Short-course radiotherapy followed by chemotherapy before total mesorectal excision (TME) versus preoperative chemoradiotherapy, TME, and optional adjuvant chemotherapy in locally advanced rectal cancer (RAPIDO): a randomised, open-label, phase 3 trial

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

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Pathologic Outcomes of Short-Course and Long-Course Radiotherapy for Locally Advanced Rectal Cancers Treated With Total Neoadjuvant Therapy

INTRODUCTION

Total neoadjuvant therapy (TNT) for patients with locally advanced rectal cancer (LARC) is now the standard of care. Randomized trials suggest the use of short-course radiotherapy (SCRT) and long-course radiotherapy (LCRT) are oncologically equivalent.

OBJECTIVE

To describe pathologic outcomes after surgical resections of patients receiving SCRT versus LCRT as part of TNT for LARC.

PARTICIPANTS

All patients with LARC treated at a single tertiary hospital who underwent proctectomy after completing TNT were included. Patients were excluded if adequate details of TNT were not available in the electronic medical record.

RESULTS

A total of 53 patients with LARC were included. Thirty-nine patients (73.5%) received LCRT and 14 (26.4%) received SCRT. Forty-nine patients (92.5%) were clinical stage III (cN1-2) prior to treatment. The average lymph node yield after proctectomy was 20.9 for SCRT and 17.0 for LCRT (P = .075). Of the 49 patients with clinically positive nodes before treatment, 76.9% of those who received SCRT and 72.2% of those who received LCRT achieved pN0 disease after TNT. Additionally, there were no significant differences in rates of pathologic complete response between patients who received SCRT and LCRT, 7.1% and 12.8%, respectively (P = .565).

CONCLUSION

Pathologic outcomes of patients with LARC treated with SCRT or LCRT, as part of TNT, may be similar. Further prospective trials are needed to assess long-term clinical outcomes and to determine best treatment protocols.

Pathologic Complete Response, Total Neoadjuvant Therapy and the Survival Paradox in Locally Advanced Rectal Cancer

BACKGROUND

Pathologic complete response (pCR) after preoperative chemoradiation (nCRT) correlates with improved overall survival for patients with locally advanced rectal cancers (LARCs). Escalation protocols including total neoadjuvant therapy (TNT), which delivers multi-agent chemotherapy and chemoradiation before surgery, are associated with increased complete response rates. However, TNT is not associated with improved overall survival. The authors hypothesized that the route to pCR may be an important predictor of oncologic outcome.

METHODS

Adults with LARC between 2006 and 2017 were identified in the National Cancer Database. The cohort was limited to those who received neoadjuvant radiation (45-70 Gy) and underwent proctectomy.

RESULTS

Of 25,880 patients, 16 % received TNT and 84 % had nCRT followed by either multi-agent (27 %), single-agent (14 %), or no adjuvant chemotherapy (44 %). Overall, 18 % achieved pCR, with higher rates in the TNT cohort than in the nCRT (18 %) or multi-agent (14 %) chemotherapy cohorts. With control for covariates, the OS in the pCR cohort was similar for the patients that received single-agent therapy and those that received multi-agent adjuvant therapy, and superior to the TNT and no adjuvant therapy cohorts. Conversely, among the patients who did not achieve pCR, those who received single-agent chemotherapy had OS comparable with those who had multi-agent adjuvant therapy and TNT, which was better than no adjuvant therapy.

CONCLUSION

Patients achieving pCR after TNT had worse OS than those who had CRT alone, suggesting that the neoadjuvant route by which pCR is achieved is prognostically relevant. Therefore, in the era of neoadjuvant therapy escalation, pCR does not necessarily portend a uniformly favorable prognosis.

Colorectal cancer: Recent advances in management and treatment

Colorectal cancer (CRC) is the third most common cancer worldwide, and the second most common cause of cancer-related death. In 2020, the estimated number of deaths due to CRC was approximately 930000, accounting for 10% of all cancer deaths worldwide. Accordingly, there is a vast amount of ongoing research aiming to find new and improved treatment modalities for CRC that can potentially increase survival and decrease overall morbidity and mortality. Current management strategies for CRC include surgical procedures for resectable cases, and radiotherapy, chemotherapy, and immunotherapy, in addition to their combination, for non-resectable tumors. Despite these options, CRC remains incurable in 50% of cases. Nonetheless, significant improvements in research techniques have allowed for treatment approaches for CRC to be frequently updated, leading to the availability of new drugs and therapeutic strategies. This review summarizes the most recent therapeutic approaches for CRC, with special emphasis on new strategies that are currently being studied and have great potential to improve the prognosis and lifespan of patients with CRC.

Total Neoadjuvant Therapy Versus Neoadjuvant Chemoradiation for Locally Advanced Rectal Cancer: A Multi-Institutional Real-World Study

Total neoadjuvant therapy (TNT) has emerged as a promising approach for managing locally advanced rectal cancer (LARC), aiming to enhance resectability, increase pathological complete response (pCR), improve treatment compliance, survival, and sphincter preservation. This study compares the clinical outcomes of TNT, with either induction or consolidation chemotherapy, to those of the standard chemoradiotherapy (CRT). In this retrospective multi-institutional study, patients with stage II-III LARC who underwent CRT or TNT from seven oncology centers between 2021 and 2024 were retrospectively analyzed. The TNT group was categorized into induction or consolidation groups based on the sequence of chemotherapy and radiotherapy. Clinical and pathological data and treatment outcomes, including pCR, event-free survival (EFS), and overall survival (OS), were analyzed. Among the 276 patients, 105 received CRT and 171 underwent TNT. The TNT group showed significantly higher pCR (21.8% vs. 2.9%, p < 0.001) and lower lymphatic (26.3% vs. 42.6%, p = 0.009), vascular (15.8% vs. 32.7%, p = 0.002), and perineural invasion rates (20.3% vs. 37.6%, p = 0.003). Furthermore, 16.9% of TNT patients opted for non-operative management (NOM), compared to 0.9% in the CRT group (p < 0.001). The median interval between the end of radiotherapy and surgery was longer in the TNT group (17.6 weeks vs. 8.8 weeks, p < 0.001). The 3-year EFS was 58.3% for CRT and 71.1% for TNT (p = 0.06). TNT is associated with higher pCR, lower lymphatic and vascular invasion rates, and higher rates of NOM compared to CRT. This supports the use of TNT as a viable treatment strategy for LARC, offering potential benefits in quality of life.

Impact of Dose-Escalated Chemoradiation on Pathological Complete Response in Patients with Locally Advanced Rectal Cancer

Locally advanced rectal cancer requires a multimodal treatment. Radiotherapy is being explored for intensification to improve the rates of pathological complete responses (ypCR rates) which are correlated with better outcomes. This study reports a comparison between standard versus escalated doses in a preoperative scenario. The ypCR rates, toxicity, postoperative complications, and disease-free and overall survival at 5 years are described. From 2012 to 2019, 99 patients were analyzed retrospectively: standard arm (mean of 47.5 Gy) vs. dose-escalated arm (mean of 54.3 Gy). All patients were treated with 3DRT in 25 fractions, with concomitant capecitabine and surgery performed according to the total mesorectal excision principles in both arms. The ypCR was reported using the "College of American Pathologist grades"; the gastrointestinal (GI) and genitourinary (GU) toxicity was reported using the "Common Terminology Criteria for Adverse Events" (CTCAE 4.0). The ypCR rates were higher in the dose-escalated group (25% vs. 10.64%; p = 0.07), with a lower rate of non-treatment response (61.36% vs. 38.64%; p = 0.11). No statistical differences between the arms were found in terms of the oncological outcomes, postoperative complications (p = 0.15), second surgeries (p = 0.62), or deaths (p = 0.62). The CTCAE acute GI and GU toxicity were grade I or II in both arms. Our study presents a long-term follow-up in comparative cohorts.

"Defendit Numerus": A Pooled Analysis of 6145 Locally Advanced Rectal Cancer Treated with Preoperative Chemoradiotherapy

Objective: The optimal management of rectal cancer remains a subject of ongoing research. This meta-analysis of individual patient data assessed the benefit of chemoradiotherapy (fluorouracil-based) in local advanced rectal cancer: disease-free survival and overall survival. Methods: We pooled the data of 6145 patients from 24 studies of rectal cancer who received neoadjuvant radiotherapy with concomitant fluorouracil or capecitabine and surgery. The PRISMA 2020 abstract checklist was followed. Individual participant survival was reconstructed with an algorithm from published Kaplan-Meier curves. Results: The median OS was not reached; the mean survival time was 135.4 months (127.9-141.5). The median DFS was 176.9 months, and the mean disease-free survival time was 122.6 months (111.7-131.9). Conclusions: We provided a benchmark for future studies on rectal cancer treatment. The present results can be used in decision-making for locally advanced rectal cancer patients.

B7H3 Immune Checkpoint Overexpression Is Associated with Decreased Complete Response Rates to Neoadjuvant Therapy in Locally Advanced Rectal Cancer

BACKGROUND AND OBJECTIVES

Rectal cancer accounts for approximately one-third of colorectal cancers, with over 340,000 deaths globally in 2022. Despite advancements in treatment, the five-year overall survival for locally advanced rectal cancer (LARC) remains at 74%, with significant morbidity. B7H3 (CD276), an immune checkpoint protein, plays a role in tumor progression and resistance to therapy, and correlates with poor prognosis in various cancers, including colorectal cancer. This study aims to evaluate the expression of B7H3 in LARC and its impact on overall complete response (oCR) rates to neoadjuvant therapy.

METHODS

A retrospective study was conducted on 60 patients with LARC who received neoadjuvant chemoradiation (nCRT) followed by total mesorectal excision (TME). B7H3 expression was assessed using immunohistochemistry on surgical specimens. Expression levels were categorized as high or low based on a composite score, and their association with oCR rates was analyzed.

RESULTS

High B7H3 expression was observed in 60% of patients, with 73.5% showing expression in more than 50% of tumor cells. Patients who achieved oCR had significantly lower B7H3 expression compared to those with residual disease (p < 0.001). No nuclear expression of B7H3 was detected. No significant correlation was found between B7H3 expression and other clinicopathological variables, except for a higher likelihood of non-restorative surgery in patients with elevated B7H3 levels (p = 0.049). Mucinous adenocarcinoma had high expression of B7H3.

CONCLUSIONS

Elevated B7H3 expression is associated with reduced oCR rates in LARC, highlighting its potential role as a prognostic biomarker. Further studies with larger cohorts are warranted to validate these findings and explore B7H3-targeted therapies as a treatment strategy for LARC.

The Role of Predictive and Prognostic MRI-Based Biomarkers in the Era of Total Neoadjuvant Treatment in Rectal Cancer

The role of magnetic resonance imaging (MRI) in rectal cancer management has significantly increased over the last decade, in line with more personalized treatment approaches. Total neoadjuvant treatment (TNT) plays a pivotal role in the shift from traditional surgical approach to non-surgical approaches such as 'watch-and-wait'. MRI plays a central role in this evolving landscape, providing essential morphological and functional data that support clinical decision-making. Key MRI-based biomarkers, including circumferential resection margin (CRM), extramural venous invasion (EMVI), tumour deposits, diffusion-weighted imaging (DWI), and MRI tumour regression grade (mrTRG), have proven valuable for staging, response assessment, and patient prognosis. Functional imaging techniques, such as dynamic contrast-enhanced MRI (DCE-MRI), alongside emerging biomarkers derived from radiomics and artificial intelligence (AI) have the potential to transform rectal cancer management offering data that enhance T and N staging, histopathological characterization, prediction of treatment response, recurrence detection, and identification of genomic features. This review outlines validated morphological and functional MRI-derived biomarkers with both prognostic and predictive significance, while also exploring the potential of radiomics and artificial intelligence in rectal cancer management. Furthermore, we discuss the role of rectal MRI in the 'watch-and-wait' approach, highlighting important practical aspects in selecting patients for non-surgical management.

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

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

Persistent Lymph Node Metastases After Neoadjuvant Chemoradiotherapy for Rectal Cancer

Importance

Patients with locally advanced rectal cancer and persistent lymph node metastases (PLNM) after neoadjuvant treatment are at high risk of developing locoregional and distant metastasis, yet optimal postsurgical treatment of these patients is limited.

Objective

To analyze the association of PLNM with pretreatment clinical parameters, intensity of neoadjuvant treatment, and long-term oncological outcomes.

Design, Setting, and Participants

This cohort study is a post-hoc analysis of 3 randomized clinical trials (Surgical Oncology Working Group of Germany [CAO], Radiological Oncology Working Group of Germany [ARO], and Working Group for Internal Oncology in the German Cancer Society [AIO]) conducted in Germany in 1994, 2004, and 2012 that included 1948 patients with locally advanced rectal cancer recruited between February 1995 and January 2018. Statistical analysis was conducted between September 2023 and February 2024.

Exposures

Receiving preoperative fluorouracil-based chemoradiotherapy (CRT, comprising the preoperative group of CAO/ARO/AIO-94 and the control group of CAO/ARO/AIO-04), fluorouracil-based CRT plus oxaliplatin (experimental group of CAO/ARO/AIO-04), or total neoadjuvant treatment (TNT) with fluorouracil-based CRT plus oxaliplatin with induction or consolidation leucovorin calcium (folinic acid), fluorouracil, and oxaliplatin chemotherapy within the CAO/ARO/AIO-12 trial.

Main Outcome and Measures

The associations of PLNM with clinical parameters, intensity of neoadjuvant treatment, and cumulative incidences of LR, DM, and overall survival were assessed.

Results

A total of 1888 patients (1333 male participants [70.6%]; median [range] age, 62 [19-84] years) with locally advanced rectal adenocarcinoma (clinical tumor stage 3 to 4 and/or clinically node-positive) treated within 3 consecutive clinical trials were analyzed. A total of 522 (29%) experienced PLNM; 378 had lymph node stage (ypN) 1 (20%) after neoadjuvant treatment (ypN) 1 (20%), and 174 had ypN2 (9%). Age, clinical T-stage, N-stage, grading, carcinoembryonic antigen levels, and time interval from completion of CRT to surgery were significantly associated with PLNM, whereas sex and tumor location were not. The percentage of patients with ypN2 stage was almost halved after TNT (18 of 293 patients [6%]) compared with patients treated with fluorouracil-based CRT (114 of 1009 patients [11.3%]; χ26 = 16.693; P = .01). After a median (IQR) follow-up of 54 (37-62) months, 5-year overall survival was 86.1% (95% CI, 83.9%-88.4%) for ypN0, 74.0% (95% CI, 83.9%-88.4%) for ypN1, and 43% for ypN2 (95% CI, 35.4%-52.2%) (P < .001). The 5-year cumulative incidences of locoregional and distant metastases were, respectively, 3% (95% CI, 2.1%-4.2%) and 20% (95% CI, 18%-23%) for ypN0, 6% (95% CI, 3.4%-8.8%) and 40% (95% CI, 34%-46%) for ypN1, and 19% (95% CI, 13%-26%) and 72% (95% CI, 63%-79%) for ypN2 (both P < .001).

Conclusions and Relevance

In this cohort study, PLNM unmasked an unfavorable phenotype of rectal cancer at high risk for treatment failure. More aggressive adjuvant treatment might be considered; however, risk-adapted surveillance strategies and early recurrence-directed surgery, if feasible, are important strategies in this group of patients with CRT- and/or chemotherapy-resistant disease.

Racial comparisons in treatment of rectal adenocarcinoma and survival in the military health system

BACKGROUND

Racial disparities in treatment and outcomes of rectal cancer have been attributed to patients' differential access to care. We aimed to study treatment and outcomes of rectal cancer in the equal access Military Health System (MHS) to better understand potential racial disparities.

METHODS

We accessed the MilCanEpi database to study a cohort of patients aged 18 and older who were diagnosed with rectal adenocarcinoma between 1998 and 2014. Receipt of guideline recommended treatment per tumor stage, cancer recurrence, and all-cause death were compared between non-Hispanic White and Black patients using multivariable regression models with associations expressed as odds (AORs) or hazard ratios (AHRs) and their 95% confidence intervals (CIs).

RESULTS

The study included 171 Black and 845 White patients with rectal adenocarcinoma. Overall, there were no differences in receipt of guideline concordant treatment (AOR = 0.76, 95% CI = 0.45 to 1.29), recurrence (AHR = 1.34, 95% CI = 0.85 to 2.12), or survival (AHR = 1.08, 95% CI = 0.77 to 1.54) for Black patients compared with White patients. However, Black patients younger than 50 years of age at diagnosis (AOR = 0.34, 95% CI = 0.13 to 0.90) or with stage III or IV tumors (AOR = 0.28, 95% CI = 0.12 to 0.64) were less likely to receive guideline recommended treatment than White patients in stratified analysis.

CONCLUSIONS

In the equal access MHS, although there were no overall racial disparities in rectal cancer treatment or clinical outcomes between Black and White patients, disparities among those with early-onset or late-stage rectal cancers were noted. This suggests that factors other than access to care may play a role in the observed disparities and warrants further research.

Diverting ostomy prior to neoadjuvant treatment in rectal cancer should be used selectively: A retrospective single-center cohort study

BACKGROUND

Rectal cancer patients commonly benefit from neoadjuvant therapy before resection surgery. For these patients, an elective ostomy diversion is frequently considered, despite the absence of conclusive evidence when a diversion is advantageous. This is a retrospective observational single-center study on a 4-year consecutive rectal cancer cohort undergoing neoadjuvant therapy, aiming at improving the understanding of risks and benefits associated with ostomy diversion.

MATERIAL AND METHOD

Baseline characteristics, tumor-specific data, clinical events, and outcomes were collected using the Swedish Colorectal Cancer Registry and medical records.

RESULTS

Thirty-two (30.2%) of the 106 included patients presented with endoscopic impassable tumors at diagnosis, of which 18 (56.2%) had diverting ostomy. Three out of 14 with impassable tumor and no diversion developed a bowel obstruction. None of the patients with an endoscopically passable tumor at diagnosis (n = 74) experienced a bowel obstruction. The elective diversions (n = 40) were not associated with serious complications (Clavien-Dindo grade ⩾ 3b). Patients with a diverting ostomy (n = 30) had similar time intervals from diagnosis to neoadjuvant treatment and to definite tumor resection as those without diversion but experienced more complex primary tumor resections in terms of blood loss and operation time.

CONCLUSION

An elective diverting ostomy is a relatively safe procedure in rectal cancer patients requiring neoadjuvant therapy. More than one out of five non-diverted patients with endoscopically impassable rectal tumors developed bowel obstruction and would potentially have benefited from an elective diversion.

Artificial Intelligence Imaging Diagnosis Using Super-Resolution and Three-Dimensional Shape for Lymph Node Metastasis of Low Rectal Cancer: A Pilot Study From a Single Center

BACKGROUND

Although accurate preoperative diagnosis of lymph node metastasis is essential for optimizing treatment strategies for low rectal cancer, the accuracy of present diagnostic modalities has room for improvement.

OBJECTIVE

The study aimed to establish a high-precision diagnostic method for lymph node metastasis of low rectal cancer using artificial intelligence.

DESIGN

A retrospective observational study.

SETTINGS

A single cancer center and a college of engineering in Japan.

PATIENTS

Patients with low rectal adenocarcinoma who underwent proctectomy, bilateral lateral pelvic lymph node dissection, and contrast-enhanced multidetector row CT (slice ≤1 mm) between July 2015 and August 2021 were included in the present study. All pelvic lymph nodes from the aortic bifurcation to the upper edge of the anal canal were extracted, regardless of whether within or beyond the total mesenteric excision area, and pathological diagnoses were annotated for training and validation.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy.

RESULTS

A total of 596 pathologically negative nodes and 43 positive nodes from 52 patients were extracted and annotated. Four diagnostic methods, with and without using super-resolution images and with and without using 3-dimensional shape data, were performed and compared. The super-resolution + 3-dimensional shape data method had the best diagnostic ability for the combination of sensitivity, negative predictive value, and accuracy (0.964, 0.966, and 0.968, respectively), whereas the super-resolution only method had the best diagnostic ability for the combination of specificity and positive predictive value (0.994 and 0.993, respectively).

LIMITATIONS

Small number of patients at a single center and the lack of external validation.

CONCLUSIONS

Our results enlightened the potential of artificial intelligence for the method to become another game changer in the diagnosis and treatment of low rectal cancer. See Video Abstract .

DIAGNSTICO POR IMGENES CON INTELIGENCIA ARTIFICIAL MEDIANTE SUPERRESOLUCIN Y FORMA D PARA LA METSTASIS EN LOS GANGLIOS LINFTICOS DEL CNCER DE RECTO BAJO UN ESTUDIO PILOTO DE UN SOLO CENTRO

ANTECEDENTES:Aunque el diagnóstico preoperatorio preciso de metástasis en los ganglios linfáticos es esencial para optimizar las estrategias de tratamiento para el cáncer de recto bajo, la precisión de las modalidades de diagnóstico actuales tiene margen de mejora.OBJETIVO:Establecer un método de diagnóstico de alta precisión para las metástasis en los ganglios linfáticos del cáncer de recto bajo utilizando inteligencia artificial.DISEÑO:Un estudio observacional retrospectivo.AJUSTE:Un único centro oncológico y una facultad de ingeniería en Japón.PACIENTES:En el presente estudio se incluyeron pacientes con adenocarcinoma rectal bajo sometidos a proctectomía, disección bilateral de ganglios linfáticos pélvicos laterales y tomografía computarizada con múltiples detectores con contraste (corte ≤1 mm) entre julio de 2015 y agosto de 2021. Se resecaron todos los ganglios linfáticos pélvicos desde la bifurcación aórtica hasta el borde superior del canal anal, independientemente de si estaban dentro o más allá del área de escisión mesentérica total, y se registraron los diagnósticos patológicos para entrenamiento y validación.PRINCIPALES MEDIDAS DE RESULTADO:Sensibilidad, especificidad, valor predictivo positivo, valor predictivo negativo y precisión.RESULTADOS:Se extrajeron y registraron un total de 596 ganglios patológicamente negativos y 43 positivos de 52 pacientes. Se realizaron y compararon cuatro métodos de diagnóstico, con y sin imágenes de súper resolución y sin datos de imagen en 3D. El método de superresolución + datos de imagen en 3D tuvo la mejor capacidad de diagnóstico para la combinación de sensibilidad, valor predictivo negativo y precisión (0,964, 0,966 y 0,968, respectivamente), mientras que el método de súper resolución solo tuvo la mejor capacidad de diagnóstico para la combinación de especificidad y valor predictivo positivo (0,994 y 0,993, respectivamente).LIMITACIONES:Pequeño número de pacientes en un solo centro y falta de validación externa.CONCLUSIONES:Nuestros resultados iluminan el potencial de la inteligencia artificial para que el método se convierta en otro elemento de cambio en el diagnóstico y tratamiento del cáncer de recto bajo. (Traducción ---Dr. Fidel Ruiz Healy ).

Risk Factors for Recurrence After Surgery for Rectal Cancer in a Modern, Nationwide Population-Based Cohort

BACKGROUND

The success of modern multimodal treatment in rectal cancer is dependent on risk prediction. Better knowledge of the risk of locoregional and distant recurrence, in relation to preoperative treatment, pathological stage, and commonly used risk factors, is needed when deciding on adjuvant therapy and surveillance.

METHODS

The Swedish ColoRectal Cancer Registry was used to identify patients diagnosed with rectal adenocarcinoma between 2011 and 2018. Readily available variables, including patient, tumor, and treatment factors were exposures. Cox proportional hazard models were used to identify important risk factors for recurrence and calculate recurrence risks.

RESULTS

A total of 9428 curatively resected patients were included and followed for a median of 72 months. Eighteen percent had distal recurrence and 3% had locoregional recurrence at 5 years. Risk factors with major impact on distal recurrence were pT4a (hazard ratio [HR] 5.1, 95% confidence interval [CI] 3.3-8.0), pN2b (HR 3.4, 95% CI 2.7-4.2), tumor deposit (HR 1.7, 95% CI 1.5-1.9), lymph node yield (HR 1.5, 95% CI 1.3-1.8), and tumor level 0-5 cm (HR 1.5, 95% CI 1.3-1.8). Pathologic stage and number of risk factors identified groups with markedly different recurrence risks in all neoadjuvant treatment groups.

CONCLUSIONS

Readily available risk factors, as a complement to stage, are still valid and robust in all neoadjuvant treatment groups. Tumor deposit is important, while circumferential resection margin might no longer be important with improved oncological treatments and high-quality TME surgery. Tailored surveillance is possible in selected groups using risk stratification based on stage and risk factors.

Tailoring rectal cancer surgery: Surgical approaches and anatomical insights during deep pelvic dissection for optimal outcomes in low-lying rectal cancer

This review article explores advanced surgical approaches and anatomical insights for tailoring rectal cancer surgery, particularly focusing on low-lying rectal cancer. With the evolution of imaging technologies, precise preoperative planning has become possible, enhancing the visualization of anatomy surrounding the rectum and enabling more accurate assessments of circumferential resection margin (CRM) involvement. The article emphasizes the dynamic nature of rectal cancer treatment, advocating for individualized surgical planning based on comprehensive preoperative imaging and intraoperative assessment. This approach aims to optimize patient care by integrating recent advancements and anatomical insights into clinical practice for the management of low-lying rectal cancer. Particularly, the article discusses the importance of customizing the excision of Denonvilliers' fascia (DVF) based on tumor characteristics for optimal oncologic and functional outcomes, especially for anteriorly located tumors. It highlights the need for precise dissection techniques to ensure a negative CRM while preserving critical anatomical structures. Additionally, the review addresses the surgical management of tumors at the anorectal ring and introduces the Gate Approach for deep anterolateral pelvic dissection. Special attention is given to tumors impacting the membranous and prostate urethra, emphasizing tailored surgical approaches to balance complete tumor resection with the preservation of urogenital functions.

Neoadjuvant Chemotherapy in Colon Cancer: More Than Just an Optical Illusion

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Photon Counting Computed Tomography in Rectal Cancer: Associations Between Iodine Concentration, Histopathology and Treatment Response: A Pilot Study

RATIONALE AND OBJECTIVES

Common computed tomography (CT) investigation plays a limited role in characterizing and assessing the response of rectal cancer (RC) to neoadjuvant radiochemotherapy (NARC). Photon counting computed tomography (PCCT) improves the imaging quality and can provide multiparametric spectral image information including iodine concentration (IC). Our purpose was to analyze associations between IC and histopathology in RC and to evaluate the role of IC in response prediction to NARC.

MATERIALS AND METHODS

Overall, 41 patients were included into the study, 14 women and 27 men, mean age, 65.5 years. PCCT in a portal venous phase of the abdomen was performed. In every case, a polygonal region of interest (ROI) was manually drawn on iodine maps. Normalized IC (NIC) was also calculated. Tumor stage, grade, lymphovascular invasion, circumferential resection margin, and tumor markers were analyzed. Tumor regression grade (absence/presence of tumor cells) after NARC was analyzed. NIC values in groups were compared to Mann-Whitney-U tests. Sensitivity, specificity, and area under the curve values were calculated. Intraclass correlation coefficient (ICC) was calculated.

RESULTS

ICC was 0.93, 95%CI= (0.88; 0.96). Tumors with lymphovascular invasion showed higher NIC values in comparison to those without (p = 0.04). Tumors with response grade 2-4 showed higher pretreatment NIC values in comparison to lesions with response grade 0-1 (p = 0.01). A NIC value of 0.36 and higher can predict response grade 2-4 (sensitivity, 73.9%; specificity, 91.7%; area under the curve, 0.85).

CONCLUSION

NIC values showed an excellent interreader agreement in RC. NIC can predict treatment response to NARC.

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

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

Preoperative short-course radiotherapy followed by chemotherapy and PD-1 inhibitor administration for locally advanced rectal cancer: A study protocol of a randomized phase II/III trial (STELLAR II study)

AIM

For patients with locally advanced rectal cancer, previous STELLAR studies have shown that a new adjuvant treatment paradigm of short-course radiotherapy followed by neoadjuvant chemotherapy can achieve pathological complete response rates superior to those of standard care; however, the 3-year DFS is inferior to neoadjuvant concurrent radiotherapy. Recent studies have shown that immune checkpoint inhibitors may improve the prognosis of rectal cancer and have good synergy with radiotherapy. Therefore, neoadjuvant chemotherapy combined with immune checkpoint inhibitors after a short course of radiotherapy has the potential to further improve complete response rates and prognosis.

METHOD

The STELLAR II study is a multicentre, open label, two-arm randomized, phase II/III trial of short-course radiotherapy followed by neoadjuvant chemotherapy concurrent with immunotherapy for locally advanced rectal cancer. A total of 588 patients with locally advanced rectal cancer (LARC) will be randomly assigned to the experimental and control groups. The experimental group will receive short-course radiotherapy and neoadjuvant chemotherapy in combination with sindilizumab, while the control group will receive short-course radiotherapy and neoadjuvant chemotherapy. Both groups will subsequently receive either total rectal mesenteric resection or a watch & wait (W&W) strategy. The phase II primary endpoint is the complete remission rate, and the secondary endpoints include grade 3-4 adverse events, perioperative complications, R0 resection rate, overall survival, local recurrence rate, distant metastasis rate and quality of life score. A seamless phase II/III randomized controlled design will be used to investigate the effectiveness and safety of the TNT strategy with the addition of immunotherapy. The trial opened, and the first patient was recruited on 31 August 2022. Trial registration number and date of registration: ClinicalTrials.gov NCT05484024, 29 July 2022.

DISCUSSION

The STELLAR II trial will prospectively evaluate the efficacy of TNT treatment strategies that incorporate immune checkpoint inhibitors. The trial will yield important information to guide routine management of patients with local advanced rectal cancer.

Total neoadjuvant treatment using short-course radiotherapy and four CAPOX cycles in locally advanced rectal cancer with high-risk criteria for recurrence: a Swedish nationwide cohort study (LARCT-US)

Background

Total neoadjuvant treatment (TNT) for locally advanced rectal cancer (LARC) increases pathologic complete response (pCR) rate and reduces the risk of systemic recurrences over chemoradiotherapy (CRT) in randomised trials, e.g., the RAPIDO trial. A modified RAPIDO schedule was prospectively explored in Sweden to evaluate TNT in routine health care before the RAPIDO results were published.

Methods

Between July 2016 and June 2020, 273 patients with high-risk LARC (clinical tumour stage cT4, clinical nodal stage cN2, extramural vascular invasion, involved mesorectal fascia or enlarged lateral lymph nodes) were treated in a prospective observational cohort study at 16 hospitals (LARCT-US). Another 189 patients at 18 (including the 16) hospitals were similarly treated (ad modum LARCT-US, AdmL) during the same period. Inclusion and exclusion criteria were identical to the RAPIDO trial. Patients received short-course radiotherapy (5 × 5 Gy for 5 days) followed by four cycles of CAPOX or six FOLFOX-6, followed by total mesorectal excision or, if clinical complete response (cCR), inclusion into a watch-and-wait (W&W) study. The primary endpoint was complete response (CR), i.e., the sum of pCR in specimens and cCR exceeding one year in W&W patients. Safety was assessed in all patients.

Findings

Compared to the RAPIDO trial, patients were older, and tumours more advanced. Median follow-up was 4.8 years (IQR 4.2-5.2). In LARCT-US all patients received radiotherapy and 268 (98%) started chemotherapy whereas in AdmL all patients received radiotherapy and chemotherapy. In LARCT-US 34 patients had pCR and 31 sustained cCR resulting in a CR-rate of 24% (95% CI 20-28). In AdmL, results were similar (23%, 95% CI 17-30). Locoregional recurrences were 6% (95% CI 4-10) and 5% (95% CI 2-9), respectively, both at 3 years and at last follow-up. Neurotoxicity, recorded in LARCT-US, was lower than in RAPIDO (EORTC-QLQ-CIPN20 tingling toes or feet mean score 24 (SD 31) vs 43 (SD 37)). One treatment-associated death occurred.

Interpretation

Despite older patients and more advanced tumours, results similar to the RAPIDO trial were obtained. Hence, two chemotherapy cycles less do not compromise the results maintaining a high CR-rate. This TNT schedule resulted in favourable outcomes in a nation-wide real-life situation.

Funding

Swedish Cancer Society.

Hypofractionated Radiation Therapy: A Cross-sectional Survey Study of US Radiation Oncologists

OBJECTIVES

For many malignancies, hypofractionated radiotherapy (HFRT) is an accepted standard associated with decreased treatment time and costs. United States provider beliefs regarding HFRT likely impact its adoption but are poorly studied. We surveyed US-based radiation oncologists (ROs) to gauge HFRT utilization rates for prostate (PC), breast (BC), and rectal cancer (RC) and to characterize the beliefs governing these decisions.

METHODS

From July to October 2021, an anonymized, online survey was electronically distributed to ROs actively practicing in the United States. Demographic and practice characteristic information was collected. Questions assessing rates of offering HFRT for PC, BC, and RC and perceived limitations towards using HFRT were administered.

RESULTS

A total of 203 eligible respondents (72% male, 72% White, 53% nonacademic practice, 69% with 11+ years in practice) were identified. Approximately 50% offered stereotactic body radiation therapy (SBRT) for early/favorable intermediate risk PC. Although >90% of ROs offered whole-breast HFRT for early-stage BC, only 33% offered accelerated partial-breast irradiation (APBI). Overall, 41% of ROs offered short-course neoadjuvant RT for RC. The primary reported barriers to HFRT utilization were lack of data, inexperience, and referring provider concerns.

CONCLUSIONS

HFRT is safe, effective, and beneficial, yet underutilized-particularly prostate SBRT, APBI, and short-course RT for RC. Skills retraining and education of ROs and referring providers may increase utilization rates.

Clinical Outcomes in T4 and/or N2 Rectal Cancer Treated With Neoadjuvant Chemoradiotherapy: A Retrospective Study

INTRODUCTION

Total neoadjuvant therapy (TNT) in the management of locally advanced rectal cancer (LARC) did not show survival benefit over the standard long course chemoradiotherapy. Trials of TNT did not address the impact of each risk feature in isolation from other high-risk features.

METHODOLOGY

In this retrospective study, we describe the clinical outcomes of patients with T4 and/or N2 rectal adenocarcinoma who were treated with chemoradiotherapy followed by total mesorectal excision (TME). After obtaining the local regulatory approvals, demographic and clinical data were collected for patients in Manitoba between January 2007 and December 2019.

RESULTS

The cohort included 331 patients. 61 patients had T4-only disease and 218 had N2-only disease. Mean age was 59.65 years. 74.3% received adjuvant chemotherapy (ACT), but only 56.5% completed the planned course. R0 resection was achieved in 93.4% of patients (78.7% and 97.2% in T4 and N2, respectively). Median follow up was 4.93 years. 3-year overall recurrence rate was 29%. 3-year locoregional recurrence (LRR) rate was 8% (16% and 6% in T4 and N2, respectively). 3-year overall survival (OS) rate was 84% in the whole cohort (72.6% and 87.1% in T4 and N2, respectively). Incomplete surgical resection was a poor prognostic factor for both OS and LRR. ACT was associated with a survival benefit in the whole cohort (P = .001) and in the N2 sub-cohort (P = 003) but there was no survival benefit observed in T4 sub-cohort. ACT did not have an impact on LRR.

CONCLUSIONS

Achieving R0 resection in LARC with neoadjuvant therapy improves recurrence and survival rates. T4 disease carries a worse clinical outcome than N2 and consideration should be given to upstage T4 to stage III. Different high-risk features in LARC predict different clinical outcomes. In the era of TNT, personalization of treatment strategy based on these factors could potentially improve outcomes.

Remodeling the hepatic immune microenvironment and demolishing T cell traps to enhance immunotherapy efficacy in liver metastasis

Immune checkpoint inhibitors (ICIs) exhibit compromised therapeutic efficacy in many patients with advanced cancers, particularly those with liver metastases. Much of this incapability can be ascribed as an irresponsiveness resulting from the "cold" hepatic tumor microenvironment that acts as T cell "traps" for which there currently lack countermeasures. We report a novel nanomedicine that converts the hepatic immune microenvironment to a "hot" phenotype by targeting hepatic macrophage-centric T cell elimination. Using the nanomedicine, composed of KIRA6 (an endothelium reticulum stress inhibitor), α-Tocopherol nanoemulsions, and anti-PD1 antibodies, we found its potency in murine models of orthotopic colorectal tumors and hepatic metastases, restoring immune responses and enhancing anti-tumor effects. A post-treatment scrutiny of the immune microenvironment landscape in the liver reveals repolarization of immunosuppressive hepatic macrophages, upregulation of Th1-like effector CD4+ T cells, and rejuvenation of dendritic cells along with CD8+ T cells. These findings suggest adaptations of liver-centric immune milieu modulation strategies to improve the efficacy of ICIs for a variety of "cold" tumors and their liver metastases.

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

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

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

OBJECTIVE(S)

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

METHODS

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

RESULTS

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

CONCLUSION

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

Identification of perineural invasion at imaging staging as a novel potential risk factor in rectal cancer: A case report

Treatment of rectal cancer has improved over the years thanks to a multidisciplinary approach. A correct staging has a fundamental role for risk stratification and to define the best treatment for each patient. Unfortunately, approximately 30% of patients with locally advanced rectal cancers will experience tumor recurrence. Thus, the identification of novel clinical-pathological and radiological prognostic factors represents an urgent unmet clinical need. Here we report the case of a patient with radically resected localized rectal cancer who developed an impressive early pelvic recurrence. To better understand the clinical scenario, we have studied the possible factors related to the aggressiveness of the disease. The only poor prognosticfactor that was evidenced at histological report was perineural invasion. Therefore, we questioned whether we could evaluate perineural invasion with imaging, similar to head and neck tumors. Learning from this clinical case, we believe that improving the risk stratification and radiology reporting is necessary to provide the best care for the patient and allow for a better prognosis prediction. Of course, our data should be considered as hypothesis generating and should be further investigated and validated in larger and prospective studies.

Baseline MRI predictors of successful organ preservation in the Organ Preservation in Rectal Adenocarcinoma (OPRA) trial

BACKGROUND

Prospective randomized trials have not yet identified baseline features predictive of organ preservation in locally advanced rectal cancers treated with total neoadjuvant therapy and a selective watch-and-wait strategy.

METHODS

This was a secondary analysis of the OPRA trial, which randomized patients with stage II-III rectal adenocarcinoma to receive either induction or consolidation total neoadjuvant therapy. Patients were recommended for total mesorectal excision, or watch and wait based on clinical response at 8 ± 4 weeks after completing treatment. Standardized baseline clinical and radiological variables were collected prospectively. Survival outcomes, including total mesorectal excision-free survival, disease-free survival, and overall survival, were assessed by intention-to-treat analysis. Cox proportional hazards models were used to evaluate associations between baseline variables and survival outcomes.

RESULTS

Of the 324 patients randomized for the OPRA trial, 38 (11.7%) had cT4 tumours, 230 (71.0%) cN-positive disease, 101 (32.5%) mesorectal fascia involvement, and 64 (19.8%) extramural venous invasion. Several baseline features were independently associated with recommendation for total mesorectal excision on multivariable analysis: nodal disease (HR 1.66, 95% c.i. 1.12 to 2.48), extramural venous invasion (HR 1.57, 1.07 to 2.29), mesorectal fascia involvement (HR 1.45, 1.01 to 2.09), and tumour length (HR 1.11, 1.00 to 1.22). Of these, nodal disease (HR 2.02, 1.15 to 3.53) and mesorectal fascia involvement (HR 2.02, 1.26 to 3.26) also predicted worse disease-free survival. Age (HR 1.03, 1.00 to 1.06) was associated with overall survival.

CONCLUSION

Baseline MRI features, including nodal disease, extramural venous invasion, mesorectal fascia involvement, and tumour length, independently predict the likelihood of organ preservation after completion of total neoadjuvant therapy. Mesorectal fascia involvement and nodal disease are associated with disease-free survival.

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

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

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

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

Factors associated with pathological complete remission after neoadjuvant chemoradiotherapy in locally advanced rectal cancer: a real-world clinical setting

Objective

This study aims to identify factors associated with achieving a pathological complete remission (pCR) in patients with locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy (nCRT).

Methods

We conducted a cohort analysis of 171 LARC patients who underwent curative resection post-nCRT at the First Affiliated Hospital of Guangxi Medical University between January 2015 and December 2021. The data encompassed clinical and pathological information. Univariate and binary logistic regression multivariate analyses were employed to examine the factors influencing pCR achievement after nCRT. Kappa value tests were utilized to compare clinical staging after nCRT with postoperative pathological staging.

Results

Postoperative histopathology revealed that of the 171 patients, 40 (23.4%) achieved TRG 0 grade (pCR group), while 131 (76.6%) did not achieve pCR, comprising 36 TRG1, 42 TRG2, and 53 TRG3 cases. Univariate analysis indicated that younger age (p=0.008), reduced tumor occupation of intestinal circumference (p =0.008), specific pathological types (p=0.011), and lower pre-nCRT CEA levels (p=0.003) correlated with pCR attainment. Multivariate analysis identified these factors as independent predictors of pCR: younger age (OR=0.946, p=0.004), smaller tumor occupation of intestinal circumference (OR=2.809, p=0.046), non-mucinous adenocarcinoma pathological type (OR=10.405, p=0.029), and lower pre-nCRT serum CEA levels (OR=2.463, p=0.031). Clinical re-staging post-nCRT compared to postoperative pathological staging showed inconsistent MRI T staging (Kappa=0.012, p=0.718, consistency rate: 35.1%) and marginally consistent MRI N staging (Kappa=0.205, p=0.001, consistency rate: 59.6%).

Conclusion

LARC patients with younger age, presenting with smaller tumor circumferences in the intestinal lumen, lower pre-nCRT serum CEA levels, and non-mucinous adenocarcinoma are more likely to achieve pCR after nCRT. The study highlights the need for improved accuracy in clinical re-staging assessments after nCRT in LARC.

Nonoperative management and local excision after neoadjuvant chemoradiation therapy for rectal cancer

Locally advanced extraperitoneal rectal cancer represents a significant clinical challenge, and currently, the standard treatment is based on neoadjuvant chemoradiation therapy (CRT) followed by radical surgical resection with total mesorectal excision (TME). In the last 30 years, its management has undergone significant changes due to the improvement of complementary radio- and chemotherapy treatments, the improvement of minimally invasive surgical approaches and the diffusion of organ-sparing approaches, such as nonoperative management, commonly called "watch and wait" (NOM) and local excision (LE), in highly selected patients who achieve a major or complete response to neoadjuvant CRT. This review aimed to critically examine the efficacy and oncological safety of NOM and LE compared to those of standard TME in rectal cancer patients after neoadjuvant CRT. Both the pros and cons of these approaches were strictly analyzed, providing a comprehensive and critical overview of these novel management strategies for rectal cancer.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Arterial Mucosal Linear Enhancement at Contrast-enhanced MRI to Exclude Residual Tumor after Neoadjuvant Chemotherapy and Radiation Therapy for Rectal Cancer

Background A watch-and-wait regimen for locally advanced rectal cancer after neoadjuvant chemotherapy and radiation therapy (NCRT) relies on identifying complete tumor response. However, the concordance between a complete response at combined T2-weighted and diffusion-weighted MRI (T2DWI) and pathologic complete response (pCR; ie, ypT0N0) in the tumor is unsatisfactory. Purpose To assess whether identification of mucosal linear enhancement (MLE) at arterial-phase contrast-enhanced (CE) T1-weighted MRI is associated with ypT0 status in patients with locally advanced rectal cancer after NCRT and to evaluate whether combining MLE at CE T1-weighted MRI and negative lymph node metastasis (LNM) at T2DWI can improve identification of pCR. Materials and Methods This retrospective study included patients with locally advanced rectal cancer who underwent total mesorectal excision after NCRT between July 2020 and July 2023 at a tertiary referral academic center. Restaging MRI included T2DWI and arterial-phase CE T1-weighted MRI for primary tumor assessment and T2DWI for evaluation of LNM status. Imaging features associated with ypT0 status were identified at multivariable regression analysis. Results In total, 239 patients (mean age, 58 years ± 12 [SD]; 180 male patients) were assessed. MLE was more common in the ypT0 group than in the ypT1-4 group after NCRT (73% vs 4%, respectively; P < .001). MLE was associated with higher odds of ypT0 status in an adjusted analysis (odds ratio, 137; 95% CI: 25, 767; P < .001). The combination of MLE and negative LNM status achieved an area under the receiver operating characteristic curve of 0.84 (95% CI: 0.79, 0.88) for pCR. Conclusion MLE at CE MRI was associated with higher odds of complete tumor response. Combining MLE and negative LNM status showed good performance for identifying complete tumor response and may exclude residual tumors after NCRT in patients with locally advanced rectal cancer. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Schoellnast in this issue.

Identification and validation of a machine learning model of complete response to radiation in rectal cancer reveals immune infiltrate and TGFβ as key predictors

BACKGROUND

It is uncertain which biological features underpin the response of rectal cancer (RC) to radiotherapy. No biomarker is currently in clinical use to select patients for treatment modifications.

METHODS

We identified two cohorts of patients (total N = 249) with RC treated with neoadjuvant radiotherapy (45Gy/25) plus fluoropyrimidine. This discovery set included 57 cases with pathological complete response (pCR) to chemoradiotherapy (23%). Pre-treatment cancer biopsies were assessed using transcriptome-wide mRNA expression and targeted DNA sequencing for copy number and driver mutations. Biological candidate and machine learning (ML) approaches were used to identify predictors of pCR to radiotherapy independent of tumour stage. Findings were assessed in 107 cases from an independent validation set (GSE87211).

FINDINGS

Three gene expression sets showed significant independent associations with pCR: Fibroblast-TGFβ Response Signature (F-TBRS) with radioresistance; and cytotoxic lymphocyte (CL) expression signature and consensus molecular subtype CMS1 with radiosensitivity. These associations were replicated in the validation cohort. In parallel, a gradient boosting machine model comprising the expression of 33 genes generated in the discovery cohort showed high performance in GSE87211 with 90% sensitivity, 86% specificity. Biological and ML signatures indicated similar mechanisms underlying radiation response, and showed better AUC and p-values than published transcriptomic signatures of radiation response in RC.

INTERPRETATION

RCs responding completely to chemoradiotherapy (CRT) have biological characteristics of immune response and absence of immune inhibitory TGFβ signalling. These tumours may be identified with a potential biomarker based on a 33 gene expression signature. This could help select patients likely to respond to treatment with a primary radiotherapy approach as for anal cancer. Conversely, those with predicted radioresistance may be candidates for clinical trials evaluating addition of immune-oncology agents and stromal TGFβ signalling inhibition.

FUNDING

The Stratification in Colorectal Cancer Consortium (S:CORT) was funded by the Medical Research Council and Cancer Research UK (MR/M016587/1).

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Essential knowledge and technical tips for total mesorectal excision and related procedures for rectal cancer

Total mesorectal excision (TME) has greatly improved rectal cancer surgery outcomes by reducing local recurrence and enhancing patient survival. This review outlines essential knowledge and techniques for performing TME. TME emphasizes the complete resection of the mesorectum along embryologic planes to minimize recurrence. Key anatomical insights include understanding the rectal proper fascia, Denonvilliers fascia, rectosacral fascia, and the pelvic autonomic nerves. Technical tips cover a step-by-step approach to pelvic dissection, the Gate approach, and tailored excision of Denonvilliers fascia, focusing on preserving pelvic autonomic nerves and ensuring negative circumferential resection margins. In Korea, TME has led to significant improvements in local recurrence rates and survival with well-adopted multidisciplinary approaches. Surgical techniques of TME have been optimized and standardized over several decades in Korea, and minimally invasive surgery for TME has been rapidly and successfully adopted. The review emphasizes the need for continuous research on tumor biology and precise surgical techniques to further improve rectal cancer management. The ultimate goal of TME is to achieve curative resection and function preservation, thereby enhancing the patient's quality of life. Accurate TME, multidisciplinary-based neoadjuvant therapy, refined sphincter-preserving techniques, and ongoing tumor research are essential for optimal treatment outcomes.

Feasibility of a tailored operative strategy from organ preservation to pelvic exenteration for cT4 rectal cancer depending on neoadjuvant response

PURPOSE

Improvements in neoadjuvant therapy for locally advanced cT4 rectal cancer have led to improved tumour response and thus a variety of suitable management strategies. The aim of this study was to report management and outcomes of patients with cT4 rectal cancer undergoing a spectrum of treatment strategies from organ preservation (OP) to pelvic exenteration (PE).

METHODS

Patients who underwent elective treatment for cT4 rectal cancer between 2016 and 2021 were included. All patients were treated with curative intent. Surgical management was adapted to tumour response. Kaplan-Meier curves were generated to compare 3-year overall survival (3y-OS), local recurrence (3y-LR) and distant metastases (3y-DM) between different strategies.

RESULTS

Among 152 patients included, 13 (8%) underwent OP, 71 (47%) TME and 68 (45%) APR/PE. The median follow-up was 31.3 months. Patients undergoing OP had a lower tumour pretreatment (p < 0.001). Compared to patients with TME, those with APR/PE had a higher rate of ypT4 (p = 0.001) with a lower R0 rate (p = 0.044). The 3y-OS and 3y-DM were 78% and 15.1%, respectively, without significant differences. The 3y-LR was 6.6%, and patients with OP had a significantly worse 3y-local regrowth compared to 3y-LR in patients with TME and APR/PE (30.2% vs. 5.4% vs. 2%, p = 0.008).

CONCLUSION

cT4 tumours may be suitable for the full spectrum of rectal cancer management from organ preservation to pelvic exenteration depending on tumour response to neoadjuvant therapy. However, careful attention is required in OP as local regrowth in up to 30% of cases reinforces the need for sustained active surveillance in Watch&Wait programmes.

Deciphering the Dilemma: Choosing the Optimal Total Neoadjuvant Treatment Strategy for Locally Advanced Rectal Cancer

Rectal cancer management has evolved significantly, particularly with neoadjuvant treatment strategies. This narrative review examines the development and effectiveness of these therapies for locally advanced rectal cancer (LARC), highlighting the historical quest that led to current neoadjuvant alternatives. Initially, trials showed the benefits of adding radiotherapy (RT) and chemotherapy (CT) to surgery, reducing local recurrence (LR). The addition of oxaliplatin to chemoradiotherapy (CRT) further improved outcomes. TNT integrates chemotherapy and radiotherapy preoperatively to enhance adherence, timing, and systemic control. Key trials, including PRODIGE 23, CAO/ARO/AIO 12, OPRA, RAPIDO, and STELLAR, are analyzed to compare short-course and long-course RT with systemic chemotherapy. The heterogeneity and difficulty in comparing TNT trials due to different designs and outcomes are acknowledged, along with their promising long-term results. On the other hand, it briefly discusses the potential for non-operative management (NOM) in select patients, a strategy gaining traction due to favorable outcomes in specific trials. As a conclusion, this review underscores the complexity of rectal cancer treatment, emphasizing individualized approaches considering patient preferences and healthcare resources. It also highlights the importance of interpreting impressive positive or negative results with caution due to the variability in study designs and patient populations.

Outcomes associated with total neoadjuvant therapy with non-operative intent for rectal adenocarcinoma

Purpose/objectives

To evaluate rates of clinical complete response (cCR), surgery-free survival, permanent ostomy-free survival, and factors associated with these outcomes in patients treated with total neoadjuvant therapy (TNT) with intent for non-operative management of rectal adenocarcinoma.

Methods

A retrospective review was conducted of patients treated with TNT for stage II-IV rectal adenocarcinoma (n=45) at our institution between 2013 - 2022 with curative intent. All patients received radiation with concurrent capecitabine and additional chemotherapy, either prior to or following chemoradiation (CRT), with intent for non-operative management. Response rates were determined based on post-treatment MRI and endoscopy. Kaplan-Meier method was utilized to estimate the 1- and 2-year surgery- and permanent ostomy-free survivals. Cox regression was used to evaluate associations between surgery- and permanent ostomy-free survivals and various factors of interest, including patient and tumor characteristics and clinical response. Chi-squared analysis compared rates of cCR and surgery by sequence of TNT modality and cell count ratios.

Results

Of the 45 patients treated with TNT, most patients had low-lying rectal tumors with a median distance of 4.1 cm from the anal verge (range, 0.0 - 12.0). Overall, 64.4% (n=29) achieved cCR after TNT. 13 patients (28.9%) underwent surgical resection following TNT, 12 of whom had incomplete response and one who elected to undergo surgery after reaching cCR. At median follow up of 32.0 months (range, 7.1 - 86.1), 22.2% (n=10) of patients had a permanent colostomy, with only 2 of these completed for tumor regrowth after cCR. At one and two years, respectively, surgery-free survival was 77.3% and 66.2%, and permanent ostomy-free survival was 90.9% and 78.2%. Rates of cCR were higher in patients who received CRT first compared to those who received chemotherapy first (72.2% vs. 33.3%, p=0.029) and rates of surgery were also lower in patients who received CRT first compared to those who received chemotherapy first (19.4% vs. 66.7%, p=0.005). On Cox regression model, cCR on 6 month post-CRT endoscopy was associated with surgery-free survival (p=0.006) and permanent ostomy-free survival (p=0.033). Clinical response at earlier follow up points did not predict surgery- nor permanent ostomy-free survival.

Conclusion

These results support evidence that TNT may be a non-surgical option for select patients with rectal adenocarcinoma who desire organ preservation. In this investigation at a single institution, the treatment response on 6-month post-CRT endoscopy was the best predictor of surgery- and permanent ostomy-free survival, which are outcomes that are important to patient quality of life. CRT followed by consolidation chemotherapy was associated with higher rates of cCR and lower rates of surgery compared to those treated with induction chemotherapy.

Alliance A022104/NRG-GI010: The Janus Rectal Cancer Trial: a randomized phase II/III trial testing the efficacy of triplet versus doublet chemotherapy regarding clinical complete response and disease-free survival in patients with locally advanced rectal cancer

BACKGROUND

Recent data have demonstrated that in locally advanced rectal cancer (LARC), a total neoadjuvant therapy (TNT) approach improves compliance with chemotherapy and increases rates of tumor response compared to neoadjuvant chemoradiation (CRT) alone. They further indicate that the optimal sequencing of TNT involves consolidation (rather than induction) chemotherapy to optimize complete response rates. Data, largely from retrospective studies, have also shown that patients with clinical complete response (cCR) after TNT may be managed safely with the watch and wait approach (WW) instead of preemptive total mesorectal resection (TME). However, the optimal consolidation chemotherapy regimen to achieve cCR has not been established, and a randomized clinical trial has not robustly evaluated cCR as a primary endpoint. Collaborating with a multidisciplinary oncology team and patient groups, we designed this NCI-sponsored study of chemotherapy intensification to address these issues and to drive up cCR rates, to provide opportunity for organ preservation, improve quality of life for patients and improve survival outcomes.

METHODS

In this NCI-sponsored multi-group randomized, seamless phase II/III trial (1:1), up to 760 patients with LARC, T4N0, any T with node positive disease (any T, N +) or T3N0 requiring abdominoperineal resection or coloanal anastomosis and distal margin within 12 cm of anal verge will be enrolled. Stratification factors include tumor stage (T4 vs T1-3), nodal stage (N + vs N0) and distance from anal verge (0-4; 4-8; 8-12 cm). Patients will be randomized to receive neoadjuvant long-course chemoradiation (LCRT) followed by consolidation doublet (mFOLFOX6 or CAPOX) or triplet chemotherapy (mFOLFIRINOX) for 3-4 months. LCRT in both arms involves 4500 cGy in 25 fractions over 5 weeks + 900 cGy boost in 5 fractions with a fluoropyrimidine (capecitabine preferred). Patients will undergo assessment 8-12 (± 4) weeks post-TNT completion. The primary endpoint for the phase II portion will compare cCR between treatment arms. A total number of 312 evaluable patients (156 per arm) will provide statistical power of 90.5% to detect a 17% increase in cCR rate, at a one-sided alpha = 0.048. The primary endpoint for the phase III portion will compare disease-free survival (DFS) between treatment arms. A total of 285 DFS events will provide 85% power to detect an effect size of hazard ratio 0.70 at a one-sided alpha of 0.025, requiring enrollment of 760 patients (380 per arm). Secondary objectives include time-to event outcomes (overall survival, organ preservation time and time to distant metastasis) and adverse event rates. Biospecimens including archival tumor tissue, plasma and buffy coat, and serial rectal MRIs will be collected for exploratory correlative research. This study, activated in late 2022, is open across the NCTN and had accrued 330 patients as of May 2024. Study support: U10CA180821, U10CA180882, U24 CA196171; https://acknowledgments.alliancefound.org .

DISCUSSION

Building on data from modern day rectal cancer trials and patient input from national advocacy groups, we have designed The Janus Rectal Cancer Trial studying chemotherapy intensification via a consolidation chemotherapy approach with the intent to enhance cCR and DFS rates, increase organ preservation rates, and improve quality of life for patients with rectal cancer.

TRIAL REGISTRATION

Clinicaltrials.gov ID: NCT05610163; Support includes U10CA180868 (NRG) and U10CA180888 (SWOG).

Colorectal cancer

Despite decreased incidence rates in average-age onset patients in high-income economies, colorectal cancer is the third most diagnosed cancer in the world, with increasing rates in emerging economies. Furthermore, early onset colorectal cancer (age ≤50 years) is of increasing concern globally. Over the past decade, research advances have increased biological knowledge, treatment options, and overall survival rates. The increase in life expectancy is attributed to an increase in effective systemic therapy, improved treatment selection, and expanded locoregional surgical options. Ongoing developments are focused on the role of sphincter preservation, precision oncology for molecular alterations, use of circulating tumour DNA, analysis of the gut microbiome, as well as the role of locoregional strategies for colorectal cancer liver metastases. This overview is to provide a general multidisciplinary perspective of clinical advances in colorectal cancer.

Combination of neoadjuvant and adjuvant chemotherapy with FOLFOX compared with adjuvant chemotherapy in management of locally advanced rectal cancers: a randomized trial of a promising therapeutic approach

BACKGROUND

Colorectal cancer (CRC) is a significant malignancy with widespread implications. Despite progress in surgical interventions for rectal cancer, improvements in overall prognosis remain disproportionate. Standard preoperative chemoradiation, while established as the standard treatment for the majority of rectal cancers, exhibits limited effectiveness in enhancing disease-free survival (DFS) and mitigating distant metastases, particularly in cases of locally advanced rectal cancer (LARC).

METHODS

This randomised clinical trial assessed 286 patients with LARC in two paralleled groups. Group A underwent six courses of neoadjuvant MFOLFOX chemotherapy, chemoradiation, surgery, and six adjuvant chemotherapy cycles. Group B received concurrent chemoradiation, surgery, and twelve adjuvant chemotherapy cycles. Patient evaluations were achieved at multiple stages of treatment and follow-up.

RESULTS

Group A had significantly lower local recurrence (11.64%) than Group B (21.74%, P = 0.025). The distant metastasis rate in Group A (8.90%) was lower than in Group B (20.29%) but was not significant (p = 0.143). More patients in Group A experienced downstaging (80.82% vs. 60.87%, p < 0.001). Specifically, 72.60% demonstrated downstaging of tumour invasion and 54.79% downstaging of lymph node involvement, compared to 57.25% and 41.30% in Group B (p = 0.009 and p = 0.025, respectively) as well as higher pCR rate (26.03% vs. 15.25%, p = 0.030) and three-year DFS rate (82.19% vs. 71.01%, p = 0.035) in group A compare to group B.

CONCLUSION

This innovative strategy for LARC showed promising results with lower local recurrence and higher rates of downstaging and pCR. Treatment side effects were similar in both groups but less frequent in Group A. Anaemia was the most common haematological side effect (A: 58%, B: 68%), and peripheral sensory neuropathy was the most common non-haematological complication (A: 63%, B: 64%). These findings suggest this regimen could be a valuable therapeutic approach for LARC.

TRIAL REGISTRATION

This trial was registered on 2023-12-08 within the IRCT.IR database under the number IRCT20210308050628N1.

Chemoradiation, Consolidation Chemotherapy, and Watch and Wait for Early Rectal Cancer

As watch and wait has become an attractive management alternative among patients with rectal cancer who achieve a clinical complete response to neoadjuvant chemoradiation, the focus of organ preservation has now shifted toward the use of this approach in patients with early rectal cancer. These patients would otherwise be treated without the use of neoadjuvant therapy for oncological reasons. The sole purpose of any neoadjuvant treatment here would be the achievement of a complete clinical response in an attempt to avoid total mesorectal excision. This has become particularly interesting after the incorporation of total neoadjuvant therapy regimens. These regimens have resulted in significantly higher rates of complete tumor regression and therefore become an interesting alternative among early rectal cancer patients where organ preservation is desired. The present review provides an overview of the currently available evidence and the preliminary experience with this rather controversial approach.