Increasing the rates of complete response to neoadjuvant chemoradiotherapy for distal rectal cancer: results of a prospective study using additional chemotherapy during the resting period

The Role of Intraoperative Radiotherapy Treatment of Locally Advanced Rectal Cancer

Intraoperative radiation therapy (IORT) has been used in the treatment of locally advanced and recurrent rectal cancers for the last several decades. Given the heterogeneity of patients treated and different indications for use and dosing at different institutions, it has been difficult to discern if IORT adds any appreciable benefit to standard of care therapies. Herein, the rationale for IORT in rectal cancer is discussed along with the most modern and best available data in 2023. IORT is likely indicated in patients with locally advanced and locally recurrent rectal cancer with threatened margins (R0 or R1 resection) to help improve local control. High-quality imaging and multidisciplinary discussion are necessary to ensure optimal patient selection. Appropriate counseling of the patient and excellent team communication are of the utmost importance given the challenging nature of these cases and the prognostic implications of R1 and R2 resections in this patient population.

Treatment of Locally Advanced Rectal Cancer in the Era of Total Neoadjuvant Therapy: A Systematic Review and Network Meta-Analysis

Importance

Treatment of locally advanced rectal cancer (LARC) involves neoadjuvant chemoradiotherapy plus total mesorectal excision and adjuvant chemotherapy. However, total neoadjuvant therapy (TNT) protocols (ie, preoperative chemotherapy in addition to radiotherapy) may allow better adherence and early treatment of distant micrometastases and may increase pathological complete response (pCR) rates.

Objective

To assess the efficacy and tolerability of TNT protocols for LARC.

Data Sources

MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science Core Collection electronic databases and ClinicalTrials.gov for unpublished studies were searched from inception to March 2, 2024.

Study Selection

Randomized clinical trials including adults with LARC who underwent rectal resection as a final treatment were included. Studies including nonoperative treatment (watch-and-wait strategy), treatments other than rectal resection, immunotherapy, or antiangiogenic agents were excluded. Among the initially identified studies, 2.9% met the selection criteria.

Data Extraction and Synthesis

Two authors independently screened the records and extracted data. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA)-compliant pairwise and network meta-analyses with a random-effects model were performed in a frequentist framework, and the certainty of evidence was assessed according to the confidence in network meta-analysis approach.

Main Outcomes and Measures

The primary outcome was pCR, defined as the absence of residual tumor at pathological assessment after surgery. Secondary outcomes included tolerability, toxic effects, perioperative outcomes, and long-term survival.

Results

Of 925 records identified, 27 randomized clinical trials, including 13 413 adults aged 18 years or older (median age, 60.0 years [range, 42.0-63.5 years]; 67.2% male) contributed to the primary network meta-analysis. With regard to pCR, long-course chemoradiotherapy (L-CRT) plus consolidation chemotherapy (relative risk [RR], 1.96; 95% CI, 1.25-3.06), short-course radiotherapy (S-RT) plus consolidation chemotherapy (RR, 1.76; 95% CI, 1.34-2.30), and induction chemotherapy plus L-CRT (RR, 1.57; 95% CI, 1.09-2.25) outperformed standard L-CRT with single-agent fluoropyrimidine-based chemotherapy. Considering 3-year disease-free survival, S-RT plus consolidation chemotherapy (RR, 1.08; 95% CI, 1.01-1.14) and induction chemotherapy plus L-CRT (RR, 1.12; 95% CI, 1.01-1.24) outperformed L-CRT, in spite of an increased 5-year locoregional recurrence rate of S-RT plus consolidation chemotherapy (RR, 1.65; 95% CI, 1.03-2.63).

Conclusions and Relevance

In this systematic review and network meta-analysis, 3 TNT protocols were identified to outperform the current standard of care in terms of pCR rates, with good tolerability and optimal postoperative outcomes, suggesting they should be recognized as first-line treatments.

Local Regrowth and the Risk of Distant Metastases Among Patients Undergoing Watch-and-Wait for Rectal Cancer: What Is the Best Control Group? Multicenter Retrospective Study

BACKGROUND

A proportion of rectal cancer patients who achieve a clinical complete response may develop local regrowth. Although salvage appears to provide appropriate local control, the risk of distant metastases is less known.

OBJECTIVE

To compare the risk of distant metastases between patients who achieve a clinical complete response (watch-and-wait strategy) and subsequent local regrowth and patients managed by surgery after chemoradiation.

DESIGN

Retrospective multicenter cohort study.

SETTINGS

This study used data of patients from 3 institutions who were treated between 1993 and 2019.

PATIENTS

Patients with initial clinical complete response (after neoadjuvant therapy) followed by local regrowth and patients with near-complete pathological response (≤10%) after straightforward surgery after chemoradiation were included.

MAIN OUTCOME MEASURES

Univariate and multivariate analyses were performed to identify risk factors for distant metastases. Kaplan-Meier curves were created (log-rank test) to compare survival outcomes. Analyses were performed using time zero as last day of radiation therapy or as date of salvage resection in the local regrowth group.

RESULTS

Twenty-one of 79 patients with local regrowth developed distant metastases, whereas only 10 of 74 after upfront total mesorectal excision following neoadjuvant chemoradiation therapy ( p  = 0.04). Local regrowth and final pathology (ypT3-4) were the only independent risk factors associated with distant metastases. When using date of salvage resection as time zero, distant metastases-free survival rates were significantly inferior for patients with local regrowth (70% vs 86%; p  = 0.01).

LIMITATIONS

Small number of patients, many neoadjuvant therapies, and selection bias.

CONCLUSIONS

Patients undergoing watch-and-wait strategy who develop local regrowth are at higher risk for development of distant metastases compared to patients with near-complete pathological response managed by upfront surgery after chemoradiation. See Video Abstract.

NUEVO CRECIMIENTO LOCAL Y EL RIESGO DE METSTASIS A DISTANCIA ENTRE PACIENTES SOMETIDOS A OBSERVACIN Y ESPERA POR CNCER DE RECTO CUL ES EL MEJOR GRUPO DE CONTROL ESTUDIO RETROSPECTIVO MUTICNTRICO

ANTECEDENTES:Una proporción de pacientes que logran una respuesta clínica completa pueden desarrollar un nuevo crecimiento local. Si bien el rescate parece proporcionar un control local apropiado, el riesgo de metástasis a distancia es menos conocido.OBJETIVO:Comparar el riesgo de metástasis a distancia entre los pacientes que logran una respuesta clínica completa (estrategia de observación y espera) y el nuevo crecimiento local posterior con los pacientes tratados con cirugía después de la quimiorradiación.DISEÑO:Estudio de cohorte multicéntrico retrospectivo.CONFIGURACIÓN:Este estudio utilizó datos de pacientes de 3 instituciones que fueron tratados entre 1993 y 2019.PACIENTES:Pacientes con respuesta clínica completa inicial (después de la terapia neoadyuvante) seguida de crecimiento local nuevo y pacientes con respuesta patológica casi completa (≤10 %) después de cirugía directa después de quimiorradiación.PRINCIPALES MEDIDAS DE RESULTADO:Se realizó un análisis univariante/multivariante para identificar los factores de riesgo de metástasis a distancia. Se crearon curvas de Kaplan-Meier (prueba de rango logarítmico) para comparar los resultados de supervivencia. El análisis se realizó utilizando el tiempo cero como último día de radioterapia (1) o como fecha de resección de rescate (2) en el grupo de recrecimiento local.RESULTADOS:Veintiuno de 79 pacientes con recrecimiento local desarrollaron metástasis a distancia, mientras que solo 10 de 74 después de una cirugía sencilla (p = 0,04). El recrecimiento local y la patología final (ypT3-4) fueron los únicos factores de riesgo independientes asociados con las metástasis a distancia. Cuando se utilizó la fecha de la resección de rescate como tiempo cero, las tasas de supervivencia sin metástasis a distancia fueron significativamente inferiores para los pacientes con recrecimiento local (70 frente a 86 %; p = 0,01).LIMITACIONES:Pequeño número de pacientes, muchas terapias neoadyuvantes, sesgo de selección.CONCLUSIONES:Los pacientes sometidos a observación y espera que desarrollan un nuevo crecimiento local tienen un mayor riesgo de desarrollar metástasis a distancia en comparación con los pacientes con una respuesta patológica casi completa manejados con cirugía por adelantado después de la quimiorradiación. (Traducción-Dr. Xavier Delgadillo ).

What is the optimal timing of surgery after short-course radiotherapy for rectal cancer?

BACKGROUND

Short-course neoadjuvant radiotherapy is a valuable tool in managing rectal cancers and has improved local recurrence rates. However, limited and conflicting data has resulted in variable usage and a lack of consensus on the optimal timing of surgery following short-course radiotherapy. This review aims to provide a contemporary summation of the available evidence regarding the optimal time interval between short-course neoadjuvant radiotherapy and surgery.

METHODS

A focused literature search was undertaken using the PubMed and Embase databases from January 1980 until January 2023. Randomised control trials, large observational studies and systematic reviews focusing on the use of short-course preoperative radiotherapy for localised rectal cancers, with a focus on the timing of surgery, were included. Primary outcomes were overall survival, disease-free survival and perioperative complications.

RESULTS

Five randomised control trials, two meta-analyses, and two large, population-based studies were included for their eligibility and relevance. Increased downstaging and fewer postoperative complications are demonstrated in patients receiving delayed surgery (> four weeks), but more recent data raise concerns regarding increased rates of local recurrence in this cohort. Studies directly comparing different time intervals to surgery following short-course radiotherapy have failed to demonstrate an effect on overall survival.

CONCLUSIONS

This review highlights the complexities and relative shortcomings of the available data with few high-quality studies and randomised control trials directly comparing different time intervals to surgery following short-course radiotherapy. Continuing research is needed to confirm existing findings and explore gaps in the current literature.

Radiotherapy in the preoperative neoadjuvant treatment of locally advanced rectal cancer

Radiotherapy and chemotherapy are effective treatments for patients with locally advanced rectal cancer (LARC) and can significantly improve the likelihood of R0 resection. Radiotherapy can be used as a local treatment to reduce the size of the tumor, improve the success rate of surgery and reduce the residual cancer cells after surgery. Early chemotherapy can also downgrade the tumor and eliminate micrometastases throughout the body, reducing the risk of recurrence and metastasis. The advent of neoadjuvant concurrent radiotherapy (nCRT) and total neoadjuvant treatment (TNT) has brought substantial clinical benefits to patients with LARC. Even so, given increasing demand for organ preservation and quality of life and the disease becoming increasingly younger in its incidence profile, there is a need to further explore new neoadjuvant treatment options to further improve tumor remission rates and provide other opportunities for patients to choose watch-and-wait (W&W) strategies that avoid surgery. Targeted drugs and immunologic agents (ICIs) have shown good efficacy in patients with advanced rectal cancer but have not been commonly used in neoadjuvant therapy for patients with LARC. In this paper, we review several aspects of neoadjuvant therapy, including radiation therapy and chemotherapy drugs, immune drugs and targeted drugs used in combination with neoadjuvant therapy, with the aim of providing direction and thoughtful perspectives for LARC clinical treatment and research trials.

Magnetic resonance imaging accuracy in staging early and locally advanced rectal cancer

INTRODUCTION

Magnetic Resonance Imaging (MRI) is the standard pretreatment staging in patients with rectal cancer. Accurate tumor staging is paramount to determining the appropriate treatment course for patients diagnosed with rectal cancer. The current study aims to re-evaluate the accuracy of pre-operative MRI in staging of both early and locally advanced rectal cancer following completion of neoadjuvant therapy (NAT) compared to the pathologic stage.

METHODS

A retrospective review of patients treated for rectal cancer between 2015 and 2020 at a single academic institution. All patients underwent rectal cancer protocol MRIs before surgical resection. Analysis was carried out in two groups: early rectal cancer: T1/2 N0 tumors with upfront surgical resection (N = 40); and locally advanced disease: T3 or greater or N+ disease receiving NAT, with restaging MRI following NAT (n = 63).

RESULTS

103 patients were included in analysis. MRI accuracy in early tumors was 35% ICC = 0.52 (95% CI 0.25-0.71) T stage and 66% ICC = 0 (95% CI -0.24, 0.29) for 29 patients with nodal data for N stage. There was 28% understaging of T2 tumors and 34% understaging of N0 stage by MRI. Post NAT MRI had 44% accuracy ICC = 0.57 (95% CI -0.15-0.20) T stage and 60% accuracy ICC = 0.32 (95% CI 0.08-0.52) N stage. Tumor invasion was overstaged on MRI: 40% T2, 29% T3, 90% T4. Nodal inaccuracy was due to overstaging, 61% N1, 90% N2.

CONCLUSIONS

In locally advanced rectal cancer MRI overstaged tumors, this could be due to the continued effect of NAT from MRI to resection. This overstaging is of little clinical significance as it doesn't alter the treatment plan, except in cases of complete clinical response. In early rectal cancer, MRI had limited accuracy compared to pathology, understaging a quarter of patients who would benefit from NAT before surgery. Other adjunct imaging modalities should be considered to improve accuracy in staging early rectal cancer and consideration of complete response and enrollment in watch and wait protocols.

A multi-centre randomized controlled trial investigating Consolidation Chemotherapy with and without oxaliplatin in distal rectal cancer and Watch & Wait

BACKGROUND

Neoadjuvant chemoradiation(nCRT) has been considered the preferred initial treatment strategy for distal rectal cancer. Advantages of this approach include improved local control after radical surgery but also the opportunity for organ preserving strategies (Watch and Wait-WW). Consolidation chemotherapy(cCT) regimens using fluoropyrimidine-based with or without oxalipatin following nCRT have demonstrated to increase complete response and organ preservation rates among these patients. However, the benefit of adding oxaliplatin to cCT compared to fluoropirimidine alone regimens in terms of primary tumor response remains unclear. Since oxalipatin-treatment may be associated with considerable toxicity, it becomes imperative to understand the benefit of its incorporation into standard cCT regimens in terms of primary tumor response. The aim of the present trial is to compare the outcomes of 2 different cCT regimens following nCRT (fluoropyrimidine-alone versus fluoropyrimidine + oxaliplatin) for patients with distal rectal cancer.

METHODS

In this multi-centre study, patients with magnetic resonance-defined distal rectal tumors will be randomized on a 1:1 ratio to receive long-course chemoradiation (54 Gy) followed by cCT with fluoropyrimidine alone versus fluoropyrimidine + oxaliplatin. Magnetic resonance(MR) will be analyzed centrally prior to patient inclusion and randomization. mrT2-3N0-1 tumor located no more than 1 cm above the anorectal ring determined by sagittal views on MR will be eligible for the study. Tumor response will be assessed after 12 weeks from radiotherapy(RT) completion. Patients with clinical complete response (clinical, endoscopic and radiological) may be enrolled in an organ-preservation program(WW). The primary endpoint of this trial is decision to organ-preservation surveillance (WW) at 18 weeks from RT completion. Secondary endpoints are 3-year surgery-free survival, TME-free survival, distant metastases-free survival, local regrowth-free survival and colostomy-free survival.

DISCUSSION

Long-course nCRT with cCT is associated with improved complete response rates and may be a very attractive alternative to increase the chances for organ-preservation strategies. Fluoropyrimidine-based cCT with or without oxaliplatin has never been investigated in the setting of a randomized trial to compare clinical response rates and the possibility of organ-preservation. The outcomes of this study may significantly impact clinical practice of patients with distal rectal cancer interested in organ-preservation.

TRIAL REGISTRATION

www.

CLINICALTRIALS

gov NCT05000697; registered on August 11^th, 2021.

Watch and Wait Approach for Rectal Cancer

The administration of neoadjuvant chemoradiotherapy (nCRT) followed by total mesorrectal excision (TME) and selective use of adjuvant chemotherapy can still be considered the standard of care in locally advanced rectal cancer (LARC). However, avoiding sequelae of TME and entering a narrow follow-up program of watch and wait (W&W), in select cases that achieve a comparable clinical complete response (cCR) to nCRT, is now very attractive to both patients and clinicians. Many advances based on well-designed studies and long-term data coming from big multicenter cohorts have drawn some important conclusions and warnings regarding this strategy. In order to safely implement W&W, it is important consider proper selection of cases, best treatment options, surveillance strategy and the attitudes towards near complete responses or even tumor regrowth. The present review offers a comprehensive overview of W&W strategy from its origins to the most current literature, from a practical point of view focused on daily clinical practice, without losing sight of the most important future prospects in this area.

Trends in the Characteristics, Treatment, and Outcomes of Rectal Adenocarcinoma in the US From 2004 to 2019: A National Cancer Database Analysis

Importance

Rectal cancer management has significantly evolved over the last 2 decades.

Objective

This study aimed to evaluate trends in the characteristics, treatment, and outcomes of rectal adenocarcinoma across 16 years.

Design, Setting, and Participants

This retrospective, observational case series study used data from the National Cancer Database (NCDB) to evaluate patients diagnosed with rectal adenocarcinoma from 2004 through 2019. Data analysis was performed from March to May 2022.

Exposures

Trends in the treatment and outcomes of rectal adenocarcinoma in the US between 2004 and 2019 were explored. This period was subdivided into 4 equal periods: 2004-2007, 2008-2011, 2012-2015, and 2016-2019.

Main Outcomes and Measures

Patient and tumor characteristics, treatments, short-term outcomes, and overall survival.

Results

A total of 318 548 patients diagnosed with rectal adenocarcinoma were included in the analysis, 191 369 (60.1%) of whom were males and 127 179 (39.9%%) were females. The mean (SD) age of the patients was 63.5 (13.4) years, and 46 824 patients (14.8%) were younger than 50 years. Among the patients, 10 859 (3.4%) were of Asian race and ethnicity, 28 464 (8.9%) were Black, and 271 236 (85.1%) were White. The percentage of patients younger than 50 years who were diagnosed with rectal cancer increased by 1.5%, from 13.9% in period 1 to 15.4% in period 4. Patients in the last period (2016-2019) presented more often with stages III (36.2% vs 30.2% vs 25.0% vs 23.4%; P < .001) and IV (21.5% vs 19.3% vs 18.1% vs 18.6%; P < .001) disease compared with those in the remaining 3 periods. The use of chemotherapy (36.8% vs 48.1% vs 49.1% vs 47.0%; P < .001) and immunotherapy (0.4% vs 0.2% vs 3.5% vs 6.5%; P < .001) significantly increased across the 4 periods. Although neoadjuvant radiotherapy was used more often across the periods studied (28.6% in period 1 to 34.3% in period 4), the use of adjuvant radiotherapy was reduced by half (12.9% to 6.0%). The median (IQR) time from diagnosis to definitive surgery increased from 95 (15-126) days in period 1 to 128 (47-158) days in period 4. The rate of use of open surgery decreased by half (60.1% in period 2 to 30.1% in period 4), and the use of robotic surgery significantly increased (5.2% in period 2 to 28.4% in period 4). The conversion rate was significantly reduced (11.2% in period 2 to 7.3% in period 4) and the median (IQR) hospital stay decreased by 2 days, from 6 (3-9) days to 4 (2-7) days. The median (IQR) overall survival significantly increased across the periods (from 83.1 months [95% CI, 81.8-84.6 months] in period 1 to 92.1 months [95% CI, 90.2-93.6 months] in period 3; P < .001).

Conclusion and Relevance

The findings of this case series study suggest a treatment trend of increased use of chemotherapy, immunotherapy, sphincter-saving surgery, and minimally invasive surgery. In addition, the time between diagnosis and definitive surgery increased by a median of 33 days. This treatment trend was associated with a significant improvement in the overall survival, reduction in the conversion rate by 3.9%, and a 2-day shorter hospital stay. These findings have major clinical relevance to the management of rectal cancer. The improvements seen in short-term outcomes and survival of patients diagnosed with rectal cancer can probably be attributed to the treatment trends observed. Continued improvement in outcomes warrant further updates in treatments.

Clinical feasibility of the therapeutic strategies total neoadjuvant therapy and "watch and wait" in the treatment of rectal cancer patients with recurrence after clinical complete response

Purpose

In recent years, total neoadjuvant therapy (TNT) has emerged as a new therapeutic strategy against advanced rectal cancer (RC). After administration of TNT, some patients show complete clinical response (cCR) to treatment however, disputes about the effects of TNT and the alternative treatment plans in case of recurrence after cCR still exist.

Methods

A total of 100 patients were included in this paper. CR and non-CR was observed when these patients were administered with TNT at the First Affiliated Hospital of Dalian Medical University, China from May 2015 to June 2021. These patients received different chemotherapeutic regimens, with close monitoring and watch and wait (W&W) strategy being applied by a multidisciplinary team (MDT). According to treatment results, patients were divided into a cCR group and a non-cCR group; according to the recurrence during W&W, they were divided into a recurrence group and a no-local-recurrence group. This study analyzed the factors that may affect the prognosis, and summarized the surgery and treatment after recurrence.

Results

The TNT strategy was effective, and 85% of patients achieved local remission. However, W&W did not affect the survival time of CR patients, nor did it cause new distant metastasis due to local recurrence during the observation period (P > 0.05). However, for patients with positive CRM, we do not recommend W&W as the first choice of treatment (P < 0.05).

Conclusion

(1) Whole-course neoadjuvant therapy was an effective treatment scheme for advanced mid-term rectal cancer. The total local reduction rate of this group of cases was 85.00%, meaning that 25 patients achieved CR. (2) W&W was safe and reliable, and CR patients could receive it as the preferred treatment. (3) CRM was an independent risk factor for local recurrence in CR patients. We do not recommend W&W as the preferred treatment for CR patients with positive CRM.

The Effect of Continuing Chemotherapy after Chemoradiotherapy during the Time to Surgery on Tumor Response and Survival for Local Advanced Rectal Cancer

Aim

The current standard treatment of locally advanced rectal carcinoma is total mesorectal excision and postoperative adjuvant chemotherapy after neoadjuvant concurrent chemoradiotherapy (NCRT). Many studies have shown that pathological complete response (pCR) is an important prognostic factor for patients receiving NCRT. Many studies have therefore been conducted to increase pCR rates by changing the perioperative treatment strategies. Prolonging the chemotherapy time may be a reasonable way to increase the effectiveness of NCRT, pCR, and survival rates. We investigated whether neoadjuvant consolidation chemotherapy had an effect on tumor response and survival.

Methods

The data of 163 patients diagnosed with locally advanced rectal carcinoma were evaluated. The data of 107 patients (Group 1) who were radiologically T3–T4 and/or N+ and received chemotherapy after NCRT until their operations were compared with the data of 56 patients (Group 2) who were operated after NCRT.

Results

Group 1 patients had tumor and node downstaging. Their pCR was found significantly higher than in Group 2 (p = 0.005). In Group 1 patients with T3, pCR was significantly higher than for those with T4. The elapsed time between NCRT and surgery was significantly longer in patients with pCR (respectively, p = 0.012 and p = 0.008).

Conclusion

Neoadjuvant consolidation chemotherapy after NCRT is a safe approach that can lead to higher pathological complete response rates. The time until surgery with neoadjuvant consolidation chemotherapy may provide the chance to follow the patient without surgery in addition to increasing pCR.

MORPHEUS Phase II–III Study: A Pre-Planned Interim Safety Analysis and Preliminary Results

Background: We explored image-guided adaptive endorectal brachytherapy patients electing non-operative management for rectal cancer. We present the first pre-planned interim analysis. Methods: In this open-label phase II–III randomized study, patients with operable cT2-3ab N0 M0 rectal cancer received 45 Gy in 25 fractions of pelvic external beam radiotherapy (EBRT) with 5-FU/Capecitabine. They were randomized 1:1 to receive either an EBRT boost of 9 Gy in 5 fractions (Arm A) or three weekly adaptive brachytherapy (IGAEBT) boosts totaling 30 Gy (Arm B). Patient characteristics and toxicity are presented using descriptive analyses; TME-free survival between arms with the intention to treat the population is explored using the Kaplan–Meier method. Results: A total of 40 patients were in this analysis. Baseline characteristics were balanced; acute toxicities were similar. Complete clinical response (cCR) was 50% (n = 10/20) in Arm A and 90% in Arm B (n = 18/20). Median follow-up was 1.3 years; 2-year TME-free survival was 38.6% (95% CI: 16.5–60.6%) in the EBRT arm and 76.6% (95% CI: 56.1–97.1%) in the IGAEBT arm. Conclusions: Radiation intensification with IGAEBT is feasible. This interim analysis suggests an improvement in TME-free survival when comparing IGAEBT with EBRT, pending confirmation upon completion of this trial.

Impact of total neoadjuvant therapy consisting of consolidation chemotherapy on locally advanced rectal cancer survival

PURPOSE

The objective was to compare disease-free survival (DFS) and distant metastasis in patients with neoadjuvant chemoradiotherapy (NCRT) and total neoadjuvant therapy (TNT) for locally advanced rectal cancer.

METHODS

Patients with cT3-4N0M0 or cTxN1-2M0 rectal cancer were included in this retrospective study. Patients who received NCRT (radiotherapy with concurrent capecitabine) or TNT (radiotherapy with two concurrent cycles of capecitabine and oxaliplatin (CAPOX) followed by another two cycles of CAPOX) during January 2011 and November 2016 at Beijing Chaoyang Hospital, Capital Medical University were included. All patients had received radical surgery. Adverse events, pathological response and survival outcomes in the two groups were compared.

RESULTS

One hundred eighty-two patients were enrolled, 120 in the TNT and 62 in the NCRT groups. No significant between-group differences in neoadjuvant therapy-associated adverse events or surgical complications were found. TNT achieved a higher pathological complete response (pCR) rate (25.8%) compared with NCRT (12.9%, P = 0.044). Patients in the TNT group had a higher 3-year DFS rate (82.8% versus 75.7%, P = 0.041) and lower distant metastasis rate (19.2% versus 33.1%, P = 0.049) than those in the NCRT group. Multivariate analysis showed that NCRT was an independent risk factor for DFS (95%CI 2.023-13.415, P = 0.001) and distant metastasis (95% CI 2.149-20.082, P = 0.001).

CONCLUSION

With similar adverse events and a higher pCR rate when compared with NCRT, TNT might be considered as a safe and effective therapeutic strategy to improve prognosis in patients with locally advanced rectal cancer.

Non-Operative Management of Patients with Rectal Cancer: Lessons Learnt from the OPRA Trial

Over the past decade, the management of locally advanced rectal cancer (LARC) has progressively become more complex. The introduction of total neoadjuvant treatment (TNT) has increased the rates of both clinical and pathological complete response, resulting in excellent long-term oncological outcomes. As a result, non-operative management (NOM) of LARC patients with a clinical complete response (cCR) after neoadjuvant therapy has gained acceptance as a potential treatment option in selected cases. NOM is based on replacement of surgical resection with safe and active surveillance. However, the identification of appropriate candidates for a NOM strategy without compromising oncologic safety is currently challenging due to the lack of an objective standardization. NOM should be part of the treatment plan discussion with LARC patients, considering the increasing rates of cCR, patient preference, quality of life, expectations, and the potential avoidance of surgical morbidity. The recently published OPRA trial showed that organ preservation is achievable in half of rectal cancer patients treated with TNT, and that chemoradiotherapy followed by consolidation chemotherapy may an appropriate strategy to maximize cCR rates. Ongoing trials are investigating optimal algorithms of TNT delivery to further expand the pool of patients who may benefit from NOM of LARC.

The "Immunoscore" in rectal cancer: could we search quality beyond quantity of life?

Because of the function and anatomical environment of the rectum, therapeutic strategies for local advanced rectal cancer (LARC) must deal with two challenging stressors that are a high-risk of local and distal recurrences and a high-risk of poor quality of life (QoL). Over the last three decades, advances in screening tests, therapies, and combined-modality treatment options and strategies have improved the prognosis of patients with LARC. However, owing to the heterogeneous nature of LARC and genetic status, the patient may not respond to a specific therapy and may be at increased risk of side-effects without the life-prolonging benefit. Indeed, each therapy can cause its own side-effects, which may worsen by a combination of treatments resulting in long-term poor QoL. In LARC, QoL has become even more essential with the increasing incidence of rectal cancer in young individuals. Herein, we analyzed the value of the Immunoscore-Biopsy (performed on tumor biopsy at diagnosis) in predicting outcomes, alone or in association with clinical and imaging data, for each therapy used in LARC.

Locally Advanced Rectal Cancer: What We Learned in the Last Two Decades and the Future Perspectives

The advancement in surgical techniques, optimization of systemic chemoradiotherapy, and development of refined diagnostic and imaging modalities have brought a phenomenal shift in the treatment of the locally advanced rectal cancer. Although each therapeutic option has shown substantial progress in their field, it is finding their ideal amalgamation which has baffled the clinician and researchers alike. In the effort to identifying the perfect salutary treatment plan, we have even shifted our attention from the trimodal approach to non-operative "watchful waiting" to more recent individualized care. In this article, we acknowledge the scientific progress in the management of locally advanced rectal cancer and compare the opportunities as well as the obstacles while implementing them clinically. We also explore the current challenges and controversies surrounding the multidisciplinary approach and highlight the new trends and recent advances with an ultimate goal to improve the patients' quality of life.

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.

Significant decrease of the pathological stage I rectal carcinoma in the era of neoadjuvant therapy-A matter of concern

BACKGROUND

Neoadjuvant treatment (nTx) for rectal cancer is commonly reserved for UICC stages II/III. Patients with stage I tumours (T1-2N0M0) are not candidates for nTx. The accuracy of treatment allocation depends on the precision of clinical staging, which is liable to understaging and overstaging. The study aimed at exploring changes in the proportion of stage pI patients with the introduction of nTx over a 26-year period.

MATERIALS AND METHODS

All consecutive patients with histologically proven rectal cancer excluding carcinoma in situ were retrieved from a prospective database of our colorectal unit. Time periods were defined as per the use of nTx: baseline phase 1994-1997; implementation phase 1998-2005 and guideline phase 2006-2019. Trends over time regarding proportion of applied nTx and stage pI tumours were investigated.

RESULTS

Overall, 1468 patients met the inclusion criteria. There were no major differences in patients' characteristics, especially proportion of synchronous metastases (stage IV) over time. nTx was applied to 1.2% of patients without metastases in the baseline phase, to 29.6% in the implementation phase, and to 59.6% in the guideline phase (p < 0.001). Corresponding proportions for patients with stage pI were 31.0%, 26.3% and 14.2%, respectively (p < 0.001).

CONCLUSION

With a stable proportion of stage IV carcinomas indicating no major changes in the patient cohorts, we could document a significant decrease of stage pI patients with increasing use of nTx. This trend clearly signals overtreatment caused by clinical T- and N-staging. More precise criteria are needed to better select patients with rectal cancer for nTx.

The Evolving Field of Neoadjuvant Therapy in Locally-advanced Rectal Cancer: Evidence and Prospects

The standard treatment of locally advanced rectal cancer comprises neoadjuvant chemoradiation followed by total mesorectal excision. This strategy provides low local recurrence rate, however distant recurrence is still an issue and may impact on survival rates. Novel approaches in the neoadjuvant setting have been tested to improve early and late outcomes, as well as to reduce treatment-related toxicity and morbidity. In this review, we discuss the current literature of neoadjuvant treatment in locally advanced rectal cancer, including total neoadjuvant methods, protocols for radiation delivery, chemotherapy regimen and efforts to add novel targeted therapies, selective withdrawal of surgery or radiotherapy, and future perspectives. Moreover, we highlight relevant issues that have emerged with these new treatment possibilities.

The effects of neoadjuvant chemoradiotherapy and an in-hospital exercise training programme on physical fitness and quality of life in locally advanced rectal cancer patients: a randomised controlled trial (The EMPOWER Trial)

BACKGROUND

The EMPOWER trial aimed to assess the effects of a 9-week exercise prehabilitation programme on physical fitness compared with a usual care control group. Secondary aims were to investigate the effect of (1) the exercise prehabilitation programme on psychological health; and (2) neoadjuvant chemoradiotherapy (NCRT) on physical fitness and psychological health.

METHODS

Between October 2013 and December 2016, adults with locally advanced rectal cancer undergoing standardised NCRT and surgery were recruited to a multi-centre trial. Patients underwent cardiopulmonary exercise testing (CPET) and completed HRQoL questionnaires (EORTC-QLQ-C30 and EQ-5D-5L) pre-NCRT and post-NCRT (week 0/baseline). At week 0, patients were randomised to exercise prehabilitation or usual care (no intervention). CPET and HRQoL questionnaires were assessed at week 0, 3, 6 and 9, whilst semi-structured interviews were assessed at week 0 and week 9. Changes in oxygen uptake at anaerobic threshold (VO2 at AT (ml kg-1 min-1)) between groups were compared using linear mixed modelling.

RESULTS

Thirty-eight patients were recruited, mean age 64 (10.4) years. Of the 38 patients, 33 were randomised: 16 to usual care and 17 to exercise prehabilitation (26 males and 7 females). Exercise prehabilitation significantly improved VO2 at AT at week 9 compared to the usual care. The change from baseline to week 9, when adjusted for baseline, between the randomised groups was + 2.9 ml kg -1 min -1; (95% CI 0.8 to 5.1), p = 0.011.

CONCLUSION

A 9-week exercise prehabilitation programme significantly improved fitness following NCRT. These findings have informed the WesFit trial (NCT03509428) which is investigating the effects of community-based multimodal prehabilitation before cancer surgery.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01914068 . Registered 1 August 2013.

Assessment of the non-surgical treatment of patients with rectal cancer who underwent neoadjuvant treatment with chemotherapy and radiotherapy at the oncology department

Objective To describe the partial results of a study in patients with rectal cancer who underwent neoadjuvant treatment with chemotherapy and radiotherapy regarding the rate of complete clinical response, disease-free survival, anorectal function, and quality of life.

Material and methods This was a prospective study from June 2015 to June 2018, in patients with low- or mid-rectum adenocarcinoma and clinical stage II or III, treated with radiotherapy and chemotherapy (IMRT 54 Gy for six weeks) concomitant with 5-fluorouracil (5-FU) 380 mg/m2 and folinic acid (LV) 20 mg/m2 for five days in the first and fifth weeks and two cycles after radiotherapy (5-FU 400 mg/m2 and LV 20 mg/m2) every 28 days. After the treatment, clinical examination, rectosigmoidoscopy, pelvic magnetic resonance imaging, chest and upper abdomen computed tomography, and CEA testing were performed. Resection surgery was performed in those with incomplete clinical response (iCR). Those with complete clinical response (cCR) are under observation (wait-and-see policy). Manometry and scintigraphic function and quality of life scales were collected before treatment and at 30 and 90 days after the end of treatment.

Results As of June 2018, 11 patients were recruited. One was excluded from the analysis for presenting severe toxicity, suggestive of dihydropyrimidine dehydrogenase (DPD) deficiency, after the first chemotherapy cycle. All others completed the treatment. Two patients presented toxicity grade 3/4 related to chemotherapy and had their doses reduced. Seven patients (70%) presented iRC; three underwent rectosigmoidectomy, and the anatomopathological evaluation indicated complete pathological response in two cases (28.5%). Three (30%) presented cCR and did not present evidence of disease after a mean follow-up of 19 months. Patients presented improvement of anorectal function and quality of life.

Conclusions Advances in the neoadjuvant treatment of rectal tumors contributed to better rates of complete pathological responses. New paradigms promote an increase in the complete clinical response rates, which would allow organ preservation and consequent reduction of surgical morbidity.

Curative therapy for rectal cancer

Introduction: A comprehensive trimodality approach has become the standard of care for patients with locally advanced rectal cancer. However, the sequencing and duration of chemotherapy and chemoradiotherapy around surgery varies between clinical studies and geographical regions. Growing evidence is also mounting for strategies such as total neoadjuvant therapy and non-operative management for carefully selected patients.Areas covered: We provide a perspective review of the current evidence and controversies in the treatment of locally advanced rectal cancer including the recent updates from the 2020 ASCO annual conference.Expert opinion: With ongoing advances in the management of locally advanced rectal cancer, a multidisciplinary team approach is necessary as treatments could involve multiple approaches. Chemoradiotherapy whether short or long course followed by at least 3 months of systemic chemotherapy may be the preferred option to balance local and distant disease control. Albeit the choice of doublet or triplet chemotherapy is still controversial. As total neoadjuvant treatment becomes part of the standard of care in rectal cancer, modification of the surveillance schedule is needed to detect early recurrences which may be limited by resources and availability of services.

Adding Three Cycles of CAPOX after Neoadjuvant Chemoradiotherapy Increases the Rates of Complete Response for Locally Advanced Rectal Cancer

BACKGROUND AND OBJECTIVES

the total neoadjuvant chemoradiotherapy (TNT) includes different strategies, but the most appropriate model remains uncertain. The purpose of this retrospectively study was to evaluate the safety and pathological response in the consolidation chemotherapy model.

METHODS

patients with cT3/T4 or TxN + M0 rectal cancer that were receiving neoadjuvant chemoradiotherapy (CRT) (50 Gy with oral capecitabine)/TNT (CRT followed by three cycles of CAPOX) during September 2017 to September 2019 in our department were included. All of the patients were recommended to receive radical surgery.

RESULTS

a total of 197 patients were included. Eighty-one patients received CRT, while one hundred and sixteen patients received TNT. Nine patients did not undergo surgery because of the distant metastases (one patient (1.2%) in CRT group, two patients (1.7%) in TNT group) or a refusal of resection (two patients in CRT group, four patients in TNT group). The pathological complete response (pCR) rate was 32.7% in TNT compared with 12.8% in CRT (p = 0.002). There was no statistically significant difference in grade 3 acute toxicities of neoadjuvant treatment and surgical complications between the two groups.

CONCLUSIONS

the consolidation chemotherapy model is safe for patients with locally advanced rectal cancer and it has a high pCR rate. The long-term follow-up is necessary to be evaluated in a future prospective, randomized trial.

Outcomes of neoadjuvant chemoradiotherapy followed by radical resection for T4 colorectal cancer

BACKGROUND

Patients with clinical T4 colorectal cancer (CRC) have a poor prognosis because of compromised surgical margins. Neoadjuvant therapy may be effective in downstaging tumors, thereby rendering possible radical resection with clear margins.

AIM

To evaluate tumor downsizing and resection with clear margins in T4 CRC patients undergoing neoadjuvant concurrent chemoradiotherapy followed by surgery.

METHODS

This study retrospectively included 86 eligible patients with clinical T4 CRC who underwent neoadjuvant concurrent chemoradiotherapy followed by radical resection. Neoadjuvant therapy consisted of radiation therapy at a dose of 45-50.4 Gy and chemotherapy agents, either FOLFOX or capecitabine. A circumferential resection margin (CRM) of < 1 mm was considered to be a positive margin. We defined pathological complete response (pCR) as the absence of any malignant cells in a specimen, including the primary tumor and lymph nodes. A multivariate logistic regression model was used to identify independent predictive factors for pCR.

RESULTS

For 86 patients who underwent neoadjuvant chemoradiotherapy and surgery, the rate of pCR was 14%, and the R0 resection rate was 91.9%. Of the 61 patients with rectal cancer, 7 (11.5%) achieved pCR and 5 (8.2%) had positive CRMs. Of the 25 patients with colon cancer, 5 (20%) achieved pCR and 2 (8%) had positive CRMs. We observed that the FOLFOX regimen was an independent predictor of pCR (P = 0.046). After a median follow-up of 47 mo, the estimated 5-year overall survival (OS) and disease-free survival (DFS) rates were 70.8% and 61.4%, respectively. Multivariate analysis revealed that a tumor with a negative resection margin was associated with improved DFS (P = 0.014) and OS (P = 0.001). Patients who achieved pCR exhibited longer DFS (P = 0.042) and OS (P = 0.003) than those who did not.

CONCLUSION

Neoadjuvant concurrent chemoradiotherapy engenders favorable pCR and R0 resection rates among patients with T4 CRC. The R0 resection rate and pCR are independent prognostic factors for patients with T4 CRC.

Nonoperative Management for T2 Low Rectal Cancer: A Western Approach

The possibility of organ preservation in early rectal cancer has gained popularity during recent years. Patients with early tumor stage and low risk for local recurrence do not usually require neoadjuvant chemoradiation for oncological reasons. However, these patients may be considered for chemoradiation exclusively for the purpose of achieving a complete clinical response and avoid total mesorectal excision. In addition, cT2 tumors may be more likely to develop complete response to neoadjuvant therapy and may constitute ideal candidates for organ-preserving strategies. In the setting where the use of chemoradiation is exclusively used to avoid major surgery, one should consider maximizing tumor response. In this article, we will focus on the rationale, indications, and outcomes of patients with early rectal cancer being treated by neoadjuvant chemoradiation to achieve organ preservation by avoiding total mesorectal excision.

Conditional Survival in Patients With Rectal Cancer and Complete Clinical Response Managed by Watch and Wait After Chemoradiation: Recurrence Risk Over Time

OBJECTIVE

Analyze conditional recurrence-free survival (cRFS) for rectal cancer patients with complete clinical response (cCR) after neoadjuvant chemoradiation (nCRT) managed nonoperatively after each year without recurrence.

SUMMARY BACKGROUND DATA

Select patients with cCR after nCRT have been managed nonoperatively. Risk factors for local recurrence, the need for prolonged follow-up, and the risk of recurrence over time are not well defined.

METHODS

Retrospective review of patients with rectal cancer cT2-4N0-2M0 treated with nCRT. Mean follow-up was 64 months. Patients who achieved cCR were managed nonoperatively. cRFS was used to investigate the evolution of recurrence-odds, as patients remain recurrence-free after completion of nCRT. Three-year cRFS was estimated at "x" years after completion of nCRT based on the formula cRFS3 = RFS(x+3)/RFS(x).

RESULTS

One hundred ninety-seven patients with cCR after nCRT were included. Overall survival and recurrence-free survival (RFS) at 5 years were 81.9% (95% CI 74.0%-87.6%) and 60.4% (95% CI 52.5%-67.4%) respectively. Using cRFS estimates, the probability of remaining disease-free for an additional 3 years if the patient survived without disease at 1, 3, and 5 years, was 77.4% (95% CI 68.8%-83.8%), 91.0% (95% CI 81.9%-95.7%), and 94.3% (95% CI 82.9%-98.2%), respectively. In contrast, actuarial RFS rates for similar intervals were 79.1% (95% CI 72.5%-84.2%), 64.2% (95% CI 56.5%-70.8%), and 60.4% (95% CI 52.5%-67.4%). After 2 years disease-free, 3 year cRFS became similar for T2 and T3 cancers. In contrast, patients undergoing extended nCRT became less likely to develop recurrences only after initial 2 years of successful organ-preservation.

CONCLUSIONS

Conditional survival suggests that patients have significantly lower risks (≤10%) of developing recurrences after 2 years of achieving cCR following nCRT.

Quantitative CT measurement of left colonic and pelvic mesenteric adipose volume in radiation proctitis

Background

The edema of left colonic and pelvic mesenteric adipose tissues has long been recognized in surgery as a characteristic feature of radiation proctitis (RP). However, the correlation between mesenteric adipose volume and RP has not been extensively clarified. The purpose of this study was thus to assess the variation of left colonic and pelvic mesenteric adipose volume in RP.

Methods

From March 2013 to June 2015, the data of 52 patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy, including 23 patients with RP and 29 with non-RP (nRP), were retrieved. The mesenteric adipose volume was quantified via a computed tomography (CT) reconstruction method. Corresponding analyses were conducted to observe the correlation between the relative change of mesenteric adipose volume and the thickening degree of the rectal wall.

Results

The baseline data of the RP group and the nRP group were comparable. There was no significant difference in the relative change of the left colonic mesenteric adipose volume in each vertebral space from the third lumbar vertebra to the first sacral vertebra before and after radiotherapy. The relative change of pelvic mesenteric adipose volume (ΔVp%) was notably higher in the RP group compared to the nRP group. With a ΔVp% cutoff value of 3.67%, the sensitivity and specificity for the diagnosis of RP were 65.2% and 86.2%, respectively. According to the correlation analysis, ΔVp% in the RP group was significantly correlated with the thickening degree of the rectal wall after radiotherapy (r=0.47, P=0.024).

Conclusions

The increment of the relative change of pelvic mesenteric adipose volume quantitatively measured by CT can be clinically useful in identifying RP.

Watch and wait approach in rectal cancer: Current controversies and future directions

According to the main international clinical guidelines, the recommended treatment for locally-advanced rectal cancer is neoadjuvant chemoradiotherapy followed by surgery. However, doubts have been raised about the appropriate definition of clinical complete response (cCR) after neoadjuvant therapy and the role of surgery in patients who achieve a cCR. Surgical resection is associated with significant morbidity and decreased quality of life (QoL), which is especially relevant given the favourable prognosis in this patient subset. Accordingly, there has been a growing interest in alternative approaches with less morbidity, including the organ-preserving watch and wait strategy, in which surgery is omitted in patients who have achieved a cCR. These patients are managed with a specific follow-up protocol to ensure adequate cancer control, including the early identification of recurrent disease. However, there are several open questions about this strategy, including patient selection, the clinical and radiological criteria to accurately determine cCR, the duration of neoadjuvant treatment, the role of dose intensification (chemotherapy and/or radiotherapy), optimal follow-up protocols, and the future perspectives of this approach. In the present review, we summarize the available evidence on the watch and wait strategy in this clinical scenario, including ongoing clinical trials, QoL in these patients, and the controversies surrounding this treatment approach.

Induction chemotherapy followed by neoadjuvant chemoradiotherapy and surgery for patients with locally advanced rectal cancer: a systematic review and meta-analysis

BACKGROUND

Controversy persists about whether additional induction chemotherapy (ICT) before neoadjuvant chemoradiation (NCRT) yields improved oncological outcomes. We performed a systematic review and meta-analysis to compare ICT+ NCRT+ surgery(S) with NCRT+ S in patients with locally advanced rectal cancer (LARC).

METHODS

We searched the PubMed, EMBASE, Cochrane Library, and China Biology Medicine (CBM) databases. The data were analyzed with Stata version 12.0 software.

RESULTS

We identified 9 relevant trials that enrolled 1538 patients. We detected no significant difference in the 5-year overall survival (OS) (OR 1.50, 95% CI 0.48-4.64), disease-free survival (DFS) (OR 1.03, 95% CI 0.73-1.46), local recurrence (LR) (OR 0.80, 95% CI 0.45-1.43), and distant metastasis (DM) rates (OR 1.03, 95% CI 0.55-1.93) between patients who did and did not receive ICT. The addition of ICT before NCRT had a similar pathological complete response rate compared to NCRT (OR 1.26, 95% CI 0.90-1.77). Our findings suggest that between the ICT + NCRT+S and NCRT+S groups, ICT improved the incidence of grade 3 to 4 toxicity effects (OR 4.81, 95% CI 2.38-9.37), but between the ICT + NCRT+S and NCRT+S+ adjuvant chemotherapy (ACT) groups, ICT might reduce toxicity (OR 0.19, 95% CI 0.08-0.50). ICT had no significant impact on surgical complications (OR 0.97, 95% CI 0.63-1.51).

CONCLUSIONS

The addition of ICT before NCRT seemingly shows no survival benefit on patients with LARC, and might increase the toxicity.

Neo-adjuvant chemotherapy alone for the locally advanced rectal cancer: a systematic review

Neo-adjuvant chemoradiation (NA-CRT) is the standard of management for the locally advanced rectal cancer (LARC), achieving very low rates of local recurrence (LR). However, NA-CRT fails to control distant recurrence and improve survival, whilst it is associated with increased postoperative morbidity and increased acute and late toxicity. In recent years, neo-adjuvant chemotherapy (NACTx) appears in the literature as an alternative to NA-CRT in patients with LARC. In the present study, the authors review all current evidence on the specific subject. Following a systematic search of the literature, 25 studies were identified reporting on short- or long-term outcomes of NACTx for LARC. Seventeen studies were prospective or retrospective series, and 8 comparative. Of the comparative studies, one was a randomized control trial (RCT) comparing NACTx to NA-CRT and to the combination of NACTx/NA-CRT, and another a non-randomized study comparing NACTx to NA-CRT. Chemotherapeutic regimens were 5-fluoropyrimidine and oxaliplatin based. In some of them, irinotecan or/and bevacizumab was added. A pooled analysis showed that NACTx is associated with a mean anastomotic leak rate of 6.8%. In the RCT, postoperative morbidity and overall toxicity was significantly less in the NACTx group. Mean T downstaging (ypStage 0-I) was 49.6%, mean N downstaging 69.6% and mean pathologic complete response (pCR) 10.7%. The RCT showed an inferior pCR rate after NACTx than after NA-CRT, but similar rates of T downstaging. Mean LR was 8.6% and mean distant recurrence 17.2%. Satisfactory survival rates are reported by several studies. NACTx seems to be an alternative to NA-CRT for patients with LARC, associated with low anastomotic leak, adequate tumour downstaging, low LR and rather high survival rates. Further data deriving from high-quality studies are necessary to assess safety and efficacy of NACTx as a substitute to NA-CRT, for at least a subset of patients with LARC.

Metformin as an Alternative Radiosensitizing Agent to 5-Fluorouracil During Neoadjuvant Treatment for Rectal Cancer

BACKGROUND

Neoadjuvant chemoradiation for locally advanced rectal cancer combining 5-fluorouracil with radiation increases tumor regression compared with radiation alone. However, it occurs at the cost of significant treatment-related toxicity. Patients with rectal cancer using metformin have been associated with improved response to radiotherapy.

OBJECTIVE

The purpose of this study was to evaluate the radiosensitizing effects of metformin in vitro and in vivo and compare it with a standard combination of radiation/5-fluorouracil.

DESIGN

Colorectal cancer cell lines SW480, HT29, and HCT116 were used as models. Cell viability was compared under treatments with radiation, radiation/5-fluorouracil, metformin, radiation/metformin, and radiation/5-fluorouracil/metformin. Nude mice were injected subcutaneously with SW480 cells and treated for 1 week with radiation/5-fluorouracil, metformin, radiation/metformin, or radiation/5-fluorouracil/metformin. Tumor volume was evaluated for 4 weeks after treatment completion. The phosphorylation status of key proteins of the PI3K/Akt/mTOR pathway was determined by immunoblots.

SETTINGS

This was an experimental study conducted in vitro and in vivo.

PATIENTS

Animal models/cell lines were used.

MAIN OUTCOME MEASURES

The end point was to investigate how metformin compares with 5-fluorouracil as a radiosensitizer.

RESULTS

All cell lines significantly decreased cell viability after treatment with radiation/metformin when compared with radiation alone. Radiation/metformin was superior to radiation/5-fluorouracil in SW480 (37% vs 74%; p < 0.001). In HT29 and in HCT116, radiation/metformin was inferior to radiation/5-fluorouracil (40.0% vs 13.8%, p < 0.001 and 40.0% vs 7.0%, p < 0.001), mainly because of increased 5-fluorouracil toxicity (≤20% of cell viability). In vivo assays indicated that radiation/metformin treatment was comparable with radiation/5-fluorouracil (557 vs 398 mm; p > 0.05) and that the addition of metformin to the standard radiation/5-fluorouracil did not improve tumor response (349 mm; p > 0.05). Metformin exerted strong PI3K/Akt/mTOR pathway inactivation effects after 24-hour exposure (increasing pAMPK, p < 0.01; decreasing pAkt, p < 0.01; and pS6, p <0.05).

LIMITATIONS

In vitro and in vivo chemoradiation regimens cannot be directly translated to human delivery methods.

CONCLUSIONS

Metformin enhances tumor response to radiation in vitro and in vivo. Metformin is an attractive alternative radiosensitizing agent to be considered in future studies/trials. See Video Abstract at http://links.lww.com/DCR/B219. LA METFORMINA COMO AGENTE RADIOSENSIBILIZADOR ALTERNATIVO A 5FU DURANTE EL TRATAMIENTO NEOADYUVANTE PARA CÁNCER DE RECTO: La quimiorradiación neoadyuvante para el cáncer de recto localmente avanzado que combina 5FU con radiación aumenta la regresión tumoral en comparación con la radiación sola. Sin embargo, se produce a costa de una toxicidad significativa relacionada con el tratamiento. Los pacientes con cáncer de recto que usan metformina se han asociado con una mejor respuesta a la radioterapia.Evaluar los efectos radiosensibilizantes de metformina in vitro e in vivo y compararlo con la combinación estándar de radiación / 5FU.Se usaron como modelos las líneas celulares de cáncer colorrectal SW480, HT29 y HCT116. La viabilidad celular se comparó en tratamientos con radiación, radiación / 5FU, metformina, radiación / metformina y radiación / 5FU / metformina. A los ratones desnudos se les inyectó por vía subcutánea células SW480 y fueron tratados durante una semana con radiación / 5FU, metformina, radiación / metformina o radiación / 5FU / metformina. El volumen tumoral se evaluó durante 4 semanas después de la finalización del tratamiento. El estado de fosforilación de las proteínas clave de la vía PI3K / Akt / mTOR se determinó mediante inmunotransferencias.Estudio experimental in vitro e in vivo.Modelo animal / líneas celulares.El punto final fue investigar cómo la metformina se compara con 5FU como un radiosensibilizador.Todas las líneas celulares disminuyeron significativamente la viabilidad celular después del tratamiento con radiación / metformina en comparación con la radiación sola. La radiación / metformina fue superior a la radiación / 5FU en SW480 (37% frente a 74%; p <0,001). En el HT29 y el HCT116 la radiación / metformina fue inferior a la radiación / 5FU (40% vs 13.8%, p <0.001 y 40% vs 7%, p <0.001; respectivamente), debido principalmente al aumento de la toxicidad de 5FU (≤20% de la célula viabilidad). Los ensayos in vivo indicaron que el tratamiento con radiación / metformina era comparable a la radiación / 5FU (557 vs 398 mm, p > 0.05), y que la adición de metformina a la radiación estándar / 5FU no mejoró la respuesta tumoral (349 mm, p > 0.05). La metformina ejerció fuertes efectos de inactivación de la vía PI3K / Akt / mTOR después de 24 horas de exposición (aumentando pAMPK p < 0.01, disminuyendo pAkt, p < 0.01; y pS6, p < 0.05).Los regímenes de CRT in vitro e in vivo no se pueden traducir directamente a los métodos de entrega en humanos.La metformina mejora la respuesta tumoral a la radiación in vitro e in vivo. La metformina es un agente alternativo de radiosensibilización atractivo para ser considerado en futuros estudios / ensayos. Consulte Video Resumen en http://links.lww.com/DCR/B219. (Traducción-Dr Gonzalo Hagerman).

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

Purpose

Colorectal cancer is becoming an increasing concern in the middle-aged population of Iran. This study aimed to compare the preliminary results of short-course and long-course neoadjuvant chemoradiotherapy treatment for rectal cancer patients.

Materials and Methods

In this clinical trial we recruited patients with rectal adenocarcinoma located from 5 cm to 15 cm above the anal verge. Patients in group I (short-course) received three-dimensional conformational radiotherapy with a dose of 25 Gy/5 fractions in 1 week plus concurrent XELOX regimen (capecitabine 625 mg/m² from day 1–5 twice daily and oxaliplatin 50 mg/m² on day 1 once daily). Patients in group II (long-course) received a total dose of 50–50.4 Gy/25–28 fractions for 5 to 5.5 weeks plus capecitabine 825 mg/m² twice daily. Both groups underwent consolidation chemotherapy followed by delayed surgery at least 8 weeks after radiotherapy completion. The pathological response was assessed with tumor regression grade.

Results

In this preliminary report on complications and pathological response, 66 patients were randomized into two study groups. Mean duration of radiotherapy in groups I and II was 5 ± 1 days (range, 5 to 8 days) and 38 ± 6 days (range, 30 to 58 days). The median follow-up was 18 months. Pathological complete response was achieved in 32.3% and 23.1% of patients in the short-course and long-course groups, respectively (p = 0.558). Overall, acute grade 3 or higher treatment-related toxicities occurred in 24.2% and 22.2% of patients in group I and II, respectively (p = 0.551). No acute grade 4 or 5 adverse events were observed in either group except one grade 4 hematologic toxicity that was seen in group II. Within one month of surgery, no significant difference was seen regarding grade ≥3 postoperative complications (p = 0.333).

Conclusion

For patients with rectal cancer located at least 5 cm above the anal verge, short-course radiotherapy with concurrent and consolidation chemotherapy and delayed surgery is not different in terms of acute toxicity, postoperative morbidity, complete resection, and pathological response compared to long-course chemoradiotherapy.

Microsatellite Instability (MSI) as an Independent Predictor of Pathologic Complete Response (PCR) in Locally Advanced Rectal Cancer: A National Cancer Database (NCDB) Analysis

OBJECTIVE

The relationship between microsatellite instability (MSI) and response to neoadjuvant chemoradiation in rectal cancer is not well understood.

BACKGROUND

We utilized the National Cancer Database (NCDB) to investigate the association between MSI and pathologic complete response (pCR) in this patient population.

METHODS

We analyzed 5086 patients between 2010 and 2015 with locally advanced rectal cancer who were tested for MSI and treated definitively with chemoradiation followed by surgery. Primary comparison groups were between 4450 MSI-negative(-) and 636 MSI-positive(+) patients. Multivariable regression analysis was conducted to identify demographic, therapeutic, and clinical characteristics predictive of pCR. Cox proportional-hazard ratios were used for survival.

RESULTS

All patients were treated with definitive chemoradiation (median dose 50.4 Gy) followed by resection within 4 months. MSI(+) patients were associated with earlier year of diagnosis and higher-grade tumors (P < 0.05).The overall pCR rate was 8.6%, including 8.9% for MSI(-) and 5.9% for MSI(+) tumors (P = 0.01). Along with lower T stage, MSI(+) cases were significantly associated with a reduced pCR rate (odds ratio 0.65, 95% confidence interval 0.43-0.96) with multivariable analysis. The 5-year survival for patients with pCR was 93% compared with 73% without it (<0.001).

CONCLUSION

Microsatellite instability was independently associated with a reduction in pCR for locally advanced rectal cancer after neoadjuvant chemoradiation in this NCDB-based analysis.

Strategy for the practice of digestive and oncological surgery during the Covid-19 epidemic

The Covid-19 pandemic is changing the organization of healthcare and has a direct impact on digestive surgery. Healthcare priorities and circuits are being modified. Emergency surgery is still a priority. Functional surgery is to be deferred. Laparoscopic surgery must follow strict rules so as not to expose healthcare professionals (HCPs) to added risk. The question looms large in cancer surgery-go ahead or defer? There is probably an added risk due to the pandemic that must be balanced against the risk incurred by deferring surgery. For each type of cancer-colon, pancreas, oesogastric, hepatocellular carcinoma-morbidity and mortality rates are stated and compared with the oncological risk incurred by deferring surgery and/or the tumour doubling time. Strategies can be proposed based on this comparison. For colonic cancers T1-2, N0, it is advisable to defer surgery. For advanced colonic lesions, it seems judicious to undertake neoadjuvant chemotherapy and then wait. For rectal cancers T3-4 and/or N+, chemoradiotherapy is indicated, short radiotherapy must be discussed (followed by a waiting period) to reduce time of exposure in the hospital and to prevent infections. Most complex surgery with high morbidity and mortality-oesogastric, hepatic or pancreatic-is most often best deferred.

[Strategy for the practice of digestive and oncologic surgery in COVID-19 epidemic situation]

La pandémie due au COVID-19 modifie l’organisation des soins et change la réalisation de la chirurgie digestive. Les priorités sanitaires et les circuits de soins sont modifiés. La chirurgie d’urgence reste prioritaire. Les interventions pour chirurgie fonctionnelles sont à reporter. La chirurgie par laparoscopie doit suivre des règles strictes pour ne pas exposer les professionnels à un surrisque. Le questionnement principal concerne la chirurgie oncologique, opérer ou reporter ? Il existe probablement un sur risque opératoire induit par la pandémie qui doit être mis en balance avec le retard de prise en charge chirurgical. Pour chaque type de cancer, colon, pancréas, œsogastrique, hépatocarcinome, la morbi-mortalité est rappelée et mise en parallèle avec le risque oncologique lié au retard à la chirurgie et/ou au temps de doublement de la tumeur. Cette comparaison permet de proposer des stratégies, ainsi pour les cancers coliques (T1-2, N0), il est souhaitable de retarder la chirurgie. Pour les lésions coliques avancées, il semble prudent de recommander une chimiothérapie néo adjuvante et d’attendre. Pour les cancers du rectum T3-4 et/ou N+, une radio-chimiothérapie est indiquée, une radiothérapie courte devra être discutée (suivie d’une période d’attente) afin de réduire le temps d’exposition à l’hôpital et d’éviter les infections. La majorité des chirurgies complexes à forte morbi-mortalité, œsogastrique, hépatique ou pancréatique doivent sans doute le plus souvent être reportée.

Unintended consequences of treating early rectal cancers for complete clinical response with chemoradiotherapy

The aim was to examine the current trend in rectal cancer, which is to extend ’watch-and-wait’ to earlier-stage tumors, not normally treated with chemoradiotherapy, to define the up-side and down-side regarding quality of life (QOL) and anorectal/sexual/urinary function from this approach. We reviewed the literature regarding a ‘watch-and-wait’ strategy after neoadjuvant chemoradiotherapy. The primary outcome measure was complete clinical response. Secondary measures included colostomy rate, functional outcomes and QOL. There is a trend to use chemoradiotherapy in earlier tumors using dose-escalation of radiation and/or additional chemotherapy, resulting in high rates of complete clinical response, which may impact adversely on QOL if radical surgery is subsequently required. Focusing on organ-preservation as the primary goal of treatment rather than overall functional outcomes and QOL for the whole population, may not provide patients with sufficient information for optimal decision-making.

Executive Summary of the American Radium Society Appropriate Use Criteria for Local Excision in Rectal Cancer

The goal of treatment for early stage rectal cancer is to optimize oncologic outcome while minimizing effect of treatment on quality of life. The standard of care treatment for most early rectal cancers is radical surgery alone. Given the morbidity associated with radical surgery, local excision for early rectal cancers has been explored as an alternative approach associated with lower rates of morbidity. The American Radium Society Appropriate Use Criteria presented in this manuscript are evidence-based guidelines for the use of local excision in early stage rectal cancer that include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) used by a multidisciplinary expert panel to rate the appropriateness of imaging and treatment procedures. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment. These guidelines are intended for the use of all practitioners and patients who desire information regarding the use of local excision in rectal cancer.

"Watch and Wait" for complete clinical response after neoadjuvant chemoradiotherapy for rectal cancer

The management of rectal cancer has evolved substantially over recent decades, becoming increasingly complex. This was once a disease associated with high mortality and limited treatment options that typically necessitated a permanent colostomy, has now become a model for multidisciplinary evaluation, treatment and surgical advancement. Despite advances in the rates of total mesorectal excision, decreased local recurrence and increased 5-year survival rates, the multimodal treatment of rectal cancer is associated with a significant impact on long-term functional and quality of life outcomes including risks of bowel, bladder and sexual dysfunction, and potential need for a permanent stoma. There is great interest in strategies to decrease the toxicity of treatment, including selective use of radiation, chemotherapy or even surgery. The modern concept of selective use of surgery for patients with rectal cancer are based on the observed pathological complete response in approximately 10-20% of patients following long-course chemoradiation therapy. While definitive surgical resection remains the standard of care for all patients with non-metastatic rectal cancer, a growing number of studies are providing supportive evidence for a watch-and-wait, organ preserving approach in highly selected patients with rectal cancer. However, questions regarding the heterogeneity of patient selection, optimal method for inducing pathological complete response, methods and intervals for assessing treatment response and adequacy of follow-up remain unanswered. The aim of this review is to provide an up-to-date summary of the current evidence for the watch-and-wait management of rectal cancer following a complete clinical response after neoadjuvant chemoradiation.

Image Guided Adaptive Endorectal Brachytherapy in the Nonoperative Management of Patients With Rectal Cancer

PURPOSE

Organ preservation or nonoperative management of rectal cancer is of growing interest. Image guided adaptive endorectal brachytherapy is a radiation dose escalation modality: we explored its role in elderly patients unfit for surgery and patients refusing surgery.

METHODS AND MATERIALS

In this registry study, patients with rectal cancer who were ineligible for surgery received 40 Gy in 16 fractions of pelvic external beam radiation therapy. They subsequently received 3 weekly image guided adaptive brachytherapy boosts of 10 Gy to the residual tumor, for a total of 30 Gy in 3 fractions. Complete clinical response (cCR) and local control were the primary endpoints.

RESULTS

94 patients were included; the median age was 81.1 years. With a median follow-up of 1.9 years, the proportion of cCR was 86.2%, the tumor regrowth proportion was 13.6%, and the cumulative incidence of local relapse was 2.7% at 1 year and 16.8% at 2 years. When considering responders and nonresponders, the 2-year local control was 71.5%. The overall survival at 2 years was 63.6%. Acute rectal grade 1 to 2 toxicity included all patients: 12.8% of patients had late bleeding requiring iron replacement, blood transfusions, or argon plasma therapy.

CONCLUSIONS

Results of this registry study, evaluating radiation dose escalation for elderly medically unfit patients with unselected tumors, reveal that a high proportion of patients achieved cCR with a manageable toxicity profile. This technology will likely contribute to the challenging nonoperative management paradigm of rectal cancer.

Oncological and Survival Outcomes in Watch and Wait Patients With a Clinical Complete Response After Neoadjuvant Chemoradiotherapy for Rectal Cancer: A Systematic Review and Pooled Analysis

OBJECTIVE

The aim of this study was to evaluate the oncological and survival outcomes of a Watch and Wait policy in rectal cancer after a clinical complete response (cCR) following neoadjuvant chemoradiotherapy.

BACKGROUND

The detection of a cCR after neoadjuvant treatment may facilitate a nonoperative approach in selected patients. However, the long-term safety of this strategy remains to be validated.

METHOD

This is a systematic review of the literature to determine the oncological outcomes in Watch and Wait patients. The primary outcome was the cumulative rate of local regrowth, success of salvage surgery, and incidence of metastases. We also evaluated survival outcomes. A pooled analysis of manually extracted summary statistics from individual studies was carried out using inverse variance weighting.

RESULTS

Seventeen studies comprising 692 patients were identified; incidence of cCR was 22.4% [95% confidence interval (CI),14.3-31.8]. There were 153 (22.1%) local regrowths, of which 96% (n = 147/153) manifested in the first 3 years of surveillance. The 3-year cumulative risk of local regrowth was 21.6% (95% CI, 16.0-27.8). Salvage surgery was performed in 88% of patients, of which 121 (93%) had a complete (R0) resection. Fifty-seven metastases (8.2%) were detected, and 35 (60%) were isolated without evidence of synchronous regrowths; 3-year incidence was 6.8% (95% CI, 4.1-10.2). The 3-year overall survival was 93.5% (95% CI, 90.2-96.2).

CONCLUSION

In rectal cancer patients with a cCR following neoadjuvant chemoradiotherapy, a Watch and Wait policy appears feasible and safe. Robust surveillance with early detection of regrowths allows a high rate of successful salvage surgery, without an increase in the risk of systemic disease, or adverse survival outcomes.

Endoscopy and magnetic resonance imaging-based prediction of ypT stage in patients with rectal cancer who received chemoradiotherapy: Results from a prospective study of 110 patients

Accurate tumor response determination remains inconclusive after preoperative chemoradiation therapy (CRT) for rectal cancer. This study aimed to investigate whether clinical assessment, such as endoscopy and magnetic resonance imaging (MRI), can accurately predict ypT stage and select candidates for pelvic organ-preserving surgery in rectal cancer after preoperative CRT. A total of 110 patients who underwent preoperative CRT followed by curative resection for rectal cancer were prospectively enrolled. Magnetic resonance tumor regression grade (mrTRG) using T2-MRI, endoscopic evaluation, and combination modality (combination of endoscopy and mrTRG) were used to analyze tumor response after preoperative CRT. Endoscopic findings were categorized as 3 grades and the mrTRG was assessed into 5 grades. Twenty-nine patients (26.4%) had achieved pathologic complete response. When predicting ypT0, endoscopy showed significantly higher area under the curve (AUC 0.818) than did mrTRG (AUC 0.568) and combination modality (AUC 0.768) in differentiating good response from poor response (P < .001). Both endoscopy and combination modality showed significantly higher diagnostic performance in sensitivity (79.31%), positive predictive value (PPV 67.65%), negative predictive value (NPV 92.11%), and accuracy (84.55%) than those of MR tumor response (sensitivity 37.93%, PPV 36.67%, NPV 77.50%, and accuracy 66.36%) for the prediction of ypT0 (P < .001). Combination modality showed significantly higher diagnostic performance in sensitivity (56.92%), NPV (56.92%), and accuracy (67.27%) compared with those of mrTRG. Neither endoscopy, nor mrTRG, nor the combination modality had adequate diagnostic performances to be clinically acceptable in selecting candidates for nonoperative treatment strategies. However, endoscopy may be incorporated in clinical restaging strategy in planning the extent of surgical resection in patients with rectal cancer.

The impact of total neo-adjuvant treatment on nonoperative management in patients with locally advanced rectal cancer: The evaluation of 66 cases

BACKGROUND

The study aimed to assess if adherence to a total-neoadjuvant-treatment (TNT) protocol followed by observation(watch-and-wait) led to the successful nonoperative-management of low-rectal-cancer.

METHODS

In this study, patients with primary, resectable-T3-T4, N0-N1 distal-rectal-adenocarcinoma underwent-chemoradiotherapy + consolidation-chemotherapy (TNT). During the-TNT-period, endoscopy, MRI, and FDG-PET/CT were performed. We allocated patients with complete-clinical-tumor-regression, who underwent endoscopy every two months, MRI every-four-months, and PET/CT every-six-months-after-treatment, to the observation-group(OG). All other patients were referred for surgery. The OG was followed-up. The primary endpoint was local tumor-ecurrence after allocation to the OG.

RESULTS

Between 2015 and 2018, we enrolled 66-patients. Of 60-patients who were eligible to participate, 39 had complete-clinical-response(cCR) and were allocated to the OG, six underwent local-excision (LE), and 15 underwent total-mesorectal-excision (TME). The median follow-up duration was 22 (9-42) months. The local-recurrence-rate in the OG was 15.3%, and the LE and TME rates were 16.6% and 0%, respectively. All recurrence cases were salvaged through either LE or TME. The-distant-metastasis rate was 5.1%, 16.6%, and 12.5% in the OG, LE, and TME groups, respectively. The endoscopic negative-predictive-value(NPV) was 50%, and the positive-predictive-value(PPV) was 76.9% in the surgery group (LE + TME). MRI; NPV-50%, PPV-76.9%. PET/CT; NPV-100%, PPV-93.3%. Six patients(28.57%) from surgery group achieved complete pathological response (cPR).

CONCLUSION

Our results indicated a high proportion of selected-rectal-cancers with-cCR after neo-adjuvant-therapy could potentially be managed non-operatively, and major surgery may be avoided.

Role of magnetic resonance imaging in organ-preserving strategies for the management of patients with rectal cancer

Total mesorectal excision has been the most effective treatment strategy adopted to reduce local recurrence rates among patients with rectal cancer. The morbidity associated with this radical surgical procedure led surgeons to challenge the standard therapy particularly when dealing with superficial lesions or good responders after neoadjuvant radiotherapy, to which radical surgery may be considered overtreatment. In this subset of patients, less invasive procedures in an organ-preserving strategy may result in good oncological and functional outcomes. In order to tailor the most appropriate treatment option, accurate baseline staging and reassessment of tumor response are relevant. MRI is the most robust tool for the precise selection of patients that are candidates for organ preservation; therefore, radiologists must be familiar with the criteria used to guide the management of these patients. The purpose of this article is to review the relevant features that radiologists should know in order to provide valuable information during the multidisciplinary discussion and ultimate management decision.

Efficacy and safety of consolidation chemotherapy during the resting period in patients with local advanced rectal cancer

It remains controversial as to whether a long interval between neoadjuvant chemoradiotherapy (NCRT) and surgery may provide clinical benefits for patients with local advanced rectal cancer (LARC). The addition of consolidation chemotherapy during the resting period was recently considered as a treatment option. The present study aimed to verify the efficacy and safety of consolidation chemotherapy during the resting period in patients with LARC. A total of 156 patients with local advanced stage T3-4N0-2 rectal cancer were enrolled between January 2010 and July 2016. Patients were divided into two groups, those who received consolidation chemotherapy prior to surgery (n=76) and the control group who did not (n=80). Multivariate logistic regression and the Kaplan-Meier method were used to explore the predictors of pathological complete response (pCR) and survival. The demographic and tumor characteristics were comparable between the two groups. The consolidation group yielded significantly higher pCR and near pCR rates compared with the control group (P=0.015). Patients in the consolidation group who also underwent standard adjuvant chemotherapy displayed improved 3-year disease-free survival (DFS) compared with the control group (P=0.036). Notably, the addition of consolidation chemotherapy between NCRT and surgery did not significantly increase the incidence of surgical complications and grade 3 or 4 toxicities when compared with the control group. Consolidation chemotherapy was associated with increased pCR/near pCR rates and improved 3-year DFS, and displayed a manageable safety profile. The present study provided primary evidence for the efficacy and safety of consolidation chemotherapy in LARC. Further prospective studies are warranted in the future to verify these results.