Local recurrences in western low rectal cancer patients treated with or without lateral lymph node dissection after neoadjuvant (chemo)radiotherapy: An international multi-centre comparative study

Clinical characteristics and predictive factors of pathological lateral pelvic lymph node metastasis in patients with rectal cancer

In recent years, selective lateral lymph node dissection (LLND) has been performed more frequently. The present study aimed to explore the clinical characteristics and predictive factors of pathological lateral pelvic lymph node metastasis (LPLNM), which may be helpful for pre-treatment decisions. The present study included 64 patients with rectal cancer and clinically suspected LPLNM who underwent total mesorectal excision (TME) and LLND between February 2019 and April 2024. According to pathological outcomes, the patients were divided into the negative LPLN (n=40) and positive LPLN (n=24) groups. The primary endpoints were the overall pathological LPLNM positivity rate and different clinical characteristics between the two groups. The secondary endpoint was the identification of predictive factors of pathological LPLNM before surgery. Among the 64 patients, 24 (37.5%) had pathologically confirmed LPLNM, and pathological LPLNM was related to initial lymph node size. When initial LPLN size was <7 mm, the pathological LPLNM rate was 10.5%, whereas when LPLN size was between 7 and 10 mm, the rate was 34.6%, and when LPLN size was >10 mm, the rate was 68.4%. Initial LPLN size (≥7.1 mm, P=0.003) and cN stage (N1-2, P=0.005) were significantly associated with pathological LPLNM. In multivariate analysis of risk factors, initial LPN size (≥7.1 mm; hazard ratio=4.856, 95% confidence interval 1.158-20.359, P=0.031) was the only independent risk factor for pathological LPLNM. When the cut-off initial LPLN size was 7.1 mm, the sensitivity and specificity were 87.5 and 52.5%, respectively, and the area under the curve was 0.748 (P=0.0009). When both LPLN size ≥7.1 mm and cN1-2 were satisfied, the sensitivity was 66.7%, the specificity increased to 77.5%, and the positive and negative predictive values were 64.0 and 79.5%, respectively. In conclusion, initial LPLN size and cN stage were identified as significant clinical characteristics associated with pathological LPLNM. Patients with an initial LPLN size of ≥7.1 mm and with cN1-2 stage cancer could benefit from TME + LLND surgery.

Features of Lateral Pelvic Lymph Nodes Associated With Pathological Involvement After Total Neoadjuvant Therapy in Patients Undergoing Lateral Pelvic Lymph Node Dissection

BACKGROUND

There is a lack of consensus regarding treating involved lateral pelvic lymph nodes in rectal cancer.

OBJECTIVE

This study aimed to evaluate the clinical and MRI-based factors associated with pathological lateral pelvic lymph node metastasis in patients undergoing total neoadjuvant therapy and lateral pelvic lymph node dissection.

DESIGN

This is a retrospective study.

SETTINGS

This study was conducted at a single comprehensive cancer center.

PATIENTS

A total of 107 patients with advanced low rectal cancer with pretreatment enlarged lateral pelvic lymph nodes (≥7 mm in long axis) undergoing total neoadjuvant therapy with long-course chemoradiotherapy, followed by total mesorectal excision and lateral pelvic lymph node dissection, were enrolled.

MAIN OUTCOME MEASURES

Pathological lateral pelvic lymph node metastasis and survival.

RESULTS

Among 107 patients, short-axis lateral node diameter at baseline was <7 mm in 48 patients and ≥7 mm in 59 patients. The ≥7 mm group showed significantly higher rates of pathological lateral pelvic lymph node metastasis (44.1% vs 2.1%; p < 0.0001). In this group, pathological lateral pelvic lymph node metastasis was independently associated with pretreatment malignant features and posttreatment short-axis diameter ≥4 mm. Five-year relapse-free survival was significantly lower in patients with posttreatment lateral node diameter ≥4 mm than those with <4 mm (71.1% vs 86.2%, p = 0.0364). Patients with pathological lateral pelvic lymph node metastasis had significantly lower overall survival, relapse-free survival, and local recurrence-free survival rates.

LIMITATIONS

Selection bias exists in a retrospective analysis.

CONCLUSIONS

Pathological lateral pelvic lymph node metastasis is rare in patients with pretreatment short-axis diameter <7 mm. In patients with pretreatment short-axis diameter ≥7 mm, pretreatment malignant features and posttreatment short-axis diameter are both associated with pathological lateral pelvic lymph node metastasis. These factors should be considered when deciding whether to proceed with lateral pelvic lymph node dissection after total neoadjuvant therapy. See Video Abstract.

CARACTERSTICAS DE LOS GANGLIOS LINFTICOS PLVICOS LATERALES ASOCIADOS CON AFECTACIN PATOLGICA DESPUS DE LA TERAPIA NEOADYUVANTE TOTAL EN PACIENTES SOMETIDOS A DISECCIN LATERAL DE GANGLIOS LINFTICOS PLVICOS

ANTECEDENTES:No existe consenso sobre el tratamiento de los ganglios linfáticos pélvicos laterales afectados en el cáncer rectal.OBJETIVO:Este estudio tuvo como objetivo evaluar los factores clínicos y basados en imágenes de resonancia magnética asociados con la metástasis patológica de los ganglios linfáticos pélvicos laterales en pacientes sometidos a terapia neoadyuvante total y disección lateral de ganglios linfáticos pélvicos.DISEO:Este es un estudio retrospectivo.EORNO CLINICO:Este estudio se llevó a cabo en un solo centro oncológico integral.PACIENTES:Se inscribieron 107 pacientes con cáncer rectal bajo avanzado con ganglios linfáticos pélvicos laterales agrandados antes del tratamiento (≥7 mm en el eje largo) sometidos a terapia neoadyuvante total con quimiorradioterapia de larga duración, seguida de escisión mesorrectal total y disección de ganglios linfáticos pélvicos laterales.PRINCIPALES MEDIDAS DE RESULTADOS:Metástasis patológica de ganglios linfáticos pélvicos laterales y supervivencia.RESULTADOS:Entre 107 pacientes, 48 tenían un diámetro ganglionar lateral en el eje corto <7 mm al inicio, mientras que 59 tenían ≥7 mm. El grupo de ≥7 mm mostró tasas significativamente más altas de metástasis patológica de los ganglios linfáticos pélvicos laterales (44,1% vs 2,1%; p < 0,0001). En este grupo, la metástasis patológica de los ganglios linfáticos pélvicos laterales se asoció de forma independiente con características malignas previas al tratamiento y un diámetro ganglionar lateral posterior al tratamiento ≥4 mm. La supervivencia sin recidiva a los cinco años fue significativamente menor en pacientes con un diámetro ganglionar lateral posterior al tratamiento ≥4 mm que en aquellos con un diámetro <4 mm (71,1% vs 86,2%, p = 0,0364). Los pacientes con la metástasis patológica de los ganglios linfáticos pélvicos laterales tuvieron tasas de supervivencia global, supervivencia sin recidiva y supervivencia sin recurrencia local significativamente más bajas.LIMITACIONES:Existe sesgo de selección en un análisis retrospectivo.CONCLUSIONES:La metástasis patológica de los ganglios linfáticos pélvicos laterales es poco frecuente en pacientes con un diámetro del eje corto previo al tratamiento <7 mm. En pacientes con un diámetro del eje corto previo al tratamiento ≥7 mm, las características malignas previas al tratamiento y el diámetro del eje corto posterior al tratamiento se asocian con metástasis patológica de los ganglios linfáticos pélvicos laterales. Estos factores deben tenerse en cuenta al decidir si se debe proceder a la disección de los ganglios linfáticos pélvicos laterales después de la terapia neoadyuvante total. (Traducción- Dr. Francisco M. Abarca-Rendon).

The oncologic benefits of lateral lymph node dissection after neoadjuvant therapy - local control or survival?

Lateral pelvic lymph node dissection (LPLND) for rectal adenocarcinoma is an established treatment modality for selected patients with abnormal lateral pelvic lymph nodes on magnetic resonance imaging (MRI) imaging. The goal of this treatment is to achieve a true R0 resection, including lymphadenectomy, with the aim of improving patient oncological outcome, potentially at the expense of surgical and functional complications. However, there remain several areas of controversy resulting from a distinct lack of clarity regarding effective patient selection, lymph node size criteria, the role and extent of routine neoadjuvant treatment versus surgery alone in selected cases, the impact on patient survival metrics and whether the existing data are even valid in the era of total neoadjuvant therapy (TNT). Furthermore, the lack of widely disseminated surgical standardisation and expertise in performing this procedure potentially contributes to the lack of utilisation in certain countries and regions. In this narrative review, we summarize the current state of the literature and attempt to answer the question of what oncological benefits there are, if any, from LPLND after neoadjuvant therapy in rectal cancer, and whether these justify the risks and potential need for inter-hospital transfer.

Who is a candidate at the initial presentation? Prediction of positive lateral lymph node and survival after dissection

Metastatic lateral pelvic lymph node (LPN) in rectal cancer has a significant clinical impact on the prognosis and treatment strategies. But there are still debates regarding prediction of lateral pelvic lymph node metastasis and its oncological impact. This review explores the evidence for predicting lateral pelvic lymph node metastasis and survival in locally advanced rectal cancer. Until now many studies have reported that magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) are considered as essential tools for predicting metastatic LPN, with MRI-based size criteria, particularly the short-axis diameter of LPN. But several studies have reported that the addition of tumor location or artificial intelligence (AI) can further enhance diagnostic accuracy. Western practices focus more on neoadjuvant chemoradiation (nCRT), while Eastern countries focus more on lateral pelvic lymph node dissection (LPND). LPND has been shown to reduce lateral local recurrence (LLR) rates compared to total mesorectal excision (TME) alone, particularly in patients with enlarged LPNs, but its impact on overall survival is uncertain. The decision to perform LPND should be individualized according to LPN size and response to nCRT; and through selective LPND based on those criteria, patients could achieve a balance between the benefit of local control and the risk of surgical complications from LPND, such as sexual and urinary dysfunction.

The Learning Curve for Robotic Lateral Pelvic Lymph Node Dissection for Rectal Cancer: A View From the West

BACKGROUND

Lateral pelvic lymph node dissection is performed for selected patients with rectal cancer with persistent lateral nodal disease after neoadjuvant therapy. This technique has been slow to be adopted in the West because of concerns regarding technical difficulty. This is the first report on the learning curve for lateral pelvic lymph node dissection in the United States or Europe.

OBJECTIVE

This study aimed to analyze the learning curve associated with robotic lateral pelvic lymph node dissection.

DESIGN

Retrospective observational cohort.

SETTING

Tertiary academic cancer center.

PATIENTS

Consecutive patients from 2012 to 2021.

INTERVENTION

All patients underwent robotic lateral pelvic lymph node dissection.

MAIN OUTCOME MEASURES

The primary end points were the learning curves for the maximum number of nodes retrieved and urinary retention, which was evaluated with simple cumulative sum and 2-sided Bernoulli cumulative sum charts.

RESULTS

Fifty-four procedures were included. A single-surgeon learning curve (n = 35) and an institutional learning curve are presented in the analysis. In the single-surgeon learning curve, a turning point marking the end of a learning phase was detected at the 12th procedure for the number of retrieved nodes and at the 20th procedure for urinary retention. In the institutional learning curve analysis, 2 turning points were identified at the 13th procedure, indicating progressive improvements for the number of retrieved nodes, and at the 27th procedure for urinary retention. No sustained alarm signals were detected at any time point.

LIMITATIONS

The retrospective nature, small sample size, and the referral center nature of the reporting institution may limit generalizability.

CONCLUSIONS

In a setting of institutional experience with robotic colorectal surgery, including beyond total mesorectal excision resections, the learning curve for robotic lateral pelvic lymph node dissection is acceptably short. Our results demonstrate the feasibility of the acquisition of this technique in a controlled setting, with sufficient case volume and proctoring to optimize the learning curve. See Video Abstract.

LA CURVA DE APRENDIZAJE DE LA DISECCIN ROBTICA DE LOS GANGLIOS LINFTICOS PLVICOS LATERALES EN EL CNCER DE RECTO UNA VISIN DESDE OCCIDENTE

ANTECEDENTES:La disección lateral de los ganglios linfáticos pélvicos se realiza en pacientes seleccionados con cáncer de recto con enfermedad ganglionar lateral persistente tras el tratamiento neoadyuvante. La adopción de esta técnica en Occidente ha sido lenta debido a la preocupación por su dificultad técnica. Éste es el primer informe sobre la curva de aprendizaje de la disección de los ganglios linfáticos pélvicos laterales en EE.UU. o Europa.OBJETIVO:El objetivo de este estudio fue analizar la curva de aprendizaje asociada a la disección robótica de los ganglios linfáticos pélvicos laterales.DISEÑO:Cohorte observacional retrospectiva.LUGAR:Centro oncológico académico terciario.PACIENTES:Pacientes consecutivos desde 2012 al 2021.INTERVENCIÓN:Todos los pacientes fueron sometieron a disección robótica de ganglios linfáticos pélvicos laterales.PRINCIPALES MEDIDAS DE RESULTADO:Los criterios de valoración primarios fueron las curvas de aprendizaje tomando en cuenta el mayor número de ganglios recuperados y la retención urinaria que fueron evaluados con gráficos de suma acumulativa simple y de suma acumulativa de Bernoulli de dos caras.RESULTADOS:Fueron incluidos 54 procedimientos. En el análisis se presentan una curva de aprendizaje de un solo cirujano (n = 35) y una curva de aprendizaje institucional. En la curva de aprendizaje de un solo cirujano, se detectó un punto de inflexión que marcaba el final de una fase de aprendizaje en el duodécimo procedimiento para el número de ganglios extraídos y en el vigésimo para la retención urinaria. En el análisis de la curva de aprendizaje institucional, se identificaron dos puntos de inflexión en las intervenciones 13.ª y 26.ª, que indicaron mejoras progresivas en el número de ganglios extraídos, y en la 27.ª en la retención urinaria. No se detectaron señales de alarma sostenidas en ningún momento.LIMITACIONES:La naturaleza retrospectiva, el pequeño tamaño de la muestra y la naturaleza de centro de referencia de la institución informante que pueden limitar la capacidad de generalizarse.CONCLUSIONES:En un entorno de experiencia institucional con cirugía robótica colorrectal incluyendo más allá de las resecciones TME, la curva de aprendizaje para la disección robótica de ganglios linfáticos pélvicos laterales es aceptablemente corta. Nuestros resultados demuestran la viabilidad de la adquisición de esta técnica en un entorno controlado, con un volumen de casos suficiente y una supervisión que puede optimizar la curva de aprendizaje. (Traducción-Dr. Osvaldo Gauto ).

The role of lateral pelvic lymph node dissection in advanced rectal cancer: a review of current evidence and outcomes

Metastatic lateral pelvic lymph nodes (LPNs) in rectal cancer significantly impact the prognosis and treatment strategies. Western practices emphasize neoadjuvant chemoradiotherapy (CRT), whereas Eastern approaches often rely on LPN dissection (LPND). This review examines the evolving role of LPND in the context of modern treatments, including total neoadjuvant therapy (TNT), and the impact of CRT on the management of clinically suspicious LPNs. We comprehensively reviewed the key literature comparing the outcomes of LPND versus preoperative CRT for rectal cancer, focusing on recent advancements and ongoing debates. Key studies, including the JCOG0212 trial and recent multicenter trials, were analyzed to assess the efficacy of LPND, particularly in conjunction with preoperative CRT or TNT. Current evidence indicates that LPND can reduce local recurrence rates compared to total mesorectal excision alone in patients not receiving radiation therapy. However, the benefit of LPND in the context of neoadjuvant CRT is influenced by the size and pretreatment characteristics of LPNs. While CRT can effectively control smaller metastatic LPNs, larger or clinically suspicious LPNs may require LPND for optimal outcomes. Advances in surgical techniques, such as robotic-assisted LPND, offer potential benefits but also present challenges and complications. The role of TNT in controlling metastatic LPNs and improving patient outcomes is emerging but remains underexplored. The decision to perform LPND should be individualized based on patient-specific factors, including LPN size, response to neoadjuvant treatment, and surgeon expertise. Future research should focus on optimizing treatment protocols and further evaluating the role of TNT in managing metastatic LPNs.

Efficacy of lateral lymph node dissection for local control of rectal cancer: A multicenter study

Background

This study aimed to evaluate the efficacy of lateral lymph node dissection (LLND) for rectal cancer by comparing the local control in patients with and without pathological lateral lymph node metastasis (LLNM).

Methods

We included 189 patients with rectal cancer who underwent total mesorectal excision and LLND at 13 institutions between 2017 and 2019. Patients with and without pathological LLNM were defined as the pLLNM (+) and (-) groups, respectively. Propensity score-matching helped to balance the basic characteristics of both groups. The incidences of local recurrence (LR) and lateral lymph node recurrence (LLNR) were compared between the groups.

Results

In the entire cohort, 39 of the 189 patients had pathological LLNM. The 3-year LR and LLNR rates were 18.3% and 4.0% (p = 0.01) and 7.7% and 3.3% (p = 0.22) in the pLLNM (+) and (-) groups, respectively. After propensity score matching, the data from 62 patients were analyzed. No significant differences in LR or LLNR were observed between both groups. The 3-year LR and LLNR rates were 16.4% and 9.8% (p = 0.46) and 9.7% and 9.8% (p = 0.99) in the pLLNM (+) and (-) groups, respectively.

Conclusion

LLND would lead to comparable local control in the pLLNM (+) and (-) groups if the clinicopathological characteristics except for LLNM are similar.

The current multidisciplinary management of rectal cancer

Multidisciplinary management of rectal cancer has rapidly evolved over the last several years. This review describes recent data surrounding total neoadjuvant therapy, organ preservation, and management of lateral pelvic lymph nodes. It then presents our treatment algorithm for management of rectal cancer at The University of Texas MD Anderson Cancer Center in the context of this and other existing literature. As part of this discussion, the review describes how we tailor management based upon both patient and tumor-related factors in an effort to optimize patient outcomes.

Quality assessment of surgery for colorectal cancer: Where do we stand?

Quality assurance in surgery has been one of the most important topics of debate among colorectal surgeons in the past decade. It has produced new surgical standards that led in part to the impressive oncological outcomes we see in many units today. Total mesorectal excision, complete mesocolic excision (CME), and the Japanese D3 lymphadenectomy are now benchmark techniques embraced by many surgeons and widely recommended by surgical societies. However, there are still ongoing discrepancies in outcomes largely based on surgeon performance. This is one of the main reasons why many countries have shifted colorectal cancer surgery only to high volume centers. Defining markers of surgical quality is thus a perquisite to ensure that standards and oncological outcomes are met at an institutional level. With the evolution of CME surgery, various quality markers have been described, mostly based on measurements on the surgical specimen and lymph node yield, while others have proposed radiological markers (i.e. arterial stumps) measured on postoperative scans as part of the routine cancer follow-up. There is no ideal marker; however, taken together and assembled into a new score or set of criteria may become a future point of reference for reporting outcomes of colorectal cancer surgery in research studies and defining subspecialization requirements both at an individual and hospital level.

Management of lateral pelvic lymph nodes in rectal cancer: Is it time to reach an Agreement?

In this editorial, we proceed to comment on the article by Chua et al, addressing the management of metastatic lateral pelvic lymph nodes (mLLN) in stage II/III rectal cancer patients below the peritoneal reflection. The treatment of this nodal area sparks significant controversy due to the strategic differences followed by Eastern and Western physicians, albeit with a higher degree of convergence in recent years. The dissection of lateral pelvic lymph nodes without neoadjuvant therapy is a standard practice in Eastern countries. In contrast, in the West, preference leans towards opting for neoadjuvant therapy with chemoradiotherapy or radiotherapy, that would cover the treatment of this area without the need to add the dissection of these nodes to the total mesorectal excision. In the presence of high-risk nodal characteristics for mLLN related to radiological imaging and lack of response to neoadjuvant therapy, the risk of lateral local recurrence increases, suggesting the appropriate selection of strategies to reduce the risk of recurrence in each patient profile. Despite the heterogeneous and retrospective nature of studies addressing this area, an international consensus is necessary to approach this clinical scenario uniformly.

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.

Prediction model of the risk for lateral local recurrence in locally advanced rectal cancer without enlarged lateral lymph nodes: Lessons from a Japanese multicenter pooled analysis of 812 patients

Aim

Although the oncological impact of lateral lymph node dissection on enlarged lateral lymph nodes has been gradually accepted over the last decade, that on lateral lymph nodes without swelling remains doubtful. This study aimed to develop a prediction model for the future risk of lateral local recurrence and to clarify the value of adding lateral lymph node dissection in locally advanced rectal cancer without enlarged lateral lymph nodes.

Methods

This retrospective, multi-institutional study recruited 812 patients with cStage II/III low rectal cancer without enlarged lateral lymph nodes <7 mm. Total lateral local recurrence was a hypothetical value of future risk of lateral local recurrence when lateral lymph node dissection was never performed.

Results

Overall, total lateral local recurrences were observed in 67 patients (8.3%). In the multivariate analyses, the strongest risk factor for total local recurrences was no preoperative chemoradiotherapy (odds ratio [OR][95%Cl]: 33.2 [4.56-241.7], P < 0.001), followed by tumor distance ≤40 mm (OR [95%Cl]: 2.71 [1.51-4.86], P < 0.001) and lateral lymph node 5-7 mm (OR[95%Cl]: 2.38 [1.26-4.48], P = 0.007). In patients with lateral lymph nodes of 5-7 mm, the total lateral recurrence rate was 4.8% after preoperative chemoradiotherapy. Lateral lymph node dissection could reduce from a total lateral local recurrence of 21.6% to an actual lateral local recurrence of 8.0% in patients without preoperative treatment.

Conclusion

We introduce a novel prediction model of future risk of lateral local recurrences, which has the potential to enable us to indicate lateral lymph node dissection selectively according to the patients' risks.

The influence of neoadjuvant chemoradiotherapy combined with lateral lymph nodes dissection or not on the local recurrence of low to intermediate-stage II/III rectal cancer

BACKGROUND

Currently, the treatment options for stage II/III rectal cancer with preoperative lateral lymph nodes (LLN) enlargement are highly controversial between East and West, and the indications for diagnosing suspiciously positive enlarged LLN are inconsistent both nationally and internationally. Oriental scholars (especially Japanese) consider the LLN as a regional disease, they consider that prophylactic lateral lymph nodes dissection (LLND), regardless of whether the LLN is enlarged or not, is considered necessary if the tumor is found beneath the peritoneal reflex and invades the muscle layer. Western scholars regard LLN as distant metastases, recommending neoadjuvant chemoradiotherapy (nCRT) in conjunction with total rectal mesenteric resection (TME). In recent years, it has been found that neither of the two standard treatment regimens, East and West, significantly improved local control of tumors in patients with LLN enlargement. In contrast, nCRT combined with LLND significantly lowers the local recurrence (LR) rate. It has also been suggested that combination therapy regimens do not improve patient prognosis but increase treatment-related complications. Therefore, the suitable therapeutic option for rectal cancer with an enlarged LLN needs to be further explored.

AIM

Exploring appropriate treatment options for low to intermediate-stage II/III rectal cancer with LLN enlargement, as well as risk variables that may affect the LR in these patients with LLN enlarged.

METHODS AND PATIENTS

In this research, we retrospectively analyzed 110 patients with locally advanced mid-low (low boundary of tumor is no more than 10 cm from the anus) rectal cancer who were treated at Harbin Medical University Cancer Hospital arranged from 2017.1 to 2020.6. These patients had received nCRT and TME, and their initial rectal nuclear magnetic resonance imaging (MRI) revealed an enlarged LLN (short axis of LLN, SA ≥ 5 mm). Of these, 40 patients underwent LLND, thus, 110 patients were grouped into two groups: nCRT+TME (LLND-, n = 70) and nCRT+TME + LLND (LLND+, n = 40), and their 3 years prognoses were compared.

RESULTS

After a median follow-up of 49.0 months, the 3-year LR rate of the LLND- group was notably greater than the LLND+ group (22.8% vs. 7.5%, p = 0.04). However, there was no noteworthy difference in the 3-year progression-free survival (PFS, 70.5% vs. 77.5%, p > 0.05) rate or distant metastasis (DM) rate (20.0% vs. 17.5%, p > 0.05). Additionally, the LLND+ group experienced significantly more postoperative complications than the LLND- group (15.0% vs. 4.2%, p = 0.05). Subgroups analysis for the LLND- group revealed that patients with LLN short axis regression (ΔSA) > 35.9% after nCRT had significantly lower 3-year LR rate than patients with ΔSA ≤ 35.9% (9.1% vs. 35.1%, p = 0.01). Patients in the LLND- group with ΔSA > 35.9%, however, had comparable 3-year LR rate and DM rates to those in the LLND+ group.

CONCLUSION

LLN is an independent indicator for prognosis among people with low to intermediate-stage II/III malignant rectal tumors. Patients with poor SA regression (ΔSA ≤ 35.9%) after nCRT have a greater risk of positive LLN and a more substantial LR, and nCRT combined with LLND reduced the LR rate significantly, but considerably prolonged operative time, surgical bleeding, and postoperative complications. Patients with better SA regression (ΔSA > 35.9%), however, have a lower possibility of LR and might not need LLN clearance, in these cases, nCRT+TME is advised.

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.

Morphological characteristics of lateral pelvic lymph nodes in locally advanced lower rectal cancer: A retrospective study

Aim

This study aimed to investigate the potential of the size and aspect ratio of metastatic and non-metastatic lateral pelvic lymph nodes (LPLNs) as low-risk markers for locally advanced lower rectal cancer, without treatment by neoadjuvant chemoradiation therapy or LPLN dissection.

Methods

This single-center, retrospective cohort study evaluated 310 consecutive patients diagnosed with lower rectal cancer (T: T3/T4, N: any, and M: M0) who underwent curative surgery without neoadjuvant therapies between 2010 and 2018. The harvested LPLNs were categorized into groups A (metastasis-positive lymph nodes), B (metastasis-negative lymph nodes in the area bearing metastasis-positive lymph nodes), C (metastasis-negative lymph nodes in a metastasis-negative area in metastasis-positive patients), and D (lymph nodes in non-metastatic patients). The main outcome measure was the relationship among lymph node size, aspect ratio, and metastasis in the LPLNs.

Results

Overall, 3962 LPLNs were harvested. The long and short axes and the aspect ratio were significantly longer and higher, respectively, in group A than in the other groups (P < .001). The aspect ratio in group B was significantly higher than that in groups C and D (P < .001). The aspect ratio in group C was significantly higher than that in group D (P < .001). Furthermore, no metastasis-positive lymph nodes had an aspect ratio of less than 0.4. Metastasis-positive LPLNs tended to be larger and rounder than their metastasis-negative counterparts.

Conclusions

Metastatic LPLNs in patients with lower rectal cancer are significantly larger and have a higher aspect ratio. Lymph nodes with aspect ratios of <0.4 were metastasis negative.

Predictive value of a serum tumor biomarkers scoring system for clinical stage II/III rectal cancer with neoadjuvant chemoradiotherapy

BACKGROUND

Multiple classes of molecular biomarkers have been studied as potential predictors for rectal cancer (RC) response. Carcinoembryonic antigen (CEA) is the most widely used blood-based marker of RC and has proven to be an effective predictive marker. Cancer antigen 19-9 (CA19-9) is another tumor biomarker used for RC diagnosis and postoperative monitoring, as well as monitoring of the therapeutic effect. Using a panel of tumor markers for RC outcome prediction is a practical approach.

AIM

To assess the predictive effect of pre-neoadjuvant chemoradiotherapy (NCRT) CEA and CA19-9 levels on the prognosis of stage II/III RC patients.

METHODS

CEA and CA19-9 levels were evaluated 1 wk before NCRT. According to the receiver operating characteristic curve analysis, the optimal cut-off point of CEA and CA19-9 levels for the prognosis were 3.55 and 19.01, respectively. The novel serum tumor biomarker (NSTB) scores were as follows: score 0: Pre-NCRT CEA < 3.55 and CA19-9 < 19.01; score 2: Pre-NCRT CEA > 3.55 and CA19-9 > 19.01; score 1: Other situations. Pathological information was recorded according to histopathological reports after the operation.

RESULTS

In the univariate analysis, pre-NCRT CEA < 3.55 [P = 0.025 for overall survival (OS), P = 0.019 for disease-free survival (DFS)], pre-NCRT CA19-9 < 19.01 (P = 0.014 for OS, P = 0.009 for DFS), a lower NSTB score (0-1 vs 2, P = 0.009 for OS, P = 0.005 for DFS) could predict a better prognosis. However, in the multivariate analysis, only a lower NSTB score (0-1 vs 2; for OS, HR = 0.485, 95%CI: 0.251-0.940, P = 0.032; for DFS, HR = 0.453, 95%CI: 0.234-0.877, P = 0.019) and higher pathological grade, node and metastasis stage (0-I vs II-III; for OS, HR = 0.363, 95%CI: 0.158-0.837, P = 0.017; for DFS, HR = 0.342, 95%CI: 0.149-0.786, P = 0.012) were independent predictive factors.

CONCLUSION

The combination of post-NCRT CEA and CA19-9 was a predictive factor for clinical stage II/III RC patients receiving NCRT, and the combined index had a stronger predictive effect.

Magnetic Resonance Imaging Directed Surgical Decision Making for Lateral Pelvic Lymph Node Dissection in Rectal Cancer After Total Neoadjuvant Therapy (TNT)

OBJECTIVE

Lateral pelvic lymph node (LPLN) metastases are an important cause of preventable local failure in rectal cancer. The aim of this study was to evaluate clinical and oncological outcomes following magnetic resonance imaging (MRI)-directed surgical selection for lateral pelvic lymph node dissection (LPLND) after total neoadjuvant therapy (TNT).

METHODS

A retrospective consecutive cohort analysis was performed of rectal cancer patients with enlarged LPLN on pretreatment MRI. Patients were categorized as LPLND or non-LPLND. The main outcomes were lateral local recurrence rate, perioperative and oncological outcomes and factors associated with decision making for LPLND.

RESULTS

A total of 158 patients with enlarged pretreatment LPLN and treated with TNT were identified. Median follow-up was 20 months (interquartile range 10-32). After multidisciplinary review, 88 patients (56.0%) underwent LPLND. Mean age was 53 (SD±12) years, and 54 (34.2%) were female. Total operative time (509 vs 429 minutes; P =0.003) was greater in the LPLND group, but median blood loss ( P =0.70) or rates of major morbidity (19.3% vs 17.0%) did not differ. LPLNs were pathologically positive in 34.1%. The 3-year lateral local recurrence rates (3.4% vs 4.6%; P =0.85) did not differ between groups. Patients with LPLNs demonstrating pretreatment heterogeneity and irregular margin (odds ratio, 3.82; 95% confidence interval: 1.65-8.82) or with short-axis ≥5 mm post-TNT (odds ratio 2.69; 95% confidence interval: 1.19-6.08) were more likely to undergo LPLND.

CONCLUSIONS

For rectal cancer patients with evidence of LPLN metastasis, the appropriate selection of patients for LPLND can be facilitated by a multidisciplinary MRI-directed approach with no significant difference in perioperative or oncologic outcomes.

Systematic review and meta-analysis of long-term oncological outcomes of lateral lymph node dissection for metastatic nodes after neoadjuvant chemoradiotherapy in rectal cancer

BACKGROUND

Standard Western management of rectal cancers with pre-treatment metastatic lateral lymph nodes (LLNs) is neoadjuvant (chemo)radiotherapy (nCRT) followed by total mesorectal excision (TME). In recent years, there is growing interest in performing an additional lateral lymph node dissection (LLND). The aim of this systematic review and meta-analysis was to investigate long-term oncological outcomes of nCRT followed by TME with or without LLND in patients with pre-treatment metastatic LLNs.

METHODS

PubMed, Ovid MEDLINE, Embase, Cochrane Library and Clinicaltrials.gov were searched to identify comparative studies reporting long-term oncological outcomes in pre-treatment metastatic LLNs of nCRT followed by TME and LLND (LLND+) vs. nCRT followed by TME only (LLND-). Newcastle-Ottawa risk-of-bias scale was used. Outcomes of interest included local recurrence (LR), disease-free survival (DFS), and overall survival (OS). Summary meta-analysis of aggregate outcomes was performed.

RESULTS

Seven studies, including 946 patients, were analysed. One (1/7) study was of good-quality after risk-of-bias analysis. Five-year LR rates after LLND+ were reduced (range 3-15%) compared to LLND- (11-27%; RR = 0.40, 95%CI [0.25-0.62], p < 0.0001). Five-year DFS was not significantly different after LLND+ (range 61-78% vs. 46-79% for LLND-; RR = 0.72, 95%CI [0.51-1.02], p = 0.143), and neither was five-year OS (range 69-91% vs. 72-80%; RR = 0.72, 95%CI [0.45-1.14], p = 0.163).

CONCLUSION

In rectal cancers with pre-treatment metastatic LLNs, nCRT followed by an additional LLND during TME reduces local recurrence risk, but does not impact disease-free or overall survival. Due to the low quality of current data, large prospective studies will be required to further determine the value of LLND.

Laparoscopic versus open lateral pelvic lymph node dissection in locally advanced rectal cancer: multicentre retrospective cohort study

BACKGROUND

Lateral pelvic lymph node dissection (LPLND) is an option in the treatment of rectal cancer and may reduce local recurrence/improve disease-free survival. Advancements in minimally invasive technology have improved the ability to identify anatomy and neurovascular structures that may help in LPLND. The aim of this retrospective study was to evaluate the technical feasibility and oncological safety of laparoscopic LPLND compared with the open LPLND.

METHOD

Between July 2010 and July 2019, patients from three tertiary referral hospitals who underwent LPLND with total mesorectal excision for primary rectal cancer were included. Baseline patient characteristics, perioperative outcomes, pathologic results, recurrence, and survival were compared between the laparoscopic and open groups.

RESULTS

There were 126 and 70 patients in the laparoscopic and open groups respectively. The laparoscopic group had less estimated blood loss (100 ml versus 300 ml, P < 0.001) and lower transfusion rate (0.8 per cent versus 10.0 per cent; P = 0.003) but longer operating times (318 min versus 270 min, P = 0.004). The laparoscopic group had fewer wound infections (1.6 per cent versus 10.0 per cent, P = 0.011) and neuropathy (0 per cent versus 4.3 per cent, P = 0.044). Lateral pelvic recurrence rate was 7.6 per cent in the laparoscopic group and 19.6 per cent in the open group (P = 0.053). Recurrence-free survival (72.2 per cent versus 63.5 per cent; P = 0.190) and overall survival (93.3 per cent versus 85.0 per cent; P = 0.118) were not significantly different.

CONCLUSION

Laparoscopic LPLND was associated with improved perioperative outcomes and non-inferior oncological outcomes.

Surgical Treatment of Low-Lying Rectal Cancer: Updates

Despite innovative advancements, distally located rectal cancer remains a critical disease of challenging management. The crucial location of the tumor predisposes it to a circumferential resection margin (CRM) that tends to involve the anal sphincter complex and surrounding organs, with a high incidence of delayed anastomotic complications and the risk of the pelvic sidewall or rarely inguinal lymph node metastases. In this regard, colorectal surgeons should be aware of other issues beyond total mesorectal excision (TME) performance. For decades, the concept of extralevator abdominoperineal resection to avoid compromised CRM has been introduced. However, the complexity of deep pelvic dissection with poor visualization in low-lying rectal cancer has led to transanal TME. In contrast, neoadjuvant chemoradiotherapy (NCRT) has allowed for the execution of more sphincter-saving procedures without oncologic compromise. Significant tumor regression after NCRT and complete pathologic response also permit applying the watch-and-wait protocol in some cases, now with more solid evidence. This review article will introduce the current surgical treatment options, their indication and technical details, and recent oncologic and functional outcomes. Lastly, the novel characteristics of distal rectal cancer, such as pelvic sidewall and inguinal lymph node metastases, will be discussed along with its tailored and individualized treatment approach.

Lateral Pelvic Lymph Node Dissection After Neoadjuvant Chemoradiotherapy in Patients With Rectal Cancer: A Single-Center Experience and Literature Review

Purpose

We aimed to evaluate the surgicopathological outcomes of lateral pelvic lymph node dissection (LPLD) and long-term oncological outcomes of selective LPLD after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer and compare them to those of total mesorectal excision (TME) alone based on pretreatment magnetic resonance imaging (MRI).

Methods

We compared the TME-alone group (2001–2009, n=102) with the TME with LPLD group (2011–2016, n=69), both groups having lateral lymph nodes (LLNs) of ≥5 mm in short axis diameter. The surgicopathological outcomes were analyzed retrospectively. Oncological outcomes were analyzed using the Kaplan-Meier method.

Results

The rates of overall postoperative 30-day morbidity (42.0% vs. 26.5%, P=0.095) and urinary retention (13.7% vs. 10.1%, P=0.484) were not significantly different between the LPLD and TME-alone groups, respectively. Pathologically proven LLN metastasis was identified in 24 (34.8%) LPLD cases after nCRT. The LPLD group showed a lower 5-year local recurrence (LR) rate (27.9% vs. 4.6%, P<0.001) and better recurrence-free survival (RFS) (59.6% vs. 78.2%, P=0.008) than those of the TME-alone group, while the 5-year overall survival was not significantly different between the 2 groups (76.2% vs. 86.5%, P=0.094).

Conclusion

This study suggests that LPLD is a safe and feasible procedure. The oncological outcomes suggest that selective LPLD improves LR and RFS in patients with clinically suspicious LLNs on pretreatment MRI. Considering that lateral nodal disease is not common, a multicenter large-scale study is necessary.

Lateral lymph node dissection in rectal cancer: State of the art review

Half of the local regional recurrences from rectal cancer are nowadays located in the lateral compartments, most likely due to lateral lymph node (LLN) metastases. There is evidence that a lateral lymph node dissection (LLND) can lower the lateral local recurrence rate. An LLND without neoadjuvant (chemo)radiotherapy in patients with or without suspected LLN metastases has been the standard of care in the East, while Western surgeons believed LLN metastases to be cured by neoadjuvant treatment and total mesorectal excision (TME) only. An LLND in patients without enlarged LLNs might result in overtreatment with low rates of pathological LLNs, but in patients with enlarged LLNs who are treated with (C)RT and TME only, the risk of a lateral local recurrence significantly increases to 20%. Certain Eastern and Western centers are increasingly performing a selective LLND after neoadjuvant treatment in the presence of suspicious LLNs due to new scientific insights, but (inter)national consensus on the indication and surgical approach of LLND is lacking. An LLND is an anatomically challenging procedure with intraoperative risks such as bleeding and postoperative morbidity. It is therefore essential to carefully select the patients who will benefit from this procedure and where possible to perform the LLND in a minimally invasive manner to limit these risks. This review gives an overview of the current evidence of the assessment of LLNs, the indications for LLND, the surgical technique, pitfalls in performing this procedure and the future studies are discussed, aiming to contribute to more (inter)national consensus.

Intra- and Interobserver Variability in Magnetic Resonance Imaging Measurements in Rectal Cancer Patients

Colorectal cancer is the second most common cancer in Europe, and accurate lymph node staging in rectal cancer patients is essential for the selection of their treatment. MRI lymph node staging is complex, and few studies have been published regarding its reproducibility. This study assesses the inter- and intraobserver variability in lymph node size, apparent diffusion coefficient (ADC) measurements, and morphological characterization among inexperienced and experienced radiologists. Four radiologists with different levels of experience in MRI rectal cancer staging analyzed 36 MRI scans of 36 patients with rectal adenocarcinoma. Inter- and intraobserver variation was calculated using interclass correlation coefficients and Cohens-kappa statistics, respectively. Inter- and intraobserver agreement for the length and width measurements was good to excellent, and for that of ADC it was fair to good. Interobserver agreement for the assessment of irregular border was moderate, heterogeneous signal was fair, round shape was fair to moderate, and extramesorectal lymph node location was moderate to almost perfect. Intraobserver agreement for the assessment of irregular border was fair to substantial, heterogeneous signal was fair to moderate, round shape was fair to moderate, and extramesorectal lymph node location was substantial to almost perfect. Our data indicate that subjective variables such as morphological characteristics are less reproducible than numerical variables, regardless of the level of experience of the observers.

Malignant Features in Pretreatment Metastatic Lateral Lymph Nodes in Locally Advanced Low Rectal Cancer Predict Distant Metastases

INTRODUCTION

Pretreatment enlarged lateral lymph nodes (LLN) in patients with locally advanced low rectal cancer are predictive for local recurrences after neoadjuvant (chemo)radiotherapy (n(C)RT) followed by total mesorectal excision (TME). Not much is known of the impact on oncological outcomes when in addition malignant features are present in enlarged LLN.

PATIENTS AND METHODS

A multicenter retrospective cohort study was conducted at five tertiary referral centers in the Netherlands and Australia. All patients were diagnosed with locally advanced low rectal cancer with LLN on pretreatment magnetic resonance imaging (MRI) and underwent n(C)RT followed by TME. LLN were considered enlarged with a short axis of ≥ 5 mm. Malignant features were defined as nodes with internal heterogeneity and/or border irregularity. Outcomes of interest were local recurrence-free survival (LRFS), distant metastatic-free survival (DMFS), and overall survival (OS).

RESULTS

Out of 115 patients, the majority was male (75%) and the median age was 64 years (range 26-85 years). Median pretreatment LLN short axis was 7 mm (range 5-28 mm), and 60 patients (52%) had malignant features. After a median follow-up of 47 months, patients with larger LLN (7 + mm) had a worse LRFS (p = 0.01) but no difference in DMFS (p = 0.37) and OS (p = 0.54) compared with patients with smaller LLN (5-6 mm). LLN patients with malignant features had no difference in LRFS (p = 0.20) but worse DMFS (p = 0.004) and OS (p = 0.006) compared with patients without malignant features in the LLN. Cox regression analysis identified LLN short axis as an independent factor for LR. Malignant features in LLN were an independent factor for DMFS.

CONCLUSION

The current study suggests that pretreatment enlarged LLN that also harbor malignant features are predictive of a worse DMFS. More studies will be required to further explore the role of malignant features in LLN.