MRI-based indications for neoadjuvant radiochemotherapy in rectal carcinoma: interim results of a prospective multicenter observational study

Cost-Effectiveness Analysis: Selective Use of Neoadjuvant Chemoradiation in Locally Advanced Rectal Cancer

BACKGROUND

Locally advanced rectal cancer has high cure rates with trimodal therapy. Studies sparing neoadjuvant chemoradiation in selected patients show comparable outcomes.

OBJECTIVE

This study aimed to determine the cost-effectiveness of selective use of neoadjuvant chemoradiation in this population.

DESIGN

A cost-effectiveness analysis model compared selective and blanket use chemoradiation for locally advanced rectal cancer.

SETTINGS

Literature review, expert consensus, and a prospective database populated the model. Health care utilization costs were based on information from the Centers for Medicare and Medicaid Services.

PATIENTS

Adult patients with stage II and III rectal cancer were selected.

MAIN OUTCOMES MEASURES

Primary outcomes were cost, effectiveness in quality-adjusted disease-free life years, net monetary benefit, and incremental cost-effectiveness ratios in dollars per quality-adjusted disease-free life years. Base-case 5-year disease-free survival for both strategies was 65%. One-way sensitivity analysis found the probability of 5-year disease-free survival for selective ranged between 40% and 65%. Probabilistic sensitivity analysis assessed second-order variability.

RESULTS

Base-case 5-year disease-free survival demonstrated selective use is dominant with lower cost and higher quality-adjusted disease-free life years. For selective use, cost is $153,176, effectiveness is 2.71 quality-adjusted life years, and net monetary benefit is -$17,564 and for blanket use cost is $176,362, effectiveness is 2.64 quality-adjusted life years, and net monetary benefit is -$44,217. One-way sensitivity analysis shows selective use is dominant for disease-free survival above 61.25% and is preferred for disease-free survival above 53.7%. Probabilistic sensitivity analysis shows selective use is optimal in 88% of the iterations for a population of 10,000 patients.

LIMITATIONS

Model was based on data from the literature, prospective database, and expert consensus.

CONCLUSION

In a population of patients with locally advanced rectal cancer with base-case disease-free survival of 65%, selective use of neoadjuvant chemoradiation is the superior strategy as long as disease-free survival in this group remains above 53%. See Video Abstract at http://links.lww.com/DCR/C199.

ANLISIS DE COSTOEFECTIVIDAD USO SELECTIVO DE QUIMIORRADIACIN NEOADYUVANTE EN CNCER DE RECTO LOCALMENTE AVANZADO

ANTECEDENTES:El cáncer de recto localmente avanzado tiene altas tasas de curación con la terapia trimodal. Los estudios que evitan la quimiorradiación neoadyuvante en pacientes seleccionados muestran resultados comparables.OBJETIVO:Determinar la relación costo-efectividad del uso selectivo de quimiorradiación neoadyuvante en esta población.DISEÑO:Un modelo de análisis de costo-efectividad comparó la quimiorradiación selectiva y de uso general para el cáncer de recto localmente avanzado.AJUSTES:Revisión de literatura, consenso de expertos y una base de datos prospectiva poblaron el modelo. Los costos de utilización de la atención médica se basaron en los Centros de Servicios de Medicare y Medicaid.PACIENTES:Se seleccionaron pacientes adultos con cáncer de recto en estadio II y III.PRINCIPALES MEDIDAS DE RESULTADOS:Los resultados primarios fueron el costo, efectividad en años de vida sin enfermedad ajustados por calidad, el beneficio monetario neto y la relación costo-efectividad incremental en $/años de vida sin enfermedad ajustados por calidad. La supervivencia libre de enfermedad a 5 años del caso base para ambas estrategias fue del 65%. El análisis de sensibilidad unidireccional varió la probabilidad de supervivencia libre de enfermedad a 5 años para uso selectivo entre 40%-65%. El análisis de sensibilidad probabilístico evaluó la variabilidad de segundo orden.RESULTADOS:El caso base de 5 años de supervivencia libre de enfermedad demostró que el uso selectivo es dominante con menor costo y años de vida libre de enfermedad ajustados de mayor calidad. El costo, la efectividad y el beneficio monetario neto para el uso selectivo y general fueron ($153 176; 2,71 QALY; -$17 564) y ($176 362; 2,64 QALY; -$44 217). El análisis de sensibilidad unidireccional demostró que el uso selectivo es dominante para la supervivencia sin enfermedad por encima del 61,25% y se prefiere para la supervivencia sin enfermedad por encima del 53,7%. El análisis de sensibilidad probabilístico demostró que el uso selectivo es óptimo en el 88% de las iteraciones para una población de 10 000 pacientes.LIMITACIONES:Modelo basado en datos de literatura, base de datos prospectiva y consenso de expertos.CONCLUSIÓN:En una población de pacientes con cáncer de recto localmente avanzado con caso base de supervivencia libre de enfermedad del 65%, el uso selectivo de quimiorradiación neoadyuvante para el cáncer de recto localmente avanzado es la estrategia superior, siempre y cuando la supervivencia libre de enfermedad en este grupo se mantenga por encima del 53%. Consulte Video Resumen en http://links.lww.com/DCR/C199. (Traducción-Dr. Fidel Ruiz Healy).

ACR Appropriateness Criteria® Staging of Colorectal Cancer: 2021 Update

Preoperative imaging of rectal carcinoma involves accurate assessment of the primary tumor as well as distant metastatic disease. Preoperative imaging of nonrectal colon cancer is most beneficial in identifying distant metastases, regardless of primary T or N stage. Surgical treatment remains the definitive treatment for colon cancer, while organ-sparing approach may be considered in some rectal cancer patients based on imaging obtained before and after neoadjuvant treatment. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Circumferential Resection Margin Status as a Predictive Factor for Recurrence in Preoperative MRI for Advanced Lower Rectal Cancer Without Preoperative Therapy

BACKGROUND

In Japan, total mesorectal excision plus lateral lymph node dissection without preoperative therapy is the standard treatment for advanced lower rectal cancer. Although long-term oncologic outcomes with preoperative therapy based on circumferential resection margin status in preoperative MRI has been reported, outcomes without preoperative therapy are unknown.

OBJECTIVE

This study evaluated long-term oncologic outcomes of radical surgery without preoperative therapy in advanced lower rectal cancer based on circumferential resection margin status in preoperative MRI, with the aim of defining appropriate patient populations for preoperative therapy.

DESIGN

This retrospective analysis compared long-term oncologic outcomes with preoperative MRI in patients with lower rectal cancer.

SETTINGS

Patients were identified through a database managed by our institute.

PATIENTS

In total, 338 patients with lower rectal cancer who underwent radical surgery between 2000 and 2014 at the National Cancer Center Hospital without preoperative therapy were included.

MAIN OUTCOME MEASURES

The main outcome was relapse-free survival.

RESULTS

The median follow-up period was 61.7 months (range, 3-153 months). Five-year relapse-free survival rates in MRI-predicted circumferential resection margin negative patients and positive patients were 76.0% and 55.6% (p < 0.001). Univariate and multivariate analyses revealed pN stage (HR, 2.35; 95% CI, 1.470-3.770; p < 0.001), lymphatic invasion (HR, 2.03; 95% CI, 1.302-3.176; p = 0.002), venous invasion (HR, 2.15; 95% CI, 1.184-3.9; p = 0.01), surgical procedure (HR, 1.72; 95% CI, 1.115-2.665; p = 0.01), and MRI-predicted circumferential resection margin (HR, 1.850; 95% CI, 1.206-2.838; p = 0.0051) to be independent risk factors for postoperative recurrence.

LIMITATIONS

This study was retrospective in design.

CONCLUSIONS

Magnetic resonance imaging-predicted circumferential resection margin was associated with relapse-free survival without preoperative therapy, indicating its potential for use in selecting optimal preoperative therapy. See Video Abstract at http://links.lww.com/DCR/B335. ESTADO DEL MARGEN DE RESECCIÓN CIRCUNFERENCIAL COMO FACTOR PREDICTIVO DE RECURRENCIA EN LA RESONANCIA MAGNÉTICA PREOPERATORIA, PARA EL CÁNCER RECTAL BAJO AVANZADO SIN TERAPIA PREOPERATORIA: En Japón, la escisión mesorrectal total con disección de ganglios linfáticos laterales y sin terapia preoperatoria, es el tratamiento estándar para el cáncer rectal bajo avanzado. Aunque se han reportado resultados oncológicos a largo plazo con terapia preoperatoria, basada en el estado del margen de resección circunferencial en la resonancia magnética preoperatoria, se desconocen los resultados sin terapia preoperatoria.Este estudio evaluó los resultados oncológicos a largo plazo de cirugía radical sin terapia preoperatoria, en cáncer rectal bajo avanzado, basado en el estado del margen de resección circunferencial en la resonancia magnética preoperatoria, con el objetivo de definir poblaciones de pacientes apropiadas para terapia preoperatoria.Este análisis retrospectivo comparó los resultados oncológicos a largo plazo con resonancia magnética preoperatoria, en pacientes con cáncer rectal bajo.Los pacientes fueron identificados a través de una base de datos administrada por nuestro instituto.Se incluyeron un total de 338 pacientes con cáncer rectal bajo, que se sometieron a cirugía radical entre 2000 y 2014 en el Hospital Nacional del Centro de Cáncer, sin terapia preoperatoria.El resultado principal fue la supervivencia libre de recaídas.La mediana del período de seguimiento fue de 61,7 meses (rango, 3-153 meses). Las tasas de supervivencia sin recaídas a cinco años, con margen de resección circunferencial predicho por resonancia magnética, en pacientes negativos y pacientes positivos fueron 76.0% y 55.6% (p <0.001), respectivamente. Los análisis univariados y multivariados revelaron estadio pN (razón de riesgo [HR], 2.35; intervalo de confianza [IC] del 95%, 1.470-3.770; p <0.001), invasión linfática (HR, 2.03; IC del 95%, 1.302-3.176; p = 0.002), invasión venosa (HR, 2.15; IC 95%, 1.184-3.9; p = 0.01), procedimiento quirúrgico (HR, 1.72; IC 95%, 1.115-2.665; p = 0.01) y circunferencial predicho por resonancia magnética en margen de resección (HR, 1.850; IC 95%, 1.206-2.838; p = 0.0051), como factores de riesgo independientes, para la recurrencia postoperatoria.Este estudio fue retrospectivo en diseño.El margen de resección circunferencial predicho de resonancia magnética, se asoció con una supervivencia libre de recaída sin terapia preoperatoria, lo que indica su potencial para uso en la selección de la terapia óptima preoperatoria. Consulte Video Resumen en http://links.lww.com/DCR/B335.

Avoidance of Overtreatment of Rectal Cancer by Selective Chemoradiotherapy: Results of the Optimized Surgery and MRI-Based Multimodal Therapy Trial

BACKGROUND

Neoadjuvant chemoradiotherapy (nCRT) in patients with rectal cancer carries a high risk of adverse effects. The aim of this study was to examine the selective application of nCRT based on patient risk profile, as determined by MRI, to find the optimal range between undertreatment and overtreatment.

STUDY DESIGN

In this prospective multicenter observational study, nCRT before total mesorectal excision (TME) was indicated in high-risk patients with involved or threatened mesorectal fascia (≤1 mm), or cT4 or cT3 carcinomas of the lower rectal third. All other patients received primary surgery.

RESULTS

Of the 1,093 patients, 878 (80.3%) were treated according to the protocol, 526 patients (59.9%) underwent primary surgery, and 352 patients (40.1%) underwent nCRT followed by surgery. The 3-year locoregional recurrence (LR) rate was 3.1%. Of 604 patients with clinical stages II and III, 267 (44.2%) had primary surgery; 337 (55.8%) received nCRT followed by TME. The 3-year LR rate was 3.9%, without significant differences between groups. In patients with clinical stages II and III who underwent primary surgery, 27.3% were diagnosed with pathological stage I.

CONCLUSIONS

The results justify the restriction of nCRT to high-risk patients with rectal cancer classified by pretreatment MRI. Provided that a high-quality MRI diagnosis, TME surgery, and standardized examination of the resected specimen are performed, nCRT, with its adverse effects, costs, and treatment time can be avoided in more than 40% of patients with stage II or III rectal cancer with minimal risk of undertreatment. (clinicaltrials.gov NCT325649).

Safety and Feasibility of Using Magnetic Resonance Imaging Criteria to Identify Patients With "Good Prognosis" Rectal Cancer Eligible for Primary Surgery: The Phase 2 Nonrandomized QuickSilver Clinical Trial

Importance

Chemoradiotherapy (CRT), followed by surgery, is the recommended approach for stage II and III rectal cancer. While CRT decreases the risk of local recurrence, it does not improve survival and leads to poorer functional outcomes than surgery alone. Therefore, new approaches to better select patients for CRT are important.

Objective

To conduct a phase 2 study to evaluate the safety and feasibility of using magnetic resonance imaging (MRI) criteria to select patients with "good prognosis" rectal tumors for primary surgery.

Design, Setting, and Participants

Prospective nonrandomized phase 2 study at 12 high-volume colorectal surgery centers across Canada. From September 30, 2014, to October 21, 2016, a total of 82 patients were recruited for the study. Participants were patients newly diagnosed as having rectal cancer with MRI-predicted good prognosis rectal cancer. The MRI criteria for good prognosis tumors included distance to the mesorectal fascia greater than 1 mm; definite T2, T2/early T3, or definite T3 with less than 5 mm of extramural depth of invasion; and absent or equivocal extramural venous invasion.

Interventions

Patients with rectal cancer with MRI-predicted good prognosis tumors underwent primary surgery.

Main Outcomes and Measures

The primary outcome was the proportion of patients with a positive circumferential resection margin (CRM) rate. Assuming a 10% baseline probability of a positive CRM, a sample size of 75 was estimated to yield a 95% CI of ±6.7%.

Results

Eighty-two patients (74% male) participated in the study. The median age at the time of surgery was 66 years (range, 37-89 years). Based on MRI, most tumors were midrectal (65% [n = 53]), T2/early T3 (60% [n = 49]), with no suspicious lymph nodes (63% [n = 52]). On final pathology, 91% (n = 75) of tumors were T2 or greater, 29% (n = 24) were node positive, and 59% (n = 48) were stage II or III. The positive CRM rate was 4 of 82 (4.9%; 95% CI, 0.2%-9.6%).

Conclusions and Relevance

The use of MRI criteria to select patients with good prognosis rectal cancer for primary surgery results in a low rate of positive CRM and suggests that CRT may not be necessary for all patients with stage II and III rectal cancer.

Trial Registration

ISRCTN.com identifier: ISRCTN05107772.

MRI-Based Use of Neoadjuvant Chemoradiotherapy in Rectal Carcinoma: Surgical Quality and Histopathological Outcome of the OCUM Trial

BACKGROUND

Preoperative magnetic resonance imaging (MRI) allows highly reliable imaging of the mesorectal fascia (mrMRF) and its relationship to the tumor. The prospective multicenter observational study OCUM uses these findings to indicate neoadjuvant chemoradiotherapy (nCRT) in rectal carcinoma.

METHODS

nCRT was indicated in patients with positive mrMRF (≤ 1 mm) in cT4 and cT3 carcinomas of the lower rectal third.

RESULTS

A total of 527 patients (60.2%) underwent primary total mesorectal excision, and 348 patients (39.8%) underwent long-term nCRT followed by surgery. The mrMRF was involved in 4.6% of the primary surgery group and 80.7% of the nCRT group. Rates of resections within the mesorectal plane (90.8%), sparing of pelvic nerves on both sides (97.8%), and number of regional lymph nodes (95.3% with ≥ 12 lymph nodes examined) are indicative of high-quality surgery. Resection was classified as R0 in 98.3%, the pathological circumferential resection margin (pCRM) was negative in 95.1%. Patients in the nCRT group had more advanced carcinomas with a significantly higher rate of abdominoperineal excision. Independent risk factors for pCRM positivity were advanced stage (T4), metastatic lymph nodes, resection in the muscularis propria plane, and location in the lower third.

CONCLUSIONS

The risk classification of rectal cancer patients by MRI seems to be highly reliable and allows the restriction of nCRT to approximately half of the patients with clinical stage II and III rectal carcinoma, provided there is a high-quality MRI diagnostic protocol, high-quality surgery, and standardized examination of the resected specimen.

Selection of Patients With Rectal Cancer for Preoperative Chemoradiotherapy: Are T Category and Nodal Status All That Matters?

BACKGROUND

Although the accuracy of preoperative MRI staging has been established on follow-up histopathologic examination, the reproducibility of MRI staging has been evaluated in studies with expert radiologists reading a large sample of MRI images and therefore is not generalizable to the real-world setting.

OBJECTIVE

The purpose of this study was to evaluate the interrater reliability of MRI for distance to the mesorectal fascia, T category, mesorectal lymph node status, and extramural depth of invasion for preoperative staging of primary rectal cancer.

DESIGN

This was a prospective, cross-sectional survey.

SETTINGS

The study was conducted in Ontario, Canada.

PARTICIPANTS

Participants included GI radiologists.

INTERVENTIONS

Participants read 5 preselected staging MRIs using a synoptic report and participated in an educational Webinar.

MAIN OUTCOME MEASURES

Distance to the mesorectal fascia, T category, extramural depth of invasion, and mesorectal lymph node status for each MRI were abstracted. Data were analyzed in aggregate using percentage of agreement, Fleiss κ, and interclass correlation coefficients to assess interrater reliability.

RESULTS

Reliability was highest for distance to the mesorectal fascia with an intraclass correlation of 0.58 (95% CI, 0.27-0.80). Kappa scores for T category, mesorectal lymph node status, and extramural depth of invasion were 0.38 (95% CI, 0.23-0.46), 0.41 (95% CI, 0.32-0.49), and 0.37 (95% CI, 0.16-0.82). There was no difference when radiologists were stratified by experience or volume.

LIMITATIONS

Scores may have been affected by MRI selection, because they were chosen to demonstrate diagnostic challenges for the Webinar and did not reflect a representative sample.

CONCLUSIONS

Interrater reliability was highest for distance to mesorectal fascia, and therefore, it may be a more reliable criterion than T category, extramural depth of invasion, or mesorectal lymph node status. Combined with the fact that an uninvolved mesorectal fascia is more consistent with the overall goal of rectal cancer surgery, it should be considered as an important MRI criterion for preoperative treatment decision making in the real-world setting. See Video Abstract at http://links.lww.com/DCR/A763.

Oncological outcome after MRI-based selection for neoadjuvant chemoradiotherapy in the OCUM Rectal Cancer Trial

BACKGROUND

It is not clear whether all patients with rectal cancer need chemoradiotherapy. A restrictive use of neoadjuvant chemoradiotherapy (nCRT) based on MRI findings for rectal cancer was investigated in this study.

METHODS

This prospective multicentre observational study included patients with stage cT2-4 rectal cancer, with any cN and cM0 status. Carcinomas in the middle and lower third that were 1 mm or less from the mesorectal fascia, all cT4 tumours, and all cT3 tumours of the lower third were classified as high risk, and these patients received nCRT followed by total mesorectal excision (TME). All other carcinomas with a minimum distance of more than 1 mm from the mesorectal fascia and those in the upper third were classified as low risk; these patients underwent TME alone (no nCRT). Patients were followed for at least 3 years. Outcomes were the rates of local recurrence, distant metastasis and survival.

RESULTS

Among 545 patients included, 428 were treated according to the study protocol: 254 (59·3 per cent) had TME alone and 174 (40·7 per cent) received nCRT and TME. Median follow-up was 60 months. The 3- and 5-year local recurrence rates were 1·3 and 2·7 per cent respectively, with no differences between the two treatment protocols. Patients with disease requiring nCRT had higher 3- and 5-year rates of distant metastasis (17·3 and 24·9 per cent respectively versus 8·9 and 14·4 per cent in patients who had TME alone; P = 0·005) and worse disease-free survival compared with that in patients who did not need nCRT (3- and 5-year rates 76·7 and 66·7 per cent, versus 84·9 and 76·0 per cent in the TME-alone group; P = 0·016).

CONCLUSION

Restriction of nCRT to high-risk patients achieved good results.

ACR Appropriateness Criteria® Pretreatment Staging of Colorectal Cancer

Colorectal cancers are common tumors in the United States and appropriate imaging is essential to direct appropriate care. Staging and treatment differs between tumors arising in the colon versus the rectum. Local staging for colon cancer is less integral to directing therapy given radical resection is often standard. Surgical options for rectal carcinoma are more varied and rely on accurate assessment of the sphincter, circumferential resection margins, and peritoneal reflection. These important anatomic landmarks are best appreciated on high-resolution imaging with transrectal ultrasound or MRI. When metastatic disease is suspected, imaging modalities that provide a global view of the body, such as CT with contrast or PET/CT may be indicated. Rectal cancer often metastasizes to the liver and so MRI of the liver with and without contrast provides accurate staging for liver metastases. This article focuses on local and distant staging and reviews the appropriateness of different imaging for both variants. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Long-term outcomes of surgery alone versus surgery following preoperative chemoradiotherapy for early T3 rectal cancer: A propensity score analysis

Recently, a few studies have raised the question of whether preoperative chemoradiotherapy (PCRT) is essential for all T3 rectal cancers. This case-matched study aimed to compare the long-term outcomes of surgery alone with those of PCRT + surgery for magnetic resonance imaging (MRI)-assessed T3ab (extramural depth of invasion ≤5 mm) and absent mesorectal fascia invasion (clear MRF) in mid/lower rectal cancer patients.From January 2006 to November 2012, 203 patients who underwent curative surgery alone (n = 118) or PCRT + surgery (n = 85) were enrolled in this retrospective study. A 1:1 propensity score-matched analysis was performed to eliminate the inherent bias. Case-matching covariates included age, sex, body mass index, histologic grade, carcinoembryonic antigen, operation method, follow-up period, tumor height, and status of lymph node metastasis. The end-points were the 5-year local recurrence (LR) rate and disease-free-survival (DFS).After propensity score matching, 140 patients in 70 pairs were included. Neither the 5-year LR rate nor the DFS was significantly different between the 2 groups (the 5-year LR rate, P = 0.93; the 5-year DFS, P = 0.94). The 5-year LR rate of the surgery alone was 2% (95% confidence interval [CI] 0.2%-10.9%) versus 2% (95% CI 0.2%-10.1%) in the PCRT + surgery group. The 5-year DFS of the surgery alone was 87% (95% CI 74.6%-93.7%) versus 88% (95% CI 77.8%-93.9%) in the PCRT + surgery group.In patients with MRI-assessed T3ab and clear MRF mid/lower rectal cancer, the long-term outcomes of surgery alone were comparable with those of the PCRT + surgery. The suggested MRI-assessed T3ab and clear MRF can be used as a highly selective indication of surgery alone in mid/lower T3 rectal cancer. Additionally, in those patients, surgery alone can be tailored to the clinical situation.

[Spincter preservation after selective chemoradiotherapy of rectal cancer. Interim results of the OCUM study]

BACKGROUND

In a prospective multicenter observational study (OCUM) neoadjuvant chemoradiotherapy (nRCT) was selectively administered depending on the risk of local recurrence and based on the distance between tumor and mesorectal fascia in pretherapeutic high-resolution magnetic resonance imaging (MRI).

OBJECTIVE

Frequency and quality of abdominoperineal excision (APE) and sphincter preserving operations.

PATIENTS AND METHODS

Of 642 patients treated in 13 hospitals 389 received surgery alone and 253 nRCT followed by surgery. By univariate and multivariate analysis risk factors for APE were determined. Quality parameters were the quality grade of mesorectal excision, the pathohistological involvement of the circumferential resection margin and intraoperative local dissemination of tumor cells.

RESULTS AND DISCUSSION

In 12.8 % of the patients APE was performed. Independent risk factors for APE were tumor location in the lower third of the rectum and the individual hospitals, where APE varied between 0 and 32 %. This variation was chiefly caused by the different case mix. Hospitals with a high APE rate (> 30 %) treated significantly more patients with very low lying carcinomas (< 3 cm above the anal verge) and more advanced tumors. The median height of the tumor in cases of APE was nearly equal in all participating hospitals. Independent on the number of cases the quality of rectal surgery was high. Within the patient groups of primary surgery and nRCT the oncological quality parameter did not significantly differ between sphincter preservation and APE. As far as sphincter preservation is concerned the results justify a selective application of nRCT in patients with rectal carcinoma. The long-term results still have to be awaited.

[Lymph node dissection after primary surgery and neoadjuvant radiochemotherapy of rectal cancer. Interim analysis of a multicenter prospective observational study (OCUM)]

INTRODUCTION

The OCUM trial (NCT01325649) aims to clarify whether low rates of local recurrence are also achieved when the indications for neoadjuvant radiochemotherapy are not based on the clinical TNM staging but on preoperative magnetic resonance imaging with measurement of the tumor distance to the circumferential resection margin. In this interim analysis the lymph node status in OCUM patients was investigated as a surrogate parameter for quality of surgery and histopathological work-up.

MATERIAL AND METHODS

Until now a total of 560 patients have been included in this study. Total mesorectal excision (TME) without pretreatment was undertaken in 338 patients (60.4 %) and neoadjuvant radiochemotherapy was administered in 222 (39.6 %) patients. The histological work-up was performed according to the guidelines of the German Association of Pathologists. Data are given as median values and ranges in brackets.

RESULTS

The lymph node yield was 24 (7-79) in 338 patients undergoing primary TME surgery without pretreatment, while 20 (3-56) lymph nodes were identified in patients after neoadjuvant radiochemotherapy (p = 0.001). A minimum of 12 lymph nodes were analyzed in 335 out of 338 patients (99.1 %) and in 209 out of 222 patients (94.1 %) following neoadjuvant radiochemotherapy (p = 0.001). Lymph node metastasis was identified (p = 0.362) in 116 out of 338 patients without pretreatment (34.3 %) and in 71 out of 222 patients after neoadjuvant radiochemotherapy (32.0 %). Patient age did not influence the number of identified lymph nodes or rate of lymph node metastasis.

CONCLUSION

In this trial the number of identified lymph nodes suggests that the quality of surgery and histopathological work-up were adequate compared to the standards defined by national guidelines. Neoadjuvant radiochemotherapy led to a reduced lymph node yield compared to surgery without pretreatment; however, this did not influence the rate of lymph node metastasis.

High Rate of Positive Circumferential Resection Margins Following Rectal Cancer Surgery: A Call to Action

OBJECTIVES

To identify predictors of positive circumferential resection margin following rectal cancer resection in the United States.

BACKGROUND

Positive circumferential resection margin is associated with a high rate of local recurrence and poor morbidity and mortality for rectal cancer patients. Prior study has shown poor compliance with national rectal cancer guidelines, but whether this finding is reflected in patient outcomes has yet to be shown.

METHODS

Patients who underwent resection for stage I-III rectal cancer were identified from the 2010-2011 National Cancer Database. The primary outcome was a positive circumferential resection margin. The relationship between patient, hospital, tumor, and treatment-related characteristics was analyzed using bivariate and multivariate analysis.

RESULTS

A positive circumferential resection margin was noted in 2859 (17.2%) of the 16,619 patients included. Facility location, clinical T and N stage, histologic type, tumor size, tumor grade, lymphovascular invasion, perineural invasion, type of operation, and operative approach were significant predictors of positive circumferential resection margin on multivariable analysis. Total proctectomy had nearly a 30% increased risk of positive margin compared with partial proctectomy (OR 1.293, 95%CI 1.185-1.411) and a laparoscopic approach had nearly 22% less risk of a positive circumferential resection margin compared with an open approach (OR 0.882, 95%CI 0.790-0.985).

CONCLUSIONS

Despite advances in surgical technique and multimodality therapy, rates of positive circumferential resection margin remain high in the United States. Several tumor and treatment characteristics were identified as independent risk factors, and advances in rectal cancer care are necessary to approach the outcomes seen in other countries.

Use of Preoperative Magnetic Resonance Imaging to Select Patients with Rectal Cancer for Neoadjuvant Chemoradiation--Interim Analysis of the German OCUM Trial (NCT01325649)

INTRODUCTION

Introduction of total mesorectal excision (TME) surgery for rectal cancer decreased local recurrence dramatically. Additional neoadjuvant chemoradiation (nCR) is frequently given in UICC II and III tumors based on TNM staging which is of limited accuracy. We aimed to evaluate determination of circumferential margin by magnetic resonance imaging (mrCRM) as an alternative criterium for nCR.

METHODS

Multicenter prospective cohort study which enrolled 642 patients in 13 centers with non-metastasized rectal adenocarcinoma. Patients with T4 tumors or patients with a mrCRM of 1 mm or less were treated by neoadjuvant chemoradiation. All others proceeded directly to surgery when inclusion criteria and no exclusion criteria were met. Quality of TME and accuracy of mrCRM determination were assessed during pathology workup.

RESULTS

TME was complete in 381 of 389 patients after surgery without nCR (97.9%) and in 245 of 253 patients (96.8%) after nCR. Negative pathology circumferential margins (pCRM) were seen in 97.4% without nCR and in 89% of patients after nCR. Negative pCRM was predicted by negative mrCRM in 98.3% of rectal cancers. NCR was given to 253 of 642 patients (39.5%). Lymph node count was 23 (range 7-79; median/range) for surgery without nCR and 19 (range 2-56) for surgery after nCR.

CONCLUSIONS

Surgical quality determined by pathology workup of specimen was very good in this study. Magnetic resonance imaging guided indication for nCR allows to achieve superb results concerning surrogate parameters for good oncological outcome. Thus, use of neoadjuvant chemoradiation with its potential detrimental side effects may be substantially reduced in selected patients.

Multimodal Rectal Cancer Treatment: In Some Cases, Less May Be More

A series of clinical trials in the last several decades has resulted in the development of multimodality treatment of locally advanced rectal cancer that includes neoadjuvant (preoperative) chemoradiotherapy, total mesorectal excision, and postoperative adjuvant chemoradiotherapy. Owing to this regimen, patients with locally advanced rectal cancer have better survival rates than patients with colon cancer, but at the cost of substantial morbidity and reduced quality of life. The challenge is to identify treatment approaches that maintain or even improve oncologic outcomes while preserving quality of life. We have identified different tumor characteristics that are associated with recurrence and probability of survival for locally advanced rectal cancer. This risk stratification, based on baseline clinical staging and tumor response to chemoradiotherapy, has led us to question whether all patients with locally advanced rectal cancer require every component of the multimodal regimen. In this article, we will review recent evidence that some patients with locally advanced rectal cancer can be spared one or more treatment modalities without compromising long-term oncologic outcomes and while preserving quality of life.

Comparative Outcomes of Neoadjuvant Treatment Prior to Total Mesorectal Excision and Total Mesorectal Excision Alone in Selected Stage II/III Low and Mid Rectal Cancer

BACKGROUND

Current guidelines advocate that all rectal cancer patients with American Joint Committee on Cancer (AJCC) stages II and III disease should be subjected to neoadjuvant therapy. However, improvements in surgical technique have resulted in single-digit local recurrence rates with surgery only.

METHODS

Operative, postoperative, and oncological outcomes of patients with and without neoadjuvant therapy were compared between January 2002 and December 2013. For this purpose, all patients resected with low anterior rectal resection (LAR) and total mesorectal excision (TME) who had or had not been irradiated were identified from the authors' prospectively maintained database. Patients who were excluded were those with high rectal cancer or AJCC stage IV disease; in the surgery-only group, patients with AJCC stage I disease or with pT4Nx rectal cancer; and in the irradiated patients, patients with ypT4Nx or cT4Nx rectal cancer.

RESULTS

Overall, 454 consecutive patients were included. A total of 342 (75 %) patients were irradiated and 112 (25 %) were not irradiated. Median follow-up for all patients was 48 months. Among patients with and without irradiation, pathological circumferential resection margin positivity rates (2.9 vs. 1.8 %, p = 0.5) were not different. At 5 years, in irradiated patients compared with surgery-only patients, the incidence of local recurrence was decreased (4.5 vs. 3.8 %, p = 0.5); however, systemic recurrences occurred more frequently (10 vs. 17.8 %, p = 0.2). Irradiation did not affect overall or disease-free survival (neoadjuvant treatment vs. surgery-only: 84.9 vs. 88.2 %, p = 0.9; 76 vs. 79.1 %, p = 0.8).

CONCLUSIONS

The current study adds to the growing evidence that suggests a selective rather than generalized indication for neoadjuvant treatment in stages II and III rectal cancer.

QuickSilver: A Phase II Study Using Magnetic Resonance Imaging Criteria to Identify "Good Prognosis" Rectal Cancer Patients Eligible for Primary Surgery

Background

Recently, two nonrandomized, prospective cohort studies used magnetic resonance imaging (MRI) to assess the circumferential resection margin to identify “good prognosis” rectal tumors eligible for primary surgery and have reported favorable outcomes.

Objective

The objective of this project was to conduct a Phase II trial to assess the safety and feasibility of MRI criteria to identify “good prognosis” rectal tumors eligible for primary surgery in the North American setting.

Methods

Patients with newly diagnosed primary rectal cancer attending surgical clinics at participating centers will be invited to participate in the study. The inclusion criteria for the study are: (1) diagnosis of rectal cancer (0-15 cm) from the anal verge on endoscopy and proximal extent of tumor at or below the sacral promontory on computed tomography (CT) or MRI; (2) meets all MRI criteria for “good prognosis” rectal tumor as defined by the study protocol; (3) 18 years or older; and (4) able to provide written consent. The initial assessment will include: (1) clinical and endoscopic examination of the primary tumor; (2) CT chest, abdomen, and pelvis; and (3) pelvic MRI. All potentially eligible cases will be presented at a multidisciplinary cancer conference to assess for eligibility based on the MRI criteria for “good prognosis” tumor which include: (1) predicted circumferential resection margin (CRM) > 1 mm; (2) definite T2, T2/early T3, or definite T3 tumor with < 5 mm of extramural depth of invasion (EMD); (3) any N0, N1, or N2; and (4) absence of extramural venous invasion (EMVI). All patients fulfilling the MRI criteria for “good prognosis” rectal cancer and the inclusion and exclusion criteria will be invited to participate in the study and proceed to primary surgery. The safety of the MRI criteria will be evaluated by assessing the positive CRM rate and is the primary outcome for the study.

Results

We expect to have a minimum of 300 potentially eligible patients, and based on a 30% eligibility rate and 80% participation rate, it is expected that 75 patients will be recruited over the two year study period. A Data Safety Monitoring Committee has been organized, and the study will be stopped if a positive CRM of >10% is reported at any interim assessment, which will occur after every 25 patients accrued in the study.

Conclusions

It is expected that the results of this study will show that use of MRI criteria to identify “good prognosis” rectal cancers eligible for primary surgery will be safe (ie, positive margin less than 10%). Therefore, these results will have significant potential to change the current management of rectal cancer in North America and result in improved quality of life for rectal cancer patients and survivors, while reducing overall health care costs.

Trial Registration

ISRCTN05107772; http://www.controlled-trials.com/ISRCTN05107772/ (Archived by WebCite at http://www.webcitation/6WhhUhXkA).

Optimisation of preoperative assessment in patients diagnosed with rectal cancer

AIMS

Treatment decision making for patients with rectal cancer is complex and optimal preoperative assessment is important to ensure patients receive appropriate and high-quality care. Therefore, our objective was to develop an evidence-based, multidisciplinary guideline to assist physicians treating rectal cancer to ensure that preoperative assessment is optimal.

MATERIALS AND METHODS

A multidisciplinary expert panel of physicians who treat rectal cancer was selected as members of the Cancer Care Ontario Preoperative Assessment for Rectal Cancer Guideline Development Group (GDG). This group initially met to identify important clinical questions with respect to optimisation of preoperative assessment in patients diagnosed with rectal cancer. A systematic review, specific to each of these clinical questions, was then conducted using MEDLINE, EMBASE and the Cochrane Library databases. The GDG met at regular intervals to review the evidence and to develop guidelines to address each of the clinical questions.

RESULTS

The GDG identified seven important clinical questions with respect to the optimisation of preoperative assessment in patients diagnosed with rectal cancer. The clinical questions pertained to: (i) investigations required to assess distant metastasis (one question); (ii) imaging for local staging of rectal cancer (five questions); (iii) multidisciplinary cancer conference (MCC) (one question); (iv) restaging-magnetic resonance imaging (one question). The systematic reviews related to these clinical questions yielded 31 articles that were abstracted and reviewed by the GDG. Based on the systematic reviews, a guideline was developed containing seven recommendations that were either adapted from existing guidelines, based on review of the evidence or by consensus when evidence was limited.

CONCLUSIONS

A set of seven recommendations have been developed in order to optimise pretreatment assessment in patients with rectal cancer by promoting evidence-based practice. These guidelines are based on the best available evidence and have been peer reviewed by two independent multidisciplinary expert panels for relevance and validity.

Neoadjuvant chemotherapy without radiotherapy for locally advanced rectal cancer

ABSTRACT 

Chemoradiotherapy or short-course radiotherapy followed by surgery is a standard treatment for locally advanced rectal cancer. This multimodality strategy has reduced the risk of local recurrence but failed to improve survival. Moreover, mid- and long-term side effects of radiotherapy have been reported. Alternative strategies have been investigated in an attempt to minimize treatment-related toxicities and improve outcome. Neoadjuvant chemotherapy without radiotherapy is an attractive therapeutic option that yields theoretical advantages. Moreover, if carefully selected, patients may be spared the effects of radiotherapy without compromising the oncology outcome. The authors review the available evidence on neoadjuvant chemotherapy without radiotherapy in locally advanced rectal cancer and try to anticipate potential algorithms of treatment selection to implement in clinical practice in the future.

Adenocarcinomas of the upper third of the rectum and the rectosigmoid junction seem to have similar prognosis as colon cancers even without radiotherapy, SAKK 40/87

PURPOSE

To investigate the prognosis of adenocarcinomas of the upper third of the rectum and the rectosigmoid-junction without radiotherapy.

METHODS

Patients from a multicenter randomized controlled trial from 1987-1993 on adjuvant chemotherapy for R0-resected colorectal cancers with stage I-III disease were retrospectively allocated: cancers of the lower two-thirds of the rectum (11 cm or less from anal-verge, Group A, n = 205), of the upper-third of the rectum and rectosigmoid-junction (>11-20 cm from anal-verge, Group B, n = 142), and of the colon (>20 cm from anal-verge, Group C, n = 378). The total mesorectal excision (TME) technique had not been introduced yet. The adjuvant chemotherapy turned out to be ineffective. None of the patients received neoadjuvant or adjuvant radiotherapy.

RESULTS

The patients had a regular follow-up (median, 8.0 years). The 5-year disease-free survival (DFS) rate was 0.54 (95%CI, 0.47-0.60) in Group A, 0.68 (95%CI, 0.60-0.75) in Group B, and 0.69 (95%CI, 0.64-0.74) in Group C. The 5-year overall survival (OS) rate was 0.64 (95%CI, 0.57-0.71) in Group A, 0.79 (95%CI, 0.71-0.85) in Group B, and 0.77 (95%CI, 0.73-0.81) in Group C. Compared with Group C, patients in Group A had a significantly worse OS (hazard ratio [HR] for death 2.10) and a worse DFS (HR for relapse/death 1.93), while patients in Group B had a similar OS (HR 1.12) and DFS (HR 1.07).

CONCLUSIONS

Adenocarcinomas of the upper third of the rectum and the rectosigmoid-junction seem to have similar prognosis as colon cancers. Even for surgeons not familiar with the TME technique, preoperative radiotherapy may be avoided for most rectosigmoid cancers above 11 cm from anal-verge.

MRI-based treatment of rectal cancer: is prognostication of the recurrence risk solid enough to render radiation redundant?

BACKGROUND

Most current guidelines recommend neoadjuvant short course radiotherapy (sRT) or radio-chemotherapy (nRCT) for rectal cancer stage II and III. After the introduction of total mesorectal excision (TME) and magnetic resonance imaging (MRI), this proceeding has been questioned and omission of neoadjuvant treatment according to preoperative MRI-criteria has been propagated. Aim of the present paper is to review the state of evidence regarding MRI-based treatment decision depending on the predicted width of the circumferential resection margin (CRM).

METHODS

A comprehensive survey of the literature was performed using the search terms "rectal cancer", "radiotherapy", "radio-chemotherapy", "MRI-based therapy", "circumferential resection margin". Data from lately published observational studies were compared to results from randomized trials and outcome analyses of the Norwegian national cancer registry.

RESULTS

Only one observational study using MRI-based treatment according to the anticipated CRM provided 5 year local recurrence data, however only for 65 patients. The second study did not yet evaluate recurrence rates. Two randomized trials comparing sRT to primary TME showed significantly worse outcome for non-irradiated patients. Data from the Norwegian rectal cancer registry demonstrate that TME alone is associated with higher LRR than achievable with preoperative RT.

CONCLUSIONS

Current evidence does not support the omission of neoadjuvant treatment for stage II-III rectal cancer on the basis of an MRI-predicted negative CRM. Randomized studies are warranted to clarify whether and for which subgroups TME alone is safe in terms of local recurrences.

Neoadjuvant therapy before surgical treatment

Neoadjuvant treatment in terms of preoperative radiotherapy reduces local recurrence in rectal cancer, but this improvement has little if any impact on overall survival. Currently performed optimal quality-controlled total mesorectal excision (TME) surgery for patients in the trial setting can be associated with very low local recurrence rates of less than 10% whether the patients receive radiotherapy or not. Hence metastatic disease is now the predominant issue. The concept of neoadjuvant chemotherapy (NACT) is a potentially attractive additional or alternative strategy to radiotherapy to deal with metastases. However, randomised phase III trials, evaluating the addition of oxaliplatin at low doses plus preoperative fluoropyrimidine-based chemoradiotherapy (CRT), have in the main failed to show a significant improvement on early pathological response, with the exception of the German CAO/ARO/AIO-04 study. The integration of biologically targeted agents into preoperative CRT has also not fulfilled expectations. The addition of cetuximab appears to achieve relatively low rates of pathological complete responses, and the addition of bevacizumab has raised concerns for excess surgical morbidity. As an alternative to concurrent chemoradiation (which delivers only 5-6 weeks of chemotherapy), potential options include an induction component of 6-12 weeks of NACT prior to radiotherapy or chemoradiation, or the addition of chemotherapy after short-course preoperative radiotherapy (SCPRT) or chemoradiation (defined as consolidation chemotherapy) which utilises the "dead space" of the interval between the end of chemoradiation and surgery, or delivering chemotherapy alone without any radiotherapy.

Rectal cancer : when is the local recurrence risk low enough to refrain from the aim to prevent it?

Recently, preliminary results of the OCUM study (optimized surgery and MRI-based multimodal therapy of rectal cancer) were published and raised concern in the scientific community. In this observational study, the circumferential resection margin status assessed in preoperative MRI (mrCRM) was used to decide for either total mesorectal excision (TME) alone or neoadjuvant radiochemotherapy (nRCT). In contrast to current guidelines, neither T3 stage (with negative CRM) nor clinically positive lymph nodes were an indication for nRCT. Pathologically node-positive patients received chemotherapy (ChT). Overall, 230 patients were included, of whom 96 CRM-positive patients received nRCT. The CRM was accurately predicted in MRI, the rate of mesorectal plane resection was high. Recurrence rates have not yet been reported, but an impressive rate of down-staging for both T and N stage after nRCT was observed, while acute side effects were minimal. Nonetheless, the authors conclude that a substantial number of patients could be "spared severe radiation toxicity" and propagate their concept for prospectively replacing current guidelines. This is based on the hypothesis that CRM is a valid surrogate parameter for the risk of local recurrence and in case of a negative CRM, nRCT becomes dispensable. Moreover, it is assumed that lymph node status is no more relevant. Both assumptions are a contradiction to recent data from randomized studies as specified below. As 5-year locoregional recurrence rate (LRR) of only of 5-8% and < 5% in low risk rectal cancer can be achieved by the addition of RT, the noninferiority of surgery alone can not be presumed unless the expected 5-year LRR is ≤ 5-8%, whereas any excess of this range renders the study design inacceptable. Unless a publication explicitly specifies 5-year LRR, results are not exploitable for clinical decisions.