Review of Neoadjuvant Chemotherapy Alone in Locally Advanced Rectal Cancer

Correlation study of functional magnetic resonance index and clinicopathological features of rectal cancer

PURPOSE

To investigate the correlation between DCE-MRI, R2*, IVIM, and clinicopathological features of rectal cancer.

METHODS

This was a prospective study, enrolling 42 patients with rectal cancer, 20 of whom underwent rectal mesorectal excision. Dynamic contrast-enhanced magnetic resonance imaging scanning was performed preoperatively in all patients, and additional preoperative scanning of R2* imaging and intravoxel incoherent motion was performed in those who underwent surgery. Artificially delineate the ROI around the tumor. Functional magnetic resonance index parameters Ktrans, Ve, R2*, D, D*, and f were estimated by computer software to analyze postoperative pathological reports of patients undergoing total mesenteric resection. Correlation and significance analyses of imaging metrics and pathologic features were performed by GraphPad Prism 9 to assess statistical significance.

RESULTS

DEC-MRI, R2*, and IVIM have certain application values in the distance from the lower margin of the tumor to the anorectal ring, imaging T stage and N stage, tumor markers CEA and CA199, immunohistochemical indexes Ki-76 and P53, lymph node cancer metastasis, and rectal fascia status (P < 0.05).

CONCLUSION

DEC-MRI, R2*, and IVIM provide reliable quantitative parameters for preoperative clinicopathological evaluation of patients with rectal cancer.

Differential clinical outcomes after 3 versus 5 years in a comparison of preoperative chemotherapy with and without radiotherapy in locally advanced rectal cancer: A national cohort propensity score-matched study

Background

Preoperative chemotherapy alone might be a good alternative to preoperative chemoradiotherapy for patients with locally advanced rectal cancer, yet long-term real-world data from the same cohort are lacking.

Methods

Patients diagnosed with stage II-III rectal adenocarcinoma from 2011 to 2015 were randomly sampled from the SEER-Plus database to evaluate the superiority of preoperative chemoradiotherapy versus preoperative chemotherapy alone.

Findings

A total of 1314 eligible patients were enrolled, with a median follow-up of 74.0 months. At 3-year follow-up, neither overall survival (OS) nor cancer-specific survival (CSS) was significantly different between the two treatment groups. At 5-year follow-up, CSS was similar across groups (HR 0.768, 95% CI 0.532-1.108; P = 0.156), but the 5-year OS was significantly better in the preoperative chemoradiotherapy group than in the preoperative chemotherapy group (HR 0.682, 95% CI 0.538-0.866; P = 0.002). Besides, the landmark analysis indicated a direct contrast in the CSS within 3 years (HR 1.101, 95% CI 0.598-2.029; P = 0.756) versus that at 3-5 years (HR 0.597, 95% CI 0.377-0.948; P = 0.027). The landmark analysis also showed directly contrasting OS outcomes within 3 years (HR 0.761, 95% CI 0.533-1.086; P = 0.130) versus those at 3-5 years (HR 0.621, 95% CI 0.451-0.857; P = 0.003).

Interpretation

In patients with locally advanced rectal cancer under real-world treatment practices, the addition of preoperative radiotherapy to chemotherapy improves survival outcomes at 3-5 years' follow-up but not at 3-year follow-up.

Development of a Diagnostic Artificial Intelligence Tool for Lateral Lymph Node Metastasis in Advanced Rectal Cancer

BACKGROUND

Metastatic lateral lymph node dissection can improve survival in patients with rectal adenocarcinoma, with or without chemoradiotherapy. However, the optimal imaging diagnostic criteria for lateral lymph node metastases remain undetermined.

OBJECTIVE

To develop a lateral lymph node metastasis diagnostic artificial intelligence tool using deep learning, for patients with rectal adenocarcinoma who underwent radical surgery and lateral lymph node dissection.

DESIGN

Retrospective study.

SETTINGS

Multicenter study.

PATIENTS

A total of 209 patients with rectal adenocarcinoma, who underwent radical surgery and lateral lymph node dissection at 15 participating hospitals, were enrolled in the study and allocated to training (n = 139), test (n = 17), or validation (n = 53) cohorts.

MAIN OUTCOME MEASURES

In the neoadjuvant treatment group, images taken before pretreatment were classified as baseline images and those taken after pretreatment as presurgery images. In the upfront surgery group, presurgery images were classified as both baseline and presurgery images. We constructed 2 types of artificial intelligence, using baseline and presurgery images, by inputting the patches from these images into ResNet-18, and we assessed their diagnostic accuracy.

RESULTS

Overall, 124 patients underwent surgery alone, 52 received neoadjuvant chemotherapy, and 33 received chemoradiotherapy. The number of resected lateral lymph nodes in the training, test, and validation cohorts was 2418, 279, and 850, respectively. The metastatic rates were 2.8%, 0.7%, and 3.7%, respectively. In the validation cohort, the precision-recall area under the curve was 0.870 and 0.963 for the baseline and presurgery images, respectively. Although both baseline and presurgery images provided good accuracy for diagnosing lateral lymph node metastases, the accuracy of presurgery images was better than that of baseline images.

LIMITATIONS

The number of cases is small.

CONCLUSIONS

An artificial intelligence tool is a promising tool for diagnosing lateral lymph node metastasis with high accuracy.

DESARROLLO DE UNA HERRAMIENTA DE INTELIGENCIA ARTIFICIAL PARA EL DIAGNSTICO DE METSTASIS EN GANGLIOS LINFTICOS LATERALES EN CNCER DE RECTO AVANZADO

ANTECEDENTES:Disección de nódulos linfáticos laterales metastásicos puede mejorar la supervivencia en pacientes con adenocarcinoma del recto, con o sin quimiorradioterapia. Sin embargo, aún no se han determinado los criterios óptimos de diagnóstico por imágenes de los nódulos linfáticos laterales metastásicos.OBJETIVO:Nuestro objetivo fue desarrollar una herramienta de inteligencia artificial para el diagnóstico de metástasis en nódulos linfáticos laterales mediante el aprendizaje profundo, para pacientes con adenocarcinoma del recto que se sometieron a cirugía radical y disección de nódulos linfáticos laterales.DISEÑO:Estudio retrospectivo.AJUSTES:Estudio multicéntrico.PACIENTES:Un total de 209 pacientes con adenocarcinoma del recto, que se sometieron a cirugía radical y disección de nódulos linfáticos laterales en 15 hospitales participantes, se inscribieron en el estudio y se asignaron a cohortes de entrenamiento (n = 139), prueba (n = 17) o validación (n = 53).PRINCIPALES MEDIDAS DE RESULTADO:En el grupo de tratamiento neoadyuvante, las imágenes tomadas antes del tratamiento se clasificaron como imágenes de referencia y las posteriores al tratamiento, como imágenes previas a la cirugía. En el grupo de cirugía inicial, las imágenes previas a la cirugía se clasificaron como imágenes de referencia y previas a la cirugía. Construimos dos tipos de inteligencia artificial, utilizando imágenes de referencia y previas a la cirugía, ingresando los parches de estas imágenes en ResNet-18. Evaluamos la precisión diagnóstica de los dos tipos de inteligencia artificial.RESULTADOS:En general, 124 pacientes se sometieron a cirugía solamente, 52 recibieron quimioterapia neoadyuvante y 33 recibieron quimiorradioterapia. El número de nódulos linfáticos laterales removidos en los cohortes de entrenamiento, prueba y validación fue de 2,418; 279 y 850, respectivamente. Las tasas metastásicas fueron 2.8%, 0.7%, y 3.7%, respectivamente. En el cohorte de validación, el área de recuperación de precisión bajo la curva fue de 0.870 y 0.963 para las imágenes de referencia y antes de la cirugía, respectivamente. Aunque tanto las imágenes previas a la cirugía como las iniciales proporcionaron una buena precisión para diagnosticar metástasis en los nódulos linfáticos laterales, la precisión de las imágenes previas a la cirugía fue mejor que la de las imágenes iniciales.LIMITACIONES:El número de casos es pequeño.CONCLUSIÓN:La inteligencia artificial es una herramienta prometedora para diagnosticar metástasis en los nódulos linfáticos laterales con alta precisión. (Traducción-Dr. Aurian Garcia Gonzalez ).

Evaluation of patients via colonoscopy who underwent positron emission tomography/computerized tomography due to colon involvement

OBJECTIVE

Fluorodeoxyglucose is not a tumor-specific agent and it can also be involved in benign conditions, which may cause diagnostic confusion. This research aims to elucidate the colonoscopic findings of patients who underwent colonoscopy due to colon involvement in positron emission tomography/computerized tomography.

METHODS

A total of 71 patients who underwent colonoscopy due to colonic involvement in positron emission tomography/computerized tomography at SBU Keçiören Training and Research Hospital Gastroenterology Clinic Endoscopy Unit have been analyzed retrospectively. Demographic characteristics of the patients, areas of involvement in positron emission tomography/computerized tomography, and severity have been obtained from the hospital database.

RESULTS

The gastrointestinal involvement area of 22.5% (n=16) of the patients was ascending colon, 15.5% (n=11) was sigmoid, 15.5% (n=11) was rectum, 12.7% (n=9) was stomach, 11.3% (n=8) was transverse colon, 8.5% (n=6) was anal canal, 5.6% (n=4) was esophagus, and 5.6% (n=4) was descending colon. The endoscopic findings of 19.7% (n=14) patients were normal, whereas 29.6% (n=21) had polyps, 9.9% (n=7) had cancer, 2.8% (n=2) had an ulcer, 15.5% (n=11) had gastritis, 14.1% (n=10) had hemorrhoids, and 7% (n=5) had colitis.

CONCLUSION

Fluorodeoxyglucose-positron emission tomography can detect unexpected distant metastases with high sensitivity because it allows whole-body imaging. Curative resection significantly contributes to the choice of treatment modality in the pre-operative period of colorectal cancer patients with planned surgery.

Neoadjuvant Modified FOLFOXIRI With Selective Radiotherapy in Locally Advanced Rectal Cancer: Long-term Outcomes of Phase II Study and Propensity-Score-Matched Comparison With Chemoradiotherapy

BACKGROUND

Neoadjuvant modified FOLFOXIRI (folinic acid, 5-fluorouracil, oxaliplatin, and irinotecan) chemotherapy with selective radiotherapy did not compromise pathologic complete response and tumor downstaging in locally advanced rectal cancer.

OBJECTIVE

The study aimed to analyze disease-free survival and local recurrence of neoadjuvant chemotherapy with modified FOLFOXIRI (mFOLFOXIRI).

DESIGN

This was a prospective single-arm phase II study. A propensity score-adjusted method was implemented to compare outcomes against historical controls of chemoradiotherapy.

SETTINGS

The study was conducted at single institutions.

PATIENTS

One hundred 6 patients with stage II and III rectal cancers were included.

INTERVENTION

All patients received neoadjuvant mFOLFOXIRI chemotherapy before total mesorectal excision. Patients with mesorectal fascia-positive or ycT4a/b after reevaluation with MRI received radiation before surgery. Otherwise, immediate total mesorectal excision would be performed.

MAIN OUTCOME AND MEASURES

The primary end point was tumor downstaging (ypStage 0-I) rate, which was reported previously. Disease-free survival and local recurrence rate were the main outcomes for the current study.

RESULTS

After a median follow-up of 43.3 months, the 2-year disease-free survival rate was 85.6% and the 3-year disease-free survival rate was 78.9%. The local recurrence rate was 7.8% after surgery. After propensity score matching, 73 patients were available for comparison in each group. The pathologic complete response rate was 23.3% and 13.7% ( p = 0.14), the proportion of ypStage 0-I was 45.2% vs 39.7% ( p = 0.5), the 3-year disease-free survival was 87.6% vs 75.8% (HR = 0.46; 95% CI, 0.22-0.95, p = 0.037). The local recurrence rate in the mFOLFOXIRI group was 5.5% and in the chemoradiotherapy group was 4.1% ( p = 0.70). Patients receiving mFOLFOXIRI had a lower incidence of anastomotic fistula compared with the chemoradiotherapy group (5.5% vs 17.8%, p = 0.02).

LIMITATIONS

This was a single-arm, nonrandomized phase II study.

CONCLUSIONS

Neoadjuvant mFOLFOXIRI with selective radiotherapy was feasible and safe, and it improved 3-year disease-free survival compared with propensity score-matched historical controls who received chemoradiotherapy. See Video Abstract at http://links.lww.com/DCR/B989 .Trial registration: NCT02217020.

FOLFOXIRI MODIFICADO NEOADYUVANTE CON RADIOTERAPIA SELECTIVA EN CNCER DE RECTO LOCALMENTE AVANZADO RESULTADOS A LARGO PLAZO DEL ESTUDIO DE FASE II Y COMPARACIN EMPAREJADA POR PUNTUACIN DE PROPENSIN CON QUIMIORRADIOTERAPIA

ANTECEDENTES:La quimioterapia neoadyuvante con FOLFOXIRI modificado (ácido folínico, 5-fluoruracilo, oxaliplatino e irinotecan) con radioterapia selectiva no comprometió la respuesta patológica completa ni la reducción del estadio del tumor en el cáncer de recto localmente avanzado.OBJETIVO:El estudio tuvo como objetivo analizar la sobrevida libre de enfermedad y la recurrencia local de la quimioterapia neoadyuvante con FOLFOXIRI modificado (mFOLFOXIRI).DISEÑO:Este fue un estudio prospectivo de fase II de un solo brazo. Se implementó un método ajustado por puntaje de propensión para comparar los resultados con los controles históricos de quimiorradioterapia.ESCENARIO:El estudio se realizó en instituciones individuales.PACIENTES:Se incluyeron 106 pacientes con cáncer de recto en estadio II y III.INTERVENCIÓN:Todos los pacientes recibieron quimioterapia neoadyuvante con mFOLFOXIRI antes de la escisión total del mesorrecto. Los pacientes con fascia mesorrectal positiva o ycT4a/b después de la reevaluación con MRI recibirían radiación antes de la cirugía. En caso contrario, se realizaría una escisión mesorrectal total inmediata.PRINCIPALES RESULTADOS Y MEDIDAS:El criterio principal de valoración fue la tasa de disminución del estadio del tumor (ypEstadio 0-I), que se informó anteriormente. La sobrevida libre de enfermedad y la tasa de recurrencia local son los principales resultados del estudio actual.RESULTADOS:Después de una mediana de seguimiento de 43,3 meses, las tasas de sobrevida libre de enfermedad a 2 y 3 años fueron del 85,6 % y 78,9 %, respectivamente. La tasa de recidiva local fue del 7,8% tras la cirugía. Después del emparejamiento por puntaje de propensión, 73 pacientes estaban disponibles para la comparación en cada grupo. La tasa de respuesta patológica completa fue de 23,3 % y de 13,7 % (p = 0,14), la proporción de ypEstadio 0-I fue del 45,2 % frente al 39,7 % (p = 0,5), la SLE a los 3 años fue del 87,6 % frente al 75,8 % (HR = 0,46, IC del 95 % 0,22-0,95, p = 0,037) y la tasa de recurrencia local fue del 5,5 % y del 4,1 % (p = 0,70) en el grupo de mFOLFOXIRI frente al grupo de quimiorradioterapia, respectivamente. Los pacientes que recibieron mFOLFOXIRI tuvieron una menor incidencia de fístula anastomótica en comparación con el grupo de quimiorradioterapia (5,5 % frente a 17,8 %, p = 0,02).LIMITACIONES:Este fue un estudio de fase II no aleatorizado de un solo brazo.CONCLUSIONES:El mFOLFOXIRI neoadyuvante con radioterapia selectiva fue factible y seguro, y mejoró la SSE a los 3 años en comparación con los controles históricos emparejados por puntaje de propensión que recibieron quimiorradioterapia. Consulte Video Resumen en http://links.lww.com/DCR/B989 . (Traducción-Dr. Felipe Bellolio ).

Effect of mistletoe extract on tumor response in neoadjuvant chemoradiotherapy for rectal cancer: a cohort study

Background

Mistletoe extract, used as a complementary chemotherapeutic agent for cancer patients, has anticancer effects against various malignancies. The aim of the present study was to evaluate the effect of mistletoe extract (Abnoba Viscum Q®) on tumor responses to neoadjuvant chemoradiotherapy (NCRT) for locally advanced rectal cancer.

Methods

This study included patients with rectal cancer who underwent NCRT between January 2018 and July 2020. In the mistletoe group (MG), the patients were administered Abnoba Viscum Q® subcutaneously during chemoradiotherapy—maintained just before surgery. Patient demographics, clinical outcomes, histopathological outcomes, and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) assay results were compared between the MG and non-mistletoe group (NMG). Two rectal cancer cell lines (SNU-503 and SNU-503R80Gy) were treated with Abnoba Viscum Q® to assess its mechanistic effects in vivo.

Results

Overall, the study included 52 patients (MG: n = 15; NMG: n = 37). Baseline demographics between the two groups were similar, except carbohydrate antigen 19-9 levels and tumor location from the anal verge. There was no difference in the clinical stage between the two groups. A better tumor response in the MG, relative to the NMG, was observed with respect to tumor regression grade (TRG), T stage, and overall tumor–node–metastasis stage. Tumor response was significantly better in the MG than in the NMG in terms of pathologic complete response rate (53.3% vs. 21.6%, P = 0.044), good TRG response (66.7% vs. 32.4%, P = 0.024), T downstaging (86.7% vs. 43.2%, P = 0.004), and overall downstaging (86.7% vs. 56.8%, P = 0.040). The toxicities during NCRT were minimal in both groups. More apoptotic cells were noted in MG samples than in the NMG samples on TUNEL staining. Cleaved caspase-3 level following treatment with Abnoba Viscum Q® was higher in SNU-503R80Gy cells than in SNU-503 cells.

Conclusion

Patients treated with chemoradiation combined with mistletoe extract showed better outcomes than patients not treated with mistletoe extract in terms of tumor responses. This diversity in treatment may improve the efficacy of NCRT, leading to better oncologic outcomes. Prospective and randomized studies with long-term follow-up are warranted to confirm and extend these results.

Surgical oncology in the age of multimodality therapy for cancer of the upper and lower gastrointestinal tract

INTRODUCTION

To date, all efforts to fight gastrointestinal cancer, regardless of its origin and entity, have resulted in complex therapeutic regimens involving a combination of systemic therapy, radiation therapy and surgery. It is generally accepted across all disciplines that not one, but the combination and the proper timing of all modalities result in the best oncologic outcome.

AREAS COVERED

Here, we provide insight into the current and future value of multimodal therapeutic approaches for upper and lower gastrointestinal cancer. Various aspects of treatment as well as open questions regarding indication and timing of multimodal strategies are addressed in this review.

EXPERT OPINION

In order to further improve the survival and quality of life of patients with gastrointestinal tumors in the future, scientifically proven multimodal therapy concepts are needed first and foremost. In addition, markers are pivotal to assign individual patients to a specific concept and to monitor the success of therapy. The main question is in which situation a neoadjuvant, perioperative or adjuvant radio-, chemo- or immunotherapy is superior. In fact, almost every curatively intended concept still contains surgical resection. Thus, improvement in surgical technique is also critical for multimodality concepts.

Indications for neoadjuvant treatment based on risk factors for poor prognosis before and after neoadjuvant chemotherapy alone in patients with locally advanced rectal cancer

INTRODUCTION

The oncological benefit of neoadjuvant chemotherapy (NAC) alone for locally advanced rectal cancer (LARC) remains controversial. The aim of this study was to clarify the clinical risk factors for poor prognosis before and after NAC for decision making regarding additional treatment in patients with LARC.

MATERIALS AND METHODS

We examined a total of 96 patients with MRI-defined poor-risk locally advanced mid-low rectal cancer treated by NAC alone between 2006 and 2018. Survival outcomes and clinical risk factors for poor prognosis before and after NAC were analyzed.

RESULTS

In the median follow-up duration after surgery of 60 months (3-120), the rates of 5-year overall survival (OS), relapse-free survival (RFS), and local recurrence (LR) were 83.6%, 78.4%, and 8.2%, respectively. In the multivariate analyses, patients with cT4 disease had a significantly higher risk of poor OS (HR; 6.10, 95% CI; 1.32-28.15, P = 0.021) than those with cT3 disease. After NAC, ycN+ was significantly associated with a higher risk of poor OS (HR; 5.92, 95% CI; 1.27-27.62, P = 0.024) and RFS (HR; 2.55, 95% CI; 1.01-6.48, P = 0.048) than ycN-. In addition, patients with CEA after NAC (post-CEA) ≥ 5 ng/ml had a significantly higher risk LR (HR; 5.63, 95% CI; 1.06-29.93, P = 0.043).

CONCLUSION

NAC alone had an insufficient survival effect on patients with cT4 disease, ycN+, or an elevated post-CEA level. In contrast, NAC alone is a potential treatment for other patients with LARC.

Recent advances in (chemo-)radiation therapy for rectal cancer: a comprehensive review

The role of radiation therapy in the treatment of (colo)-rectal cancer has changed dramatically over the past decades. Introduced with the aim of reducing the high rates of local recurrences after conventional surgery, major developments in imaging, surgical technique, systemic therapy and radiation delivery have now created a much more complex environment leading to a more personalized approach. Functional aspects including reduction of acute or late treatment-related side effects, sphincter or even organ-preservation and the unsolved problem of still high distant failure rates have become more important while local recurrence rates can be kept low in the vast majority of patients. This review summarizes the actual role of radiation therapy in different subgroups of patients with rectal cancer, including the current standard approach in different subgroups as well as recent developments focusing on neoadjuvant treatment intensification and/or non-operative treatment approaches aiming at organ-preservation.

Locally advanced rectal cancer: The past, present, and future

From a series of clinical trials in the last several decades, current treatment paradigms for locally advanced rectal cancer include: (1) preoperative long-course radiotherapy (RT) combined with radiosensitizing chemotherapy; (2) preoperative short-course RT alone followed by adjuvant postoperative chemotherapy; and (3) total neoadjuvant therapy with induction chemotherapy followed by chemoradiotherapy. Other strategies under active investigation in both institutional and cooperative trials include neoadjuvant chemotherapy alone without RT in select patients, total neoadjuvant therapy, watchful waiting after a clinical complete response as an alternative to surgical resection, and the use of different chemotherapeutic and targeted agents. The focus of this review is on established and novel therapeutic strategies for locally advanced rectal cancer.

Efficacy and Feasibility of Adding Induction Chemotherapy to Neoadjuvant Chemoradiation in Locally Advanced Rectal Cancer: A Phase II Clinical Trial

PURPOSE

Currently, neoadjuvant chemoradiation (CRT) followed by total mesorectal resection is considered the standard of care for treating locally advanced rectal cancer. This study aimed to investigate the efficacy and feasibility of adding induction chemotherapy to neoadjuvant CRT in locally advanced rectal cancer.

METHODS

This phase-II clinical trial included 54 patients with newly diagnosed, locally advanced (clinical T3-4 and/or N1-2, M0) rectal cancer. All patients were treated with 3 cycles of preoperative chemotherapy using the XELOX (capecitabine + oxaliplatin) regimen before and after a concurrent standard long course of CRT (45-50.4 Gy) followed by standard radical surgery. Pathologic complete response (PCR) rate and toxicity were the primary and secondary endpoints, respectively.

RESULTS

The study participants included 37 males and 17 females, with a median age of 59 years (range, 20-80 years). Twenty-nine patients (54%) had clinical stage-II disease, and 25 patients (46%) had clinical stage-III disease. Larger tumor size (P = 0.006) and distal rectal location (P = 0.009) showed lower PCR compared to smaller tumor size and upper rectal location. Pathologic examinations showed significant tumor regression (6.1 ± 2.7 cm vs. 1.9 ± 1.8 cm, P < 0.001) with 10 PCRs (18.5%) compared to before the intervention. The surgical margin was free of cancer in 52 patients (96.3%). Treatment-related toxicities were easily tolerated, and all patients completed their planned treatment without interruption. Grade III and IV toxicities were infrequent.

CONCLUSION

The addition of induction chemotherapy to neoadjuvant CRT is an effective and well-tolerated treatment approach in patients with rectal cancer.

Neoadjuvant Modified FOLFOX6 With or Without Radiation Versus Fluorouracil Plus Radiation for Locally Advanced Rectal Cancer: Final Results of the Chinese FOWARC Trial

PURPOSE

In the multicenter, open-label, phase III FOWARC trial, modified infusional fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) plus radiotherapy resulted in a higher pathologic complete response rate than fluorouracil plus radiotherapy in Chinese patients with locally advanced rectal cancer. Here, we report the final results.

METHODS

Adults ages 18 to 75 years with stage II/III rectal cancer were randomly assigned (1:1:1) to five cycles of infusional fluorouracil (leucovorin 400 mg/m², fluorouracil 400 mg/m², and fluorouracil 2.4 g/m² over 48 hours) plus radiotherapy (46.0 to 50.4 Gy delivered in 23 to 25 fractions during cycles 2 to 4) followed by surgery and seven cycles of infusional fluorouracil, the same treatment plus intravenous oxaliplatin 85 mg/m² on day 1 of each cycle (mFOLFOX6), or four to six cycles of mFOLFOX6 followed by surgery and six to eight cycles of mFOLFOX6. The primary end point was 3-year disease-free survival (DFS).

RESULTS

In total, 495 patients were randomly assigned to treatment. After a median follow-up of 45.2 months, DFS events were reported in 46, 39, and 46 patients in the fluorouracil plus radiotherapy, mFOLFOX6 plus radiotherapy, and mFOLFOX6 arms. In each arm, the probability of 3-year DFS was 72.9%, 77.2%, and 73.5% (P = .709 by the log-rank test), the 3-year probability of local recurrence after R0/1 resection was 8.0%, 7.0%, and 8.3% (P = .873 by the log-rank test), and the 3-year overall survival rate was 91.3%, 89.1%, and 90.7% (P = .971 by log-rank test), respectively.

CONCLUSION

mFOLFOX6, with or without radiation, did not significantly improve 3-year DFS versus fluorouracil with radiation in patients with locally advanced rectal cancer. No significant difference in outcomes was found between mFOLFOX6 without radiotherapy and fluorouracil with radiotherapy, which requires additional investigation of the role of radiotherapy in these regimens.

Placement of a self-expandable metallic stent as a bridge to surgery for large bowel obstruction induced by effective neoadjuvant therapy: report of three cases

BACKGROUND

Self-expandable metallic stent placement is a widely performed palliative procedure or bridge to surgery for obstructive colorectal cancer. However, the feasibility of this procedure for large bowel obstruction induced by effective neoadjuvant therapy is unclear.

CASE PRESENTATION

We herein report three such cases involving a 61-year-old man who underwent neoadjuvant chemoradiotherapy for lower rectal cancer, a 56-year-old woman who underwent neoadjuvant chemotherapy for lower rectal cancer, and a 63-year-old woman who underwent neoadjuvant chemotherapy for lower rectal cancer. All were emergently hospitalized with large bowel obstruction that developed while undergoing neoadjuvant therapy. Colonoscopy revealed smooth strictures caused by effective neoadjuvant therapy. Self-expandable metallic stents were placed across the obstruction as a bridge to surgery, and laparoscopic low anterior resection was uneventfully performed in all patients.

CONCLUSIONS

We successfully treated three patients with large bowel obstruction induced by a good response to neoadjuvant therapy using self-expandable metallic stents as a bridge to surgery. Further studies with larger sample sizes are warranted to assess the feasibility of this strategy.

Comparison of guidelines for the management of rectal cancer

A comparison between NCCN, ESMO and JSCCR Guidelines is presented, concerning the treatment of rectal cancer, with an analysis and discussion of their discrepancies. Differences indicate areas for research.

A Multicenter Phase 2 Study on the Feasibility and Efficacy of Neoadjuvant Chemotherapy Without Radiotherapy for Locally Advanced Rectal Cancer

BACKGROUND

This prospective multicenter phase 2 study aimed to evaluate the feasibility and efficacy of neoadjuvant chemotherapy (NAC) without radiotherapy for locally advanced rectal cancer (LARC).

METHODS

Patients with LARC (cStage II and III) were included in the study. Those with cT4b tumor were excluded. Six cycles of modified FOLFOX6 (mFOLFOX6) plus either bevacizumab or cetuximab, depending on KRAS status, were administered before surgery. The primary end point of the study was the R0 resection rate. The secondary end points were adverse effect, rate of NAC completion, postoperative complications, and pathologic complete response (pCR) rate.

RESULTS

The study enrolled 60 patients from eight institutions. For the study, mFOLFOX6 was administered with cetuximab to 40 patients who had wild-type KRAS and with bevacizumab to 20 patients who had KRAS mutations. The completion rate for NAC was 88.4%. Sphincter-preserving surgery was performed for 43 patients and abdominoperineal resection for 17 patients. The median operation time was 335 min, and the median blood loss was 40 g. The R0 resection rate was 98.3%, and the pCR rate was 16.7%. The overall postoperative complication rate (≥grade 2) was 21.7%. The complications included anastomotic leakage (11.6%), surgical-site infection (6.7%), and urinary dysfunction (3.3%). The patients with wild-type KRAS did not differ significantly from those with KRAS mutations in terms of response rate, postoperative complication rate, and pCR rate.

CONCLUSION

The findings show that NAC is a feasible and promising treatment option for LARC (This study is registered with UMIN-CTR, UMIN000005654).