant chemoradiotherapy is required to improve patient selection criteria for rectal-preserving approach by local excision. Our aim was to define risk of lymph node metastasis and oncological outcomes in ypT0 rectal cancer after chemoradiotherapy and total mesorectal excision.

METHODS

All consecutive patients who underwent total mesorectal excision for a nonmetastatic rectal adenocarcinoma classified ypT0 after neoadjuvant chemoradiotherapy, with or without locoregional lymph node involvement (ypN+ or ypN-), in 14 French academic centers between 2002 and 2015 were included. Data were collected retrospectively. Overall and disease-free survival were explored.

RESULTS

Among the 383 ypT0 patients, 6% were ypN+ (23/283). Before chemoradiotherapy, 86% (327/380) were staged cT3-T4 and 41% (156/378) were staged cN+. The risk of ypN+ did not differ between cT3-T4 and cT1-T2 patients (P = .345) or between cN+ and cN- patients (P = .384). After a median follow-up of 61.1 months, we observed 95% confidence interval (92%-97%) of 5-year overall survival and 93% confidence interval (91%-96%) of 5-year disease-free survival. In Cox multivariate analysis, overall survival was altered by intra-abdominal septic complications (hazard ratio = 2.53, confidence interval [1.11-5.78], P = .028). Regarding disease-free survival, ypN+ status and administration of adjuvant chemotherapy were associated with a reduced disease-free survival (P = .001 for both). cT3/T4 staging and cN+ staging did not modify overall survival (P = .332 and P = .450) nor disease-free survival (P = .862 and P = .124).

CONCLUSION

The risk of lymph node metastasis and the oncological survival do not depend on the initial cT or cN staging in cases of ypT0 complete rectal tumor regression.

Effect of pathological complete response after neoadjuvant chemoradiotherapy on postoperative complications of rectal cancer: a systematic review and meta-analysis

BACKGROUND

Standard total mesorectal resection has become an important treatment option for locally advanced or high-risk rectal cancer after neoadjuvant chemo-radiotherapy. 15-27% of patients can achieve pathological complete response (PCR) after neoadjuvant chemo-radiotherapy (nCRT). However, the relationship between PCR and postoperative complications remains an important unsolved problem. The objective of this study was to determine whether PCR was associated with the rate of postoperative complications.

METHODS

This meta-analysis was implemented following the recommendations from Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We searched electronic literature by PubMed, EMBASE, and Google Scholar. Major outcomes of interest included anastomotic leakage, surgical-site infection, reoperation, and any postoperative complications. Other outcomes comprised postoperative hemorrhage, ileus, and mortality.

RESULTS

Eleven thousand two hundred ninety patients in 9 studies were included in the meta-analysis. The pooled analysis revealed that patients with PCR did not have a higher risk of anastomotic leakage (OR = 1.22, 95% CI 0.92-1.62, p = 0.17), reoperation (OR = 1.13, 95% CI 0.93-1.37, p = 0.22), and any postoperative complications (OR = 1.02, 95% CI 0.91-1.15, p = 0.72) than patients with non-PCR. However, the meta-analysis showed that the PCR group was superior to the non-PCR group in terms of surgical-site infection (9.38% vs. 12.44%OR = 0.68, 95% CI 0.47-0.98; p = 0.04).

CONCLUSION

PCR might not be related to the occurrence of postoperative complications in rectal cancer patients following nCRT. In addition, PCR might be associated with a lower risk of surgical-site infection.

Effects of Neoadjuvant Radiotherapy on Postoperative Complications in Rectal Cancer: A Meta-Analysis

Objective

Neoadjuvant radiotherapy (nRT) is an important treatment approach for rectal cancer. The relationship, however, between nRT and postoperative complications is still controversial. Here, we conducted a meta-analysis to evaluate such concerns.

Methods

The electronic literature from 1983 to 2021 was searched in PubMed, Embase, and Web of Science. Postoperative complications after nRT were included in the meta-analysis. The pooled odds ratio (OR) was calculated by the random-effects model. Statistical analysis was conducted by Review Manager 5.3 and STATA 14.

Results

A total of 23,723 patients from 49 studies were included in the meta-analysis. The pooled results showed that nRT increased the risk of anastomotic leakage (AL) compared to upfront surgery (OR = 1.23; 95% CI, 1.07-1.41; p=0.004). Subgroup analysis suggested that both long-course (OR = 1.20, 95% CI 1.03-1.40; p=0.02) and short-course radiotherapy (OR = 1.25, 95% CI, 1.02-1.53; p=0.04) increased the incidence of AL. In addition, nRT was the main risk factor for wound infection and pelvic abscess. The pooled data in randomized controlled trials, however, indicated that nRT was not associated with AL (OR = 1.01; 95% CI 0.82-1.26; p=0.91).

Conclusions

nRT may increase the risk of AL, wound infection, and pelvic abscess compared to upfront surgery among patients with rectal cancer.

A multicentre cohort study assessing the utility of routine blood tests as adjuncts to identify complete responders in rectal cancer following neoadjuvant chemoradiotherapy

PURPOSE

Management of rectal cancer with a complete clinical response (cCR) to neoadjuvant chemoradiotherapy (NACRT) is controversial. Some advocate "watch and wait" programmes and organ-preserving surgery. Central to these strategies is the ability to accurately preoperatively distinguish cCR from residual disease (RD). We sought to identify if post-NACRT (preoperative) inflammatory markers act as an adjunct to MRI and endoscopy findings for distinguishing cCR from RD in rectal cancer.

METHODS

Patients from three specialist rectal cancer centres were screened for inclusion (2010-2015). For inclusion, patients were required to have completed NACRT, had a post-NACRT MRI (to assess mrTRG) and proceeded to total mesorectal excision (TME). Endoluminal response was assessed on endoscopy at 6-8 weeks post-NACRT. Pathological response to therapy was calculated using a three-point tumour regression grade system (TRG1-3). Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), serum albumin (SAL), CEA and CA19-9 levels post-NACRT (preoperatively) were recorded. Variables were compared between those who had RD on post-operative pathology and those with ypCR. Statistical analysis was performed using SPSS (version 21).

RESULTS

Six hundred forty-six patients were screened, of which 422 were suitable for inclusion. A cCR rate of 25.5% (n = 123) was observed. Sixty patients who achieved cCR were excluded from final analysis as they underwent organ-preserving surgery (local excision) leaving 63 ypCR patients compared to 359 with RD. On multivariate analysis, combining cCR on MRI and endoscopy with NLR < 5 demonstrated the greatest odds of ypCR on final histological assessment [OR 6.503 (1.594-11.652]) p < 0.001]. This method had the best diagnostic accuracy (AUC = 0.962 95% CI 0.936-0.987), compared to MRI (AUC = 0.711 95% CI 0.650-0.773) or endoscopy (AUC = 0.857 95% CI 0.811-0.902) alone or used together (AUC = 0.926 95% CI 0.892-0.961).

CONCLUSION

Combining post-NACRT inflammatory markers with restaging MRI and endoscopy findings adds another avenue to aid distinguishing RD from cCR in rectal cancer.

Evaluation of Efficacy and Tolerance of Radical Radiotherapy and Radiochemotherapy in Treatment of Locally Advanced, Unresectable Rectal Cancer

Background: A retrospective evaluation of tolerance and efficacy of two schemes of neoadjuvant treatment in patients (pts) with unresectable rectal cancer: radiochemotherapy (CRT) and radiotherapy (RT), including conventional and accelerated hyperfractionation. Material and Method: A total of 145 consecutive pts with unresectable, locally advanced rectal cancer. The schemes used are RT in 73 (50%) or CRT in 72 (50%). In CRT, 54 Gy in 1.8 Gy fractions was given with chemotherapy, In the RT group, conventional fractionation (CFRT) and hyperfractionated accelerated radiotherapy (HART). HART was introduced at first as an alternative to CFRT, after radiobiological studies suggesting a therapeutic gain of hyperfractionation in other cancers, and second to administer relatively high dose needed in unresectable cancer, which is not feasible in hypofractionation because of critical organs sensitivity to high fraction doses (fd). HART was an alternative option in pts with medical contraindications to chemotherapy and to shorten overall treatment time with greater radiobiological effectiveness than CFRT. Results: Objective response (OR) in the RT and CRT group was 60% versus 75%. Resection rate (RR) in RT and CRT: 37% versus 65%. Tumor mobility and laparotomy-based unresectability were significant factors for OR. Performance status (PS), tumor mobility, and neoadjuvant treatment method were significant for RR.

Factors influencing downstaging after neoadjuvant long-course chemoradiotherapy in rectal carcinoma

PURPOSE

This single-centre cohort study was designed to identify factors that can predict primary tumour downstaging by neoadjuvant chemoradiotherapy (nCRT) in rectal carcinoma.

METHODS

Prospectively collected data from 555 patients with clinical T category (cT) cT3-4 rectal carcinoma treated between 1995 and 2019 were retrospectively analysed. All patients received long-term neoadjuvant chemoradiotherapy followed by surgery with curative intent at the Department of Surgery, University Hospital Erlangen, Germany. Patient-, tumour- and treatment-related factors with a potential impact on the downstaging of rectal carcinoma to pathological T category (pT) ≤ ypT2 and ypT0 were analysed in univariate and multivariate logistic regression analyses. The prognosis of patients with and without downstaging of the primary tumour was compared.

RESULTS

A total of 288 (51.9%) patients showed downstaging to ≤ ypT2. Eighty-six (15.5%) patients achieved clinical complete regression (ypT0). In the multivariate logistic regression analysis, the factors cT category, BMI, ECOG score, CEA, histological type, extension in the rectum and year of the start of treatment were found to be independent factors for predicting downstaging to ≤ ypT2 after neoadjuvant chemoradiotherapy. The year of treatment initiation also remained an independent significant predictor for pathological complete regression. The prognosis was superior in patients with downstaging to ≤ ypT2 in terms of locoregional and distant recurrence as well as disease-free and overall survival.

CONCLUSION

Factors predicting downstaging after long-term nCRT could be identified. This may be helpful for counselling patients and selecting the optimal treatment for patients with advanced rectal carcinoma.

Rectal cancer radiotherapy

We present the updated recommendations of the French society of oncological radiotherapy for rectal cancer radiotherapy. The standard treatment for locally advanced rectal cancer consists in chemoradiotherapy followed by radical surgery with total mesorectal resection and adjuvant chemotherapy according to nodal status. Although this strategy efficiently reduced local recurrences rates below 5% in expert centres, functional sequelae could not be avoided resulting in 20 to 30% morbidity rates. The early introduction of neoadjuvant chemotherapy has proven beneficial in recent trials, in terms of recurrence free and metastasis free survivals. Complete pathological responses were obtained in 15% of tumours treated by chemoradiation, even reaching up to 30% of tumours when neoadjuvant chemotherapy is associated to chemoradiotherapy. These good results question the relevance of systematic radical surgery in good responders. Personalized therapeutic strategies are now possible by improved imaging modalities with circumferential margin assessed by magnetic resonance imaging, by intensity modulated radiotherapy and by refining surgical techniques, and contribute to morbidity reduction. Keeping the same objectives, ongoing trials are now evaluating therapeutic de-escalation strategies, in particular rectal preservation for good responders after neoadjuvant treatment, or radiotherapy omission in selected cases (Greccar 12, Opera, Norad).

Factors Predicting Pathological Response to Neoadjuvant Chemoradiotherapy in Rectal Cancer: The Experience of a Single Institution with 269 Patients (STONE-01)

Simple Summary

Neoadjuvant chemoradiotherapy (CRT) followed by total mesorectal excision is currently the standard of care for locally advanced rectal cancer (LARC). This retrospective cohort study evaluated the pathological response after CRT in relation to treatment factors and patient and disease factors in order to find useful indicators to further improve the efficacy of CRT and create tailored therapeutic approaches. To date, the optimal timing for surgery after CRT has not been established. In literature, there are controversial results regarding the risk of higher surgical morbidity and perioperative complications due to delayed surgery. In our study carried out on 269 consecutive LARC patients, among the items analyzed, an interval time from CRT to surgery of >8 weeks was the only independent significant factor for pCR and downstaging.

Abstract

Aims: The aim of this study was to define a potential benefit of pathological complete response rate (pCR) and downstaging rate after neoadjuvant chemoradiotherapy (CRT) in relation to treatment and patient factors in locally advanced rectal cancer. Methods: We performed a retrospective cohort study. Patients were divided according to chemotherapy regimens concurrent to radiotherapy (1-drug vs. 2-drug) and according to the time interval between the end of CRT and surgery (≤8 weeks vs. >8 weeks), as well as in relation to specific relevant clinical factors. Logistic regression was used to estimate the independent factors for pCR and downstaging. Results: 269 patients were eligible for this study. Overall, pCR and downstaging rates were 26% and 75.4%, respectively. Univariate analysis showed that female gender (p = 0.01) and time to surgery >8 weeks (p = 0.04) were associated with pCR; age > 70 years (p = 0.05) and time to surgery >8 weeks (p = 0.002) were correlated to downstaging. At multivariate analysis, interval time to surgery of >8 weeks was the only independent factor for both pCR and downstaging (p = 0.02; OR: 0.5, CI: 0.27–0.93 and p = 0.003; OR: 0.42, CI: 0.24–0.75, respectively). Conclusions: This study indicates that, in our population, an interval time to surgery of >8 weeks is an independent significant factor for pCR and downstaging. Further prospective studies are needed to define the best interval time.

Current status of total neoadjuvant therapy for locally advanced rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) plus total mesorectal excision (TME) has been the standard regimen for treatment of patients with locally advanced rectal cancer (LARC), because it significantly reduces the rate of local recurrence and enables sphincter preservation. However, distant metastasis remains the major reason for treatment failure, and the value of postoperative chemotherapy is still controversial. Recent studies have examined the use of total neoadjuvant therapy (TNT), defined as induction and/or consolidation chemotherapy (CONCT) with radiotherapy (RT) or nCRT prior to surgery. The results indicated that TNT may increase the rates of chemotherapy compliance and pathological complete response (pCR), and probably improve the success rate of sphincter preservation surgery. TNT may also improve disease-free survival and overall survival, and even reduce the rate of relapse. Here, we critically appraise the existing literature on three different TNT schemes used for LARC patients.

One to Two Cycles of Consolidation Chemotherapy With Capecitabine After Neoadjuvant Chemoradiotherapy Does Not Benefit Low-Risk Patients With Locally Advanced Middle-Low Rectal Cancer

Background and Objective

Organ preservation can enable locally advanced rectal cancer (LARC) patients with clinical complete response (cCR) after neoadjuvant treatment to maintain quality of life. In this study, we aimed to evaluate whether one or two cycles of capecitabine after neoadjuvant chemoradiotherapy (NCRT) without extending the interval between the end of NCRT and surgery could increase the complete response (CR) rate in low-risk middle-low LARC patients.

Material and Methods

We retrospectively evaluated middle-low LARC patients with low risk defined as clinical T2-3b, mesorectal fascia-clear, and extramural vascular invasion-negative by magnetic resonance imaging (MRI), treated between January 2015 and July 2019. Patients were divided into two groups according to whether consolidation chemotherapy was administered after NCRT. Patients in the consolidation chemotherapy group received one or two cycles of capecitabine (1000 mg/m² twice daily from days 1 to 14). The main outcome was the CR rate, including pathological CR (pCR) and cCR.

Results

A total of 169 patients, 105 in the consolidation chemotherapy group and 64 in the non-consolidation chemotherapy group, were included in the study, and the median follow-up was 37.2 months (range, 0.4–71.2 months). Seventeen patients achieved cCR and the remaining 152 underwent surgery after neoadjuvant treatment. There was no significant difference in the CR rate (39.0% vs. 35.9%, p=0.686), ypT0-2N0 rate (65.2% vs. 63.3%, p=0.812), or ypN0 rate (83.7% vs. 88.3%, p=0.503) between the consolidation chemotherapy and non-consolidation chemotherapy groups. Among the patients achieved cCR, 3 (17.6%) experienced regrowth in the rectum and 2 (11.8%) experienced distant metastasis. There was also no significant difference in the 3-year disease-free survival (87.4% vs 85.9%, p=0.971) in patients who underwent surgery between the two groups. Multivariate logistic regression analysis indicated that normal Carcinoma Embryonic Antigen (CEA) levels (p = 0.001) were associated with a higher CR rate. Moreover, there were no significant differences in the incidences of grade ≥2 acute toxicities during neoadjuvant treatment.

Conclusion

Although there was no increase in treatment-related toxicities between the two groups, simply adding one or two cycles of capecitabine after NCRT might be insufficient to benefit low-risk middle-low LARC patients.

Evaluation and Predictive Factors of Complete Response in Rectal Cancer after Neoadjuvant Chemoradiation Therapy

The response to neoadjuvant chemoradiation therapy is an important prognostic factor for locally advanced rectal cancer. Although the majority of the patients after neoadjuvant therapy are referred to following surgery, the clinical data show that complete clinical or pathological response is found in a significant proportion of the patients. Diagnostic accuracy of confirming the complete response has a crucial role in further management of a rectal cancer patient. As the rate of clinical complete response, unfortunately, is not always consistent with pathological complete response, accurate diagnostic parameters and predictive markers of tumor response may help to guide more personalized treatment strategies and identify potential candidates for nonoperative management more safely. The management of complete response demands interdisciplinary collaboration including oncologists, radiotherapists, radiologists, pathologists, endoscopists and surgeons, because the absence of a multidisciplinary approach may compromise the oncological outcome. Prediction and improvement of rectal cancer response to neoadjuvant therapy is still an active and challenging field of further research. This literature review is summarizing the main, currently known clinical information about the complete response that could be useful in case if encountering such condition in rectal cancer patients after neoadjuvant chemoradiation therapy, using as a source PubMed publications from 2010–2021 matching the search terms “rectal cancer”, “neoadjuvant therapy” and “response”.

Association of Delayed Surgery With Oncologic Long-term Outcomes in Patients With Locally Advanced Rectal Cancer Not Responding to Preoperative Chemoradiation

Importance

Extending the interval between the end of neoadjuvant chemoradiotherapy (CRT) and surgery may enhance tumor response in patients with locally advanced rectal cancer. However, data on the association of delaying surgery with long-term outcome in patients who had a minor or poor response are lacking.

Objective

To assess a large series of patients who had minor or no tumor response to CRT and the association of shorter or longer waiting times between CRT and surgery with short- and long-term outcomes.

Design, Setting, and Participants

This is a multicenter retrospective cohort study. Data from 1701 consecutive patients with rectal cancer treated in 12 Italian referral centers were analyzed for colorectal surgery between January 2000 and December 2014. Patients with a minor or null tumor response (ypT stage of 2 to 3 or ypN positive) stage greater than 0 to neoadjuvant CRT were selected for the study. The data were analyzed between March and July 2020.

Exposures

Patients who had a minor or null tumor response were divided into 2 groups according to the wait time between neoadjuvant therapy end and surgery. Differences in surgical and oncological outcomes between these 2 groups were explored.

Main Outcomes and Measures

The primary outcomes were overall and disease-free survival between the 2 groups.

Results

Of a total of 1064 patients, 654 (61.5%) were male, and the median (IQR) age was 64 (55-71) years. A total of 579 patients (54.4%) had a shorter wait time (8 weeks or less) 485 patients (45.6%) had a longer wait time (greater than 8 weeks). A longer waiting time before surgery was associated with worse 5- and 10-year overall survival rates (67.6% [95% CI, 63.1%-71.7%] vs 80.3% [95% CI, 76.5%-83.6%] at 5 years; 40.1% [95% CI, 33.5%-46.5%] vs 57.8% [95% CI, 52.1%-63.0%] at 10 years; P < .001). Also, delayed surgery was associated with worse 5- and 10-year disease-free survival (59.6% [95% CI, 54.9%-63.9%] vs 72.0% [95% CI, 67.9%-75.7%] at 5 years; 36.2% [95% CI, 29.9%-42.4%] vs 53.9% [95% CI, 48.5%-59.1%] at 10 years; P < .001). At multivariate analysis, a longer waiting time was associated with an augmented risk of death (hazard ratio, 1.84; 95% CI, 1.50-2.26; P < .001) and death/recurrence (hazard ratio, 1.69; 95% CI, 1.39-2.04; P < .001).

Conclusions and Relevance

In this cohort study, a longer interval before surgery after completing neoadjuvant CRT was associated with worse overall and disease-free survival in tumors with a poor pathological response to preoperative CRT. Based on these findings, patients who do not respond well to CRT should be identified early after the end of CRT and undergo surgery without delay.

Brazilian society of surgical oncology: Guidelines for the surgical treatment of mid-low rectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer in North America, Western Europe, and Brazil, and represents an important public health problem. It is estimated that approximately 30% of all the CRC cases correspond to tumors located in the rectum, requiring complex multidisciplinary treatment. In an effort to provide surgeons who treat rectal cancer with the most current information based on the best evidence in the literature, the Brazilian Society of Surgical Oncology (SBCO) has produced the present guidelines for rectal cancer treatment that is focused on the main topics related to daily clinical practice.

OBJECTIVES

The SBCO developed the present guidelines to provide recommendations on the main topics related to the treatment of mid-low rectal cancer based on current scientific evidence.

METHODS

Between May and June 2021, 11 experts in CRC surgery met to develop the guidelines for the treatment of mid-low rectal cancer. A total of 22 relevant topics were disseminated among the participants. The methodological quality of a final list with 221 sources was evaluated, all the evidence was examined and revised, and the treatment guideline was formulated by the 11-expert committee. To reach a final consensus, all the topics were reviewed via a videoconference meeting that was attended by all 11 of the experts.

RESULTS

The prepared guidelines contained 22 topics considered to be highly relevant in the treatment of mid-low rectal cancer, covering subjects related to the tests required for staging, surgical technique-related aspects, recommended measures to reduce surgical complications, neoadjuvant strategies, and nonoperative treatments. In addition, a checklist was proposed to summarize the important information and offer an updated tool to assist surgeons who treat rectal cancer provide the best care to their patients.

CONCLUSION

These guidelines summarize concisely the recommendations based on the most current scientific evidence on the most relevant aspects of the treatment of mid-low rectal cancer and are a practical guide that can help surgeons who treat rectal cancer make the best therapeutic decision.

Clinical outcome of neoadjuvant chemoradiation in rectal cancer treatment

To determine the clinical and pathological outcome of locally advanced rectal cancer patients treated with neoadjuvant chemoradiation (chemoradiotherapy [CRT]) followed by curative surgery and to identify predictive factors of pathological complete response (pCR).Locally advanced rectal cancer patients undergoing CRT followed by curative surgery from January 2012 to December 2017 were included. Patient's demographic data, pretreatment tumor characteristics, type of CRT regimens, type of surgery, postoperative complications, pathological reports and follow up records were analyzed. Univariate and multivariate analyses were applied to identify predictive factors for pCR. Five-year disease free and overall survival were estimated by Kaplan-Meier method and compared between pCR and non-pCR groups.A total of 85 patients were analyzed. Eighteen patients (21.1%) achieved pCR. The sphincter-saving surgery rate was 57.6%. After univariate analyses, tumor length >4 cm (P = .007) and positive lymph nodes (P = .040) were significantly associated with decreased rate of pCR. Complete clinical response was significantly associated with higher rate of pCR (P = .015). Multivariate analyses demonstrated that tumor length >4 cm (P = .010) was significantly associated with decreased rate of pCR. After a median follow-up of 65 months (IQR 34-79), the calculated 5-year overall survival and disease-free survival rates were 81.4% and 69.7%, respectively. Patients who achieved pCR tend to had longer 5-year disease-free survival (P = .355) and overall survival (P = .361) than those who did not.Tumor length >4 cm was associated with decreased rate of pCR in locally advanced rectal cancer who had CRT followed by surgery. Longer waiting time or more intense adjuvant treatment may be considered to improved pCR and oncological outcomes.

Anus-Preserving Surgery in Advanced Low-Lying Rectal Cancer: A Perspective on Oncological Safety of Intersphincteric Resection

The surgical management of low-lying rectal cancer, within 5 cm from the anal verge (AV), is challenging due to the possibility, or not, to preserve the anus with its sphincter muscles maintaining oncological safety. The standardization of total mesorectal excision, the adoption of neoadjuvant chemoradiotherapy, the implementation of rectal magnetic resonance imaging, and the evolution of mechanical staplers have increased the rate of anus-preserving surgeries. Moreover, extensive anatomy and physiology studies have increased the understanding of the complexity of the deep pelvis. Intersphincteric resection (ISR) was introduced nearly three decades ago as the ultimate anus-preserving surgery. The definition and indication of ISR have changed over time. The adoption of the robotic platform provides excellent perioperative results with no differences in oncological outcomes. Pushing the boundaries of anus-preserving surgeries has risen doubts on oncological safety in order to preserve function. This review critically discusses the oncological safety of ISR by evaluating the anatomical characteristics of the deep pelvis, the clinical indications, the role of distal and circumferential resection margins, the role of the neoadjuvant chemoradiotherapy, the outcomes between surgical approaches (open, laparoscopic, and robotic), the comparison with abdominoperineal resection, the risk factors for oncological outcomes and local recurrence, the patterns of local recurrences after ISR, considerations on functional outcomes after ISR, and learning curve and surgical education on ISR.

The efficacy and safety of different radiotherapy doses in neoadjuvant chemoradiotherapy for locally advanced rectal cancer

Background

This study aimed to evaluate efficacy and adverse effects of different radiotherapy (RT) doses in neoadjuvant chemoradiotherapy for locally advanced rectal cancer.

Methods

Fifty-nine patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy in hospital between January 2015 and May 2017 were enrolled in retrospective analysis. The patients were divided into the 56-Gy group and the 50-Gy group. The concurrent chemotherapy regimen was based on capecitabine. All patients received one cycle of oxaliplatin combined with capecitabine induction chemotherapy. All patients completed neoadjuvant chemoradiotherapy and received radical surgery.

Results

Of the patients in this study, 29 patients and 30 patients received a radiation dose of 56- and 50-Gy, respectively. All clinical characteristics were matched between the two groups. All patients received surgery 6 to 8 weeks after completing RT. The therapeutical effective rate in the 56-Gy group was 93.10% (27/29), compared with 66.67% in the 50-Gy group (20/30); the difference between the two groups was statistically significant (χ²=6.36, P=0.01). The pathological complete remission (pCR) rate in the 56-Gy group (37.93%, 11/29) was statistically significantly higher than that in the 50-Gy group (13.33%, 4/30) (χ²=4.71, P=0.030). The anal preservation rate in the 56-Gy group (65.5%, 19/29) was statistically significantly higher than that in the 50-Gy group (33.33%, 10/30) (χ²=6.11, P=0.01). The 56-Gy group had a local recurrence rate of 0% (0/29) and a distant metastasis rate of 10.34% (3/29), while the 50-Gy group had a local recurrence rate of 6.67% (2/30) and a distant metastasis rate of 16.67% (5/30); no significant difference existed between the two groups (χ²=2.00, 0.50, P=0.16, 0.48). The incidence of adverse reactions (gastrointestinal reactions, bone marrow suppression, and perianal skin reactions) in the 56-Gy group was not significantly different from that in the 50-Gy group (P>0.05).

Conclusions

Increasing the radiation dose can significantly improve the anal preservation and pCR rates of patients with locally advanced rectal cancer, thus improving their life quality. Moreover, it does not increase the rates of recurrence or adverse reactions. Our findings have certain clinical significance, but further prospective study is needed.

Validation of Gene Expression-Based Predictive Biomarkers for Response to Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) followed by surgery is widely used for patients with locally advanced rectal cancer. However, response to nCRT varies substantially among patients, highlighting the need for predictive biomarkers that can distinguish non-responsive from responsive patients before nCRT. This study aimed to build novel multi-gene assays for predicting nCRT response, and to validate our signature and previously-reported signatures in multiple independent cohorts.

METHODS

Three microarray datasets of pre-therapeutic biopsies containing a total of 61 non-responders and 53 responders were used as the discovery cohorts to screen for genes that were consistently associated with nCRT response. The predictive values of signatures were tested in a meta-analysis using six independent datasets as the validation cohorts, consisted of a total of 176 non-responders and 99 responders.

RESULTS

We identified four genes, including BRCA1, GPR110, TNIK, and WDR4 in the discovery cohorts. Although our 4-gene signature and nine published signatures were evaluated, they were unable to predict nCRT response in the validation cohorts.

CONCLUSIONS

Although this is one of the largest studies addressing the validity of gene expression-based classifiers using pre-treatment biopsies from patients with rectal cancer, our findings do not support their clinically meaningful values to be predictive of nCRT response.

A novel approach for radiotherapy dose escalation in rectal cancer using online MR-guidance and rectal ultrasound gel filling - Rationale and first in human

INTRODUCTION

Dose escalated radiotherapy has previously been investigated as a strategy to increase complete response rates in rectal cancer. However large safety margins are required using cone-beam computed tomography guided radiotherapy leading to high doses to organs at risk or insufficient target volume coverage in order to keep dose constraints. We herein present the first clinical application of a new technique for dose escalation in rectal cancer using online magnetic resonance (MR)-guidance and rectal ultrasound gel filling.

METHODS

A 73-year-old patient with distal cT3a cN0 cM0 rectal cancer was referred for definitive radiochemotherapy with the goal of organ preservation after multidisciplinary discussion. A dose of 45 Gy in 25 fractions with a stereotactic integrated boost to the primary tumor of 50 Gy with concomitant 5-fluorouracil was prescribed. Furthermore, a boost to the primary tumor with 3 Gy per fraction using the adapt-to-shape workflow on a 1.5 T MR-Linac was planned once weekly. For the boost fractions 100 cc of ultrasound gel was applied rectally in order to improve tumor visibility and distancing of uninvolved rectal mucosa. In order to determine the required planning target volume margin diagnostic scans of ten rectal cancer patients conducted with rectal ultrasound gel filling were studied.

RESULTS

Based on the ten diagnostic scans an average isotropic margin of 4 mm was found to be sufficient to cover 95% of the target volume during an online adaptive workflow. Three boost fractions were applied, mean treatment duration was 22:34 min. Treatment was well tolerated by the patient with no more than PRO-CTCAE grade I° toxicity of any kind. The rectal ultrasound gel filling resulted in superior visibility of the tumor and reduced the dose to the involved mucosa especially in the high dose range compared with a boost plan calculated without any filling. A considerable tumor shrinkage was observed during treatment from 17.43 cc at baseline to 4 cc in week four.

CONCLUSION

This novel method appears to be a simple but effective strategy for dose escalated radiotherapy in rectal cancer. Based on the encouraging observation, a prospective trial is currently under preparation.

Total Neoadjuvant Therapy (TNT) versus Standard Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Total neoadjuvant therapy (TNT) is a novel approach for locally advanced rectal cancer (LARC), which attempts to deliver both systemic chemotherapy and neoadjuvant chemoradiotherapy prior to surgery. However, its efficacy and safety remain controversial in randomized controlled trials (RCTs). We conducted this meta-analysis to assess such concerns.

MATERIALS AND METHODS

Head-to-head phase II/III RCTs were searched in Embase, PubMed, Web of Science, and the Cochrane Library, as well as other sources. The primary endpoint was pathologic complete response (pCR). Secondary endpoints were disease-free survival (DFS), overall survival (OS), local recurrence-free survival, distant metastasis-free survival, and the R0 resection rate.

RESULTS

Eight phase II/III RCTs involving 2,196 patients with LARC were assessed. The primary analysis demonstrated a statistically significant improvement in the pCR rate for TNT treatment (odds ratio, 1.77; 95% confidence interval [CI], 1.28-2.45; p = .0005). TNT treatment also showed improvements in DFS and OS outcomes compared with standard chemoradiotherapy (hazard ratio [HR], 0.83; 95% CI, 0.72-0.96; p = .03 and HR, 0.88; 95% CI, 0.74-1.05; p = .15). In addition, TNT treatment showed significant efficacy in reducing the risk of distant metastasis (HR, 0.81; 95% CI, 0.68-0.95; p = .012).

CONCLUSION

The overall pCR rate may be improved with TNT compared with standard treatment. The TNT strategy may also improve DFS and OS and reduce the risk of distant metastasis.

IMPLICATIONS FOR PRACTICE

Locally advanced rectal cancer (LARC) is a relatively common disease, with a poor prognosis because of its high metastatic potential. The role of total neoadjuvant therapy (TNT) has always been controversial. This meta-analysis found that TNT in LARC is associated with a significant improvement in overall pathologic complete response rate, disease-free survival, overall survival, and distant metastasis-free survival compared with standard treatment. TNT is a promising strategy for LARC, especially for patients who have little desire for surgery.

Improvement in the Assessment of Response to Preoperative Chemoradiotherapy for Rectal Cancer Using Magnetic Resonance Imaging and a Multigene Biomarker

The response to preoperative chemoradiotherapy (PCRT) is correlated with oncologic outcomes in patients with locally advanced rectal cancer. Accurate prediction of PCRT response before surgery can provide crucial information to aid clinicians in further treatment planning. This study aimed to develop an evaluation tool incorporating a genetic biomarker and magnetic resonance imaging (MRI) to improve the assessment of response in post-CRT patients with locally advanced rectal cancer. A total of 198 patients who underwent PCRT followed by surgical resection for locally advanced rectal cancer between 2010 and 2016 were included in this study. Each patient's response prediction index (RPI) score, a multigene biomarker developed in our previous study, and magnetic resonance tumor regression grade (mrTRG) score were added to create a new predictive value for pathologic response after PCRT, called the combined radiation prediction value (cRPV). Based on the new value, 121 and 77 patients were predicted to be good and poor responders, respectively, showing significantly different cRPV values (p = 0.001). With an overall predictive accuracy of 84.8%, cRPV was superior to mrTRG and RPI for the prediction of pathologic chemoradiotherapy response (mrTRG, 69.2%; RPI, 77.3%). In multivariate analysis, cRPV was found to be the sole predictor of tumor response (odds ratio, 32.211; 95% confidence interval, 14.408-72.011; p = 0.001). With its good predictive value for final pathologic regression, cRPV may be a valuable tool for assessing the response to PCRT before surgery.