The pathological assessment of mesorectal excision: implications for further treatment and quality management

Influence of Certification Program on Treatment Quality and Survival for Rectal Cancer Patients in Germany: Results of 13 Certified Centers in Collaboration with AN Institute

INTRODUCTION

The certification of oncological units as colorectal cancer centers (CrCCs) has been proposed to standardize oncological treatment and improve the outcomes for patients with colorectal cancer (CRC). The proportion of patients with CRC in Germany that are treated by a certified center is around 53%. Lately, the effect of certification on the treatment outcomes has been critically discussed.

AIM

Our aim was to investigate the treatment outcomes in patients with rectal carcinoma at certified CrCCs, in German hospitals of different medical care levels.

METHODS

We performed a retrospective analysis of a prospective, multicentric database (AN Institute) of adult patients who underwent surgery for rectal carcinoma between 2002 and 2016. We included 563 patients from 13 hospitals of different medical care levels (basic, priority, and maximal care) over periods of 5 years before and after certification.

RESULTS

The certified CrCCs showed a significant increase in the use of laparoscopic approach for rectal cancer surgery (5% vs. 55%, p < 0.001). However, we observed a significantly prolonged mean duration of surgery in certified CrCCs (161 Min. vs. 192 Min., p < 0.001). The overall morbidity did not improve (32% vs. 38%, p = 0.174), but the appearance of postoperative stool fistulas decreased significantly in certified CrCCs (2% vs. 0%, p = 0.036). Concerning the overall in-hospital mortality, we registered a positive trend in certified centers during the five-year period after the certification (5% vs. 3%, p = 0.190). The length of preoperative hospitalization (preop. LOS) was shortened significantly (4.71 vs. 4.13 days, p < 0.001), while the overall length of in-hospital stays was also shorter in certified CrCCs (20.32 vs. 19.54 days, p = 0.065). We registered a clear advantage in detailed, high-quality histopathological examinations regarding the N, L, V, and M.E.R.C.U.R.Y. statuses. In the performed subgroup analysis, a significantly longer overall survival after certification was registered for maximal medical care units (p = 0.029) and in patients with UICC stage IV disease (p = 0.041). In patients with UICC stage III disease, we registered a slightly non-significant improvement in the disease-free survival (UICC III: p = 0.050).

CONCLUSIONS

The results of the present study indicate an improvement in terms of the treatment quality and outcomes in certified CrCCs, which is enforced by certification-specific aspects such as a more differentiated surgical approach, a lower rate of certain postoperative complications, and a multidisciplinary approach. Further prospective clinical trials are necessary to investigate the influence of certification in the treatment of CRC patients.

Comparison of conventional unstained lymph nodal harvesting vs methylene blue-stained lymph nodal harvesting in colorectal specimen in staging left-sided colorectal carcinoma: a randomized controlled trial

BACKGROUND

The management and prognosis of colorectal carcinomas (CRCs) are related to the stage of the disease, which, in turn, relies on the lymph node harvest from the surgical specimen. The guidelines recommend that at least 12 lymph nodes are required, which is not achieved in most resections. In this study, we propose a method to improve the lymph node yield in such cases. This study aimed to determine whether ex vivo injection of methylene blue into the inferior mesenteric artery or its branches improves lymph node retrieval in left-sided CRCs.

METHODS

This study was conducted as a single-center, double-blinded, superiority randomized controlled trial. Patients who underwent elective surgery for left-sided CRCs with curative intent were randomized into 2 groups: stained and unstained. The sample size was calculated as 66. In all patients, details of disease stage, history of neoadjuvant therapy, and number of isolated lymph nodes were recorded.

RESULTS

The mean number of lymph nodes extracted from the stained group was significantly higher than that from the unstained group (15.9 ± 5.2 vs 9.1 ± 5.7, respectively; P < .001). Among the patients who had received neoadjuvant therapy, the yield was higher in the stained group (P < .001). The yield was found to be greater in patients who had undergone upfront surgery than in those who had undergone neoadjuvant therapy, even in the stained group (100% vs 66.7%, respectively).

CONCLUSION

The use of methylene blue injection into resected specimens of left-sided CRCs significantly improved the lymph node yield.

Does Completeness of the Mesorectal Excision Still Correlate With Local Recurrence?

BACKGROUND

Total mesorectal excision is the standard surgical procedure for rectal cancer treatment. Several studies have shown a close correlation between the prognosis of patients with rectal cancer and the completeness of the mesorectal specimen.

OBJECTIVE

To assess the correlation between macroscopic assessment of mesorectal excision and long-term oncological outcomes.

DESIGN

Retrospective analysis of an Institutional Review Board-approved database.

SETTINGS

Tertiary referral center.

PATIENTS

Patients with rectal cancer who were operated on between March 2016 and October 2019 were classified into 3 groups based on the mesorectal specimen quality: complete, near complete, and incomplete. Only patients with a follow-up of ≥2 years and without signs of preoperative distant disease were included.

MAIN OUTCOME MEASURES

Relationship between total mesorectal excision and local and distant recurrence rates in patients with rectal cancer.

RESULTS

A total of 124 patients (35.5% females) were included in the analysis, with a mean age of 58.1 (SD 12) years and a mean BMI of 26.4 (SD 4.59) kg/m². Neoadjuvant chemoradiation was administered to 71% of patients, whereas 13.7% received total neoadjuvant therapy. Restorative procedures were performed in 107 patients (86.3%), whereas 17 patients (13.7%) underwent abdominoperineal resection. The majority of mesorectal excision specimens (87.09%) were complete or near complete. Local recurrence rates were 6.3% (1/16) in the incomplete and 7.4% (8/108) in the complete/near complete group ( p = 0.86). Metachronous distant metastases occurred in 6 patients (37.5%) in the incomplete group and in 24 patients (22.2%) in the complete/near complete group (p = 0.18). Thus, specimen quality did not appear to impact disease-free survival.

LIMITATIONS

Retrospective, single-center study with relatively short follow-up.

CONCLUSIONS

In the era of a multidisciplinary approach and extensive use of neoadjuvant therapy, macroscopic completeness of total mesorectal excision may not be as valuable a prognosticator as in the past. Larger studies with longer follow-ups are needed to clarify these preliminary findings. See Video Abstract at http://links.lww.com/DCR/C129.

LA INTEGRIDAD DE LA ESCISIN MESORRECTAL TODAVA SE CORRELACIONA CON LA RECURRENCIA LOCAL

ANTECEDENTES:La escisión total desl mesorrecto es el estándar de oro para el tratamiento del cáncer de recto. Varios estudios han demostrado una estrecha correlación entre el pronóstico de los pacientes con cáncer de recto y la integridad espécimen mesorrectal.OBJETIVO:Evaluar la correlación entre la evaluación macroscópica de la escisión mesorrectal y los resultados oncológicos a largo plazo en pacientes con cáncer de recto.DISEÑO:Análisis retrospectivo de una base de datos aprobada por el IRB.ENTORNO CLINICO:El estudio se realizó en un centro de referencia terciario de una sola institución.PACIENTES:Todos los pacientes con cáncer de recto operados entre 3/2016-10/2019. Los pacientes se clasificaron en 3 grupos, según la calidad del espécimen mesorrectal: completo, casi completo e incompleto. Solo se incluyeron pacientes con seguimiento >2 años y sin signos de enfermedad a distancia preoperatoria.PRINCIPALES MEDIDAS DE RESULTADO:Identificar la relación entre la escisión mesorrectal total y las tasas de recurrencia local y a distancia en pacientes con cáncer de recto.RESULTADOS:Se incluyeron 124 pacientes (35,5% mujeres) con una edad media de 58,1 años (DE 12) y un índice de masa corporal medio de 26,4 (DE 4,59). Se administró quimiorradiación neoadyuvante al 71% de los pacientes, mientras que el 13,7% recibió terapia neoadyuvante total. Se realizaron procedimientos de restauración en 107 pacientes (86,3%), mientras que 17 pacientes (13,7%) se sometieron a resección abdominoperineal. La mayoría (87,09%) de los especímenes de escisión mesorrectal fueron completas o casi completas. Las tasas de recurrencia local fueron 1/16 (6,3%) en el grupo incompleto y 8/108 (7,4%) en el grupo completo/casi completo ( p = 0,86). Se produjeron metástasis a distancia metacrónicas en 6 pacientes (37,5%) en el grupo incompleto y 24 (22,2%) en el grupo completo/casi completo ( p = 0,18). Por lo tanto, la calidad del espécimen no pareció afectar la supervivencia libre de enfermedad.LIMITACIONES:Estudio retrospectivo de un solo centro con pequeño número de casos y seguimiento relativamente corto.CONCLUSIÓN:En la era de un enfoque multidisciplinario y el uso extensivo de la terapia neoadyuvante, la integridad macroscópica de la escisión total del mesorrecto, puede no ser un pronóstico tan valioso como en el pasado. Se necesitan estudios más amplios con períodos de seguimiento más prolongados para aclarar estos hallazgos preliminares. Consulte Video Resumen en http://links.lww.com/DCR/C129 . (Traducción-Dr. Fidel Ruiz Healy ).

Simultaneous, Multi-Channel, Near-Infrared Fluorescence Visualization of Mesenteric Lymph Nodes Using Indocyanine Green and Methylene Blue: A Demonstration in a Porcine Model

Near-infrared fluorescence (NIRF) image-guided surgery is a useful tool that can help reduce perioperative complications and improve tissue recognition. Indocyanine green (ICG) dye is the most frequently used in clinical studies. ICG NIRF imaging has been used for lymph node identification. However, there are still many challenges in lymph node identification by ICG. There is increasing evidence that methylene blue (MB), another clinically applicable fluorescent dye, can also be useful in the intraoperative fluorescence-guided identification of structures and tissues. We hypothesized that MB NIRF imaging could be used for lymph node identification. The aim of this study was to evaluate the feasibility of intraoperative lymph node fluorescence detection using intravenously (IV) administered MB and compare it to ICG via a camera that has two dedicated near-infrared (NIR) channels. Three pigs were used in this study. ICG (0.2 mg/kg) was administered via a peripheral venous catheter followed by immediate administration of MB (0.25 mg/kg). NIRF images were acquired as video recordings at different time points (every 10 min) over an hour using the QUEST SPECTRUM^® 3 system (Quest Medical Imaging, Middenmeer, The Netherlands), which has two dedicated NIR channels for simultaneous intraoperative fluorescence guidance. The 800 nm channel was used to capture ICG fluorescence and the 700 nm channel was used for MB. The target (lymph nodes and small bowel) and the background (vessels-free field of the mesentery) were highlighted as the regions of interest (ROIs), and corresponding fluorescence intensities (FI) from these ROIs were measured. The target-to-background ratio (TBR) was then computed as the mean FI of the target minus the mean FI of the background divided by the mean FI of the background. In all included animals, a clear identification of lymph nodes was achieved at all time points. The mean TBR of ICG in lymph nodes and small bowel was 4.57 ± 1.00 and 4.37 ± 1.70, respectively for the overall experimental time. Regarding MB, the mean TBR in lymph nodes and small bowel was 4.60 ± 0.92 and 3.27 ± 0.62, respectively. The Mann-Whitney U test of the lymph node TBR/small bowel TBR showed that the TBR ratio of MB was statistically significantly higher than ICG. The fluorescence optical imaging technology used allows for double-wavelength assessment. This feasibility study proves that lymph nodes can be discriminated using two different fluorophores (MB and ICG) with different wavelengths. The results suggest that MB has a promising potential to be used to detect lymphatic tissue during image-guided surgery. Further preclinical trials are needed before clinical translation.

Methylene blue can increase the number of lymph nodes harvested in colorectal cancer: a meta-analysis

AIM

The lymph node (LN) status plays an important role in colorectal cancer (CRC), which depends on adequate LN harvest. In some studies, methylene blue has been used to increase the number of LNs harvested in vitro. The purpose was to evaluate the effect of methylene blue staining on LN harvest during radical resection of CRC.

METHODS

The Cochrane Library, MEDLINE, Embase, PubMed, and Web of Science were searched from the dates of inception until 15 October 2022. Studies were included if they were randomized controlled trials or nonrandomized controlled trials for radical resection of rectal cancer according to the principle of total mesorectal excision that compared the use of methylene blue with blank control in LN harvest. The primary outcomes were the number of LNs harvested and the incidence of fewer than 12 LNs harvested.

RESULT

Of 328 articles found, a meta-analysis was conducted of 15 studies (2 randomized controlled trials and 13 non-randomized controlled trials) composed of 3104 patients. Meta-analysis showed that methylene blue could not only significantly increase the number of LNs harvested in CRC specimens (stained group 28.23 vs unstained group 16.15; weighted mean difference 12.08; 95% CI, 8.03-16.12; p < 0.001; I² = 95%), but also reduce the incidence of fewer than 12 LNs harvested (methylene blue-stained group 7.91% vs unstained group 30.90%; OR 0.12; 95% CI, 0.05-0.26; p < 0.001; I² = 78%).

CONCLUSION

Methylene blue can increase the number of LNs harvested in CRC, reduce the incidence of fewer than 12 LNs harvested, and ensure the accuracy of LN staging.

Robotic Versus Laparoscopic Partial Mesorectal Excision for Cancer of the High Rectum: A Single-Center Study with Propensity Score Matching Analysis

BACKGROUND

The role of robotic surgery for partial mesorectal excision (PME) in patients with high rectal cancer (RC) remains unexplored. This study aimed to compare the operative and postoperative outcomes of robotic (R-PME) versus laparoscopic (L-PME) PME for high RC.

METHODS

This was a single-center propensity score cohort study of consecutive patients diagnosed with RC in the high rectum (>10 to 15 cm from the anal verge) who underwent surgery between September 2012 and May 2019.

RESULTS

Of 131 selected patients (50 R-PME and 81 L-PME), 88 were matched using propensity score (44 per group). Operative and postoperative variables were similar between R-PME and L-PME patients, except for operative time (220 min and 190 min, respectively; p < 0.0001). No conversion was needed. Overall morbidity was 15.9%; 4 patients (4.5%) developed anastomotic leakage. The mean hospital stay was 7.25 days for R-PME vs. 7.64 days for L-PME (p = 0.597). R0 resection was achieved in 100% of R-PME and 90.9% of L-PME (p = 0.116). Only 3 patients (1 R-PME, 2 L-PME) received a permanent stoma (p = 1). No group differences were observed for overall or disease-free survival rates at 5 years. The costs of R-PME were significantly higher than those of L-PME.

CONCLUSION

Minimally invasive surgery can be performed safely for PME in high RC. No difference can be detected between R-PME and L-PME for both short- and long-term outcomes, leaving the choice of the surgical approach to the surgeon's experience. Specific health economic studies are needed to evaluate the cost-effectiveness of robotic surgery for RC.

Re-evaluation of possible vulnerable sites in the lateral pelvic cavity to local recurrence during robot-assisted total mesorectal excision

BACKGROUND

Despite mechanical and technical improvements in laparoscopic and robot-assisted (LAR) rectal cancer procedures, the absence of prognostic disparities among various approaches cannot improve the quality of TME. The present study re-evaluated robot-assisted total mesorectal excision (TME) procedures to determine whether these procedures may reveal technical faults that may increase the rate of local recurrence (LR).

METHODS

This study enrolled 886 consecutive patients with rectal cancer, who underwent curative robot-assisted LAR at Asan Medical Center (Seoul, Korea) between July 2010 and August 2017 (the first vs second period; n = 399 vs 487). The quality of TME and lateral pelvic mesorectal excision (LPME) were analyzed, as were LR rates and survival outcomes.

RESULTS

Complete TME and LPME were achieved in 89.2% and 80.1% of these patients, respectively, with ≤ 1% having incomplete TME excluding intramesorectal excision. LR rates were 13.5 and 14.5 times higher in patients with incomplete TME and LPME, respectively, than in patients with complete TME and LPME (14.8% vs 1.1% and 8.7% vs 0.6%; p < 0.001 each by univariate analyses). Multivariate analyses showed that defective LPME was independently associated with incomplete TME and vice versa (p < 0.001). Cox regression analysis showed that defective LPME was independently correlated with reduced 5-year disease-free survival rate (hazard ratio, 1.563; 95% confidence interval, 1.052-2.323; p = 0.027).

CONCLUSIONS

LR in rectal cancer patients was largely due to incomplete LPME, which was significantly associated with incomplete TME. Complete LPME may enhance the likelihood of complete TME, reducing LR rates.

Intra-arterial versus negative-staining of embryonal resection borders with indocyanine green (ICG) fluorescence for total mesorectal excision in colorectal cancer - an experimental feasibility study in a porcine model

Background: Colorectal cancer (CRC) is one of the most common malignancies worldwide. Laparoscopic lower rectal resections in accordance with the oncological principles are recommended as the gold standard for CRC surgical management. However, the learning curve for adopting these techniques is quite steep and the incomplete resections are predictive of local recurrence. This study was conducted in an attempt to find a way to help surgeons to overcome some of these difficulties and define the right resection margins.Material and methods: As such, we carried out two laparoscopic lower rectal resections in porcine models. The first resection was performed following the ligation and selective infusion of Indocyanine Green (ICG) into the inferior mesenteric artery (IMA), and the second after the ligation of both inferior mesenteric artery and vein (IMV) and systemic intravenous infusion of ICG. Fluorescence was detected in real time by means of an infrared imaging system.Results: Sharp resection margins were defined after intra-arterial infusion, and all the tissues in the IMA basin were colored in the first case. In the second model every organ and tissue was colored except the rectum, urinary bladder and ductus deferens.Conclusions: Although systemic intra-venous application of ICG and negative-staining of the rectum including the mesorectum is much easier compared to laparoscopic inter-arterial perfusion through IMA, image results of selevtive IMA-perfusion appear in sharper discrimination of the several layers. Further investigation should focus on simplifying this technique.

Uptake of Total Mesorectal Excision and Total Mesorectal Excision Grading for Rectal Cancer: A Statewide Study

BACKGROUND

Total mesorectal excision is associated with decreased local recurrence and improved disease-free survival following rectal cancer resection. The extent to which total mesorectal excision has been adopted in the United States is unknown.

OBJECTIVE

We sought to assess trends in total mesorectal excision performance and grading in Michigan hospitals.

DESIGN

This is a retrospective cohort study from the Michigan Surgical Quality Collaborative. Trends in total mesorectal excision performance and grade assignment were analyzed by using χ tests and linear regression.

SETTINGS

Participating hospitals (initially 14 hospitals, now 38) abstracted medical records data for rectal cancer cases from 2007 to 2016.

PATIENTS

Patients who underwent rectal cancer resection were included.

MAIN OUTCOME MEASURE

The main outcome measures were surgeon-documented total mesorectal excision performance and pathologist-reported total mesorectal excision grade.

RESULTS

Of 510 rectal cancer cases, 367 (72.0%) had surgeon-reported total mesorectal excision performance and 78 (15.3%) had pathologist-reported total mesorectal excision grade. Between-hospital variability in total mesorectal excision performance ranged from 0% to 97% and total mesorectal excision grading ranged from 0% to 90%. Total mesorectal excision grading was associated with a higher likelihood of also having adequate lymph node assessment (88.5% versus 71.9%, p = 0.002). There has been a statistically significant trend toward an increase in total mesorectal excision grading in the original 14 hospitals (p = 0.001), but not in the complete cohort of all hospitals (p = 0.057).

LIMITATIONS

This is a retrospective cohort design with sampled rectal cancer cases. In addition, there is insufficient granularity to capture all factors associated with total mesorectal excision performance or grade assignment.

CONCLUSIONS

The rates of total mesorectal excision performance and grade assignment are widely variable throughout the state of Michigan. Overall, grade assignment remains very low. This suggests an opportunity for quality improvement projects to increase total mesorectal excision performance and grading, involving both the surgeons and pathologists for effective implementation. See Video Abstract at http://links.lww.com/DCR/B53. IMPLEMENTACIÓN DE LA ESCISIÓN MESORRECTAL TOTAL Y LA CLASIFICACIÓN POR ESCISIÓN MESORRECTAL TOTAL PARA EL CÁNCER RECTAL: UN ESTUDIO A NIVEL ESTATAL.: La escisión mesorrectal total se asocia con una menor recurrencia local y una mejor supervivencia libre de enfermedad después de la resección del cáncer rectal. Se desconoce hasta que punto se ha adoptado la escisión mesorrectal total en los Estados Unidos.Se intento evaluar las tendencias en el rendimiento y la clasificación de la escisión mesorrectal total en los hospitales de Michigan.Este es un estudio de cohorte retrospectivo de la "Michigan Surgical Quality Collaborative". Las tendencias en el rendimiento de la escisión mesorrectal total y la asignación de grado se analizaron mediante pruebas de chi-cuadrada y regresión lineal.Los hospitales participantes (inicialmente 14 hospitales, ahora 38) extrajeron datos de registros médicos de los casos de cáncer rectal desde 2007 hasta 2016.Pacientes que se sometieron a resección de cáncer rectal.Las principales medidas de resultado fueron el rendimiento de la escisión mesorrectal total documentado por el cirujano y el grado de escisión mesorrectal total informada por el patólogo.De 510 casos de cáncer rectal, 367 (72.0%) tenían un rendimiento de escisión mesorrectal total reportado por el cirujano y 78 (15.3%) tenían un grado de escisión mesorrectal total reportado por el patólogo. La variabilidad entre hospitales en el rendimiento de la escisión mesorrectal total varió del 0 al 97% y la clasificación de la escisión mesorrectal total varió del 0 al 90%. La clasificación de la escisión mesorrectal total se asoció con una mayor probabilidad de tener también una evaluación adecuada de los ganglios linfáticos (88.5% versus 71.9%, p = 0.002). Ha habido una tendencia estadísticamente significativa hacia un aumento en la clasificación de la escisión mesorrectal total en los 14 hospitales originales (p = 0.001), pero no en la cohorte completa de todos los hospitales (p = 0.057).Diseño de cohorte retrospectivo con casos de cáncer rectal muestreados. Además, no hay suficiente granularidad para capturar todos los factores asociados con el rendimiento de la escisión mesorrectal total o la asignación de grados.Las tasas de rendimiento de escisión mesorrectal total y asignación de grado son muy variables en todo el estado de Michigan. En general, la asignación de calificaciones sigue siendo muy baja. Esto sugiere una oportunidad para que los proyectos de mejora de la calidad aumenten el rendimiento y la clasificación de la escisión mesorrectal total, involucrando tanto a los cirujanos como a los patólogos para una implementación efectiva. Vea el resumen del video en http://links.lww.com/DCR/B53.

Intraarterial indocyanine green (ICG) fluorescence augmentation by marking embryonal resection areas in colorectal surgery: a feasibility study in a porcine model

Aim: In this pilot animal study we examined whether it is possible to visualize the embryonal resection layers by using intraarterial indocyanine green (ICG) staining when performing total mesorectal excision (TME) for carcinoma of the rectum. Material and methods: We injected ICG into the inferior mesenteric artery (AMI) of four swines to see whether the watershed area of the arterial supply zone can be sufficiently visualized by fluorescence imaging in order to mark the right dissection area along the fascia parietalis before and during resection. Results: We observed a fluorescence signal in all the supplied areas of AMI but not in other parts of the abdominal cavity or other organs. Additionally, the mesorectum also showed a sharp border between colored and non-colored tissue. Conclusion: In this study we present that resection borders may be determined before resection based on ICG-perfusion and we showed that intraoperative exclusive coloring of the rectum including the mesorectum is possible. Visualizing resection borders based on ICG-perfusion before settling the first cut may be a new approach in oncological surgery.

Introduction to Total Mesorectal Excision

Colorectal cancer is the second leading cause of mortality in the West, and rectal cancer accounts for about 25% of the colon cancers. The concept of total mesothelial excision (TME) was the most important event in surgery for rectal cancer of the last two decades, because even without a curative approach, it reduced local recurrence and extended 5-year survival.

Grading of Total Mesorectal Excision Specimens: Assessment of Interrater Agreement

BACKGROUND

Total mesorectal excision is the standard of care for patients with rectal cancer. Pathological evaluation of the quality of the total mesorectal excision specimen is an important prognostic factor that correlates with local recurrence, but is potentially subjective.

OBJECTIVE

This study aimed to determine the degree of variation in grading, both between assessors and between fresh and formalin-fixed specimens.

DESIGN

Raters included surgeons, pathologists, pathology residents, pathologists' assistants, and pathologists' assistant trainees. Specimens were assessed by up to 6 raters in the fresh state and by 2 raters postfixation. Four parameters were evaluated: mesorectal bulk, surface regularity, defects, and coning. Interrater agreement was measured using ordinal α-values.

SETTING

The study was conducted at a single academic center.

MAIN OUTCOME MEASURES

The primary outcome was agreement between individuals when grading total mesorectal excision specimens.

RESULTS

A total of 37 total mesorectal excision specimens were assessed. Reliability between all raters for fresh specimens for mesorectal bulk, surface regularity, defects, coning, and overall grade were 0.85, 0.85, 0.92, 0.84, and 0.91. When compared with all raters, pathologists and residents had higher agreement and pathologists and surgeons had lower agreement. Ordinal α-values comparing pathologist and pathologist's assistant agreement for overall grade were similar pre- and postfixation (0.78 vs 0.80), but agreement for assessing defects decreased postfixation. Among pathologists' assistants, agreement was higher when grading specimens postfixation than when grading fresh specimens.

LIMITATIONS

Assessment bias may have occurred because of the greater number of pathologists' assistants participating than the number of residents and pathologists.

CONCLUSIONS

The results indicate good interrater agreement for the assessment of overall grade, with defects showing the best interrater agreement in fresh specimens. Although total mesorectal excision specimens may be consistently graded postfixation, the assessment of defects postfixation may be less reliable. This study highlights the need for additional knowledge-transfer activities to ensure consistency and accurate grading of total mesorectal excision specimens. See Video Abstract at http://links.lww.com/DCR/A497.

The quality of total mesorectal excision specimen: A review of its macroscopic assessment and prognostic significance

As a surgical procedure which could significantly lower the recurrence rate of cancers, total mesorectal excision (TME) has been the gold standard for middle and lower rectal cancer treatment. However, previous studies have shown that the procedure did not achieve the ideal theoretical local recurrence rates of rectal cancers. Some researchers pointed out it was very likely that not all so-called TME treatments completely removed the mesorectum, implying that some of these TME surgical treatments failed to meet oncological quality standards. Therefore, a suitable assessment tool for the surgical quality of TME is necessary. The notion of “macroscopic assessment of mesorectal excision (MAME)” was put forward by some researchers as a better assessment tool for the surgical quality of TME and has been confirmed by a series of studies. Besides providing rapid and accurate surgical quality feedbacks for surgeons, MAME also effectively assesses the prognosis of patients with rectal cancer. However, as a new assessment tool used for TME surgical quality, MAME has an only limited influence on the current guidelines and is yet to be widely applied in most countries. The aims of this review are to provide a detailed introduction to MAME for clinical practice and to summarize the current prognostic significance of MAME.

Adjuvant treatment for resected rectal cancer: impact of standard and intensified postoperative chemotherapy on disease-free survival in patients undergoing preoperative chemoradiation-a propensity score-matched analysis of an observational database

AIMS

Adjuvant chemotherapy for resected rectal cancer is widely used. However, studies on adjuvant treatment following neoadjuvant chemoradiotherapy (CRT) and total mesorectal excision (TME) have yielded conflicting results. Recent studies have focused on adding oxaliplatin to both preoperative and postoperative therapy, making it difficult to assess the impact of adjuvant oxaliplatin alone. This study was aimed at determining the impact of (i) any adjuvant treatment and (ii) oxaliplatin-containing adjuvant treatment on disease-free survival in CRT-pretreated, R0-resected rectal cancer patients.

METHOD

Patients undergoing R0 TME following 5-fluorouracil (5FU)-only-based CRT between January 1, 2008, and December 31, 2010, were selected from a nationwide registry. After propensity score matching (PSM), comparison of disease-free survival (DFS) using Kaplan-Meier analysis and log-rank test was performed in (i) patients receiving no vs. any adjuvant treatment and (ii) patients treated with adjuvant 5FU/capecitabine without vs. with oxaliplatin.

RESULTS

Out of 1497 patients, 520 matched pairs were generated for analysis of no vs. any adjuvant treatment. Mean DFS was significantly prolonged with adjuvant treatment (81.8 ± 2.06 vs. 70.1 ± 3.02 months, p < 0.001). One hundred forty-eight matched pairs were available for analysis of adjuvant therapy with or without oxaliplatin, showing no improvement in DFS in patients receiving oxaliplatin (76.9 ± 4.12 vs. 79.3 ± 4.44 months, p = 0.254). Local recurrence rate was not significantly different between groups in either analysis.

CONCLUSION

In this cohort of rectal cancer patients treated with neoadjuvant CRT and TME surgery under routine conditions, adjuvant chemotherapy significantly improved DFS. No benefit was observed for the addition of oxaliplatin to adjuvant chemotherapy in this setting.

Ex Vivo Intra-arterial Methylene Blue Injection in Rectal Cancer Specimens Increases the Lymph-Node Harvest, Especially After Preoperative Radiation

BACKGROUND

The examination of as large a number of lymph nodes as possible in rectal carcinoma resectates is important for exact staging. However, after neoadjuvant radiochemotherapy (RCT), it can be difficult to obtain a sufficient number of lymph nodes. We therefore investigated whether staining with methylene blue via the inferior mesenteric artery can lead to an increase in the yield of lymph nodes in rectal carcinoma tissue after neoadjuvant RCT.

METHODS

In a prospective, unicentric study rectal carcinoma resectates from three consecutive groups of patients were examined (Group I, no staining; Group II, staining with methylene blue; Group III, again no staining). The numbers of lymph nodes examined were compared (a) between the groups and (b) between patients who had not, or who had, received neoadjuvant RCT.

RESULTS

In all, 75 rectal carcinoma preparations were assessed. The yield of lymph nodes investigated before the use of staining (Group I) increased when staining was introduced (Group II), both for the patients without neoadjuvant RCT (20.9 vs. 31.3, p = 0.018) and for those who did receive this (15.0 vs. 35.1; p = 0.003). After withdrawal of the staining procedure (Group III), the lymph-node yield remained high for the patients without neoadjuvant RCT (31.3 vs. 30.4; p = 0.882), but it reverted to a lower value for those who did receive neoadjuvant RCT (35.1 vs. 24.2; p = 0.029). Before the introduction of staining (Group I), significantly fewer lymph nodes were examined for patients who received neoadjuvant RCT (15.0 vs. 20.9; p = 0.039). However, with staining (Group II), no difference was found associated with the use or non-use of neoadjuvant RCT (31.3 vs. 35.1; p = 0.520).

CONCLUSION

The use of methylene blue staining of rectal carcinoma preparations leads to a significant increase in the number of lymph nodes examined after neoadjuvant RCT. This can be expected to improve the accuracy of lymph-node staging of neoadjuvant-treated rectal carcinoma.

Modified methylene blue injection improves lymph node harvest in rectal cancer

BACKGROUND

The presence of nodal metastases in rectal cancer plays an important role in accurate staging and prognosis, which depends on adequate lymph node harvest. The aim of this prospective study is to investigate the feasibility and survival benefit of improving lymph node harvest by a modified method with methylene blue injection in rectal cancer specimens.

METHODS

One hundred and thirty-one patients with rectal cancer were randomly assigned to the control group in which lymph nodes were harvested by palpation and sight, or to the methylene blue group using a modified method of injection into the superior rectal artery with methylene blue. Analysis of clinicopathologic records, including a long-term follow-up, was performed.

RESULTS

In the methylene blue group, 678 lymph nodes were harvested by simple palpation and sight. Methylene blue injection added 853 lymph nodes to the total harvest as well as 32 additional metastatic lymph nodes, causing a shift to node-positive stage in four patients. The average number of lymph nodes harvested was 11.7 ± 3.4 in the control group and 23.2 ± 4.7 in the methylene blue group, respectively. The harvest of small lymph nodes (<5 mm) and the average number of metastatic nodes were both significantly higher in the methylene blue group. The modified method of injection with methylene blue had no impact on overall survival.

DISCUSSION

The modified method with methylene blue injection improved lymph node harvest in rectal cancer, especially small node and metastatic node retrieval, which provided more accurate staging. However, it was not associated with overall survival.

Long-term oncologic outcome after laparoscopic surgery for rectal cancer

BACKGROUND

Recent studies demonstrated favorable short- and mid-term results after laparoscopic surgery for rectal cancer. However, long-term results from large series are lacking. The present study analyses long-term results of laparoscopic rectal cancer surgery from a large-volume center.

METHODS

From January 1998 until March 2005, 225 patients underwent laparoscopic rectal resection due to carcinoma at the Medical Centre of the University of Regensburg. From 224 patients, a follow-up over 10 years was performed using the data of the Tumour Centre of the University of Regensburg. The data were analysed using oncological data (tumour recurrence) as well as overall survival. In addition, the effect of conversion to open resection on overall survival was analysed.

RESULTS

With a median of 10 years at follow-up, the overall and disease-free survival was 50.5 and 50.1 %, respectively. Local recurrence of all patients was 5.8 % and none of the converted patients was within this group. The median time interval for the development of local recurrence was 30 months. Six of the 13 patients with local recurrence (46.1 %) had received neoadjuvant radiochemotherapy before surgery. Patients with a conversion to open surgery had primarily a significantly worse outcome than patients resected completely laparoscopically (p = 0.003). However, this difference was no longer apparent using a multivariant analysis (hazard ratio 1.221; p = 0.478).

CONCLUSIONS

Overall survival and local recurrence rate of patients undergoing laparoscopic resection of rectal cancer are comparable to open surgery. However, in our analysis, patients undergoing laparoscopic anterior resection had a higher survival rate compared with patients with abdominoperineal resection.

Laparoscopic surgery for rectal cancer: outcomes in 513 patients

BACKGROUND

Few reports have demonstrated the feasibility and efficacy of laparoscopic resection in patients with rectal cancer (RC). The objective of the present study was to assess the effectiveness of laparoscopic resection for RC, with an emphasis on perioperative variables and long-term oncological outcomes.

METHODS

This prospective study was carried out between January 2005 and September 2010 and included 513 patients diagnosed with RC who underwent laparoscopic surgery. Patients with locally advanced RC (cT3/cT4 or N+) received neoadjuvant treatment. Adjuvant treatment was applied to patients with stage II/III disease or according to the neoadjuvant protocol. All patients were followed-up prospectively for the evaluation of complications and oncological outcome. Survival rate analysis was performed using the Kaplan-Meier method.

RESULTS

Sphincter-preserving surgery was performed on 389 patients, and the remaining 124 patients underwent abdominoperineal resection. Perioperative mortality occurred in only one patient (0.2 %), and 27 (5.3 %) intraoperative complications were recorded. The most common postoperative complication was anastomotic leakage (5.5 %). The conversion rate was 6.4 %. The mean number of harvested lymph nodes was 23.6 ± 13. The mean distance to the distal margin was 2.6 ± 1.9 (0-7) cm. Distal margin positivity was detected in 9 (1.7 %) patients. The circumferential margin was positive in 39 (7.6 %) cases. After a median follow-up period of 30 (1-78) months, recurrence occurred in a total of 59 patients (11.5 %). Local recurrence was detected in 16 patients (3.1 %), and both local and distant recurrence was found in 7 patients (1.4 %). Distant recurrence only was detected in 43 patients (8.4 %). The overall 5-year survival rate was 84 %, and the 5-year disease-free survival rate was 77.4 %. The local recurrence-free survival rate was 98.4 % at 2 years, 95.7 % at 3 years, and 94.3 % at 5 years.

CONCLUSIONS

Our results, together with the review of the literature, clearly demonstrate that laparoscopic resection for RC is a feasible method at specialized high-volume centers. The long-term outcomes are at least as good as those from open surgery as long as the principles of oncologic surgery are respected and faithfully performed.

TME quality in rectal cancer surgery

Background

The concept of total mesorectal excision has revolutionised rectal cancer surgery. TME reduces the rate of local recurrence and tumour associated mortality. However, in clinical trials only 50% of the removed rectal tumours have an optimal TME quality. Patients: During a period of 36 months we performed 103 rectal resections. The majority of patients (76%; 78/103) received an anterior resection. The remaining patients underwent either abdominoperineal resection (16%; 17/103), Hartmann's procedure (6%; 6/103) or colectomy (2%; 2/103).

Results

In 90% (93/103) TME quality control could be performed. 99% (92/93) of resected tumours had optimal TME quality. In 1% (1/93) the mesorectum was nearly complete. None of the removed tumours had an incomplete mesorectum. In 98% (91/93) the circumferential resection margin was negative. Major surgical complications occurred in 17% (18/103). 5% (4/78) of patients with anterior resection had anastomotic leakage. 17% (17/103) developed wound infections. Mortality after elective surgery was 4% (4/95).

Conclusion

Optimal TME quality results can be achieved in all stages of rectal cancer with a rate of morbidity and mortality comparable to the results from the literature. Future studies should evaluate outcome and local recurrence in accordance to the degree of TME quality.

Injection of methylene blue solution into the inferior mesenteric artery of resected rectal specimens for rectal cancer as a method for increasing the lymph node harvest

BACKGROUND

The aim of the present study was to determine whether the injection of methylene blue solution into the inferior mesenteric artery could improve the lymph node harvest in rectal specimens of rectal cancer patients treated with rectal resection with total mesorectal excision.

METHODS

The study group consisted of 20 randomly selected fresh rectal specimens from patients with stages I-III rectal cancer treated at the Surgery Clinic at the Institute of Oncology of Vilnius University during the period from February 2008 to December 2010, and 20 specimens were selected under the same conditions to serve as the control group. The patients underwent conventional rectal resection with total mesorectal excision and coloanal anastomosis for low rectal cancer performed by the same surgeon, did not receive preoperative radiotherapy and had no distant metastases. After the removal of the specimen, 30 ml of 0.5% methylene blue solution was injected into the inferior mesenteric artery of the specimens in the study group (methylene blue group). The specimens from both the methylene blue and control groups were examined using the standards established by the Lithuanian National Centre of Pathology. The pathologist was not required to make any special macroscopic preparations. A retrospective analysis of clinical and histopathological records was performed.

RESULTS

Comparison of the mean lymph node harvest showed a significant difference between methylene blue and control groups with average lymph node numbers per specimen of 18 ± 5 and 14 ± 6, respectively (p = 0.025). The specimens from 12 of the 20 patients in the methylene blue group and the specimens from 7 of the 20 patients from the control group had positive nodes.

CONCLUSIONS

Injecting methylene blue solution into the inferior mesenteric artery is an efficient and simple method for improving the lymph node harvest in the histopathological examination of rectal specimens of rectal cancer patients treated with rectal resection with total mesorectal excision.

Optimal lymph node harvest in rectal cancer (UICC stages II and III) after preoperative 5-FU-based radiochemotherapy. Acetone compression is a new and highly efficient method

INTRODUCTION

Preoperative 5-fluorouracil-based radiochemotherapy (RCT), followed by total mesorectal excision, is accepted as standard therapy in rectal cancers (UICC stages II and III). The accurate evaluation of ypN status after RCT with valuable lymph node (LN) harvest is essential for postoperative risk-adapted treatment decisions. Actual numbers of assessed LNs and validity of ypN status vary extensively depending on the methods used.

MATERIAL AND METHODS

This prospective study validates the acetone compression (AC), whole mesorectal compartment embedding (WME), and fat clearance (FC) methods for LN retrieval in n=257 rectal cancer specimens obtained from 2 high-volume surgical centers. For optimal LN retrieval, the AC method (n=161 specimens: 52 cases with RCT, 109 cases without RCT) was compared with the WME (n=64 cases, with RCT) and FC methods (n=32 cases: 17 cases with RCT, 15 cases without RCT). The efficacy of LN retrieval, costs involved, and molecular diagnostics were measured.

RESULTS

Using the AC method, 41 LNs (mean; range 14 to 86 LNs) were detectable in total mesorectal excision specimens after RCT and 44 LNs (mean; range 9 to 78 LNs) in cases without RCT. The LN yield after RCT obtained by using the AC method was equivalent to that of the WME method (mean 32 LNs/specimen; range 12 to 81 LNs) but demonstrated a better time and cost-efficacy. In addition, the AC method facilitated assessment of any tumor deposits, including perineural invasion, and did not hamper molecular analyses. The AC method increased LN retrieval 4- to-6-fold as compared with the literature and 2-fold compared with manual dissection after the FC method.

DISCUSSION

The AC method is the method of choice for accurate LN staging in locally advanced rectal cancer, especially after preoperative RCT, and is well suited for routine gastrointestinal pathology workup.

Factors influencing the quality of total mesorectal excision

BACKGROUND

Total mesorectal excision (TME) has become the standard of care for rectal cancer. Incomplete TME may lead to local recurrence.

METHODS

Data from the multicentre observational German Quality Assurance in Rectal Cancer Trial were used. Patients undergoing low anterior resection for rectal cancer between 1 January 2005 and 31 December 2009 were included. Multivariable analysis using a stepwise logistic regression model was performed to identify predictors of suboptimal TME.

RESULTS

From a total of 6179 patients, complete data sets for 4606 patients were available for analysis. Pathological tumour category higher than T2 (pT3 versus pT1/2: odds ratio (OR) 1.22, 95 per cent confidence interval 1.01 to 1.47), tumour distance from the anal verge less than 8 cm (OR 1.27, 1.05 to 1.53), advanced age (65-80 years: OR 1.25, 1.03 to 1.52; over 80 years: OR 1.60, 1.15 to 2.22), presence of intraoperative complications (OR 1.63, 1.15 to 2.30), monopolar dissection technique (OR 1.43, 1.14 to 1.79) and low case volume (fewer than 20 procedures per year) of the operating surgeon (OR 1.20, 1.06 to 1.36) were independently associated with moderate or poor TME quality.

CONCLUSION

TME quality was influenced by patient- and treatment-related factors.

Individualized magnetic resonance imaging-based neoadjuvant chemoradiation for middle and lower rectal carcinoma

AIM

In most institutions neoadjuvant chemoradiation for middle and lower rectal carcinoma is currently given to patients with tumours of clinical stages II or III (cT3,4 and/or N1,2). The possibility of a reduction in the use of neoadjuvant chemoradiation by an individualized magnetic resonance imaging (MRI)-based indication for neoadjuvant chemoradiation was analysed.

METHOD

Assessment of the pathological and oncological principles indicating for neoadjuvant treatment was used to determine the prognostic importance of the distance between the tumour and the circumferential resection margin and pretherapeutic assessment using modern MRI.

RESULTS

Based on the results of pretreatment MRI scanning, a proposal is presented for the treatment of middle and lower rectal carcinoma with neoadjuvant chemoradiation. Adopting this proposal, the frequency of neoadjuvant chemoradiation decreased from 70% to 35% and the early and late adverse effects of this therapy were reduced. In contrast, the expected locoregional recurrence rate increased from 6% to 11% if all quality criteria were met and to 18% if not.

CONCLUSION

An MRI-based indication for neoadjuvant chemoradiation is justified only for centres with regular quality assurance of MRI, surgery, radiotherapy and pathology. The proposal needs confirmation by long-term follow up and by prospective studies with larger numbers of patients.

The role of the pathologist in rectal cancer diagnosis and staging and surgical quality assessment

Since the introduction of the total mesorectal excision by Heald, many changes in the therapeutic management of rectal cancer have been incorporated. The multidisciplinary approach to colorectal cancer, integrated in a team of different specialists, ensures individualised treatment for each patient with rectal cancer. Therefore the role of the pathologist has acquired an important relevance, not only in diagnosing but also managing and evaluating the surgical specimen. The knowledge of preoperative staging, distance between tumour and anal verge or in patients subjected to a neoadjuvant treatment is necessary for the pathologist to make a detailed, accurate and good-quality report. Parameters such as the macroscopic quality of the mesorectum, the status of the circumferential resection margin and the lymph node harvest are considered basic criteria recommended by the current guidelines for the multidisciplinary team audit.

TNM staging system of colorectal carcinoma: a critical appraisal of challenging issues

CONTEXT

Colorectal cancer is the leading cause of morbidity and death among gastrointestinal tumors and ranks fourth after lung, breast, and ovarian cancers. Despite a continuous refinement of the T (tumor), N (node), and M (metastasis) staging system to express disease extent and define prognosis, and eventually to guide treatment, the outcome of patients with colorectal cancer may vary considerably even within the same tumor stage. Therefore, the need for new factors, either morphologic or molecular, that could more precisely stratify patients into different risk categories is clearly warranted.

OBJECTIVES

To present the state of the art with regard to the colorectal cancer staging system and to discuss confusing and/or challenging issues, including the assessment of peritoneal membrane involvement, vascular invasion, tumor deposits, and pathologic tumor response to neoadjuvant chemoradiotherapy.

DATA SOURCES

Literature review of relevant articles indexed in PubMed (US National Library of Medicine) and primary material from the authors' institutions.

CONCLUSIONS

Two emerging needs exist for the TNM system, namely, further stratification of patients with the same tumor stage and incorporation of nonanatomic factors, the latter including molecular and treatment factors. The identification and classification of morphologic features encountered in the pathologic examination of colorectal cancer specimens may be difficult and a source of subjective variability. Enhanced pathologic analysis, agreed-upon standard protocols, and standardization should improve the completeness and accuracy of pathology reports.

Practical and molecular evaluation of colorectal cancer: new roles for the pathologist in the era of targeted therapy

CONTEXT

Colorectal cancer is the third most common cancer and the fourth most common cause of cancer death worldwide. Patient cases are discussed in multidisciplinary meetings to decide on the best management on an individual basis. Until recently, the main task of the pathologist in such teams was to provide clinically useful reports comprising staging of colorectal cancer in surgical specimens. The advent of total mesorectal excision and the application of anti-epidermal growth factor receptor (EGFR)-targeted therapies for selected patients with metastasized colorectal cancer have changed the role of the pathologist.

OBJECTIVES

To present the traditional role of the pathologist in the multidisciplinary team treating patients with colorectal cancer, to address the technique of total mesorectal excision and its implications for the evaluation of surgical specimens, to offer background information on the various EGFR-targeted therapies, and to review the currently investigated tissue biomarkers assumed to be predictive for efficacy of such therapies, with a focus on the role of the pathologist in determining the status of such biomarkers in individual tumors.

DATA SOURCES

This article is based on selected articles pertaining to biopsy evaluation of colorectal carcinoma and reviews of EGFR-targeted therapies for this cancer. All references are accessible via the PubMed database (US National Library of Medicine and the National Institutes of Health).

CONCLUSIONS

Pathologists play an increasingly important role in the diagnosis and management of colorectal cancer because of the advent of new surgical techniques and of targeted therapies. It is expected that this role will increase further in the near future.

Rectal cancer staging

Rectal cancer staging provides critical information concerning the extent of the disease. The information gained from staging is used to determine prognosis, to guide management, and to assess response to therapy. Accurate staging is essential for directing the multidisciplinary approach to therapy. This article focuses on the evolution of staging systems, the rational for staging, and current methods used to stage rectal cancer.

[Individualizing treatment for locally advanced rectal cancer]

Based on results of the German Rectal Cancer Study Group CAO/ARO/AIO-94 trial, long-term chemoradiotherapy (RT/CTx) is recommended as standard treatment for locally advanced rectal cancer (UICC stages II/III) in the lower two thirds of the rectum (0-12 cm from the anocutaneous verge). Tumor response to neoadjuvant therapy is very heterogeneous, ranging from complete remission to total resistance to RT/CTx. To fulfill the clinical requirement of individual and risk-adapted multimodal treatment, distinct progress in translational research has been achieved (e.g. gene profiling). However, in clinical reality "individualization" of the therapy of rectal cancer patients has not actually been realized. This can be achieved only on the basis of successful randomized clinical trials (e.g. the CAO/ARO/AIO-04 and GAST-05 trials) translationally combined with basic scientific approaches. One simple first step toward individualizing rectal cancer therapy is being made with the ongoing GAST-05 trial. This investigator initiated phase II trial funded by the German Research Foundation (Deutsche Forschungsgemeinschaft) excludes preoperative RT/CTx for patients with rectal cancer localized in the upper third of the rectum, using only quality controlled principles of radical surgery (partial vs total mesorectal excision) followed by adjuvant chemotherapy.

Quality management in rectal carcinoma: what is feasible?

PURPOSE

A cohort study was carried out to analyse quality indicators in the diagnosis and treatment of rectal carcinoma.

METHODS

A total of 2,470 patients with rectal carcinoma treated between 1985 and 2007 at the Department of Surgery, University of Erlangen, were analysed and compared within four time intervals.

RESULTS

Most of the indicators analysed from 2004 to 2007 fulfilled the defined target values. The indicators for process quality of surgical treatment and the surrogate indicators of outcome quality in surgery showed excellent results. Comparing this to previous data, it displays the new developments such as introduction of multimodal treatment for high-risk patients. While the rate of locoregional recurrences decreased, no significant improvement in survival was found.

CONCLUSIONS

Careful analysis of quality indicators is important for both quality management and comparison of treatment results. The progress in diagnosis and treatment requires a continuous update of definitions and target values.

Comprehensive reviews of the interfascial plane of the retroperitoneum: normal anatomy and pathologic entities

The retroperitoneum is conventionally divided into three distinct compartments: posterior pararenal space, anterior pararenal space, and perirenal space, bounded by the posterior parietal peritoneum, transversalis fascia, and perirenal fascia. But more recent work has demonstrated that the perirenal fascia is not made up of distinct unilaminated fascia, but a single multilaminated structure with potential space. These potential spaces are represented by retromesenteric plane, retrorenal plane, lateral conal plane, and combined fascial plane. The purpose of this review was to demonstrate embryogenesis, anatomy of interfascial plane, and spreading pathways of various pathologic entities with computed tomography imaging.

Prognostic heterogeneity of endosonographic T3 rectal cancer

PURPOSE

This study aimed to assess the prognostic implications of uT3 rectal carcinomas according to the tumor thickness and to analyze the correlation between this ultrasound-based parameter and other prognostic factors.

METHODS

Seventy-four patients with uT3(pM0) rectal tumors underwent primary surgery from 1996 to 2003. Preoperative endorectal ultrasound was used to assess uN stage, maximum tumor perimeter, and maximum tumor thickness. An ultrasound maximum tumor thickness cutoff point for local recurrence subdividing T3 tumors into uT3a and uT3b was established.

RESULTS

Median follow-up was 41 months (range, 24-59). The 5-year actuarial local and overall recurrence rates were 9.82 percent (n = 7) and 42.46 percent (n = 23), respectively. uN stage(P = 0.05), circumferential resection margin involvement (P = 0.002), an ultrasound maximum tumor thickness (P = 0.01), and locally advanced tumors (P = 0.001) were related to a significantly increased risk of local recurrence. An ultrasound maximum tumor thickness (hazard ratio, 1.15; 95 percent confidence interval, 1.0-1.2) and locally advanced tumor (hazard ratio, 17.21; 95 percent confidence interval, 2.99-98.84) were preoperative independent variables for predicting local recurrence. Locally advanced tumor was the only preoperative independent prognostic factor for overall recurrence (P = 0.004; hazard ratio, 1.09; 95 percent confidence interval, 1.0-1.1). An ultrasound maximum tumor thickness with a 19-mm cutoff point, subdividing the T3 tumors into uT3a and uT3b, can be used to predict local recurrence. Locally advanced tumors (P = 0.02) and circumferential resection margin involvement (P = 0.005) showed a significant association with an ultrasound maximum tumor thickness >19 mm.

CONCLUSIONS

A maximum tumor thickness measured by endorectal ultrasound in pT3 rectal cancer is an independent prognostic factor for local and overall recurrence. An ultrasound maximum tumor thickness cutoff point of 19 mm may be useful to classify patients preoperatively and to select them for primary surgery or neoadjuvant therapy.

Resection margins in modern rectal cancer surgery

At present, the preferred treatment for rectal cancer is low anterior resection with total mesorectal excision and sphincter preservation. Complete removal of the tumor's lymphatic and vascular pad with free resection margins has led to a reduction in rates of local recurrence and improved disease-specific survival. In addition to the distal and proximal margins from the tumor edge, for an optimal outcome, it is essential to consider distal mesorectal spread and the circumferential mesorectal margin.

Adjuvant and neoadjuvant chemoradiation or radiotherapy in rectal cancer--a review focusing on open questions

BACKGROUND

The therapy of rectal cancer has been a matter of debate since decades, especially with regard to the benefits of neoadjuvant or adjuvant therapies. Principles of additional therapies have been established nearly two decades ago and are questioned nowadays on the basis of more recently modified operative techniques. Benefits and sequelae of therapies have to be balanced against each other, and it seems somewhat likely that a more differentiated strategy than simply stating that every patient with stage II and III rectal cancer needs chemoradiation or radiotherapy will, in long term, be recommended.

CONCLUSION

It should be kept in mind that results of centers of excellence and of phase-III studies with their positively selected patient populations are not representative for all the patients with rectal cancer and physicians treating them.

Anatomical considerations in TNM staging and therapeutical procedures for low rectal cancer

BACKGROUND

Separation of the mesoderm-derived muscular structures and the endoderm-derived structures of the hindgut and reclassification of their involvement based on their embryological origin may be of clinical importance in providing anatomical support for a more standardized perineal resection during abdominoperineal resection. The aim of this study was to utilize magnetic resonance images and histological studies of fetal and neonatal specimens to redefine the T3/T4 distinction by reassessment of the intersphincteric plane and the pelvic diaphragm as they pertain to cancer infiltration and as part of the embryological development of the pelvic floor muscles and their connective tissue compartments.

MATERIALS AND METHODS

Pelvic floor anatomy was studied in seven newborn children and 120 embryos and fetuses. Anatomical data were completed by magnetic resonance imaging in 82 patients with T3 and T4 rectal cancers (64 T3, 18 T4; 35 women and 47 men) undergoing neoadjuvant chemoradiation for locally advanced (T3 or T4) rectal cancers.

RESULTS

Clear demarcation between mesodermal and endodermal structures of the pelvic floor, which is equally evident in plastinated sections and magnetic resonance images, is already visible in early fetal stages. There is a constitutive overlap between the endoderm- and the ectoderm-derived components of the pelvic floor.

CONCLUSION

Our data suggest that the current classification of rectal cancer staging is confusing, where the routinely used TNM classification system unnecessarily differentiates between embryologically identical muscular structures. Tumor spread along the musculature of the hindgut beyond the dentate line could possibly explain the occasional involvement of lymph nodes outside the conventional mesorectum.

Methylene blue injection into the rectal artery as a simple method to improve lymph node harvest in rectal cancer

Adequate lymph node assessment in colorectal cancer is crucial for prognosis estimation and further therapy stratification. However, there is still an ongoing debate on required minimum lymph node numbers and the necessity of advanced techniques such as immunohistochemistry or PCR. It has been proven in several studies that lymph node harvest is often inadequate under routine analysis. Lymph nodes smaller than 5 mm are especially concerning as they can carry the majority of metastases. These small, but affected lymph nodes may escape detection in routine analysis. Therefore, fat-clearing protocols and sentinel techniques have been developed to improve accuracy of lymph node staging. We describe a novel and simple method of ex vivo methylene blue injection into the superior rectal artery of rectal cancer specimens, which highlights lymph nodes and makes them easy to detect during manual dissection. Initially, this method was developed for proving accuracy of total mesorectal excision. We performed a retrospective study comparing lymph node recovery of 12 methylene blue stained and an equal number of unstained cases. Lymph node recovery differed significantly with average lymph node numbers of 27+/-7 and 14+/-4 (P<0.001) for the methylene blue and the unstained group, respectively. The largest difference was found in size groups between 1 and 4 mm causing a shift in size distribution toward smaller nodes. Metastases were confirmed in 21 and 19 lymph nodes occurring in five and four cases, respectively. Hence, we conclude that methylene blue injection technique improves accuracy of lymph node staging by heightening the lymph node harvest in rectal resections. In our experience, it is a very simple time and cost effective method that can be easily established under routine circumstances.

Accurate staging, selective preoperative therapy and optimal surgery improves outcome in rectal cancer: a review of the recent evidence

OBJECTIVE

The current optimal management of locally advanced rectal cancer has evolved from surgical excision followed by postoperative therapy in patients with involved margins, to an increasing use of a preoperative strategy to 'down-stage and/or down-size' the tumour. This treatment strategy is based on the relationship of the tumour to the mesorectal fascia, the optimal surgical circumferential resection margin that can be achieved by total mesorectal excision. We have reviewed the recent evidence for this strategy.

METHOD

An electronic literature search using PubMed identified articles on the subject of rectal cancer between January 2000 and December 2005. The search was limited to English language publications with secondary references obtained from key articles. Articles published in high impact factor journals formed the basis of the review, together with articles related to national programmes on the management of rectal cancer. This does lead to a selection bias, particularly as the articles identified had a European bias.

CONCLUSION

The UK NHS Cancer Plan has outlined the basis for the multidisciplinary team (MDT) management of rectal cancer. Advances in preoperative assessment through accurate staging and the recognition of the importance of the relationship of the tumour to the mesorectal fascia has allowed the selection of patients for a preoperative strategy to down-size/down-stage the tumour if this fascial layer is involved or threatened. Improvements in the quality of surgical resection through the acceptance of the principle of total mesorectal excision have ensured that optimal surgery remains the cornerstone to successful treatment. Further refinements of the MDT process strive to improve outcome. Accurate radiological staging, optimal surgery and detailed histopathological assessment together with consideration of a preoperative neoadjuvant strategy should now form the basis for current treatment and future research in rectal cancer.

The total mesorectal excision specimen for rectal cancer: a review of its pathological assessment

Total mesorectal excision (TME) refers to the surgical removal of the complete perirectal soft tissue envelope, using sharp instruments under direct vision, and has become the contemporary standard of care for patients with rectal cancer. Pathologists play a key role in the evaluation of these specimens, including the quality assurance of surgical performance, as well as evaluation of the circumferential radial margin (CRM). While the latter is the most significant predictor of local recurrence, the quality of the excised mesorectum is another important factor in assessing the risk of local recurrence in patients with a negative CRM. Since proper pathological assessment of the TME specimen provides important prognostic information, as well as critical feedback to surgeons regarding technical performance, it is important to have adequate guidelines for the macroscopic handling of these specimens. The CLASSICC study of the Medical Research Council in the United Kingdom, as well as the Dutch TME trial have introduced a new standard for the pathological assessment of TME specimens, including an approach that involves assessment in both the fresh and fixed states, at least 48 hours of fixation of an intact specimen, with observations made on both the external appearance and cross-sectional slices. This article reviews the pathological assessment of the TME specimen, including basic definitions, current international guidelines, an approach to evaluating the mesorectum and a discussion of special issues relating to margins, lymph node retrieval and effects of neoadjuvant therapy.

Preoperative staging of rectal cancer with MR Imaging: correlation with surgical and histopathologic findings

Rectal cancer is a common malignancy that continues to have a highly variable outcome, with local pelvic recurrence after surgical resection usually leading to incurable disease. The success of tumor excision depends largely upon accurate tumor staging and appropriate surgical technique, although the results of recent surgical trials indicate that evaluation of the involvement of the mesorectal fat and mesorectal fascia is even more important than T staging for treatment planning. Magnetic resonance (MR) imaging is increasingly being used to evaluate tumor resectability in patients with rectal cancer and to determine which patients can be treated with surgery alone and which will require radiation therapy to promote tumor regression. High-spatial-resolution MR imaging has proved useful in clarifying the relationship between a tumor and the mesorectal fascia, which represents the circumferential resection margin at total mesorectal excision. Phased-array surface coil MR imaging in particular plays a vital role in the therapeutic management of rectal cancer. At present, phased-array MR imaging best fulfills the clinical requirements for preoperative staging of rectal cancer. However, preoperative evaluation of the other prognostic factor, nodal status, is still problematic, and further studies will be needed to better define the role of MR imaging in this context.

Can the results of anorectal (abdominoperineal) resection be improved: are circumferential resection margins too often positive?

Carefully executed surgery for rectal cancer has reduced the incidence of local recurrence after restorative resection. Three recent large prospective series have confirmed the perception of a higher positive circumferential resection margin (CRM) rate after abdominoperineal resection. Tumour spread is different for low tumours and the surgical technique of abdominoperineal resection, perhaps better known as anorectal excision, may vary between surgeons. There is a need to redefine the place of anorectal excision and the contribution that can be made by pre-operative chemoradiation and/or extended surgery to reduce local recurrence and increase survival. Defined surgery, validated by histopathological assessment, as applied to TME surgery, would determine whether the perceived higher rates are due to the differences in routes of tumour spread or to surgically related variables. Unnecessary R1 or R2 resections and operative perforation can be minimized by an understanding of the surgical anatomy, the pattern of spread and difference in operative technique between anorectal excision and a low restorative operation. Surgical technique to maximize R0 resection should be based on a detailed understanding of the pelvic fascia and the levator ani and the use of pre-operative imaging to define lines of excision. With the adoption of even lower restorative resection (intersphincteric) there is a need to reassess the method of anorectal excision. This may be achieved by histopathological assessment of CRM positivity and MDT audit to improve results. Clinical trials are essential.

Estándares de calidad de la cirugía del cáncer de recto

The results of surgery for rectal cancer have classically been measured through indicators such as morbidity, mortality, and length of hospital stay. In the last few years other parameters have been included that evaluate healthcare quality such as the functional results of the surgical technique employed and quality of life. Total resection of the mesorectum, performed by experienced surgeons, is the surgical technique of choice. Currently, the sphincter can be preserved in 70% of patients. Anastomotic dehiscence after anterior resection of the rectum is the most serious complication and the most important risk factor is the height of the anastomosis. The overall dehiscence rate should be less than 15% and operative mortality should be between 2% and 3%. The colonic reservoir improves functional outcome and consequently it is the procedure of choice to reconstruct transit after low anterior resection. Local recurrence should be less than 10% and 5-year survival should be between 70% and 80%. In general, quality of life is better after anterior resection of the rectum than after abdominoperineal amputation, despite the functional deterioration presented by some patients.

Response to neoadjuvant therapy for rectal cancer: influence on long-term results

OBJECTIVE

Pre-operative treatment with chemoradiotherapy (CRT) seems to improve local control and overall survival in patients with rectal cancer. The aims of the study were to analyse the impact on overall, disease free and cancer related survival of tumour response to pre-operative CRT and to analyse the influence of the degree of response on long-terms results.

PATIENTS AND METHODS

Patients with a locally advanced rectal cancer, treated by pre-operative CRT were studied. A radical resection of the rectal tumour with mesorectal excision was performed within 6-8 weeks. Judged on the final TNM classification patients were considered responders when the tumour showed histologically a complete response, microscopic residual disease or a partial response. Non-responders were those in whom the extent of disease remained stable or progressed. Results Radical excision was performed in 103 patients, and a palliative resection in five. Forty-three patients underwent abdominoperineal resection and 65 anterior resection of the rectum. Seventy-one (65.7%) patients showed a response to CRT, while 37 (34.3%) did not. The overall local and distant recurrence rates were 6.8% and 21.3%. Tumour recurrence (P < 0.008) and disease free survival (P < 0.007) were significantly different in responders and nonresponders. Of the 71 responders, 16 had a pathological complete response, 27 had persisting microscopic disease and 28 had macroscopic residual disease. No differences in cancer specific outcome were observed in these groups.

CONCLUSION

Pathological response to pre-operative CRT is associated with improved tumour recurrence and disease-free survival rates. Any response to pre-operative CRT appears to improve outcomes as much as a complete response.

Aktuelle Behandlungsstrategien beim Rektumkarzinom

In the last ten years, considerable progress has been achieved in the treatment of rectal cancer. According to improved interdisciplinary staging, rectal carcinomas can be treated based on a stage-dependent concept: "low-risk" pT1 (G1/G2) carcinomas can be cured by local full wall excision, while "high-risk" pT1 (G3/G4) and pT2 carcinomas require transabdominal resection. In contrast, locally advanced rectal cancers in cUICC-II/-III stages (T3/T4 or N(+)) should receive long-term, 5-FU-based, neoadjuvant chemoradiotherapy according to the excellent results of the CAO/AIO/ARO-94 trial of the German Rectal Cancer Study Group. High-quality resection must be based on radical oncologic principles such as "no-touch" technique, radicular dissection of vessels, and total mesorectal excision. Multimodal treatment is completed with adjuvant 5-FU-based chemotherapy. This therapeutic approach led to a reduction in the 5-year local recurrence rate to 6% and disease-free survival of approximately 68% in advanced rectal cancer (overall survival: 76%).

Surgical results of total mesorectal excision for rectal cancer in a specialised colorectal unit

Our aim was to review the results of total mesorectal excision (TME) in a specialised colorectal unit. Perioperative and follow-up data were prospectively collected in a computerised database. A review of all the records was made. The morbidity rate was about 14%, and was higher in patients with coloplasty due to a higher anastomotic leak rate. The local recurrence rate was 2%, the distant metastasis rate was 11%, and both local and distant metastasis occurred in 4%. About 95% of recurrence occurred within 3 years. There was better bowel function in patients with a colonic J-pouch in the first 2 years after surgery, but the advantage disappeared thereafter. There were no differences in function between descending and sigmoid colonic J-pouches. TME in a specialised colorectal unit has low morbidity and mortality. Our procedure of choice is that of a sigmoid colon J-pouch anal anastomosis.

The pathological assessment of total mesorectal excision: what are the relevant resection margins?

An accurate pathological reporting of rectal cancer specimens has important implications concerning patients' prognosis and further clinical management. Since locoregional recurrence and prognosis in rectal cancer is especially influenced by the extent of extramural tumor spread into the mesorectal lymphovascular fatty tissue, systematic investigation of the status of the circumferential mesorectal resection margin is a point of major importance to determine the completeness of tumor resection. Careful macroscopic assessment of the resection specimen should be performed to monitor the quality of mesorectal excision.

Rectal cancer: local staging and assessment of lymph node involvement with endoluminal US, CT, and MR imaging--a meta-analysis

PURPOSE

To perform a meta-analysis to compare endoluminal ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging in rectal cancer staging.

MATERIALS AND METHODS

Relevant articles published between 1985 and 2002 were included if more than 20 patients were studied, histopathologic findings were the reference standard, and data were presented for 2 x 2 tables; articles were excluded if data were reported elsewhere in more detail. Two reviewers independently extracted data on study characteristics and results. Bivariate random-effects approach was used to obtain summary estimates of sensitivity and specificity for invasion of muscularis propria, perirectal tissue, and adjacent organs and for lymph node involvement. Summary receiver operating characteristic (ROC) curves were fitted for perirectal tissue invasion and lymph node involvement.

RESULTS

Ninety articles fulfilled all inclusion criteria. For muscularis propria invasion, US and MR imaging had similar sensitivities; specificity of US (86% [95% confidence interval [CI]: 80, 90]) was significantly higher than that of MR imaging (69% [95% CI: 52, 82]) (P =.02). For perirectal tissue invasion, sensitivity of US (90% [95% CI: 88, 92]) was significantly higher than that of CT (79% [95% CI: 74, 84]) (P <.001) and MR imaging (82% [95% CI: 74, 87]) (P =.003); specificities were comparable. For adjacent organ invasion and lymph node involvement, estimates for US, CT, and MR imaging were comparable. Summary ROC curve for US of perirectal tissue invasion showed better diagnostic accuracy than that of CT and MR imaging. Summary ROC curves for lymph node involvement showed no differences in accuracy.

CONCLUSION

For local invasion, endoluminal US was most accurate and can be helpful in screening patients for available therapeutic strategies.