Effect of adding mFOLFOX6 after neoadjuvant chemoradiation in locally advanced rectal cancer: a multicentre, phase 2 trial

Total neoadjuvant therapy for locally advanced rectal cancer

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the effectiveness and safety of total neoadjuvant therapy versus standard therapy in individuals with locally advanced rectal cancer.

Personalized surveillance in colorectal cancer: Integrating circulating tumor DNA and artificial intelligence into post-treatment follow-up

Given the growing burden of colorectal cancer (CRC) as a global health challenge, it becomes imperative to focus on strategies that can mitigate its impact. Post-treatment surveillance has emerged as essential for early detection of recurrence, significantly improving patient outcomes. However, intensive surveillance strategies have shown mixed results compared to less intensive methods, emphasizing the necessity for personalized, risk-adapted approaches. The observed suboptimal adherence to existing surveillance protocols underscores the urgent need for more tailored and efficient strategies. In this context, circulating tumor DNA (ctDNA) emerges as a promising biomarker with significant potential to revolutionize post-treatment surveillance, demonstrating high specificity [0.95, 95% confidence interval (CI): 0.91-0.97] and robust diagnostic odds (37.6, 95%CI: 20.8-68.0) for recurrence detection. Furthermore, artificial intelligence and machine learning models integrating patient-specific and tumor features can enhance risk stratification and optimize surveillance strategies. The reported area under the receiver operating characteristic curve, measuring artificial intelligence model performance in predicting CRC recurrence, ranged from 0.581 and 0.593 at the lowest to 0.979 and 0.978 at the highest in training and validation cohorts, respectively. Despite this promise, addressing cost, accessibility, and extensive validation remains crucial for equitable integration into clinical practice.

Compliance and Toxicity of Total Neoadjuvant Therapy in Locally Advanced Rectal Cancer: A Systematic Review and Network Meta-analysis

PURPOSE

The individual chemotherapy- and radiotherapy-related toxicities between induction (iTNT) and consolidation total neoadjuvant therapy (cTNT) remain unclear. This network meta-analysis (NMA) comparing iTNT, cTNT, and traditional neoadjuvant chemoradiation (nCRT) evaluated the comparative treatment-related toxicities and compliance of the TNT schemas.

METHODS

A systematic review of randomized clinical trials and nonrandomized studies of interventions was performed as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-NMA guidelines. A Bayesian NMA was conducted, and odds ratios (OR) with 95% credible intervals (CrI) are reported for all outcomes.

RESULTS

Eighteen studies including 5730 patients were identified. iTNT ranked highest on rate of rectal bleeding (cTNT: OR 0.23 95% CrI 0.05-0.93; nCRT: OR 0.33, 95% CrI 0.09-0.96), proctitis (cTNT: OR 0.2, 95% CrI 0.06-0.55; nCRT: OR 0.2, 95% CrI 0.06-0.51), and postoperative diarrhea (cTNT: OR 0.37, 95% CrI 0.18-0.73; nCRT: OR 0.33, 95% CrI 0.15-0.71); cTNT ranked highest on rate of vomiting (iTNT: OR 0.24, 95% CrI 0.05-0.96; nCRT: OR 0.29, 95% CrI 0.06-0.89) and a higher rate of lymphopenia than iTNT (iTNT: OR 0.56, 95% CrI 0.34-0.99). Radiotherapy compliance was highest in cTNT (iTNT: OR 0.23, 95% CrI 0.05-0.72; nCRT: OR 0.18, 95% CrI 0.04-0.58). There was no difference in overall toxicity and mortality, chemotherapy compliance, and remaining individual system-based toxicities and postoperative complications.

CONCLUSIONS

Across all treatment strategies, iTNT had higher radiation-related gastrointestinal toxicities and postoperative diarrhea; cTNT had higher vomiting and lymphopenia rates. While no treatment strategy was superior in chemotherapy compliance, radiotherapy compliance was ranked highest in cTNT.

Quality of Life and Functional Outcomes in Patients With Locally Advanced Rectal Cancer Receiving Total Neoadjuvant Therapy Versus Concurrent Chemoradiation Therapy: An Analysis of the STELLAR Trial

PURPOSE

To explore differences in the effects of total neoadjuvant therapy (TNT) and preoperative concurrent chemoradiation therapy (CRT) on quality of life and functional outcomes in patients with locally advanced rectal cancer.

METHODS AND MATERIALS

In the study, 591 patients with distal or middle-third, clinical primary tumor stage cT3 to 4 and/or regional lymph node-positive rectal cancer were randomly assigned (1:1) to receive short-term radiation therapy (25 Gy in 5 fractions) followed by 4 cycles of CAPOX (TNT group, n = 297) or standard CRT (50 Gy in 25 fractions concurrently with oral capecitabine) (CRT group, n = 294) before surgery. After a 6-year follow-up, the surviving patients were sent surveys, including the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30, EORTC QLQ-CR29, and Wexner incontinence score questionnaires. Differences between the 2 groups were compared, and baseline data from the general population who completed the EORTC QLQ-C30 were also compared.

RESULTS

The median follow-up was 77.38 (59.07-103.20) months, with 196 out of 414 surviving patients (47.3%) completing the questionnaire. Patients in the TNT group had better emotional function (94.16 ± 10.19 vs 90.17 ± 14.63, P = .031) but more severe diarrhea (12.46 ± 21.73 vs 6.74 ± 16.03, P = .036) than did those in the CRT group. However, the mean differences between the 2 groups were <5 points, which is not clinically significant, and there were no significant differences in other quality of life items. The Wexner incontinence scores were 5 (0-6) and 3 (0-6) for the TNT and CRT groups, respectively, with no significant difference between the groups (P = .357). Compared to the general population data from the completed EORTC QLQ-C30 assessment, the patients did not exhibit differences >5 points in terms of worse function or more severe symptoms.

CONCLUSIONS

There were no significant differences in quality of life or anal function between patients receiving TNT and those receiving CRT. After 6 years, patients were able to maintain stability.

The Landmark Series: Organ Preservation in Rectal Cancer-The Watch and Wait Strategy

Radical treatment of rectal cancer has evolved quite significantly over the last few decades with the development of optimal local disease staging with magnetic resonance (MR), refined surgical techniques including total mesorectal excision (TME) with or without sphincter-preservation, and multimodality treatment with the use of chemotherapy and radiation. While oncological outcomes have shown some significant improvements in terms of local disease control and distant metastases rates, complication rates and functional sequelae remain quite significant for patients undergoing TME surgery. In this setting, organ-preserving alternatives, including transanal local excision (TAE) and Watch and Wait (WW), have become increasingly attractive to patients in an attempt to avoid major surgery (TME) as an alternative treatment strategy with no oncological compromise. In the present narrative review, the fundamentals of selection and outcomes of patients undergoing WW will be covered to provide updated information for colorectal surgeons and surgical oncologists interested in this treatment alternative in clinical practice.

MRI is more accurate than FDG-PET in assessing complete response in rectal cancer patients after neoadjuvant therapy

PURPOSE

The role of FDG-PET in the restaging rectal cancer following neoadjuvant therapy (NAT) is not clear. We compared the accuracy of FDG-PET and MRI in the assessment of rectal cancer response to NAT.

METHODS

Data of patients treated between January 2015 and September 2022 were captured from a rectal tumor registry. Restaging FDG-PET and MRI were evaluated for the presence of viable tumor. Imaging was compared to the reference standard of pathological results for patients that underwent surgery, and sustained clinical complete response for patients that entered watch and wait. Sensitivity was defined as correctly identifying patients with a complete response.

RESULTS

Eighty-two patients met the inclusion criteria. Of these, 60 patients underwent restaging MRI and 54 underwent restaging FDG-PET. Thirty-two were evaluated by both modalities. Mean age and distance from anal verge were 59.9 ± 12.7 years and 5.9 ± 3.2 cm. Baseline staging was cT1-2, cT3 and cT4 for 7 (8.5%), 62 (75.6%) and 13 (15.9%) of the patients, respectively. Baseline nodal staging was cN0 and cN + for 32 (39%) and 50 (61%) of the patients, respectively. All patients were treated with radiation with the majority 73 (89%) receiving chemoradiotherapy. There were 17 patients (21%) that had a pathological or sustained clinical complete response. All baseline characteristics were not meaningfully different between groups. MRI was more accurate than FDG-PET in all parameters including sensitivity, specificity, positive and negative predictive value and overall accuracy.

CONCLUSION

MRI outperforms FDG-PET in the identification of complete response in rectal cancer patients after NAT.

Results of radical treatment of locally advanced rectal cancer in geriatric and non-geriatric patients

BACKGROUND

It is estimated that 60% of new rectal cancer cases will be diagnosed in patients ≥ 65 years old. The geriatric patient is heterogeneous and underrepresented in clinical trials, and oncologic therapies are often tailored with little evidence. We describe a cohort of patients diagnosed with locally advanced rectal cancer in geriatric and non-geriatric patients.

MATERIALS AND METHODS

Retrospective and descriptive analysis of 137 patients, 44 (32.1%) ≥ 75 years old and 93 (67.9%) ≤ 75 years old, with diagnosis of locally advanced rectal cancer. All patients received neoadjuvant chemoradiotherapy (nCRT), followed by total mesorectal excision (TME) and adjuvant chemotherapy.

RESULTS

Mean age was 79.5 for ≥ 75 years and 62.7 for ≤ 75 years, tumor location was: upper rectum (16.1% and 11.3%), middle rectum (60.2% and 47.7%) and lower rectum (23.7% and 41%), using the Eastern Cooperative Oncology Group (ECOG) 0: 74.1% and 81.8%, ECOG 1: 25.9% and 18.2%. Pathological complete response was 21.5% and 22.7%, partial response, 57% and 59% and no response, 21.5% and 18.3%, respectively. Tumor shrinkage in both groups after neoadjuvant treatment was 34.5% and 35.46%. Local recurrence was 2.2% and 3.2% and distance recurrence, 11.3% and 8.6%, respectively.

CONCLUSION

The study shows similar outcomes in both groups following radical treatment, with similar rates of pathological complete response. However, it has notable limitations, including a small sample size and the absence of a comprehensive geriatric assessment. To enhance these findings, future research should involve larger patient cohorts with comparative analysis and clinical trials specifically focused on the geriatric population.

Total neoadjuvant treatment, non-operative management and radiotherapy-free strategies: New approaches for the management of proficient mismatch repair/microsatellite stable locally advanced rectal cancer. A narrative review and evidence-based algorithm

In recent years, new therapeutic approaches have emerged in addition to classical neoadjuvant (chemo)radiotherapy for the treatment of locally advanced rectal cancer (LARC): total neoadjuvant treatment, non-operative management, and radiotherapy-free strategy. While the introduction of these approaches in a relatively short timeframe has quickly increased our therapeutic armamentarium, on the other hand it has complicated the decision-making process regarding the choice of the most appropriate treatment strategy for each patient with LARC. Therefore, a tool to interpret the evidence from clinical trials and to translate them into daily practice is highly demanded. In the present review, we address how these new developments are changing the multimodal treatment of LARC and offer an algorithm to integrate them into clinical practice.

Perineal wound complications after total neoadjuvant therapy or chemoradiotherapy followed by abdominoperineal excision in patients with high-risk locally advanced rectal cancer in the RAPIDO trial

BACKGROUND

Perineal wound complications (PWCs) occur in 15-30% of patients after abdominoperineal excision (APE) and are associated with adverse events, such as delayed wound healing, prolonged hospitalization, a delay in initiating postoperative chemotherapy, and decreased quality of life. Preoperative radiotherapy and chemotherapy are risk factors for wound complications. It is unknown whether total neoadjuvant treatment (TNT) affects the risk of PWCs compared with chemoradiotherapy (CRT).

METHODS

This study compared patients from the experimental (EXP; short-course radiotherapy, chemotherapy, and surgery as TNT) and standard-of-care (STD; CRT, surgery, and postoperative chemotherapy depending on hospital policy) treatment arms of the RAPIDO trial who underwent APE within 6 months after preoperative treatment. The primary outcome was the incidence of PWCs (infection, abscess, dehiscence, wound discharge, presacral abscess affecting the perineum) of any grade ≤ 30 days after APE. Secondary outcomes were the incidence of PWCs >30 days after APE, length of hospital stay, characteristics associated with PWCs, and oncological outcomes in patients with versus without PWC.

RESULTS

Of the 901 patients who started treatment (460 in EXP arm, 441 in STD arm), 153 (33%) and 160 (36%) underwent APE after TNT and CRT, respectively. After TNT and CRT, the incidence of PWCs ≤30 days after APE, readmission, and reoperation was 54 of 153 (35%) versus 53 of 160 (33%) (P = 0.69), 9% versus 12% (P = 0.54), and 7% versus 8% (P = 0.75), respectively. The median length of hospital stay was 2-3 days longer for patients with PWC. Univariable analysis revealed that pretreatment albumin <35 g/l, hypertension, and haemoglobin ≤ 8.0 mmol/l were associated with PWC. Oncological outcomes were similar between patients with and without PWCs.

CONCLUSION

In the RAPIDO trial, TNT and CRT resulted in a similar incidence of PWCs among patients with high-risk locally advanced rectal cancer who underwent APE.

Impact of PD1 blockade added to neoadjuvant chemoradiotherapy on rectal cancer surgery: post-hoc analysis of the randomized POLARSTAR trial

BACKGROUND

The addition of PD1 blockade to neoadjuvant chemoradiotherapy (CRT) has been shown to significantly increase pCR rates in locally advanced rectal cancer (LARC). Yet, its impact on total mesorectal excision (TME) remains unknown.

METHODS

A post-hoc analysis of the randomized POLARSTAR trial, which enrolled patients with LARC at eight major colorectal cancer centres in Beijing to compare neoadjuvant CRT plus PD1 blockade with CRT alone, was undertaken. Patients received one of three combinations of neoadjuvant treatments before TME surgery: CRT plus concurrent PD1 blockade (concurrent group), CRT plus sequential PD1 blockade (sequential group), and CRT alone (control group). Several parameters related to TME surgery were studied.

RESULTS

For the concurrent group, the sequential group, and the control group, 52, 46, and 45 patients respectively were included in this analysis. The proportion of patients undergoing sphincter-saving plus one-stage anastomosis surgery was 92% (48 of 52), 96% (44 of 46), and 87% (39 of 45) respectively. The proportion of patients without a stoma was 21% (11 of 52), 17% (8 of 46), and 11% (5 of 45) respectively. The grade 3/4 surgical complication rate was 4% (2 of 52), 7% (3 of 46), and 4% (2 of 45) respectively. Significant differences were observed between the sequential group and the control group with respect to the proportion of patients with TRG0 (37% versus 18% respectively; P = 0.040), ypT0/is ypN0 (39% versus 20% respectively; P = 0.046), and a low neoadjuvant rectal (NAR) score (54% versus 31% respectively; P = 0.025).

CONCLUSIONS

Neoadjuvant CRT plus PD1 blockade enhances pathological tumour regression and is beneficial to the successful implementation of TME in patients with LARC. Validations with larger sample sizes are warranted.

Prognostic and Predictive Value of a Modified Diagnostic Biopsy-Adapted Immunoscore in Patients with Rectal Cancer After Neoadjuvant Treatment: A Translational Study From the STELLAR Trial

PURPOSE

The purpose of this study was to assess the prognostic significance of the modified diagnostic biopsy-adapted immunoscore (mISb) in determining the outcomes for patients with locally advanced rectal cancer (LARC) in a neoadjuvant setting.

METHODS AND MATERIALS

We included 181 patients with LARC from a single subcenter of a prospective study comparing total neoadjuvant therapy (TNT) based on short-course radiation therapy with long-term chemoradiation therapy (CRT). Tumor biopsies at baseline were stained for CD8+ and CD3+ T-cell densities. The mISb was developed using mean percentile of CD8+ T-cell density and CD8/CD3 ratio. Patients were classified into low (0%-25%), intermediate (>25%-70%), and high (>70%-100%) in both groups. The relativity among different lymphocytes and their correlation with survival were illustrated. Survival analyses and Cox regression models were used to compare the prognostic values of mISb and diagnostic biopsy immunoscore for survival outcomes and to assess the role of mISb in TNT and CRT subgroups, respectively.

RESULTS

In this study, 151 (83.4%) patients received surgery, and 30 (16.6%) followed a watch and wait strategy. A strong correlation was found between CD8+ and CD3+ T-cell densities (R = 0.86; P < .001), whereas a weak correlation was witnessed between CD8+ and CD8/CD3 ratio (R = 0.45). The 3-year disease-free survival for the entire cohort was 69.9%, with 57.2%, 68.6%, and 85.5% for the low, intermediate, and high mISb groups, respectively (P = .01), whereas diagnostic biopsy immunoscore failed to distinguish survival outcomes. Multivariate analysis revealed mISb to be an independent prognostic factor for disease-free survival in surgically treated patients (P = .01). Specifically, patients with high mISb score showed longer progression-free survival than other subgroups in the TNT cohort (P = .049), but no significant difference was found in the CRT population.

CONCLUSIONS

In this study, mISb demonstrated significant prognostic value in patients with LARC receiving preoperative therapies, especially in the TNT subgroup. These findings may help tailor the intensity of neoadjuvant therapy for patients.

Comparison of prognosis for T4b rectal cancer with different pelvic compartment involvement treated using neoadjuvant chemoradiotherapy and implications for refinement of the current T staging system: A retrospective cohort study

PURPOSE

Although classified as one stage, T4b rectal cancer actually represents a group of heterogeneous diseases. Our study aimed to assess the prognosis difference of T4b rectal cancer involving inferior pelvic and other pelvic compartments. This information may be helpful in refinement of the current T staging system.

METHODS

We retrospectively analysed data from 195 patients with magnetic resonance imaging-identified locally advanced T4b rectal cancer who received neoadjuvant chemoradiotherapy between January 2010 and December 2019. 104 patients had only inferior pelvic compartment involvement (group A) while 91 patients had anterior, posterior or lateral pelvic compartment involvement (group B). Short-term and long-term outcomes were compared between the two groups.

RESULTS

After neoadjuvant therapy, 80.8 % patients (84/104) in group A and 92.3 % patients (84/91) in group B underwent surgery. The R0 resection rates were 97.6 % and 89.3 %, respectively. 8.7 % patients (9/104) in group A achieved clinical complete response and adopted watch-and-wait strategy. Patients in group A had significantly superior 5-year progression-free survival (PFS) (67.8 % vs. 55.5 %, P = 0.032) and overall survival (OS) (89.6 % vs. 71.8 %, P = 0.001) than group B. Multivariable Cox regression analysis also identified pelvic compartment involvement classification as an independent predictor of PFS (hazard ratio 1.776, P = 0.046) and OS (hazard ratio 3.477, P = 0.004).

CONCLUSION

T4b rectal cancers with involvement limited to the inferior pelvic compartment had superior prognosis compared to those involving other pelvic compartments. These differences should be investigated further and taken into consideration in refinement of the current T staging system.

The Chinese Society of Clinical Oncology (CSCO): Clinical guidelines for the diagnosis and treatment of colorectal cancer, 2024 update

The 2024 updates of the Chinese Society of Clinical Oncology (CSCO) Clinical Guidelines for the diagnosis and treatment of colorectal cancer emphasize standardizing cancer treatment in China, highlighting the latest advancements in evidence-based medicine, healthcare resource access, and precision medicine in oncology. These updates address disparities in epidemiological trends, clinicopathological characteristics, tumor biology, treatment approaches, and drug selection for colorectal cancer patients across diverse regions and backgrounds. Key revisions include adjustments to evidence levels for intensive treatment strategies, updates to regimens for deficient mismatch repair (dMMR)/ microsatellite instability-high (MSI-H) patients, proficient mismatch repair (pMMR)/ microsatellite stability (MSS) patients who have failed standard therapies, and rectal cancer patients with low recurrence risk. Additionally, recommendations for digital rectal examination and DNA polymerase epsilon (POLE)/ DNA polymerase delta 1 (POLD1) gene mutation testing have been strengthened. The 2024 CSCO Guidelines are based on both Chinese and international clinical research, as well as expert consensus, ensuring their relevance and applicability in clinical practice, while maintaining a commitment to scientific rigor, impartiality, and timely updates.

Correlation Between Grade of Clinical Response to Neoadjuvant Therapy for Rectal Cancer and Oncologic Outcomes in the Era of Watch-and-Wait

BACKGROUND

The watch-and-wait strategy provides an opportunity to pursue nonoperative management in rectal cancer patients with clinical complete response after neoadjuvant therapy. The management of those with near-complete response remains controversial.

OBJECTIVE

We assessed the oncologic outcomes of patients managed by watch-and-wait versus total mesorectal excision according to clinical response to neoadjuvant therapy.

DESIGN

Retrospective cohort study.

SETTINGS

Comprehensive cancer center in New York.

PATIENTS

Patients with rectal adenocarcinoma diagnosed between January 2006 and December 2020.

INTERVENTIONS

A watch-and-wait strategy of active surveillance was offered to patients if they achieved clinical complete response. Salvage surgery was used for watch-and-wait patients with local regrowth. Patients with an incomplete response underwent total mesorectal excision.

MAIN OUTCOME MEASURES

Local regrowth rate, organ preservation rate, disease-free survival, and overall survival.

RESULTS

Patients with rectal adenocarcinoma (n = 1230) were divided into 3 response cohorts-incomplete (n = 646), near-complete (n = 189), and complete (n = 395). Eighty-one patients (43%) in the near-complete group and 351 patients (89%) in the complete group entered watch-and-wait. Three-year local regrowth rates were 40% and 24% in the near-complete and complete response cohorts, respectively. The 5-year organ preservation rate was 53% in near-complete responders and 73% in complete responders. Five-year disease-free survival increased with greater clinical response to neoadjuvant therapy, with intermediate outcomes noted for patients with a near-complete (73%) compared to complete (82%) or incomplete (68%) response. Overall survival at 5 years was similar between the 3 cohorts (complete 90%, near-complete 86%, and incomplete 85%).

LIMITATIONS

Retrospective nature.

CONCLUSIONS

Greater clinical response to neoadjuvant therapy is associated with improved oncologic outcomes. Near-complete responders may avoid surgery and still achieve high organ preservation rates yet experience greater local regrowth rates than clinical complete response patients. Ongoing prospective trials integrating watch-and-wait after complete response as determined by uniform criteria will bolster the work to help treating physicians better select patients who qualify for active surveillance. See Video Abstract .

CORRELACIN ENTRE EL GRADO DE RESPUESTA CLNICA A LA TERAPIA NEOADYUVANTE CONTRA EL CNCER DEL RECTO Y LOS RESULTADOS ONCOLGICOS EN LA ERA DE OBSERVAR Y ESPERAR

ANTECEDENTES:La estrategia de observar y esperar brinda la oportunidad de buscar un tratamiento no quirúrgico en pacientes con cáncer del recto con respuesta clínica completa después de la terapia neoadyuvante. El tratamiento de aquellos con respuesta casi completa sigue siendo controversial.OBJETIVO:Evaluamos los resultados oncológicos de los pacientes tratados con observar y esperar versus escisión mesorrectal total según la respuesta clínica a la terapia neoadyuvante.DISEÑO:Estudio de cohorte retrospectivo.CONFIGURACIÓN:Centro oncológico integral en Nueva York.PACIENTES:Pacientes con adenocarcinoma rectal diagnosticado entre enero de 2006 y diciembre de 2020.INTERVENCIONES:Se ofreció una estrategia de observar y esperar de vigilancia activa a los pacientes si lograban una respuesta clínica completa. Se utilizó cirugía de rescate para pacientes en observar y esperar con recrecimiento local. Los pacientes con una respuesta incompleta se sometieron a escisión mesorrectal total.PRINCIPALES MEDIDAS DE RESULTADO:Tasa de recrecimiento local, tasa de preservación de órganos, supervivencia libre de enfermedad y supervivencia general.RESULTADOS:Los pacientes con adenocarcinoma rectal (n = 1230) se dividieron en 3 cohortes de respuesta: incompleta (n = 646), casi completa (n = 189) y completa (n = 395). Ochenta y un (43%) pacientes en el grupo casi completo y 351 (89%) pacientes en el grupo completo ingresaron en observar y esperar. Las tasas de recrecimiento local a tres años fueron del 40% y 24% en las cohortes de respuesta casi completa y completa, respectivamente. La tasa de preservación de órganos a 5 años fue del 53% en los respondedores casi completos y del 73% en los respondedores completos. La supervivencia libre de enfermedad a cinco años aumentó con una mayor respuesta clínica a la terapia neoadyuvante con resultados intermedios observados para pacientes con una respuesta casi completa (73%) en comparación con la completa (82%) o incompleta (68%). La supervivencia global a los 5 años fue similar entre las tres cohortes (completa 90%, casi completa 86% e incompleta 85%).LIMITACIONES:Naturaleza retrospectiva.CONCLUSIÓN:Una mayor respuesta clínica a la terapia neoadyuvante se asocia con mejores resultados oncológicos. Los pacientes con respuesta casi completa pueden evitar la cirugía y aun así lograr altas tasas de preservación de órganos, pero experimentar mayores tasas de recrecimiento local que los pacientes con respuesta clínica completa. Los ensayos prospectivos en curso que integran observar y esperar después de la respuesta completa según lo determinado por criterios uniformes reforzarán el trabajo para ayudar a los médicos tratantes a seleccionar mejor a los pacientes que califican para la vigilancia activa. (Traducción-Dr. Aurian Garcia Gonzalez ).

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The role of combining interim and final analysis by using endoscopic and radiologic methods in total neoadjuvant treatment

BACKGROUND

We aim to compare the relative performance of flexible sigmoidoscopy (FS), rectal magnetic resonance imaging (MRI), and their combinations during interim (i) and final (f) analysis to evaluate concordance with complete response (CR) following total neoadjuvant treatment (TNT) in rectal cancer.

METHOD

Patients who opted TNT and underwent restaging with FS and MRI between 2015 and 2022 were evaluated. Concordance between the assessment methods and CR was analyzed using the weighted-κ test.

RESULTS

A cohort comprising 208 patients revealed CR rate of 42.3 ​%. When evaluating individual methods, fFS alone demonstrated the most heightened sensitivity (68.2 ​%) for CR detection, with a moderate level of concordance (κ ​= ​0.46). Only the combinations of iFS-fFS and fFS-fMRI reached a comparable level of concordance to that achievable by fFS alone.

CONCLUSION

Among the available diagnostic tools, the combination of final MRI and FS still appears to offer the highest concordance with CR, with relatively higher sensitivity. Additionally, interim MRI may not add significant clinical value and could be omitted.

Evaluation of the effectiveness of using capecitabine versus capecitabine combined with oxaliplatin during preoperative radiotherapy for patients with rectal cancer: A retrospective cohort study

The purpose of this study was to assess and compare the clinical effectiveness of capecitabine monotherapy and that of capecitabine combined with oxaliplatin as neoadjuvant chemoradiotherapy during preoperative radiotherapy in the management of low and middle rectal cancer. A retrospective cohort study was performed. Medical data were collected from individuals with locally progressing low and middle rectal cancer admitted to a regional hospital in China. Two groups of patients were formed for different chemoradiotherapy regimens: the oxaliplatin group and the capecitabine monotherapy group. Within the oxaliplatin group, the CAPEOX regimen was applied for 2 rounds during radiotherapy, intravenous infusion of oxaliplatin was administered 1 day prior to radiotherapy. In the capecitabine monotherapy group, capecitabine was implemented once daily during radiotherapy, and no medication was taken without radiotherapy. A total of 260 patients were included in the study. When oxaliplatin is administered concurrently with preoperative radiation therapy for patients with locally progressing low and middle rectal cancer, the pathologic complete remission rate can be considerably increased without appreciably increasing adverse effects or impairing postoperative recovery. On the other hand, the long-term effectiveness against metastasis and/or recurrence showed no discernible benefit.

Comparison of Standard Neoadjuvant Therapy and Total Neoadjuvant Therapy in Terms of Effectiveness in Patients Diagnosed with Locally Advanced Rectal Cancer

Background/Objectives: The study aimed to compare the treatment effectiveness of patients with locally advanced rectal cancer undergoing standard neoadjuvant therapy or total neoadjuvant therapy. It also sought to identify prognostic factors for disease-free survival and overall survival and parameters predictive of pathological complete response. Materials and Methods: A retrospective analysis was conducted on 239 patients diagnosed with locally advanced rectal cancer between 2016 and 2022 at several medical centers in Turkey. Clinical data, including neoadjuvant chemoradiotherapy types, chemotherapy regimens, surgical outcomes, and survival metrics, were collected. Statistical analyses included chi-square tests, Kaplan-Meier survival analysis, and Cox proportional hazard models to evaluate prognostic factors for disease-free survival and overall survival and logistic regression to identify predictors of pathological complete response. Results: Among 239 patients, 46.9% received total neoadjuvant therapy, while 53.1% underwent standard neoadjuvant therapy. Total neoadjuvant therapy was associated with a significantly higher pathological complete response rate (45.5% vs. 14.9% in standard neoadjuvant therapy; p < 0.001) and longer disease-free survival (median 124.2 vs. 72.4 months). The 3-year overall survival rate for all patients was 90.7%, and disease-free survival was 76.8%. Multivariate analysis identified pathological complete response (HR: 2.34), total neoadjuvant therapy (HR: 5.12), and type of surgery (HR: 8.12) as independent prognostic factors for disease-free survival, and pathological complete response and absence of lymphovascular invasion as independent prognostic factors for overall survival. Logistic regression analysis showed that total neoadjuvant therapy (OR: 4.40) and initial neoadjuvant chemotherapy (OR: 2.02) were independent predictors of achieving pathological complete response. Conclusions: Total neoadjuvant therapy significantly improves pathological complete response rates, disease-free survival, and overall survival in patients with locally advanced rectal cancer compared to standard neoadjuvant therapy. Total neoadjuvant therapy and achieving pathological complete response are strong independent prognostic factors for both disease-free survival and overall survival, suggesting that a more intensive neoadjuvant approach may lead to better outcomes in locally advanced rectal cancer. The increased pathological complete responses rate with total neoadjuvant therapy has created an opportunity for the development of new treatment modalities and the advancement of non-surgical management strategies in the future.

Early Rectal Cancer: Advances in Diagnosis and Management Strategies

Colorectal cancer (CRC) is the second most prevalent cause of cancer-related death and the third most common cancer globally. Early-stage rectal cancer is defined by lesions confined to the bowel wall, without extension beyond the submucosa in T1 or the muscularis propria in T2, with no indication of lymph node involvement or distant metastasis. The gold standard for managing rectal cancer is total mesorectal excision (TME); however, it is linked to considerable morbidities and impaired quality of life. There is a growing interest in local resection and non-operative treatment of early RC for organ preservation. Local resection options include three types of transanal endoscopic surgery (TES): transanal endoscopic microsurgery (TEM), transanal endoscopic operations (TEO), and transanal minimally invasive surgery (TAMIS), while endoscopic resection includes endoscopic mucosal resection (EMR), underwater endoscopic mucosal resection (UEMR), and endoscopic submucosal dissection (ESD). Although the oncological outcome of local resection of early rectal cancer is debated in the current literature, some studies have shown comparable outcomes with radical surgery in selected patients. The use of adjuvant and neoadjuvant chemoradiotherapy in early rectal cancer management is also controversial in the literature, but a number of studies have reported promising outcomes. This review focuses on the available literature regarding diagnosis, staging, and management strategies of early rectal cancer and provides possible recommendations.

Is Early, Postinduction Restaging of Rectal Cancer Undergoing Total Neoadjuvant Therapy Associated With Ultimate Treatment Response?

BACKGROUND

Among patients with rectal cancer treated with total neoadjuvant therapy, it is unclear whether early, postinduction restaging is associated with final tumor response. If so, interim restaging may alter rectal cancer decision-making.

OBJECTIVE

To determine whether postinduction restaging with endoscopy and MRI is associated with final tumor response.

DESIGN

Retrospective cohort study.

SETTINGS

US tertiary care institution accredited by the National Accreditation Program for Rectal Cancer.

PATIENTS

Patients with biopsy-proven rectal cancer who underwent total neoadjuvant therapy with interim (postinduction) restaging.

MAIN OUTCOME MEASURES

Association between response assessment on postinduction restaging and final treatment response.

RESULTS

One hundred seven patients were analyzed. Patients with postinduction magnetic resonance tumor response grade 1 and 2 or complete endoscopic response were significantly more likely (OR 5.4, p < 0.01 and OR 3.7, p = 0.03, respectively) to ultimately achieve a final complete response. Likewise, the odds of a final incomplete response were significantly higher for patients with postinduction composite partial (OR 4.1, p < 0.01) or minimal (OR 12.0, p < 0.01) responses.

LIMITATIONS

Retrospective analysis and lack of detailed subclassification of partial endoscopic response may have limited the conclusions of these data. The limited sample size may also have biased these conclusions.

CONCLUSIONS

Tumor response to induction therapy is associated with the ultimate treatment response to total neoadjuvant therapy among complete or minimal responders; the significance of a partial interim response remains unclear. See Video Abstract .

EST ASOCIADA LA REESTADIFICACIN TEMPRANA POSTINDUCCIN DEL CANCER DE RECTO SOMETIDO A TERAPIA NEOADYUVANTE TOTAL CON LA RESPUESTA TERAPUTICA FINAL

ANTECEDENTES:Entre los pacientes con cáncer de recto tratados con terapia neoadyuvante total, no está claro si la re-estadificación temprana posterior a la inducción está asociada con la respuesta tumoral final. De ser así, la re-estadificación provisoria podría alterar la toma de decisiones sobre el cáncer rectal.OBJETIVO:Determinar si la re-estadificación posterior a la inducción con endoscopia y resonancia magnética están asociadas con la respuesta tumoral final.DISEÑO:Estudio de cohorte retrospectivoESCENARIO:Institución de atención terciaria de Estados Unidos, certificada por el Programa Nacional de Acreditación para el Cáncer de Recto.PACIENTES:Pacientes con cáncer rectal confirmado por biopsia que fueron sometidos a terapia neoadyuvante total con re-estadificación provisoria (posterior a la inducción).PRINCIPALES MEDIDAS DE RESULTADOS:La asociación entre la evaluación de la respuesta en la re-estadificación posterior a la inducción y la respuesta al final del tratamiento.RESULTADOS:Se estudiaron 107 pacientes. Aquellos que presentaban respuesta tumoral a la resonancia magnética post-inducción grado 1-2 o respuesta endoscópica completa tuvieron significativamente más probabilidades (OR (odds ratio) 5,4 [ p < 0,01] y OR: 3,7 [ p = 0,03], respectivamente) de lograr finalmente una respuesta completa final. Asimismo, las probabilidades de una respuesta incompleta final fueron significativamente mayores para los pacientes con respuestas parciales compuestas post-inducción (OR: 4,1, p < 0,01) o mínimas (OR: 12,0, p < 0,01).LIMITACIONES:El análisis retrospectivo y la falta de una subclasificación detallada de la respuesta endoscópica parcial pueden haber limitado las conclusiones de estos datos. El tamaño limitado de la muestra también puede haber sesgado las conclusiones mencionadas.CONCLUSIÓN:La respuesta tumoral a la terapia de inducción está asociada con la respuesta final al tratamiento con terapia neoadyuvante total entre los respondedores completos o mínimos; la importancia de una respuesta parcial provisional sigue sin estar clara. (Traducción-Dr. Xavier Delgadillo ).

Neoadjuvant chemoradiation with or without PD-1 blockade in locally advanced rectal cancer: a randomized phase 2 trial

Radiotherapy displays unique antitumor synergism with immune checkpoint inhibitors, which is indicated by high pathological complete response (pCR) rates from single-arm trials of locally advanced rectal cancer (LARC). Here we test the efficacy and safety of the radiation-immune checkpoint inhibitor combination in patients with LARC in a phase 2, randomized trial conducted in eight major colorectal cancer centers in Beijing. In total, 186 eligible all-comer (proficient mismatch repair and deficient mismatch repair) participants were enrolled. The patients were randomly assigned to receive neoadjuvant chemoradiation + concurrent/sequential PD-1 blockade (experiment groups A/B) or neoadjuvant chemoradiation alone (control group). Radical surgeries were scheduled after neoadjuvant treatments. The primary endpoint was the pCR rate. The pCR rates were 27.1%, 32.7% and 14.0% for experiment groups A and B and the control group, respectively. The difference in pCR rates between experiment group B and the control group reached statistical significance (risk ratio 2.332, 95% confidence interval 1.106-4.916; P = 0.019). No substantial differences between either one of the experiment groups and the control group were observed regarding adverse reaction, surgical complication and disease progression. Our results show that adding PD-1 blockade after neoadjuvant chemoradiation increases the pCR rate for patients with LARC and raises no substantial safety concerns. Phase 3 trials with larger sample sizes are warranted (ClinicalTrials.gov identifier NCT05245474 ).

Predictive Value of Magnetic Resonance Complete Response After Neoadjuvant Therapy for Rectal Cancer

INTRODUCTION

Previous research has demonstrated that after neoadjuvant therapy for rectal cancer, the sensitivity of magnetic resonance complete response (mrCR) for detecting pathologic complete response (pCR) in the surgical specimen ranges from 74 to 94%. Patient and provider interest in nonoperative management of rectal cancer that responds favorably to neoadjuvant therapy has grown, necessitating stronger evidence for how well radiographic complete response truly predicts pCR. We sought to determine the current association between mrCR and pCR in locally advanced rectal cancer.

METHODS

We conducted a retrospective cohort study of patients with rectal adenocarcinoma who underwent neoadjuvant chemoradiation followed by index proctectomy at a single academic referral center from January 2012 to December 2021. Our primary outcomes were mrCR, defined as the absence of residual disease on restaging MRI, and pCR, defined as the absence of residual adenocarcinoma in surgical pathology specimens.

RESULTS

Among 523 eligible patients, 157 met the inclusion criteria (38.9% females; 51.0% nonwhite; mean [SD] age, 58.6 [13.2] years). Overall, 8.9% of patients had mrCR and 7.0% had pCR. The sensitivity and positive predictive value of mrCR were 36.4% (95% CI: 10.9 to 69.2) and 28.6% (95% CI: 8.4 to 58.1). Our findings were qualitatively unchanged when only patients in the last 5 years of the study period were included. Study limitations include that neoadjuvant therapy regimens were not standardized and patients who were offered and elected to undergo nonoperative management were not included.

CONCLUSIONS

The value of mrCR in predicting pathologic response following neoadjuvant therapy in locally advanced rectal cancer is low, and mrCR should be interpreted with caution when counseling patients about nonoperative management. Early, frequent surveillance is critical in patients who elect nonoperative management after mrCR.

Is clinical complete response as accurate as pathological complete response in patients with mid-low locally advanced rectal cancer?

PURPOSE

The standard treatment for locally advanced rectal cancer involves neoadjuvant chemoradiation followed by total mesorectal excision surgery. A subset of patients achieves pathologic complete response (pCR), representing the optimal treatment outcome. This study compares the long-term oncological outcomes of patients who achieved pCR with those who attained clinical complete response (cCR) after total neoadjuvant therapy, managed using a watch-and-wait approach.

METHODS

This study retrospectively evaluated patients with mid-low locally advanced rectal cancer who underwent neoadjuvant treatment from January 1, 2005, to May 1, 2023. The pCR and cCR groups were compared based on demographic, clinical, histopathological, and long-term survival outcomes.

RESULTS

The median follow-up times were 54 months (range, 7-83 months) for the cCR group (n=73), 96 months (range, 7-215 months) for the pCR group (n=63), and 72 months (range, 4-212 months) for the pathological incomplete clinical response (pICR) group (n=627). In the cCR group, 15 patients (20.5%) experienced local regrowth, and 5 (6.8%) developed distant metastasis (DM). The pCR group had no cases of local recurrence, but 3 patients (4.8%) developed DM. Among the pICR patients, 58 (9.2%) experienced local recurrence, and 92 (14.6%) had DM. Five-year disease-free survival rates were 90.0% for cCR, 92.0% for pCR, and 69.5% for pICR (P=0.022). Five-year overall survival rates were 93.1% for cCR, 92.0% for pCR, and 78.1% for pICR. There were no significant differences in outcomes between the cCR and pCR groups (P=0.810); however, the pICR group exhibited poorer outcomes (P=0.002).

CONCLUSIONS

This study shows no significant long-term oncological differences between patients who exhibited cCR and those who experienced pCR.

Mastering rectal cancer MRI: From foundational concepts to optimal staging

MRI plays a critical role in the local staging, restaging, surveillance, and risk stratification of patients, ensuring they receive the most tailored therapy. As such, radiologists must be familiar not only with the key MRI findings that influence management decisions but also with the appropriate MRI protocols and structured reporting. Given the complexity of selecting the optimal therapy for each patient-which often requires multidisciplinary discussions-radiologists should be well-versed in relevant treatment strategies and surgical terms, understanding their significance in guiding patient care. In this manuscript, we review the most common treatment options for managing patients with rectal adenocarcinoma, emphasizing key MRI principles and protocol characteristics for accurate staging. We also highlight important anatomical landmarks and essential factors to be described during baseline assessment. Additionally, we discuss crucial information for restaging and surveillance.

A Comprehensive Approach to Neoadjuvant Treatment of Locally Advanced Rectal Cancer

At the end of the past century, the introduction of Total Mesorectal Excision (TME), preceded by either short-course radiotherapy (SCRT) or chemoradiation (CRT), established the new standard of care for locally advanced rectal cancer (LARC). Recently, significant advancements were achieved for both dMMR/MSI and pMMR/MSS LARC patients. For the 2-3% of dMMR/MSI LARCs, ablative immunotherapy emerged as a curative approach, offering the possibility of avoiding chemotherapy (CT), radiotherapy, and surgery altogether. In pMMR/MSS LARCs, the intensification of preoperative treatments with Total Neoadjuvant Treatment (TNT) afforded three outcomes: (a) a reduction of distant metastases, positively impacting on survival endpoints, (b) a significant increase of complete clinical response (cCR) rate, paving the way for non-operative management (NOM), and (c) the selective omission of radiotherapy following induction CT. The choice of the most appropriate therapeutic strategy can only be made through the shared decision-making process between physician and patient based on risk stratification and patient preferences.

Curative-Intended Management of Synchronous Esophageal and Rectal Cancer-A Systematic Literature Review

PURPOSE

Synchronous esophageal (EC) and rectal carcinoma (RC) is a rare and challenging condition, particularly in curative-intended treatment. Especially locally advanced tumors may not be suitable for primary resection and require individual multimodal treatment. This review examines curative-intended management of synchronous EC and RC.

MATERIAL AND METHODS

A systematic literature search across five electronic databases according to the PRISMA guideline was conducted. Individual patient data was analyzed, including two additional cases from our institution.

RESULTS

We identified 9 relevant cases from 1552 results. Additionally, two male patients (62 and 65 years old) from our institution were included. Both received 5-fluorouracil/cisplatin-based chemoradiotherapy (CRT) for EC. Sequential short-course radiation (SCRT) for RC was performed in one patient. After complete response (CR) in both tumors, no consecutive surgery was performed. He underwent resection for local recurrence of RC 11 months later and is currently considered as disease-free (30 months follow-up). The second patient underwent primary resection of RC and had early progression following resection of EC. We found that most patients had advanced EC (8/11), with the majority receiving neoadjuvant (5/11) or definitive treatment (3/11). Locally advanced RC was diagnosed in 5/11 patients, primarily treated with sequential resection. Pyrimidine-based systemic treatment was common. Four relapses and two deaths were reported, but median follow-up was 11 (range 1.5-30) months only.

CONCLUSION

The review suggests that neoadjuvant multimodal approaches may offer curative potential for synchronous EC and RC, with individualized treatment protocols adapted from single-cancer protocols. Nevertheless, data on long-term outcome is limited.

What Predicts Complete Response to Total Neoadjuvant Therapy in Locally Advanced Rectal Cancer?

BACKGROUND

Total neoadjuvant therapy in the treatment of stage II and III rectal cancer involves the administration of either induction or consolidation chemotherapy with chemoradiation before surgery. Total neoadjuvant therapy is associated with an increased complete response rate, which is defined as the proportion of patients who either had a pathological complete response after surgery or sustained a clinical complete response for at least 1 year under surveillance.

OBJECTIVE

To identify the predictors of complete response to total neoadjuvant therapy and compare different diagnostic tools in predicting complete response.

DESIGN

Retrospective cohort study.

SETTINGS

A single tertiary care center.

PATIENTS

Patients with stage II and III rectal cancer who were diagnosed between January 2015 and December 2021.

INTERVENTION

Total neoadjuvant therapy.

MAIN OUTCOME MEASURES

Complete response rate, predictors of complete response, sensitivity and specificity of sigmoidoscopy, and MRI in predicting complete response.

RESULTS

One hundred nineteen patients (mean age 56 [±11.3] years, 47 [39.5%] women, 100 [84%] stage III rectal cancer) were included. The median tumor size was 5.1 (4-6.5) cm, and 63 (52.9%) were low rectal tumors. Twenty-one patients (17.6%) had extramural vascular invasion and 62 (52.1%) had elevated CEA at baseline. One hundred eight patients (90.8%) received consolidation chemotherapy. After total neoadjuvant therapy, 88 of 119 patients (73.9%) underwent surgery, of whom 20 (22.7%) had pathological complete response. Thirty-one patients (26.1%) underwent watch-and-wait, of whom 24 (77.4%) had sustained clinical complete response. Overall, the complete response rate was 37%. Low rectal tumors (OR 1.5 [95% CI, 1.03-2.4], p = 0.04) and absence of extramural vascular invasion (OR 2.2 [95% CI, 1.1-5.6], p = 0.01) were predictors of complete response. In predicting complete response, sigmoidoscopy was more sensitive (76.0% vs 62.5%) and specific (72.5% vs 69.2%) than MRI. The specificity further increased when 2 techniques were combined (82.5%).

LIMITATIONS

Retrospective study.

CONCLUSIONS

The complete response rate after total neoadjuvant therapy was 37%. Low rectal tumors and the absence of extramural vascular invasion were predictors of complete response. Sigmoidoscopy was better in predicting incomplete response, whereas combination (MRI and sigmoidoscopy) was better in predicting complete response. See Video Abstract.

QU PREDICE LA RESPUESTA COMPLETA A LA TERAPIA NEOADYUVANTE TOTAL EN EL CNCER DE RECTO LOCALMENTE AVANZADO

ANTECEDENTES:La terapia neoadyuvante total en el tratamiento del cáncer de recto en estadios II-III implica la administración de quimioterapia de inducción o de consolidación con quimio radiación antes de la cirugía. La terapia neoadyuvante total se asocia con una mayor tasa de respuesta completa, que se define como la proporción de pacientes que tuvieron una respuesta patológica completa después de la cirugía o una respuesta clínica completa sostenida al menos durante un año bajo vigilancia.OBJETIVO:Identificar los predictores de respuesta completa a la terapia neoadyuvante total y comparar diferentes herramientas de diagnóstico para predecir la respuesta completa.DISEÑO:Estudio de cohorte retrospectivo.LUGARES:Un único centro de atención terciaria.PACIENTES:Pacientes con cáncer de recto en estadio II-III diagnosticados entre enero de 2015 y diciembre de 2021.INTERVENCIÓN(S):Terapia neoadyuvante total.PRINCIPALES MEDIDAS DE RESULTADO:Tasa de respuesta completa, predictores de respuesta completa, sensibilidad y especificidad de la sigmoidoscopia y la resonancia magnética para predecir la respuesta completa.RESULTADOS:Se incluyeron 119 pacientes [edad media 56 (±11,3) años, 47 (39,5%) mujeres, 100 (84%) cáncer de recto en estadio III]. La mediana del tamaño tumoral fue de 5,1 (4-6,5) cm, 63 (52,9%) fueron tumores rectales bajos. Veintiún (17,6%) pacientes tenían invasión vascular extramural (EMVI), 62 (52,1%) tenían CEA elevado al inicio del estudio. Ciento ocho (90,8%) pacientes recibieron quimioterapia de consolidación. Después de la TNT, 88 (73,9%) de 119 pacientes fueron intervenidos quirúrgicamente, de los cuales 20 (22,7%) tuvieron respuesta patológica completa. Treinta y un (26,1%) pacientes fueron sometidos a observación y espera, de los cuales 24 (77,4%) tuvieron una respuesta clínica completa sostenida. La tasa de respuesta completa general fue del 37%. Los tumores rectales bajos [OR 1,5 (IC 95% 1,03-2,4), p = 0,04] y la ausencia de EMVI [OR 2,2 (IC 95% 1,1-5,6), p = 0,01] fueron predictores de respuesta completa. Para predecir la respuesta completa, la sigmoidoscopia fue más sensible (76,0 % frente a 62,5 %) y específica (72,5 % frente a 69,2 %) que la resonancia magnética. La especificidad aumentó aún más cuando se combinaron dos técnicas (82,5%).LIMITACIONES:Estudio retrospectivo.CONCLUSIONES:La tasa de respuesta completa después de la terapia neoadyuvante total fue del 37%. Los tumores rectales bajos y la ausencia de EMVI fueron predictores de respuesta completa. La sigmoidoscopia fue mejor para predecir la respuesta incompleta, mientras que la combinación (MRI y sigmoidoscopia) fue mejor para predecir la respuesta completa. (Traducción-Dr Osvaldo Gauto ).

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

Background

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

Methods

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

Results

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

Conclusion

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

Systematic review registration

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

Nonoperative management of rectal cancer

The management of locally advanced rectal cancer has changed drastically in the last few decades due to improved surgical techniques, development of multimodal treatment approaches and the introduction of a watch and wait (WW) strategy. For patients with a complete response to neoadjuvant treatment, WW offers an opportunity to avoid the morbidity associated with total mesorectal excision in favor of organ preservation. Despite growing interest in WW, prospective data on the safety and efficacy of nonoperative management are limited. Challenges remain in optimizing multimodal treatment regimens to maximize tumor regression and in improving the accuracy of patient selection for WW. This review summarizes the history of treatment for rectal cancer and the development of a WW strategy. It also provides an overview of clinical considerations for patients interested in nonoperative management, including restaging strategies, WW selection criteria, surveillance protocols and long-term oncologic outcomes.

Wavelets-Based Texture Analysis of Post Neoadjuvant Chemoradiotherapy Magnetic Resonance Imaging as a Tool for Recognition of Pathological Complete Response in Rectal Cancer, a Retrospective Study

Background: Patients with locally advanced rectal cancer (LARC) treated by neoadjuvant chemoradiotherapy (nCRT) may experience pathological complete response (pCR). Tools that can identify pCR are required to define candidates suitable for the watch and wait (WW) strategy. Automated image analysis is used for predicting clinical aspects of diseases. Texture analysis of magnetic resonance imaging (MRI) wavelets algorithms provides a novel way to identify pCR. We aimed to evaluate wavelets-based image analysis of MRI for predicting pCR. Methods: MRI images of rectal cancer from 22 patients who underwent nCRT were captured at best representative views of the tumor. The MRI images were digitized and their texture was analyzed using different mother wavelets. Each mother wavelet was used to scan the image repeatedly at different frequencies. Based on these analyses, coefficients of similarity were calculated providing a variety of textural variables that were subsequently correlated with histopathology in each case. This allowed for proper identification of the best mother wavelets able to predict pCR. The predictive formula of complete response was computed using the independent statistical variables that were singled out by the multivariate regression model. Results: The statistical model used four wavelet variables to predict pCR with an accuracy of 100%, sensitivity of 100%, specificity of 100%, and PPV and NPV of 100%. Conclusions: Wavelet-transformed texture analysis of radiomic MRI can predict pCR in patients with LARC. It may provide a potential accurate surrogate method for the prediction of clinical outcomes of nCRT, resulting in an effective selection of patients amenable to WW.

Landscape of Biomarkers and Pathologic Response in Rectal Cancer: Where We Stand?

Colorectal cancer (CRC) is a neoplasm with a high prevalence worldwide, with a multimodal treatment that includes a combination of chemotherapy, radiotherapy, and surgery in locally advanced stages with acceptable pathological complete response (pCR) rates, this has improved with the introduction of total neoadjuvant therapy (TNT) reaching pCR rates up to 37% in compare with classic neoadjuvant treatment (NAT) where pCR rates of around 20-25% are achieved. However, the patient population that benefits most from this therapy has not been determined, and there is a lack of biomarkers that can predict the course of the disease. Multiple biomarkers have been studied, ranging from hematological and molecular markers by imaging technique and combinations of them, with contradictory results that prevent their use in routine clinical practice. In this review, we evaluate the most robust prognostic biomarkers to be used in clinical practice, highlighting their advantages and disadvantages and emphasizing biomarker combinations and their predictive value.

Oncological Outcomes and Response Rate After Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer: A Network Meta-Analysis Comparing Induction vs. Consolidation Chemotherapy vs. Standard Chemoradiation

TNT is now considered the preferred option for stage II-III locally advanced rectal cancer (LARC). However, the prognostic benefit and optimal sequence of TNT remains unclear. This network meta-analysis (NMA) compared short- and long-term outcomes amongst patients with LARC receiving total neoadjuvant therapy (TNT) as induction (iTNT) or consolidation chemotherapy (cTNT) with those receiving neoadjuvant chemoradiation (nCRT) alone. A systematic literature search was performed between 2012 and 2023. A Bayesian NMA was conducted using a Markov Chain Monte Carlo method with a random-effects model and vague prior distribution to calculate odds ratios (OR) with 95% credible intervals (CrI). The surface under the cumulative ranking (SUCRA) curves were used to rank treatment(s) for each outcome. In total, 11 cohorts involving 8360 patients with LARC were included. There was no significant difference in disease-free survival (DFS) and overall survival (OS) amongst the 3 treatments. Compared with nCRT, both cTNT (OR 2.36; 95% CrI, 1.57-3.66) and iTNT (OR 1.99; 95% CrI, 1.44-2.95) significantly improved complete response (CR) rate. Notably, cTNT ranked as the best treatment for CR (SUCRA 0.90) and iTNT as the best treatment for 3-year DFS and OS (SUCRA 0.72 and 0.87, respectively). Both iTNT and cTNT strategies significantly improved CR rates compared with nCRT. cTNT was ranked highest for CR rates, while iTNT was ranked highest for 3-year survival outcomes. However, no other significant differences in DFS, OS, sphincter-saving surgery, R0 resection and postoperative complications were found amongst the treatment groups.

Localized Rectal Cancer: Indian Consensus and Guidelines

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

Could elective nodal irradiation for locally advanced rectal cancer be omitted in the context of total neoadjuvant therapy? An analysis of the recurrence sites of rectal cancer

Purpose

This study aims to optimize neoadjuvant radiotherapy target area for locally advanced rectal cancer (LARC) patients undergoing total neoadjuvant therapy (TNT) by examining local recurrence patterns.

Methods and materials

We retrospectively analyzed the clinical data of rectal cancer patients who undergone local recurrence after surgery. Recurrence sites were categorized and compared with initial diagnosis imaging, focusing on visible and suspicious lesions.

Results

Of the 126 patients who met our criteria, 186 lesions were analyzed. Within these, 75.40% of cases (95/126) and 83.33% of lesions (155/186) were located within the pelvic cavity. Conversely, 3.97% of cases (5/126) and 3.33% of lesions (6/186) occurred outside the pelvic cavity. Additionally, 20.63% of cases (26/126) and 13.44% of lesions (25/186) were found in both regions. Recurrences were predominantly observed in mesenteric regions (MR) (40.86%, 76/186) and presacral regions (PR) (32.26%, 60/186). In addition, 86.51% of patients (109/126) had recurrent lesions in HRA and the suspected lesions areas. Further analysis showed that initial CEA levels and adjuvant therapy types were identified as independent predictors for recurrence in MR/PR and initially suspected lesions. 86.51% of patients had recurrent lesions in HRA and the suspected lesions areas.

Conclusion

The MR, PR, and areas of initial suspicious lesions are high-risk zones for post-surgical recurrence of LARC. Exploratory study of involved-field irradiation (IFI) can be carried out in the context of TNT in LARC.

Total neoadjuvant therapy followed by total mesorectal excision for rectal cancer in older patients real world data and proof of concept

Background

Rectal cancer (RC) commonly affects older patients. Total Neoadjuvant Therapy (TNT) has been introduced to improve local and systemic control of RC. The aim was to present real-world data of older patients receiving TNT followed by surgery after a frailty assessment and verify feasibility and safety of this approach.

Methods

This was a single-center retrospective study which enrolled all patients ≥70 years of age with RC who underwent TNT followed by surgery between November 2017 and April 2022. Data regarding cancer characteristics, neoadjuvant chemoradiotherapy (CRT), and toxicity were recorded. All patients underwent surgery 12-16 weeks after the end of therapy. Intra- and postoperative outcomes were recorded. Pre- and postoperative functional evaluation was carried out.

Results

Fifteen patients were enrolled. Mean age was 74 (70-81) years. Mean distance of the tumor from the anal verge was 5.2 cm. Fourteen patients had positive nodes (93.3%), 11 (73.3%) showed involvement of the circumferential margin (CRM+) and 10 (66.6%) had extramural vascular invasion (EMVI+). Ten patients (66.6%) received mFOLFOX-6 and 5 CAPOX (33.3%) followed by CRT. After CRT, positive nodes were reported in 4 cases (26.6%), CRM+ in 4 (26.6%), and EMVI+ in 1 (6.6%). Transanal total mesorectal excision (taTME) was performed in all cases. Median operative time was 280 min (110-420). Median length of stay was 4 days (3-29). One Clavien-Dindo grade 4 complication, no readmissions, and no variations in pre- and postoperative functional status within 30 days from surgery were reported. No positive distal or CRMs were detected. Three pathologic complete responses were reported (20%).

Conclusions

TNT followed by TME is feasible and safe in older patients, with good clinical and oncologic outcomes. Patient evaluation is crucial for maximizing cancer care in fit older patients.

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

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

Changing of gamma-H2AX in peripheral blood mononuclear cells during concurrent chemoradiation in locally advanced rectal cancer patients: a potential response predictor

Background

The most detrimental effect of DNA damage from radiation is DNA double-strand breaks, making it critical to identify reliable biomarkers for treatment response in cancer therapy. Gamma-H2AX (γ-H2AX), a marker of DNA double-strand breaks, was evaluated in this study as a potential biomarker for treatment response in locally advanced rectal cancer patients undergoing preoperative concurrent chemoradiation (CCRT).

Methods

Thirty patients with locally advanced rectal cancer received preoperative CCRT. Peripheral blood mononuclear cells (PBMCs) were collected at five time points: baseline, 24 hours after the first radiation fraction, mid-treatment, end of treatment, and six weeks post-CCRT. γ-H2AX levels were measured in these samples. MRI was used to assess treatment response based on magnetic resonance tumor regression grade (mrTRG). Patients were classified as responders or non-responders based on mrTRG. T-test and repeated measures analysis of variance (ANOVA) evaluated dynamic changes in γ-H2AX levels, and a multilevel linear regression model analyzed the relationship between γ-H2AX levels and treatment response.

Results

Nineteen out of thirty patients (63.33%) were classified as responders. Significant dynamic changes in γ-H2AX levels were observed between non-responders and responders (P=0.01). The multilevel linear regression model showed a trend towards increased γ-H2AX levels in responders [1.17, 95% confidence interval (CI): -0.02 to 2.34, P=0.053]. Significant differences in γ-H2AX levels were observed from baseline to mid-treatment, end of treatment, and six weeks post-CCRT. Pathologic complete response (pCR) after CCRT was associated with significantly higher γ-H2AX ratios compared to those without pCR (P=0.04). However, no significant difference was identified in the multilevel linear regression model.

Conclusions

γ-H2AX may have potential as a biomarker for treatment response in locally advanced rectal cancer patients undergoing preoperative CCRT, although further validation is required.

Optimal Sequence for Total Neoadjuvant Therapy in Locally Advanced Rectal Cancer: An Evidence-Based Review

INTRODUCTION

Historically, multimodal therapeutic strategies involving preoperative chemoradiotherapy (CRT), surgery, and adjuvant chemotherapy (CT) have been employed to treat locally advanced rectal cancer (LARC). Total Neoadjuvant Therapy (TNT) is showing promise in improving outcomes. Despite its benefits, the optimal sequencing within TNT-whether induction chemotherapy should precede or follow chemoradiotherapy-remains a critical question. This study endeavors to explore the effects of different TNT sequencing strategies on patient outcomes, including tumor downstaging, pathological response, organ preservation, and the balance between efficacy and tolerability.

METHODS

Our methodology entailed a comprehensive literature review conducted on Medline, focusing on recent research, including retrospective studies, systematic reviews, and clinical trials. The review emphasized the comparison of induction chemotherapy versus consolidation chemotherapy within TNT regimens, assessing outcomes such as pathological response, organ preservation rates, and adverse effects. To ensure the selection of appropriate and high-quality studies, specific inclusion and exclusion criteria were applied.

RESULTS

The analysis revealed that induction chemotherapy might lead to decreased adherence to subsequent chemoradiotherapy while offering an early intervention against micrometastasis and potentially improving overall chemotherapy compliance. Conversely, consolidation chemotherapy has been associated with higher pathological complete response (pCR) rates and improved tolerability, indicating its potential for patients requiring local symptom relief or those eligible for a nonoperative management approach. Comparative studies like CAO/ARO/AIO-12 and the OPRA trials have significantly contributed to our understanding, suggesting that while both strategies have distinct advantages, the choice between induction and consolidation chemotherapy should be tailored based on individual patient profiles and tumor characteristics.

CONCLUSION

This narrative review underscores the importance of a nuanced approach to TNT sequencing in locally advanced rectal cancer, highlighting the need for further research to refine treatment strategies.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Evaluating complete response rates and predictors in total neoadjuvant therapy for rectal cancer

BACKGROUND

There is a paradigm shift in the management of locally advanced rectal cancer (LARC) from conventional neoadjuvant treatment to total neoadjuvant therapy (TNT). Despite its growing acceptance, there are limited studies that have examined its effects on disease presentation. In addition, it is important to determine the factors that play a role in complete response (CR). Our previous data from 119 patients revealed that the CR rate was 37%, and low rectal tumors and the absence of extramural vascular invasion (EMVI) were predictors of CR. Unfortunately, there continues to be a lack of data, and reliable markers are still needed to consistently identify the best respondents. Therefore, this study aimed to determine the factors associated with CR. Moreover, this study hypothesized that both predictive factors and the CR ratio might evolve over time because of the growing patient population.

METHODS

This retrospective study included patients who completed TNT for LARC at our tertiary care center between 2015 and 2022. The primary outcome was to determine the predictors of CR. The secondary outcomes were the 2-year disease-free survival (DFS) rate and overall survival (OS) rate. CR consists of patients who sustained clinical CR (cCR) for at least 12 months under watch and wait or had pathologic CR (pCR) after surgery.

RESULTS

Of 339 patients with LARC, 208 (61.3%) successfully completed TNT. Among 208 patients, 57 (27.4%) achieved cCR, and 166 (80.0%) sustained cCR without tumor regrowth after 1 year. The remaining 151 patients (72.6%) underwent surgery, and 42 patients had pCR. The final CR rate was 42.3%. The median age of the patients was 56 years (IQR, 49-66). Moreover, 132 participants (63.5%) were male, whereas 76 participants (36.5%) were female. The median tumor size was 4.95 cm (IQR, 3.60-6.43), with most tumors in the low rectum (119 [57.2%]). Based on the MRI findings, the mesorectal facia (MRF) involvement rate was 25.0% (n = 52), and EMVI was observed in 43 patients (20.7%). Low rectal tumors, the absence of MRF involvement, and the absence of EMVI were predictors of CR. With a median follow-up of 24.7 months, 2-year DFS and OS were significantly higher among patients with CR than among patients with incomplete response (91.3% vs 71.0% [P < .01] and 98.8% vs 90.2% [P = .03], respectively).

CONCLUSION

An increasing CR rate was observed in our updated dataset compared with that in our previous study. In addition to previously identified predictors, low tumor location, and the absence of EMVI, the absence of MRF involvement was determined as a predictor of CR. Our findings offer valuable insights into clinical practice and help clinicians set clear expectations when counseling patients.

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

BACKGROUND AND OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes and failure patterns after chemoradiotherapy for locally advanced rectal cancer with positive lateral pelvic lymph nodes: a propensity score-matched analysis

PURPOSE

This study aimed to use propensity score matching (PSM) to explore the long-term outcomes and failure patterns in locally advanced rectal cancer (LARC) patients with positive versus negative lateral pelvic lymph node (LPLN).

MATERIALS AND METHODS

Patients with LARC were retrospectively divided into LPLN-positive and LPLN-negative groups. Clinical characteristics were compared between the groups using the chi-square test. PSM was applied to balance these differences. Progression-free survival (PFS) and overall survival (OS), and local-regional recurrence (LRR) and distant metastasis (DM) rates were compared between the groups using the Kaplan-Meier method and log-rank tests.

RESULTS

A total of 651 LARC patients were included, 160 (24.6%) of whom had positive LPLN and 491 (75.4%) had negative LPLN. Before PSM, the LPLN-positive group had higher rates of lower location (53.1% vs. 43.0%, P = 0.025), T4 stage (37.5% vs. 23.2%, P = 0.002), mesorectal fascia (MRF)-positive (53.9% vs. 35.4%, P < 0.001) and extramural venous invasion (EMVI)-positive (51.2% vs. 27.2%, P < 0.001) disease than the LPLN-negative group. After PSM, there were 114 patients for each group along with the balanced clinical factors, and both groups had comparable surgery, pathologic complete response (pCR), and ypN stage rates. The median follow-up was 45.9 months, 3-year OS (88.3% vs. 92.1%, P = 0.276) and LRR (5.7% vs. 2.8%, P = 0.172) rates were comparable between LPLN-positive and LPLN-negative groups. Meanwhile, despite no statistical difference, 3-year PFS (78.8% vs. 85.9%, P = 0.065) and DM (20.4% vs. 13.3%, P = 0.061) rates slightly differed between the groups. 45 patients were diagnosed with DM, 11 (39.3%) LPLN-positive and 3 (17.6%) LPLN-negative patients were diagnosed with oligometastases (P = 0.109).

CONCLUSIONS

Our study indicates that for LPLN-positive patients, there is a tendency of worse PFS and DM than LPLN-negative patients, and for this group patients, large samples are needed to further confirm our conclusion.

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.

Efficacy and safety of MR-guided adaptive simultaneous integrated boost radiotherapy to primary lesions and positive lymph nodes in the neoadjuvant treatment of locally advanced rectal cancer: a randomized controlled phase III trial

BACKGROUND

In locally advanced rectal cancer (LARC), optimizing neoadjuvant strategies, including the addition of concurrent chemotherapy and dose escalation of radiotherapy, is essential to improve tumor regression and subsequent implementation of anal preservation strategies. Currently, dose escalation studies in rectal cancer have focused on the primary lesions. However, a common source of recurrence in LARC is the metastasis of cancer cells to the proximal lymph nodes. In our trial, we implement simultaneous integrated boost (SIB) to both primary lesions and positive lymph nodes in the experimental group based on magnetic resonance-guided adaptive radiotherapy (MRgART), which allows for more precise (and consequently intense) targeting while sparing neighboring healthy tissue. The objective of this study is to evaluate the efficacy and safety of MRgART dose escalation to both primary lesions and positive lymph nodes, in comparison with the conventional radiotherapy of long-course concurrent chemoradiotherapy (LCCRT) group, in the neoadjuvant treatment of LARC.

METHODS

This is a multi-center, randomized, controlled phase III trial (NCT06246344). 128 patients with LARC (cT3-4/N+) will be enrolled. During LCCRT, patients will be randomized to receive either MRgART with SIB (60-65 Gy in 25-28 fractions to primary lesions and positive lymph nodes; 50-50.4 Gy in 25-28 fractions to the pelvis) or intensity-modulated radiotherapy (50-50.4 Gy in 25-28 fractions). Both groups will receive concurrent chemotherapy with capecitabine and consolidation chemotherapy of either two cycles of CAPEOX or three cycles of FOLFOX between radiotherapy and surgery. The primary endpoints are pathological complete response (pCR) rate and surgical difficulty, while the secondary endpoints are clinical complete response (cCR) rate, 3-year and 5-year disease-free survival (DFS) and overall survival (OS) rates, acute and late toxicity and quality of life.

DISCUSSION

Since dose escalation of both primary lesions and positive nodes in LARC is rare, we propose conducting a phase III trial to evaluate the efficacy and safety of SIB for both primary lesions and positive nodes in LARC based on MRgART.

TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov with the Identifier: NCT06246344 (Registered 7th Feb 2024).

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.

Brazil-TNT: A Randomized Phase 2 Trial of Neoadjuvant Chemoradiation Followed by FOLFIRINOX Versus Chemoradiation for Stage II/III Rectal Cancer

BACKGROUND

Neoadjuvant radiation and oxaliplatin-based systemic therapy (total neoadjuvant therapy-TNT) have been shown to increase response and organ-preservation rates in localized rectal cancer. However, trials have been heterogeneous regarding treatment protocols and few have used a watch-and-wait (WW) approach for complete responders. This trial evaluates if conventional long-term chemoradiation followed by consolidation of FOLFIRINOX increases complete response rates and the number of patients managed by WW.

METHODS

This was a pragmatic randomized phase II trial conducted in 2 Cancer Centers in Brazil that included patients with T3+ or N+ rectal adenocarcinoma. After completing a long-course 54 Gy chemoradiation with capecitabine patients were randomized 1:1 to 4 cycles of mFOLFIRINOX (Oxaliplatin 85, irinotecan 150, 5-FU 2400)-TNT-arm-or to the control arm, that did not include further neoadjuvant treatment. All patients were re-staged with dedicated pelvic magnetic resonance imaging and sigmoidoscopy 12 weeks after the end of radiation. Patients with a clinical complete response were followed using a WW protocol. The primary endpoint was complete response: clinical complete response (cCR) or pathological response (pCR).

RESULTS

Between April 2021 and June 2023, 55 patients were randomized to TNT and 53 to the control arm. Tumors were 74% stage 3, median distance from the anal verge was 6 cm, 63% had an at-risk circumferential margin, and 33% an involved sphincter. The rates of cCR + pCR were (31%) for TNT versus (17%) for controls (odds ratio 2.19, CI 95% 0.8-6.22 P = .091) and rates of WW were 16% and 9% (P = ns). Median follow-up was 8.1 months and recurrence rates were 16% versus 21% for TNT and controls (P = ns).

CONCLUSIONS

TNT with consolidation FOLFIRINOX is feasible and has high response rates, consistent with the current literature for TNT. This trial was supported by a grant from the Brazilian Government (PROADI-SUS - NUP 25000.164382/2020-81).

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.