Significance of lateral node dissection for advanced rectal carcinoma at or below the peritoneal reflection

Clinical influence of prophylactic lateral lymph node dissection on oncologic outcomes of patients with mid-low rectal cancer undergoing mesorectal excision: a meta-analysis

BACKGROUND

Although several recent meta-analyses have investigated the clinical influence of the addition of lateral lymph node dissection (LLND) on oncologic outcomes in patients with mid-low rectal cancer (RC) undergoing mesorectal excision (ME), most studies included in such meta-analyses were retrospectively designed. Therefore, this study aimed to explore the clinical influence of prophylactic LLND on oncologic outcomes in patients with mid-low RC undergoing ME.

METHODS

A comprehensive electronic search of the literature up to July 2022 was performed to identify studies that compared oncologic outcomes between patients with mid-low RC undergoing ME who underwent LLND and patients with mid-low RC undergoing ME who did not undergo LLND. A meta-analysis was performed using fixed-effects models and the generic inverse variance method to calculate hazard ratios (HRs) and 95% CIs, and heterogeneity was analyzed using I2 statistics.

RESULTS

A total of 6 studies, consisting of 3 randomized and 3 propensity score matching studies, were included in this meta-analysis. The results of the meta-analysis of 2 randomized studies demonstrated no significant effect of prophylactic LLND on improving oncologic outcomes concerning overall survival (OS) (HR, 1.22; 95% CI, 0.89-1.69; I2 = 0%; P = .22) and relapse-free survival (RFS) (HR, 1.03; 95% CI, 0.81-1.31; I2 = 28%; P = .83).

CONCLUSION

The results of this meta-analysis revealed no significant influence of prophylactic LLND on oncologic outcomes-OS and RFS-in patients with mid-low RC who underwent ME.

Standardization of robot-assisted pelvic lymph node dissection-Development of a common understanding of regional anatomy and surgical technique based on cross-disciplinary discussion among colorectal surgery, urology, and gynecology

BACKGROUND

Pelvic lymph node dissection is a procedure performed in gastroenterological surgery, urology, and gynecology. However, due to discrepancies in the understanding of pelvic anatomy among these departments, cross-disciplinary discussions have not been easy. Recently, with the rapid spread of robotic surgery, the importance of visual information in understanding pelvic anatomy has become even more significant. In this project, we attempted to clarify a shared understanding of pelvic anatomy through cross-disciplinary discussions.

METHOD

From May 2020 to November 2021, a total of 11 discussions were held entirely online with 5 colorectal surgery specialists, 4 urologists, and 4 gynecologists. The discussions focused on evidence from each specialty and surgical videos, aiming to create a universally understandable pelvic anatomical illustration.

RESULTS

The common area of dissection recognized across the three departments was identified as the obturator lymph nodes. A dynamic illustration of pelvic anatomy was created. In addition to a bird's-eye view of the pelvis, a pelvic half view was developed to enhance understanding of the deeper pelvic anatomy. The following insights were incorporated into the illustration: (1) the cardinal ligament in gynecology partly overlaps with the vesicohypogastric fascia in colorectal surgery; (2) the obturator lymph nodes continue cephalad into the fossa of Marcille in urology; and (3) the deep uterine vein in gynecology corresponds to the inferior vesical vein in colorectal surgery.

CONCLUSION

Based on the dynamic illustration of pelvic anatomy from cross-disciplinary discussions, we anticipate advancements in pelvic lymph node dissection aiming for curative and safe outcomes.

Essential anatomy for lateral lymph node dissection

In Western countries, the gold-standard therapeutic strategy for rectal cancer is preoperative chemoradiotherapy (CRT) following total mesorectal excision (TME), without lateral lymph node dissection (LLND). However, preoperative CRT has recently been reported to be insufficient to control lateral lymph node recurrence in cases of enlarged lateral lymph nodes before CRT, and LLND is considered necessary in such cases. We performed a literature review on aspects of pelvic anatomy associated with rectal surgery and LLND, and then combined this information with our experience and knowledge of pelvic anatomy. In this review, drawing upon research using a 3-dimensional anatomical model and actual operative views, we aimed to clarify the essential anatomy for LLND. The LLND procedure was developed in Asian countries and can now be safely performed in terms of functional preservation. Nonetheless, the longer operative time, hemorrhage, and higher complication rates with TME accompanied by LLND than with TME alone indicate that LLND is still a challenging procedure. Laparoscopic or robotic LLND has been shown to be useful and is widely performed; however, without a sufficient understanding of anatomical landmarks, misrecognition of vessels and nerves often occurs. To perform safe and accurate LLND, understanding the landmarks of LLND is essential.

Long-term outcomes of indocyanine green fluorescence imaging-guided laparoscopic lateral pelvic lymph node dissection for clinical stage II/III middle-lower rectal cancer: a propensity score-matched cohort study

BACKGROUND

We previously reported that indocyanine green fluorescence imaging (ICG-FI)-guided laparoscopic lateral pelvic lymph node dissection (LPLND) was able to increase the total number of harvested lateral pelvic lymph nodes without impairing functional preservation. However, the long-term outcomes of ICG-FI-guided laparoscopic LPLND have not been evaluated. The aim of the present study was to compare the long-term outcomes of ICG-FI-guided laparoscopic LPLND to conventional laparoscopic LPLND without ICG-FI.

METHODS

This was a retrospective, multi-institutional study with propensity score matching. The study population included consecutive patients with middle-low rectal cancer (clinical stage II to III) who underwent laparoscopic LPLND between January 2013 and February 2018. The main evaluation items in this study were the 3-year overall survival, relapse-free survival (RFS), local recurrence rate, and lateral local recurrence (LLR) rate.

RESULTS

A total of 172 patients with middle-lower rectal cancer who had undergone laparoscopic LPLND were included in this study. After propensity score matching, 58 patients were matched in each of the ICG-FI and non-ICG-FI groups. There were no substantial differences in the baseline characteristics between the two groups. The ICG-FI group and non-ICG-FI group included 40 and 38 women and had a median age of 65 (IQR 60-72) and 66 (IQR 60-73) years, respectively. The median follow-up for all patients was 63.7 (IQR 51.3-76.8) months. The estimated respective 3-year overall survival, RFS, and local recurrence rates were 93.1%, 70.7%, and 5.2% in the ICG-FI group and 85.9%, 71.7%, and 12.8% in the non-ICG-FI group (p = 0.201, 0.653, 0.391). The 3-year cumulative LLR rate was 0% in the ICG-FI group and 9.3% in the non-ICG-FI group (p = 0.048).

CONCLUSIONS

This study revealed that laparoscopic LPLND combined with ICG-FI was able to decrease the LLR rate. It appears that ICG-FI could contribute to improving the quality of laparoscopic LPLND and strengthening local control of the lateral pelvis.

TRIALS REGISTRATION

This study was registered with the Japanese Clinical Trials Registry as UMIN000041372 ( http://www.umin.ac.jp/ctr/index.htm ).

Initial experience with the transanal approach for lateral pelvic lymph node dissection in rectal cancer

BACKGROUND

The efficacy and safety of transanal lateral pelvic lymph node dissection (TaLPLND) in rectal cancer has not yet been clarified. The aim of the present study was to evaluate the short-term results as an initial experience of TaLPLND.

METHODS

This retrospective study included patients with middle to lower rectal cancer who underwent TaLPLND from July 2018 to July 2021. Our institutions targeted lymph nodes in the internal iliac area and the obturator area for lateral pelvic lymph node dissection (LPLND).

RESULTS

A total of 30 consecutive patients with rectal cancer were included in this analysis. The median age was 60 years (range, 36-83 years), and the male-female ratio was 2:1. The median operative time was 362 min (IQR, 283-661 min), and the median intraoperative blood loss was 74 ml (IQR, 5-500 ml). Intraoperative blood transfusion was required in one case. No cases required conversion to laparotomy. TaLPLND was performed bilaterally in 13 patients (43.3%). Five patients (16.7%) underwent LPLND with combined resection of the internal iliac vessels. The median distance of the distal margin from the anal verge was 20 mm. The pathological radial margin (pRM) was positive in one case, and the negative pRM rate was 96.7%. Short-term postoperative complications (Clavien-Dindo classification grade ≥ II) were observed in nine cases (30.0%). There were no cases of reoperation or mortality. The median number of harvested lateral pelvic lymph nodes was 11 (range, 3-28). On pathological examination, lateral pelvic lymph nodes were positive for metastasis in seven cases (23.3%).

CONCLUSIONS

TaLPLND appeared to be beneficial from an oncological point of view because it was close to the upstream lymphatic drainage from the tumor. The short-term outcomes of this initial experience indicate that this novel approach is feasible.

Reappraisal of the Lymphatic Drainage System of the Distal Rectum: Functional Lymphatic Flow into the Presacral Space and Its Clinical Implication in Rectal Cancer Treatment

Understanding the source and route of pelvic metastasis is essential to developing an optimal strategy for controlling local and systemic diseases of rectal cancer. This study aims to delineate the distribution of lymphatic channels and flow from the distal rectum. In fresh-frozen cadaveric hemipelvis specimens, the ligamentous attachment of the distal rectum to the pelvic floor muscles and the presacral fascia were evaluated. Using indocyanine green (ICG) fluorescence imaging, we simultaneously evaluated the gross anatomy of the lymphatic communication of the distal rectum. We also investigated the lymphatic flow in the pelvic cavity intraoperatively in rectal cancer patients who underwent radical rectal resection with total mesorectal excision (TME). In fresh cadavers, multiple small perforating lymphovascular branches exist in the retrorectal space, posteriorly connecting the mesorectum to the presacral fascia. The lymphatic flow from the distal rectum drains directly into the presacral space through the branches. In patients who underwent TME for rectal cancer, intraoperative ICG fluorescence signals were seen in the pelvic sidewalls and the presacral space. This anatomical study demonstrated that the lymphatic flow from the distal rectum runs directly to the pelvic lateral sidewalls and the presacral space, suggesting a possible route of metastasis in distal rectal cancer.

Near-Infrared Imaging Using Indocyanine Green for Laparoscopic Lateral Pelvic Lymph Node Dissection for Clinical Stage II/III Middle-Lower Rectal Cancer: A Propensity Score-Matched Cohort Study

BACKGROUND

The examination of the efficacy of near-infrared imaging using indocyanine green in laparoscopic lateral pelvic lymph node dissection remains insufficient.

OBJECTIVE

The aim of this study was to examine whether near-infrared imaging contributed to an increase in the total number of harvested lateral pelvic lymph nodes in laparoscopic lateral pelvic lymph node dissection.

DESIGN

This was a retrospective, multi-institutional study with propensity score matching.

SETTINGS

We conducted this study within the framework of the Yokohama Clinical Oncology Group in Japan.

PATIENTS

The study population included consecutive patients with middle-low rectal cancer (clinical stage II to III) who underwent laparoscopic lateral pelvic lymph node dissection between January 2013 and February 2018.

MAIN OUTCOME MEASURES

The total number of harvested lateral pelvic lymph nodes was compared in laparoscopic lateral pelvic lymph node dissection with and without near-infrared imaging.

RESULTS

A total of 172 eligible patients were included; 84 of these patients underwent laparoscopic surgery with near-infrared imaging. After propensity score matching, 58 patients were matched in each of the near-infrared and the non-near-infrared groups. The operation time in the near-infrared group was significantly longer than that in the non-near-infrared group (426 vs 369 min), and the amount of intraoperative blood loss in the near-infrared group was significantly smaller than that in the non-near-infrared group (13 vs 110 mL). The total number of harvested lateral pelvic lymph nodes in the near-infrared group was significantly higher than that in the non-near-infrared group (14 vs 9). There were no significant differences in the postoperative complication rates of the 2 groups.

LIMITATIONS

The limitations of the present study include its retrospective design.

CONCLUSIONS

This study revealed that laparoscopic lateral pelvic lymph node dissection combined with near-infrared imaging could increase the total number of harvested lateral pelvic lymph nodes without impairing functional preservation. See Video Abstract at http://links.lww.com/DCR/B800.This study was registered with the Japanese Clinical Trials Registry as UMIN000041372 (http://www.umin.ac.jp/ctr/index.htm).IMÁGENES CASI-INFRARROJAS UTILIZANDO VERDE DE INDOCIANINA EN LA DISECCIÓN LAPAROSCÓPICA DE GANGLIOS LINFÁTICOS PÉLVICOS LATERALES EN CASOS DE CÁNCER DE RECTO MEDIO-INFERIOR DE ESTADIO CLÍNICO II / III: ESTUDIO DE COHORTES CON PUNTUACIÓN DE PROPENSIÓNANTECEDENTES:El examen de la eficacia de las imágenes casi-infrarrojas utilizando le verde de indocianina en la disección laparoscópica de los ganglios linfáticos pélvicos laterales sigue siendo insuficiente.OBJETIVO:El objetivo de este estudio fue examinar si las imágenes casi-infrarrojas contribuyeron a un aumento en el número total de ganglios linfáticos pélvicos laterales recolectados durante su disección laparoscópica.DISEÑO:Estudio retrospectivo, multi-institucional con emparejamiento por puntuación de propensión.AJUSTES:Estudio realizado dentro el marco establecido por el Grupo de Oncología Clínica de Yokohama, Japón.PACIENTES:La población estudiada incluyó pacientes consecutivos con cáncer de recto medio-bajo (estadio clínico II a III) que se sometieron a una disección laparoscópica de los ganglios linfáticos pélvicos laterales entre enero de 2013 y febrero de 2018.PRINCIPALES RESULTADOS MEDIDAS:El número total de ganglios linfáticos pélvicos laterales extraídos se comparó en la disección laparoscópica de ganglios linfáticos pélvicos laterales con y sin imágenes casi-infrarrojas.RESULTADOS:Se incluyeron un total de 172 pacientes elegibles; 84 de estos pacientes se sometieron a cirugía laparoscópica con imágenes casi-infrarrojas. Después del emparejamiento por puntuación de propensión, 58 pacientes fueron emparejados en cada uno de los grupos de luz casi-infrarroja y los sin luz. El tiempo de operación en el grupo de luz casi-infrarroja fue significativamente más largo que en el grupo sin luz (426 frente a 369 min), y la cantidad de pérdida de sangre intraoperatoria en el grupo de luz casi-infrarroja fue significativamente menor que en el grupo sin luz (13 frente a 110 ml). El número total de ganglios linfáticos pélvicos laterales recolectados en el grupo de luz casi-infrarroja fue significativamente mayor que en el grupo sin luz (14 frente a 9). No hubo diferencias significativas en las tasas de complicaciones posoperatorias de los dos grupos.LIMITACIONES:Las limitaciones del presente estudio incluyen su diseño retrospectivo.CONCLUSIONES:Este estudio reveló que la disección laparoscópica de los ganglios linfáticos pélvicos laterales combinada con imágenes casi-infrarrojas podría aumentar el número total de ganglios linfáticos pélvicos laterales recolectados sin afectar la preservación funcional. Consulte Video Resumen en http://links.lww.com/DCR/B800. (Traducción-Dr. Xavier Delgadillo)Este estudio se registró en el Registro de Ensayos Clínicos de Japón como UMIN000041372 (http://www.umin.ac.jp/ctr/index.htm).

Pictorial essay on MRI local staging of rectal carcinoma: An easy approach

Rectal cancer is common and accounts for more than one-third of colorectal tumors. It is associated with significant morbidity and mortality. Previously computed tomography scan is the key imaging modality in preoperative assessment to detect local invasion and distant metastasis. However, the advent of magnetic resonance imaging (MRI) has aided in local staging and prognosticates the outcome of rectal tumor. Here, the author briefly explains why rectal MRI has a comprehensive role and provides a simple and easy way in reporting an MRI rectal carcinoma, even for a non-radiologist.

Improvement in Surgical Outcomes Using 3-Dimensional Printed Models for Lateral Pelvic Lymph Node Dissection in Rectal Cancer

BACKGROUND

Lateral pelvic lymph node dissection for rectal cancer is challenging due to the complexity of the pelvic wall anatomy, and incomplete lateral pelvic lymph node dissection may result in local recurrence in the lateral pelvis. Although 3-dimensional printed organ models are useful for understanding spatial anatomy, it is currently unclear whether they improve surgical outcomes.

OBJECTIVE

We aimed to assess whether the surgical effectiveness of lateral pelvic lymph node dissection is increased by the use of individualized 3-dimensional printed pelvic models.

DESIGN

This was a retrospective study using a propensity matching analysis.

SETTINGS

This study was conducted at a university hospital in Japan.

PATIENTS

In total, 115 patients comprising 184 pelvic sides (right, 85 sides; left, 99 sides) who underwent lateral pelvic lymph node dissection for colorectal adenocarcinoma between January 2012 and December 2019 were enrolled.

INTERVENTIONS

We compared surgical outcomes using 3-dimensional printed pelvic models with control outcomes.

MAIN OUTCOME MEASURES

The primary outcome was the number of harvested lateral pelvic lymph nodes on 1 pelvic side after the propensity matching analysis.

RESULTS

After matching, 35 pelvic sides each were allocated to the 3-dimensional model and control groups, and no significant differences were observed in patient characteristics between the 2 groups. The number of harvested lateral pelvic lymph nodes was significantly higher in the 3-dimensional model group (median, 9; range, 3-16) than in the control group (median, 6; range, 0-22; p = 0.047).

LIMITATIONS

This was a retrospective study using propensity score matching. However, historical backgrounds were not matched, and the majority of lateral pelvic lymph node dissection procedures in the 3-dimensional model group were recently performed. This limitation may have influenced surgical outcomes.

CONCLUSION

The present study demonstrated that, by referring to individualized 3-dimensional printed pelvic models, colorectal surgeons harvested a larger number of lateral pelvic lymph nodes during lateral pelvic lymph node dissection. This result suggests that 3-dimensional printed models help surgeons to complete more detailed procedures. See Video Abstract at http://links.lww.com/DCR/B776.

MEJORA DE LOS RESULTADOS QUIRRGICOS MEDIANTE EL USO DE MODELOS IMPRESOS EN D PARA LA DISECCIN LATERAL DE LOS GANGLIOS LINFTICOS PLVICOS EN EL CNCER DE RECTO

ANTECEDENTES:La disección lateral de los ganglios linfáticos de la pelvis en el cáncer de recto es un desafío debido a la complejidad de la anatomía de la pared pélvica; la disección incompleta de las mismas puede resultar en una recidiva local en dicha zona. Aunque la impresión tridimensional de modelos de órganos es útil para comprender la estructura anatómica espacial, actualmente no está claro si mejoran los resultados quirúrgicos.OBJETIVO:Nuestro objetivo fue evaluar si la efectividad quirúrgica de la disección de los ganglios linfáticos laterales de la pelvis aumenta mediante el uso individualizado de modelos pélvicos impresos en 3D.DISEÑO:Este fue un estudio retrospectivo que utilizó un análisis de coincidencia de propensión.AJUSTE:Este estudio se realizó en un hospital universitario de Japón.PACIENTES:En total, se enrolaron 115 pacientes que comprendían 184 lados pélvicos (85 de lado derecho; 99 de lado izquierdo) que fueron sometidas a disección lateral de ganglios linfáticos de la pelvis por adenocarcinoma colorrectal entre enero de 2012 y diciembre de 2019.INTERVENCIONES:Comparamos los resultados quirúrgicos mediante modelos pélvicos tridimensionales impresos con los resultados de control.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue el número de ganglios linfáticos laterales pélvicos extraídos en un lado pélvico después del análisis de coincidencia de propensión.RESULTADOS:Después del emparejamiento, se asignaron 35 lados pélvicos cada uno, tanto al modelo tridimensional como al grupo de control; no se observaron diferencias significativas con respecto a las características de los pacientes entre los dos grupos. El número de ganglios linfáticos pélvicos laterales extraídos fue significativamente mayor en el grupo del modelo tridimensional (mediana, 9; rango 3-16) que en el grupo de control (mediana, 6; rango, 0-22) (p = 0.047).LIMITACIONES:Este fue un estudio retrospectivo que utilizó el emparejamiento por puntuación de propensión. Sin embargo, antecedentes históricos no fueron encontrados y la mayoría de los procedimientos de disección de los ganglios linfáticos laterales pélvicos en el grupo del modelo tridimensional se realizaron recientemente. Esta limitación pudo haber influido en los resultados quirúrgicos.CONCLUSIONES:El presente estudio demostró que al referirse a modelos pélvicos individualizados impresos en 3D, los cirujanos colorrectales recolectaron un mayor número de ganglios linfáticos laterales de la pelvis durante la disección lateral. Este resultado sugiere que los modelos tridimensionales impresos ayudan a los cirujanos a completar procedimientos más detallados. Consulte Video Resumen en http://links.lww.com/DCR/B776.

Prognostic Impact of Lateral Pelvic Node Dissection on the Survival of Patients in Low Rectal Cancer Subgroups Based on Lymph Node Size

BACKGROUND

Lateral pelvic node (LPN) dissection (LPND) is considered a promising technique for treating low rectal cancer; however, there is insufficient evidence of its prognostic value. Using centrally reviewed preoperative pelvic magnetic resonance (MR) images, this study aimed to find the patient population who has benefited from LPND.

PATIENTS AND METHODS

MR images of patients from 69 institutes with stage II-III low rectal cancer were reviewed by experienced radiologists. Recurrence-free survival (RFS), overall survival (OS), and short-term outcomes were measured.

RESULTS

In total, 731 preoperative MR images were reviewed (excluding patients with short-axis LPN ≥ 10 mm). Of these, 322 underwent total mesorectum excision (TME) without LPND (non-LPND group), and 409 underwent TME with LPND (LPND group). Preoperative treatment was performed for 40% and 25% of patients in the non-LPND and LPND groups, respectively. The incidence of postoperative complications was higher in the LPND group (44.5%) than in the non-LPND group (33.2%; P = 0.002). Among patients with LPNs < 5 mm, OS and RFS curves were not significantly different between the groups. Among patients with LPNs ≥ 5 mm, the LPND group had significantly higher 5-year OS and RFS than the non-LPND group (OS: 81.9% versus 67.3%; RFS: 69.4% versus 51.6%). On multivariate analysis of LPN ≥ 5 mm cases, LPND was independently associated with RFS.

CONCLUSIONS

Despite the high incidence of postoperative complications, this study showed the prognostic impact of LPND on low rectal cancer patients with LPNs (≥ 5 mm, < 10 mm short axis) measured by experienced radiologists. Trial registration UMIN-ID: UMIN000013919.

Therapeutic significance of D3 dissection for low rectal cancer: a comparison of dissections between the lateral pelvic lymph nodes and the lymph nodes along the root of the inferior mesenteric artery in a multicenter retrospective cohort study

PURPOSE

D3 dissection is the standard treatment modality for locally advanced low rectal cancer in Japan. The benefit of lateral pelvic lymph node (LPLN) dissection (LPLND) and lymph nodes along the root of inferior mesenteric artery (253 LN) dissection (253 LND) for low rectal cancer has often been studied separately, and few studies have investigated their benefit in the same cohort. This study aimed to clarify the therapeutic significance of dissection of the LPLN in comparison to that of dissection of the 253 LN for low rectal cancer.

METHODS

We retrospectively evaluated 3508 patients with treatment-naïve stage I-III low rectal cancer who underwent mesorectal excision between 1997 and 2012. They were identified from the Japanese Study Group for Postoperative Follow-Up of Colorectal Cancer database. The rates of metastasis, survival, and therapeutic value index (5-year overall survival (OS) rate multiplied by metastatic rate for lymph node metastasis) were compared between LPLN and 253 LN.

RESULTS

The rates of LPLN metastasis and 253 LN metastasis were 17.9% and 1.5%, respectively. The 5-year OS was significantly different between patients with and without LPLN metastasis (55.0% vs 85.5%, P < 0.0001) and between patients with and without 253 LN metastasis (36.2% vs 83.3%, P < 0.0001). The therapeutic value indexes of LPLN and 253 LN were 9.85 and 0.54, respectively.

CONCLUSIONS

LPLND may have more therapeutic value than 253 LND for patients with treatment-naïve low rectal cancer, although both the patients with LPLN metastasis and those with 253 LN metastasis remained to have poor prognosis.

Oncological outcomes of lateral lymph node dissection (LLND) for locally advanced rectal cancer: is LLND alone sufficient?

BACKGROUND

Lateral lymph node dissection (LLND) has been considered as the standard treatment strategy for locally advanced lower rectal cancer in Japan. Controversy remains around whether all patients require LLND. This study aims to examine the long-term outcomes of patients in which LLND was performed and clarify the value of LLND.

METHOD

Consecutive 458 patients with lower rectal cancer who underwent total mesorectal excision (TME) plus LLND from 1992 to 2012 were included. The long-term outcomes and risk factors for recurrent in patients performed TME + LLND were examined. We assessed the impact of LLND on survival using an estimated therapeutic index.

RESULTS

The incidence of LLNM was 15.5%. The 5-year RFS and OS rates of patients with LLNM were 40.9% and 47.7%, while patients without LLNM had a good prognosis. The 5-year local recurrence (LR) rate was 9.2%, and independent risk factors for LR were T4 and LLNM. The LR rate of patients with LLNM was high (22.8%). The LLNM rate of the groups with 0, 1, 2, 3, or 4 risk factors (male, tumor location < 4 cm from anal verge, T4, and MLNM) was 3.8%, 9.2%, 18.1%, and 50.0%. The 5-year OS of the groups was 96.2%, 86.1%, 69.7%, and 48.5%.

CONCLUSION

Although patients with locally advanced lower rectal cancer who received LLND had a good prognosis, LLND alone was insufficient to control local recurrence in patients with metastatic lateral nodes.

Lateral lymph node dissection for mid-to-low rectal cancer: is it safe and effective in a practice-based cohort?

BACKGROUND

Most evidence regarding lateral lymph node dissection for rectal cancer is from expert settings. This study aimed to evaluate the safety and efficacy of this procedure in a practice-based cohort.

METHODS

A total of 383 patients who were diagnosed with stage II-III mid-to-low rectal cancer between 2010 and 2019 and underwent primary resection with curative intent at a general surgery unit were retrospectively reviewed. After propensity matching, 144 patients were divided into the following groups for short- and long-term outcome evaluation: mesorectal excision with lateral lymph node dissection (n = 72) and mesorectal excision (n = 72).

RESULTS

This practice-based cohort was characterized by a high pT4 (41.6%) and R1 resection (10.4%) rate. Although the operative time was longer in the lateral dissection group (349 min vs. 237 min, p < 0.001), postoperative complications (19.4% vs. 16.7%, p = 0.829), and hospital stay (18 days vs. 22 days, p = 0.059) did not significantly differ; 5-year relapse-free survival (62.5% vs. 66.4%, p = 0.378), and cumulative local recurrence (9.7% vs. 15.3%, p = 0.451) were also in the same range in both groups. In the seven locally recurrent cases in the lateral dissection group, four had undergone R1 resection.

CONCLUSIONS

Lateral lymph node dissection was found to be safe in this practice-based cohort; however, the local control effect was not obvious. To maximize the potential merits of lateral lymph node dissection, strategies need to be urgently established to avoid R1 resection in clinical practice.

Rise and fall of total mesorectal excision with lateral pelvic lymphadenectomy for rectal cancer: an updated systematic review and meta-analysis of 11,366 patients

The role of lateral lymph node dissection (LLND) during total mesorectal excision (TME) for rectal cancer is still controversial. Many reviews were published on prophylactic LLND in rectal cancer surgery, some biased by heterogeneity of overall associated treatments. The aim of this systematic review and meta-analysis is to perform a timeline analysis of different treatments associated to prophylactic LLND vs no-LLND during TME for rectal cancer.

METHODS

A literature search was performed in PubMed, SCOPUS and WOS for publications up to 1 September 2020. We considered RCTs and CCTs comparing oncologic and functional outcomes of TME with or without LLND in patients with rectal cancer.

RESULTS

Thirty-four included articles and 29 studies enrolled 11,606 patients. No difference in 5-year local recurrence (in every subgroup analysis including preoperative neoadjuvant chemoradiotherapy), 5-year distant and overall recurrence, 5-year overall survival and 5-year disease-free survival was found between LLND group and non LLND group. The analysis of post-operative functional outcomes reported hindered quality of life (urinary, evacuatory and sexual dysfunction) in LLND patients when compared to non LLND.

CONCLUSION

Our publication does not demonstrate that TME with LLND has any oncological advantage when compared to TME alone, showing that with the advent of neoadjuvant therapy, the advantage of LLND is lost. In this review, the most important bias is the heterogeneous characteristics of patients, cancer staging, different neoadjuvant therapy, different radiotherapy techniques and fractionation used in different studies. Higher rate of functional post-operative complications does not support routinely use of LLND.

Prognostic impact of the number of lateral pelvic lymph node metastases on rectal cancer

BACKGROUND

This study aimed to clarify the number of lateral pelvic lymph node metastases of colorectal cancer for which prognosis could be improved by dissection.

METHODS

We analysed the data of 30 patients with lateral pelvic lymph node metastases of rectal cancer that underwent a total mesorectal excision with lateral pelvic lymph node dissection at our institute from 1986 to 2016. We performed survival analysis on the number of lateral pelvic lymph node metastases in each of these patients and identified an optimal cut-off point of the number of lateral pelvic lymph node metastases that would predict recurrence-free survival using the receiver operating characteristic curves and an Akaike information criterion value.

RESULTS

The 5-year recurrence-free survival and overall survival of patients with one or two lateral pelvic lymph node metastases were significantly better than that of those with three or more (5-year recurrence-free survival, 63.3 vs. 0.0%, respectively; hazard ratio, 0.23; 95% CI, 0.07-0.72; P = 0.0124) (5-year overall survival, 68.2 vs. 15.6%, respectively; hazard ratio, 0.29; 95% CI, 0.09-0.92; P = 0.0300). All of the metastatic lateral pelvic lymph nodes in the group with one or two lateral pelvic lymph node metastases were restricted to the internal iliac artery or obturator nerve regions.

CONCLUSIONS

The cut-off number of lateral pelvic lymph node metastases in the internal iliac artery or obturator nerve regions of colorectal cancer cases in whom prognosis was improved by lateral pelvic lymph node dissection was 2; patients who had <3 lateral pelvic lymph node metastases had better prognoses than those with ≥3 lateral pelvic lymph node metastases.

What is the impact of systemic chemotherapy for lateral lymph nodes in patients with locally advanced low rectal cancer?

PURPOSE

Systemic chemotherapy (SC) before surgery is a potential treatment to improve survival in patients with advanced rectal cancer. However, the impact of SC on lateral lymph nodes (LLNs) remains unclear.

METHODS

A total of 78 patients with stage II/III low rectal cancer, who received 3-month oxaliplatin-based SC followed by LLN dissection (LLND) in principle, were analysed retrospectively. "Total lateral lymph node metastases (tLLNMs)" was defined as having either pathological LLNMs (pLLNMs) or lateral local recurrences (LLRs). Patients with the maximum short-axis size of LLNs ≥ 7 mm were classified into the swollen group (n = 21).

RESULTS

In the total cohort, tLLNMs included 6 pLLNMs (7.7%) and 2 LLRs (2.6%). In the non-swollen group, no patients had pLLNMs, but one had LLR (1.8%). In the swollen group, pLLNMs and LLRs were detected in 6 (28.6%) and 1 (4.8%), respectively. The swollen group was an independent risk factor for tLLNMs (P < 0.001), leading to the significantly worse 5-year relapse-free survival (RFS) of 52.4% than the others.

CONCLUSION

For patients without swollen LLNs, SC could allow for omission both of lateral irradiation and LLND. For patients with swollen LLNs, the lateral local control was favourable after SC and LLND without chemoradiotherapy (CRT); however, oxaliplatin-based SC might be insufficient to improve survival, requiring more intensive chemotherapy. CRT should be indicated according to the other risk factors of central local recurrence, although the swollen LLNs should be removed.

Lateral pelvic lymph node dissection in the management of locally advanced low rectal cancer: Summary of the current evidence

Lateral pelvic lymph nodes (LPLN) are a major site for local recurrence following curative resection for low locally advanced rectal cancer. Ongoing advances in imaging techniques have improved predicting LPLN metastasis (LPLNM) during pre-operative staging. However, there is ongoing debate on optimal management of this subgroup of patients with variation between guidance of different societies. In Japan, LPLNM is considered as local disease and addressed by lateral pelvic node dissection (LPLND) in addition to total mesorectal excision (TME). However, in the west, LPLNM is considered as metastatic disease and those patients are offered neoadjuvant chemoradiotherapy (nCRT) followed by TME surgery. The potential surgical risks and morbidity associated with LPLND as well as the uncertainty of the oncological outcome have raised the concern that patients with locally advanced low rectal cancer with LPLNM could be over or under-treated. A comprehensive review of literature was performed, summarizing the current evidence on available modalities for predicting LPLNM, the role of LPLND in the management of advanced low rectal cancer and the available surgical approaches with their impact on surgical and oncological outcomes. LPLND is associated with increased operative time, blood loss and post-operative morbidity. The potential benefits for local disease control and survival still awaits high quality studies. There has been increasing number of reports of the use minimally invasive approaches in LPLND in an attempt to reduce post-operative complications. There is need for high quality evidence to define the role of LPLND in management of patients with advanced low rectal cancer.

Japanese Evidences on Nerve-Preserving Lateral Pelvic Lymh Node Dissection for Rectal Cancer: Major Historical Milestones and Clinical Impact: The Past, Present and Future

In Japan, the standard treatment for advanced low rectal cancer has been total mesorectal excision (TME) + lateral pelvic lymph node dissection (LLND). On the other hand, in the West, preoperative chemoradiotherapy (CRT) + TME has been established as the standard. Japanese surgeons developed nerve-preserving LLND that could reduce complications associated with extended dissection. The Japan Clinical Oncology Group (JCOG)0212 trialinvestigated on the outcomes of so-called prophylactic LLND in patients without evident lateral lymph node metastasis in preoperative diagnostic imaging. Data from the JCOG0212 trial demonstrated scientific validity of the theory and practice of the Japanese approach. Data from the JCOG0212 trial supported the validity and safety of the Japanese approach, that is, TME + LLND for low rectal cancer without routine use of preoperative CRT. For future direction, modern approach for rectal cancer should involve both of the Eastern and Western strategies by combining LLND and CRT.

Short- and long-term outcomes of laparoscopic versus open lateral lymph node dissection for locally advanced middle/lower rectal cancer using a propensity score-matched analysis

BACKGROUND

There are few reports on large-scale trials for the long-term outcomes regarding laparoscopic lateral lymph node dissection (LLND). We evaluated the short- and long-term outcomes of laparoscopic versus open LLND for locally advanced middle/lower rectal cancer using a propensity score-matched analysis.

METHODS

From January 2005 to December 2016, consecutive clinical stage II to III middle/lower rectal cancer patients who underwent total mesorectal excision (TME) plus LLND were retrospectively collected at three institutions. Laparoscopic LLND was compared with open LLND for the surgical and oncological outcomes, including the long-term survival, using a propensity score-matched analysis.

RESULTS

A total of 325 patients were collected. There were 142 patients who underwent open TME plus LLND (open group) and 183 patients who underwent laparoscopic TME plus LLND (laparoscopic group). A total of 93 patients each were matched to each group. Compared to the open group, the laparoscopic group had a significantly longer operative time (327 vs. 377 min; p = 0.002) but significantly less blood loss (540 vs. 50 ml; p < 0.001), fewer Clavian-Dindo grade ≥ 2 postoperative complications (49.5% vs. 34.4%; p = 0.037) and shorter postoperative hospital stay (18 vs. 14 days; p = 0.008). Furthermore, the rate of urinary retention was significantly lower in the laparoscopic group than in the open group (16.1% vs. 6.5%; p = 0.037). The estimated 3-year overall survival, relapse-free survival, and cumulative incidence of local recurrence were 91.4%, 73.1%, and 3.4% in the open group and 90.3%, 74.2%, and 4.3% in the laparoscopic group (p = 0.879, 0.893, 0.999), respectively.

CONCLUSIONS

This study showed that laparoscopic LLND had advantages over an open approach, such as less blood loss, fewer postoperative complications, and a shorter postoperative hospital stay, and the oncologic outcomes were similar to the open approach. Laparoscopic LLND could be a viable standard approach to LLND for advanced middle/lower rectal cancer surgery.

The efficacy and safety of lateral lymph node dissection for patients with rectal cancer: A systematic review and meta-analysis

Lateral lymph node metastasis in rectal cancer was first reported in the 1950s, since then, there has been an on-going debate about the value of lateral lymph node dissection (LLND) in the management of rectal cancer. We carried out a systematic review and meta-analysis to evaluate the value of LLND for the patients with rectal cancer. To collect clinical studies for the comparison of LLND and non-LLND in patients with rectal cancer, PubMed, Embase, Cochrane Library, Web of Science, and Google Scholar databases were searched from inception to 2019.A total of 26 studies, including 6865 patients were enrolled. Data processing and statistical analyses were performed using Stata V.15.0 software and Review Manager 5.3 software. Outcome measures included the 5-year survival rate, recurrence rate, perioperative outcomes, urinary function, and male sexual function. Regarding efficacy, our meta-analysis results showed no difference in 5-year disease-free survival rate and local recurrences between the two groups, the Hazard Ratio (HR) and 95% confidence interval (CI) was1.07 and 0.89 to 1.28 (P = 0.496),and the Odds Ratio(OR) and 95% CI were 0.90 and 0.76 to 1.06 (P = 0.208), respectively. Concerning safety, the incidence of urinary dysfunction and male sexual dysfunction was significantly increased in the LLND group (OR = 2.14, 95%CI = 1.21-3.79, P = 0.009), and (OR = 4.19, 95%CI = 1.55-11.33, P = 0.005), respectively. In conclusion, LLND did not improve the long-term prognosis of patients with rectal cancer, and was associated with increased urinary dysfunction and male sexual dysfunction.

Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines 2019 for the treatment of colorectal cancer

The number of deaths from colorectal cancer in Japan continues to increase. Colorectal cancer deaths exceeded 50,000 in 2016. In the 2019 edition, revision of all aspects of treatments was performed, with corrections and additions made based on knowledge acquired since the 2016 version (drug therapy) and the 2014 version (other treatments). The Japanese Society for Cancer of the Colon and Rectum guidelines 2019 for the treatment of colorectal cancer (JSCCR guidelines 2019) have been prepared to show standard treatment strategies for colorectal cancer, to eliminate disparities among institutions in terms of treatment, to eliminate unnecessary treatment and insufficient treatment and to deepen mutual understanding between healthcare professionals and patients by making these guidelines available to the general public. These guidelines have been prepared by consensuses reached by the JSCCR Guideline Committee, based on a careful review of the evidence retrieved by literature searches and in view of the medical health insurance system and actual clinical practice settings in Japan. Therefore, these guidelines can be used as a tool for treating colorectal cancer in actual clinical practice settings. More specifically, they can be used as a guide to obtaining informed consent from patients and choosing the method of treatment for each patient. Controversial issues were selected as clinical questions, and recommendations were made. Each recommendation is accompanied by a classification of the evidence and a classification of recommendation categories based on the consensus reached by the Guideline Committee members. Here, we present the English version of the JSCCR guidelines 2019.

Diagnostic and management strategies for lateral pelvic lymph nodes in low rectal cancer-a review of the evidence

Patients with low rectal cancer who have enlarged lateral pelvic lymph nodes are known to have a worse prognosis. There is however uncertainty over what constitutes a lateral pelvic lymph node of clinical significance. As the main modality for the detection of such lymph nodes is magnetic resonance imaging (MRI), characteristics of these lateral lymph nodes identified may have prognostic value and assist with guiding treatment. Options to manage such lateral lymph nodes includes neoadjuvant chemoradiotherapy as well as lateral lymph node dissection. Surgery is extensive and may lead to significant morbidity to the patient. This review article evaluates diagnostic and management strategies in patients with lateral pelvic lymph nodes in low rectal cancer.

Optimal treatment strategy for rectal cancer based on the risk factors for recurrence patterns

BACKGROUND

For rectal cancer, multimodality therapeutic approach is necessary to prevent local recurrence and distant metastasis. However, the efficacy of additional treatments, such as neoadjuvant chemoradiotherapy (nCRT), neoadjuvant chemotherapy (NAC), and lateral pelvic lymph node dissection (LPLND), has not been scrutinized.

METHODS

Recurrence patterns were categorized into local recurrence and distant metastasis. Local recurrence was classified into two types: (1) pelvic cavity recurrence and (2) LPLN recurrence. First, we analyzed the risk factors for each recurrence pattern. Second, based on the status of clinically suspected involvement of circumferential resection margin (cCRM), the efficacy of additional treatments was investigated.

RESULTS

A total of 240 patients was enrolled. nCRT was performed for 25 (10%), NAC was for 46 (19%), and LPLND was for 35 patients (15%). As the recurrence patterns, pelvic cavity recurrence occurred in 15 (6%), LPLN recurrence in 8 (3%), and distant metastasis in 42 patients (18%). Five-year overall survival and relapse-free survival were 87% and 70%, respectively. Multivariate analysis indicated that pelvic cavity recurrence was associated with cCRM status and tumor histology, that LPLN recurrence was with serum carcinoembryonic antigen level and LPLN swelling, and that distant metastasis was with clinical N category. In the cCRM-positive subgroup (n = 66), cumulative rate of pelvic cavity recurrence was lower in the nCRT group than in the NAC or non-NAC/nCRT group (P = 0.02 and 0.09, respectively).

CONCLUSION

cCRM status was associated with pelvic cavity recurrence, and LPLN swelling was with LPLN recurrence. nCRT could reduce pelvic cavity recurrence in cCRM-positive subgroup.

Feasibility of Extended Dissection of Lateral Pelvic Lymph Nodes During Laparoscopic Total Mesorectal Excision in Patients with Locally Advanced Lower Rectal Cancer: A Single-Center Pilot Study After Neoadjuvant Chemotherapy

BACKGROUND The feasibility of additional dissection of the lateral pelvic lymph nodes (LPLNs) in patients undergoing total mesorectal excision (TME) combined with neoadjuvant chemotherapy (NAC) for locally advanced rectal cancer (LARC) is controversial. The use of laparoscopic surgery is also debated. In the present study, we evaluated the utility of laparoscopic dissection of LPLNs during TME for patients with LARC and metastatic LPLNs after NAC, based on our experience with 19 cases. MATERIAL AND METHODS Twenty-five patients with LARC with swollen LPLNs who underwent laparoscopic TME and LPLN dissection were enrolled in this pilot study. The patients were divided into 2 groups: those patients with NAC (n=19) and without NAC (n=6). Our NAC regimen involved 4 to 6 courses of FOLFOX plus panitumumab, cetuximab, or bevacizumab. RESULTS The operative duration was significantly longer in the NAC group than in the non-NAC group (648 vs. 558 minutes, respectively; P=0.022). The rate of major complications, defined as grade ≥3 according to the Clavien-Dindo classification, was similar between the 2 groups (15.8% vs. 33.3%, respectively; P=0.4016). No conversion to conventional laparotomy occurred in either group. In the NAC group, a histopathological complete response was obtained in 2 patients (10.5%), and a nearly complete response (Tis N0 M0) was observed in one patient (5.3%). Although the operation time was prolonged in the NAC group, the other perioperative factors showed no differences between the 2 groups. CONCLUSIONS Laparoscopic LPLN dissection is feasible in patients with LARC and clinically swollen LPLNs, even after NAC.

The Feasibility and Efficacy of Laparoscopic Extended Total Mesorectal Excision for Locally Advanced Lower Rectal Cancer

BACKGROUND/AIM

Extended total mesorectal excision (ETME) is defined as en bloc resection of the adjacent organs outside the mesorectal fascia, that is indicated in cases with locally advanced lower rectal cancer (T4 tumor). The aim of this study was to evaluate the clinical and oncological outcomes of laparoscopic ETME (L-ETME) for locally advanced lower rectal cancer.

PATIENTS AND METHODS

The present study analyzed clinical outcomes and oncological outcomes of 11 consecutive patients who underwent L-ETME for cT4 lower rectal cancer in Nagasaki Medical Center between 2012 and 2015.

RESULTS

Of the 11 patients, 7 underwent neoadjuvant therapy, and 7 underwent pelvic node dissection. One case (7.1%) underwent resection of anterior organs (prostate), 6 cases (54.5%) had resection of the lateral organs (neurovascular bundle, hypogastric nerve, pelvic plexus, ovary, and internal iliac blood vessels) and 4 cases (36.4%) had resection of both anterior and lateral organs. In all cases enrolled in this study, R0 resection was achieved. The median operation time and intraoperative blood loss were 416 min and 350 ml, respectively. The postoperative complication rate was 18.2% (2/11). The 3-year overall survival rate was 79.5%, and the 3-year local recurrence-free survival rate was 87.5%. There was no mortality and no re-operation in this series.

CONCLUSION

The results of the present study suggest that L-ETME is feasible and has efficacy for locally advanced lower rectal cancer.

Outcomes and prognostic factors of selective lateral pelvic lymph node dissection with preoperative chemoradiotherapy for locally advanced rectal cancer

PURPOSE

The clinical significance of preoperative chemoradiotherapy (CRT) and lateral lymph node dissection (LLND) for locally advanced rectal cancer remains unclear. We have employed total mesorectal excision and selective LLND following preoperative CRT for patients with locally advanced rectal cancer. The validity of our strategy was evaluated.

METHODS

A total of 45 patients with locally advanced rectal cancer who underwent curative surgery after CRT from November 2005 to September 2016 were retrospectively analyzed. LLND was performed only for the patients with lateral lymph nodes suspected to have metastasis based on the pretreatment images.

RESULTS

Rates of 5-year overall survival (OS) and 5-year relapse-free survival (RFS) were 85.7 and 61.8%, respectively. Univariate and multivariate analyses detected only histological response (grades 2 and 3 vs. grade 1) as a significant prognostic factor for OS and local recurrence. ypN and ypStage were significant factors for RFS by univariate analysis, while no significant factor was detected by multivariate analysis. There was no significant factor for distant recurrence. In good responders (grades 2 and 3), the local recurrence rate was 0% (P = 0.006, vs. grade 1), while distant recurrence developed in 4 of 20 cases (20%, P = 0.615, vs. grade 1). There was no local recurrence in LLND (-) group regardless the histological response.

CONCLUSIONS

Although selective LLND with preoperative CRT seems effective and valid for good responders, new treatment strategy is necessary for poor responders. Therefore, development of reliable biomarkers for histological response to CRT is an urgent need.

Incidence and Predictive Model for Lateral Pelvic Lymph Node Metastasis in Lower Rectal Cancer

The lateral pelvic lymph node recurrence after curative resection in rectal cancer has been reported in more than 20% of cases and the lateral pelvic lymph node (LPLN) metastasis is an independent risk factor for local recurrence. A prospective cohort study with diagnosis of lower rectal cancer stages II and III performed to identify the factors with significant correlation with LPLN metastasis was categorised based on the number of positive factors and proposed a risk stratification model to uncover a possible benefit of LPLD in specific patient subgroups. Forty-three patients with lower rectal cancer underwent curative surgery, total mesorectal excision with bilateral lateral pelvic lymph node dissection. Pre-operative, female gender, raised serum CEA (> 5 ng/mL), cT4, enlarged mesorectal lymph nodes, borderline enlarged LPLN on MRI, lower location (< 5 cm from anal verge), large size (> 5 cm) and non-circumferential lesion were significant predictors for LPLN metastasis. Histopathological, higher tumour grade, higher pT and pN stage, and the presence of LVI were significant factors. On cox-proportional hazard model analysis, female gender, large tumour, cT4, enlarged mesorectal lymph nodes, borderline enlarged LPLN, pN1 and positive LVI were associated with significant hazard. In conclusion, a specific group of patients with lower rectal cancer of stages II and III might be have treated with LPND in spite of concurrent chemo-radiation to achieve satisfactory oncological outcome. The proposed stratification grouping is strongly guiding the patient for lateral pelvic lymph node dissection. Further study to prove the oncological advantage of LPND is warranted at large scale.

Colorectal Cancer: What has Changed in Diagnosis and Treatment over the Last 50 Years?

Aims and background

This overview focuses on what has changed in the diagnosis and treatment of colorectal cancer over the last 50 years.

Methods

The most important international registers (SEER, European and Italian) as well as the literature have been consulted. Furthermore, many prognostic factors are analyzed with the aim to understand the reasons why 5-year survival has improved over the last two decades.

Results

Since the biologic characteristics of the tumor cannot be changed, improved survival must be supported by concomitant multiple factors, such as earlier diagnosis (as given by a more informed educational behavior and the advent of screening) as well as the wide use of colonoscopy and the technical improvement of surgical and medical treatment. However, it seems that the greatest improvement in survival is limited to 5-year controls, whereas long-term survival does not appear to show any significant improvement.

Conclusions

We can hypothesize that our efforts have just delayed the inevitable end: death. Nevertheless, further research should be done to confirm this hypothesis, perhaps in the field of molecular biology, which may also be the right approach to understanding the biologic aggressiveness of each tumor.

Robotic surgery for rectal cancer

Laparoscopic surgery has gained acceptance as a less invasive approach in the treatment of colon cancer. However, laparoscopic surgery for rectal cancer, particularly cancer of the lower rectum, is still challenging because of limited accessibility. Robotic surgery overcomes the limitations of laparoscopy associated with anatomy and offers certain advantages, including 3-D imaging, dexterity and ambidextrous capability, lack of tremors, motion scaling, and a short learning curve. Robotic rectal surgery has been reported to reduce conversion rates, particularly in low anterior resection, but it is associated with longer operative times than the conventional laparoscopic approach. Postoperative morbidities are similar between the robotic and conventional laparoscopic approaches, and oncological outcomes such as the quality of the mesorectum and the status of resection margins are also equivalent. The possible superiority of robotic surgery in terms of the preservation of autonomic function has yet to be established in research based on larger numbers of patients. Although robotic rectal surgery is safe, feasible, and appears to overcome some of the technical limitations associated with conventional laparoscopic surgery, the advantages provided by this technical innovation are currently limited. To justify its expensive cost, robotic surgery is more suitable for select patients, such as obese patients, men, those with cancer of the lower rectum, and those receiving preoperative chemoradiotherapy.

Prophylactic lateral pelvic lymph node dissection in stage IV low rectal cancer

AIM

To assess the clinical significance of prophylactic lateral pelvic lymph node dissection (LPLND) in stage IV low rectal cancer.

METHODS

We selected 71 consecutive stage IV low rectal cancer patients who underwent primary tumor resection, and enrolled 50 of these 71 patients without clinical LPLN metastasis. The patients had distant metastasis such as liver, lung, peritoneum, and paraaortic LN. Clinical LPLN metastasis was defined as LN with a maximum diameter of 10 mm or more on preoperative pelvic computed tomography scan. All patients underwent primary tumor resection, 27 patients underwent total mesorectal excision (TME) with LPLND (LPLND group), and 23 patients underwent only TME (TME group). Bilateral LPLND was performed simultaneously with primary tumor resection in LPLND group. R0 resection of both primary and metastatic sites was achieved in 20 of 50 patients. We evaluated possible prognostic factors for 5-year overall survival (OS), and compared 5-year cumulative local recurrence between the LPLND and TME groups.

RESULTS

For OS, univariate analyses revealed no significant benefit in the LPLND compared with the TME group (28.7% vs 17.0%, P = 0.523); multivariate analysis revealed that R0 resection was an independent prognostic factor. Regarding cumulative local recurrence, the LPLND group showed no significant benefit compared with TME group (21.4% vs 14.8%, P = 0.833).

CONCLUSION

Prophylactic LPLND shows no oncological benefits in patients with Stage IV low rectal cancer without clinical LPLN metastasis.

Oncological Outcomes of Lateral Pelvic Lymph Node Metastasis in Rectal Cancer Treated With Preoperative Chemoradiotherapy

BACKGROUND

Oncological outcomes of lateral pelvic lymph node metastasis in rectal cancer treated with preoperative chemoradiotherapy remain to be elucidated.

OBJECTIVE

The purpose of this study was to clarify the therapeutic effect of chemoradiotherapy on lateral pelvic lymph node metastasis, the risk factors of lateral pelvic lymph node metastasis, and oncological outcomes of lateral pelvic lymph node dissection after chemoradiotherapy.

DESIGN

This was a nonrandomized, retrospective study.

SETTINGS

The study was conducted at a tertiary referral university hospital.

PATIENTS

Patients with rectal cancer treated with chemoradiotherapy and radical surgery from 2003 to 2015 (N = 222) were included.

INTERVENTIONS

Radiation (total, 50.4 Gy in 28 fractions) with concomitant fluorouracil-based chemotherapy was administered. Lateral pelvic lymph nodes with a diameter of ≥8 mm before chemoradiotherapy were selectively dissected.

MAIN OUTCOME MEASURES

Frequency and risk factors of lateral pelvic lymph node metastasis were examined.

RESULTS

Lateral pelvic lymph node dissection was performed in 31 patients (14.0%), and 16 (51.6%) of these patients were pathologically diagnosed as positive for metastasis. Among the patients treated with total mesorectal excision alone (n = 191), 2 (0.9%) had recurrence in the lateral pelvic lymph node area, which was pathologically confirmed after salvage R0 resection. T category downstaging (73.3% vs 12.5%; p < 0.01) and high histological regression of the primary lesion (73.3% vs 18.8%; p < 0.01) were more frequent in patients with pathologically negative lateral pelvic lymph nodes than in those with positive lateral pelvic lymph nodes. Young age, short distance from the anal verge, and enlarged lateral pelvic lymph node before chemoradiotherapy were associated with lateral pelvic lymph node metastasis.

LIMITATIONS

The study was limited by its retrospective nature and small study population.

CONCLUSIONS

The incidence of lateral pelvic lymph node metastasis after chemoradiotherapy was estimated to be 8.1% (18/222). Young age, short distance from the anal verge, and enlarged lateral pelvic lymph node before chemoradiotherapy were risk factors of lateral pelvic lymph node metastasis after chemoradiotherapy.

Impact of Lateral Pelvic Lymph Node Dissection on the Survival of Patients with T3 and T4 Low Rectal Cancer

BACKGROUND

The aim of this study was to clarify the survival benefit of lateral pelvic lymph node dissection (LPLND) for patients with pathological T3 and T4 (pT3/T4) low rectal cancer.

METHODS

We evaluated the impact of LPLND on survival for pT3/T4 low rectal cancer patients. The primary endpoint of the study was overall survival (OS). The large-scale database of the Japanese Society for Cancer of the Colon and Rectum registration system was accessed and the data were analyzed using a propensity score matching method based on the likelihood of receiving LPLND. Using seven covariates, the propensity scores were calculated with multivariate logistic regression. A total of 499 propensity score-matched pairs of patients were selected from the entire cohort of 1,840 patients who had received curative resection for pT3/T4 low rectal cancer between 1995 and 2004.

RESULTS

In the matched cohort, the 5-year OS of the patients who had and had not undergone LPLND were 68.9 and 62.0 %, respectively (p = 0.013; hazard ratio [HR], 0.755; 95 % confidence interval [CI], 0.604-0.944). The 5-year OS of the patients with node-negative disease who had and had not received LPLND differed statistically significantly (5-year OS were 82.1 and 71.4 %, respectively. p = 0.006; HR, 0.579; 95 % CI 0.389-0.862). However, those with node-positive disease did not differ significantly (5-year OS were 55.5 and 53.8 %, respectively. p = 0.415; HR 0.893; 95 % CI 0.681-1.172).

CONCLUSIONS

The impact of LPLND on OS for patients with node-negative pT3/T4 low rectal cancer was suggested in this retrospective cohort study. To determine true benefits and harms of LPLND, further prospective studies may be warranted.

Extended lymphadenectomy for locally advanced and recurrent rectal cancer

PURPOSE

The purpose of this study is to assess the value of extended (lateral) lymphadenectomy (EL) in the operative management of locally advanced and recurrent rectal cancer.

METHODS

Patients that underwent exenterative surgery for locally advanced or recurrent rectal cancer between 2006 and 2009 were included in the study. A decision for EL was taken at the local multidisciplinary meeting based on the radiological findings. Perioperative and oncological outcomes were assessed and compared between the EL and non-EL group prospectively.

RESULTS

Forty-one consecutive patients were included in the study (EL = 17). The median age was 57 (40-71) for EL and 66 (39-81) years for non-EL. Of patients, 27 (EL = 13) and 14 (EL = 4) underwent pelvic exenteration and abdominosacral resection, respectively. Twelve (EL = 7) patients were diagnosed with locally advanced primary rectal cancer. Thirty-one (EL = 12) patients received neoadjuvant radiotherapy. The median intraoperative time, blood loss and hospital stay were 9 h (3-13), 1.5 l (0.3-7) and 14 days (12-72), respectively, for the EL group, and 8 h (4-15), 1.6 l (0.25-17) and 14 days (10-86), respectively, for the non-EL (p ≥ 0.394). Morbidity was similar between the two groups (EL = 4, non-EL = 9; p = 0.344). Complete tumour resection (R0) was achieved in 30 (73.17%) patients, 12 (70.58%) in the EL group and 18 (75%) in the non-EL group (p = 0.649). There was no significant difference in 5-year survival (EL = 60.7%, non-EL = 75.2%; p = 0.447), local recurrence (EL = 53.6%, non-EL = 65.4%; p = 0.489) and disease-free survival (EL = 53.6%, non-EL = 51.4%; p = 0.814).

CONCLUSIONS

The present study demonstrated that EL does not provide a statistically significant advantage in survival or recurrence rates, for patients with locally advanced primary or recurrent rectal cancer.

Clinical Significance of Extramural Tumor Deposits in the Lateral Pelvic Lymph Node Area in Low Rectal Cancer: A Retrospective Study at Two Institutions

Background

The presence of extramural tumor deposits without lymph node structure (EX) is an important prognostic factor for patients with colorectal cancer. However, the clinical significance of EX in the lateral pelvic lymph node area (LP-EX) remains unclear. This study aimed to determine the prognostic implications of LP-EX for patients with low rectal cancer.

Methods

This retrospective study involved 172 consecutive patients with stage 2 or 3 low rectal cancer who underwent curative surgery including lateral pelvic lymph node (LPLN) dissection. The patients were classified into the following three groups according to the metastatic status of the LPLN area: patients without metastasis (no-LP-M group), patients with lymph node metastasis (LP-LNM group), and patients with EX (LP-EX group). Potential prognostic factors of overall survival (OS) and relapse-free survival (RFS) were identified in uni- and multivariate analyses.

Results

Classification assigned 131 patients (76 %) to the no-LP-M group, 27 patients (16 %) to the LP-LNM group, and 14 patients (8 %) to the LP-EX group. The 5-year OS rate was 80.3 % in the no-LP-M group, 61.1 % in the LP-LNM group, and 34.9 % in the LP-EX group (P < 0.001). The corresponding 5-year RFS rates were 62.2, 33.8, and 14.3 %, respectively (P < 0.001). A multivariate Cox proportional hazards regression analysis showed that the presence of LP-EX was an independent prognostic factor for OS (P = 0.006) and RFS (P = 0.001).

Conclusions

The LP-EX classification is a useful pathologic parameter that can be used to stratify patients with metastasis in the LPLN area.

Oncological benefit of lateral pelvic lymph node dissection for rectal cancer treated without preoperative chemoradiotherapy: a multicenter retrospective study using propensity score analysis

PURPOSE

We aimed to clarify the prognostic impact of lateral pelvic lymph node (LPN) dissection (LPND) for rectal cancer through a multicenter retrospective study using propensity score analysis.

METHODS

A total of 1238 patients with pathological T2-4, M0 rectal cancer who had undergone curative operation between 2007 and 2008 were examined. Majority of the patients (96 %) were treated without preoperative chemoradiotherapy (CRT). Clinical background data of the patients treated with LPND and those treated without LPND were matched using propensity scores, and hazard ratios (HRs) for cancer-specific mortality were compared.

RESULTS

LPND was performed more frequently for lower rectal cancers and in patients with more advanced disease, and 29 % of the patients were treated with LPND. After matching background features by propensity scores, LPND did not correlate with improved cancer-specific survival (CSS) among the entire study population [HR, 0.73; 95 % confidence interval (CI) 0.41-1.31; P = 0.28]; however, LPND was correlated with significantly improved CSS in female patients (HR, 0.23; 95 % CI, 0.06-0.89; P = 0.04) but not in male patients (HR, 0.95; 95 % CI, 0.48-1.89; P = 0.89). The results were similar when patients treated with LPND finally diagnosed as pathologically negative for LPN metastasis were compared with those curatively treated without LPND.

CONCLUSIONS

It is suggested that the prognostic impact of LPND for rectal cancer treated without CRT might be different between sexes, and LPND should be considered for female rectal cancer patients although they are diagnosed as clinically negative for LPN metastasis.

Laparoscopic lateral pelvic lymph node dissection is achievable and offers advantages as a minimally invasive surgery over the open approach

BACKGROUND

Laparoscopic lateral pelvic lymph node dissection (LPLD) is a minimally invasive alternative to open surgical therapy for advanced low rectal cancer patients. This study assessed potential risk factors for lateral pelvic lymph node metastasis (LPLM) and evaluated the feasibility and oncological safety of laparoscopic LPLD compared with the conventional open approach.

METHODS

We retrospectively reviewed the clinical records of 90 patients with advanced low rectal cancer who underwent LPLD following total mesorectal excision at Kyushu University Hospital between January 2001 and July 2014. We compared the clinicopathological features between the patients with and without LPLM and the surgical outcomes between patients who underwent laparoscopic LPLD (LL) and open LPLD (OL).

RESULTS

Fourteen (15.6 %) patients had LPLM. Univariate analysis revealed that undifferentiated cancer, positive lymphatic invasion, >50 % circumferential cancer extent, mesorectal lymph node metastases (MLM), and distant metastasis were associated with LPLM. In the multivariate analysis, MLM was the only independent risk factor for LPLM. Forty-six (51.1 %) patients underwent LL, and 44 (48.9 %) patients underwent OL. The mean surgical duration was longer in the LL group than in the OL group (641.0 vs. 312.0 min, P < 0.001). The LL group also had less hemorrhage (252.0 vs. 815.0 mL, P < 0.001) and a shorter hospital stay (22.9 vs. 29.1 days, P = 0.04) than the OL group. The mean number of harvested lateral pelvic lymph nodes was larger in the LL group than in the OL group (19.5 vs. 15.8, P < 0.05). The morbidity rate and overall survival (3-year OS: 94.7 vs. 82.9 %, P = 0.25) did not differ between the two groups.

CONCLUSIONS

Patients with advanced low rectal cancer presenting MLM are good candidates for LPLD. Laparoscopic LPLD enables retrieval of more lymph nodes and may be acceptable for the treatment of advanced low rectal cancer.

The Role of Robotic Surgery for Rectal Cancer: Overcoming Technical Challenges in Laparoscopic Surgery by Advanced Techniques

The conventional laparoscopic approach to rectal surgery has several limitations, and therefore many colorectal surgeons have great expectations for the robotic surgical system as an alternative modality in overcoming challenges of laparoscopic surgery and thus enhancing oncologic and functional outcomes. This review explores the possibility of robotic surgery as an alternative approach in laparoscopic surgery for rectal cancer. The da Vinci® Surgical System was developed specifically to compensate for the technical limitations of laparoscopic instruments in rectal surgery. The robotic rectal surgery is associated with comparable or better oncologic and pathologic outcomes, as well as low morbidity and mortality. The robotic surgery is generally easier to learn than laparoscopic surgery, improving the probability of autonomic nerve preservation and genitourinary function recovery. Furthermore, in very complex procedures such as intersphincteric dissections and transabdominal transections of the levator muscle, the robotic approach is associated with increased performance and safety compared to laparoscopic surgery. The robotic surgery for rectal cancer is an advanced technique that may resolve the issues associated with laparoscopic surgery. However, high cost of robotic surgery must be addressed before it can become the new standard treatment.

Robotic-assisted lateral lymph node dissection for lower rectal cancer: short-term outcomes in 50 consecutive patients

BACKGROUND

The goal of this study was to evaluate the short-term outcomes of robotic-assisted lateral lymph node dissection for patients with advanced lower rectal cancer.

METHODS

Between 2012 and 2013, 50 consecutive patients underwent robotic-assisted lateral lymph node dissection for rectal cancer in Shizuoka Cancer Center Hospital. Perioperative outcomes including operative time, operative blood loss, length of stay, postoperative complications, and histopathological data were collected prospectively.

RESULTS

Median patient age was 62 years (range 36-74 years). Operative procedures included low anterior resections (n = 27), intersphincteric resections (n = 16), and abdominoperineal resections (n = 7). Bilateral lymph node dissection was performed in 44 patients. The median operative time was 476 min (range 320-683 min), and the median time required for lateral lymph node dissection was 165 min (range 85-257 min). The median blood loss was 27 mL (range 5-690 mL). There were no cases of open surgery or laparoscopic conversion. The median duration of postoperative hospital stay was 8 days (range 6-13 days). Clavien-Dindo classification Grade III-IV complications occurred in only one patient (2.0 %). There were no cases of anastomotic leak. There was no perioperative mortality. The median number of harvested lateral lymph nodes was 19 (range 5-47).

CONCLUSIONS

Robotic-assisted lateral lymph node dissection is a safe, feasible, and useful approach for patients with advanced lower rectal cancer.

New trends in rectal cancer treatment

SUMMARY 

The treatment philosophy for rectal cancer has changed a lot during the last three decades. In the 1970s it was more or less a pure surgical business and rectal cancer was considered radiation resistant. Owing to the unacceptable high local recurrence rates, surgery was changed (the total mesorectal excision technique) during the 1980s and treatment was, in many countries, concentrated to lager units. Moreover, the addition of adjuvant radiotherapy was tested during the same period in several randomized trials and demonstrated that the local recurrence rate could be reduced by 50%, provided the radiation dose was high enough. Since then, treatment has changed very rapidly with several interesting approaches, such as timing and type of radiotherapy, the place of chemotherapy, surgery with modern technique including laparoscopy; natural orifice transendoscopic surgery or robotics; and the whole idea of ‘wait-and-watch’ program. All of these new aspects are covered and discussed in the view of the standard-of-care in 2014.

Lateral lymph node dissection for lower rectal cancer

The mainstay of surgical therapy for rectal cancer is colectomy (including lesions) with lymph node dissection. The lymphatic spread of rectal cancer can proceed in two directions: medially toward the origin of the inferior mesenteric artery or laterally toward the pelvis aslong the internal iliac artery. To prevent postoperative recurrence, lymph nodes situated along these two axes should be adequately dissected, leaving no residual cancer cells. In Japan, the standard procedure for advanced lower rectal cancer is mesorectal excision and lateral lymph node dissection with autonomic nerve preservation. In Europe and North America, lateral lymph node dissection used to be performed, but it led to increased blood loss, complications, and dysfunction, with no improvement in survival. Lateral lymph node dissection is thus no longer performed. Instead, multidisciplinary therapy combining mesorectal excision with preoperative chemoradiotherapy is now the standard treatment for advanced rectal cancer. Although lateral lymph node dissection decreases the rate of local recurrence similar to preoperative chemoradiotherapy, whether it contributes to improved survival remains unclear. In addition, it is unlikely that prophylactic lateral lymph node dissection is required in all patients with rectal cancer. Definition of the indications for lateral lymph node dissection is thus an important concern.

Survival benefit of lateral lymph node dissection according to the region of involvement and the number of lateral lymph nodes involved

PURPOSE

The effectiveness of lateral lymph node dissection for extending the survival of patients with advanced lower rectal cancer remains unclear. The purpose of this study was to clarify the survival benefit of lateral lymph node dissection according to the region of involvement and the number of lateral lymph nodes involved.

METHODS

We reviewed 131 consecutive patients with advanced lower rectal cancer, who had undergone curative resection with total mesorectal excision plus extended lateral lymph node dissection at Wakayama Medical University Hospital. Twenty-six (19.1 %) of these patients had lateral lymph involvement. We performed univariate and multivariate analyses for the 3-year disease-free and overall survival of these patients.

RESULTS

Multivariate analysis revealed that the number (>1) and the region (common iliac artery region or external iliac artery region) of lateral lymph node metastasis are independent predictive factors for recurrence and survival. The Kaplan-Meier analysis demonstrated that patients with one lymph node metastasis in the internal iliac artery or obturator region had better survival.

CONCLUSIONS

Lateral lymph node dissection resulted in survival benefit for patients with single lateral lymph node involvement in the internal iliac artery region or the obturator region.

Initial clinical experience with robotic lateral pelvic lymph node dissection for advanced rectal cancer

Purpose

This study was conducted to evaluate the technical feasibility and safety of robotic extended lateral pelvic lymph node dissection (LPLD) in patients with advanced low rectal cancer.

Methods

A review of a prospectively-collected database at Kyungpook National University Medical Center from January 2011 to November revealed a series of 8 consecutive robotic LPLD cases with a preoperative diagnosis of lateral node metastasis. Data regarding patient demographics, operating time, perioperative blood loss, surgical morbidity, lateral lymph node status, and functional outcome were analyzed.

Results

In all eight patients, the procedures were completed without conversion to open surgery. The mean operative time of extended pelvic node dissection was 38 minutes (range, 20 to 51 minutes), the mean number of lateral lymph nodes harvested was 4.1 (range, 1 to 13), and 3 patients (38%) were found to have lymph node metastases. Postoperative mortality and morbidity were 0% and 25%, respectively, but, there was no LPLD-related morbidity. The mean hospital stay was 7.5 days (range, 5 to 12 days).

Conclusion

Robotic LPLD is safe and feasible, with the advantage of being a minimally invasive approach. Further large-scale studies comparing robotic and conventional surgery with long-term follow-up evaluation are needed to confirm these findings.