Neoadjuvant chemoradiotherapy affects the indications for lateral pelvic node dissection in mid/low rectal cancer with clinically suspected lateral node involvement: a multicenter retrospective cohort study

KLF12 as a potential biomarker for lateral pelvic lymph node metastases in advanced rectal cancer

Rectal cancer accounts for approximately 40% of colorectal cancer cases, and lateral pelvic lymph node (LPLN) metastasis in rectal cancer significantly increases the local recurrence rate. Despite its clinical significance, studies on the molecular biology of LPLN metastasis are relatively scarce. In this study, we aimed to elucidate the underlying mechanisms by identifying hub regulatory genes in LPLN tissues and analyzing differentially expressed genes shared between tumor and pericarcinomatous tissues within our clinical cohort. To investigate the biological functions of these hub regulatory genes, we performed GSEA, GO, and KEGG pathway analyses on mRNA-Seq data. Among the identified hub genes, KLF12 emerged as a pivotal regulatory gene in rectal cancer. We further explored its clinical relevance and biological function. Our findings, validated using public databases, clinical cohort data, and immunohistochemistry (IHC), identified KLF12 as a specific marker for LPLN. Additionally, KLF12 expression exhibited a strong correlation with disease-free survival (DFS). According to clinical data, significant differences in KLF12 expression exist between groups based on factors such as age, gender, tumor location, pathological N stage, and postoperative tumor residue. Both treatment outcomes (DFS) and receiver operating characteristic curves (AUCs) were significantly associated with KLF12 expression. Furthermore, KLF12 demonstrated a strong association with immune cell infiltration, immune checkpoint expression, and immunophenoscore (IPS), indicating its potential regulatory role in immunotherapy. Functional molecular experiments revealed that KLF12 overexpression inhibited the proliferation, migration, and invasion of SW620 cells. In conclusion, leveraging mRNA-Seq data, TCGA database analysis, immune infiltration data, and biological function assessments, we confirmed that KLF12 could serve as an effective predictive marker and potential therapeutic target for LPLN metastasis. These findings suggest that KLF12 may be instrumental in assessing predictive risk and identifying novel therapeutic targets for patients with rectal cancer.

Prognostic model for log odds of negative lymph node in locally advanced rectal cancer via interpretable machine learning

No studies have examined the prognostic value of the log odds of negative lymph nodes/T stage (LONT) in locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (nCRT). We aimed to assess the prognostic value of LONT and develop a machine learning model to predict overall survival (OS) and disease-free survival (DFS) in LARC patients treated with nCRT. The study included 820 LARC patients who received nCRT between September 2010 and October 2017. Univariate and multivariate Cox regression analyses identified prognostic factors, which were then used to develop risk assessment models with 9 machine learning algorithms. Model hyperparameters were optimized using random search and 10-fold cross-validation. The models were evaluated using metrics such as the area under the receiver operating characteristic curves (AUC), decision curve analysis, calibration curves, and precision and accuracy for predicting OS and DFS. Shapley's additive explanations (SHAP) was also used for model interpretation. The study included 820 patients, identifying LONT as a significant independent prognostic factor for both OS and DFS. Nine machine learning algorithms were used to create predictive models based on these factors. The extreme gradient boosting (XGB) model showed the best performance, with a mean AUC of 0.89 for OS and 0.83 for DFS in 10-fold cross-validation. Additionally, the predictions generated by the XGB model were analyzed using SHAP. Finally, we developed an online web-based calculator utilizing the XGB model to enhance the model's generalizability and to provide improved support for physicians in their decision-making processes. The study developed an XGB model utilizing LONT to predict OS and DFS in patients with LARC undergoing nCRT. Furthermore, an online web calculator was constructed using the XGB model to facilitate the model's generalization and to enhance physician decision-making.

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.

Positive lateral lymph node turned negative after neoadjuvant therapy-surgery or observation?

Since the adoption of neoadjuvant chemoradiation and total mesorectal excision as the standard in rectal cancer care, there has been marked improvement in the local recurrence rates. In this context, restaging magnetic resonance imaging (MRI) plays a key role in the assessment of tumor response, occasionally enabling organ-sparing approaches. However, the role of restaging MRI in evaluating lateral lymph nodes remains limited. Most studies suggest a high risk of lateral local recurrence regardless of a decrease in lymph node size on restaging MRI. Therefore, it is recommended that clinical decisions should rely on the primary MRI scan. Watchful waiting may be appropriate only in cases of a clinical complete response with substantial downsizing of lateral lymph nodes (≤ 4.0 mm). Notably, some lateral lymph nodes may enlarge during follow-up despite complete tumor response, in which case, lateral lymph node dissection can be considered while preserving the rectum. Thus, continuous surveillance of lateral lymph nodes is essential during watchful waiting. Restaging MRI may hold greater importance for smaller lymph nodes (5.0-6.9 mm), as those with persistent malignant features on imaging carry a 13% risk of lateral recurrence at 4 years. Understanding these risks is critical when engaging in shared decision-making with the patient.

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.

Long-term outcomes of S-1 and oxaliplatin neoadjuvant chemotherapy with total mesorectal excision and lateral lymph node dissection for rectal cancer

PURPOSE

Chemoradiotherapy (CRT) for rectal cancer is limited by its harmful side effects and its insufficient benefit on lateral lymph node metastases. The purpose of this study was to evaluate the long-term outcomes of S-1 and oxaliplatin with total mesorectal excision (TME) and lateral lymph node dissection (LLND) without radiation for rectal cancer.

METHODS

The inclusion criteria were patients with stage II or III rectal cancer located within 10 cm from the anal verge. Fifty-two patients who underwent neoadjuvant chemotherapy (NAC) followed by TME and LLND were evaluated. The primary endpoint was the 3-year local recurrence. The secondary endpoints were the 3-year rates of relapse-free survival and overall survival. Expected post-NAC and surgical outcomes were prospectively analyzed.

RESULTS

The overall recurrence rate was 15.4%, with eight patients developing distant recurrences. The local recurrence rate was 7.7% (n = 4). Among the 4 patients with local recurrence, 3 (5.8%) patients had central pelvis recurrence, and 1 (1.9%) patient had lateral pelvic recurrence. The 3-year survival rate was 98.1%, and the 3-year relapse-free survival rate was 84.6%. The risk factors for local recurrence were mucinous carcinoma (p = 0.016) and a positive resection margin (p = 0.009). Pathological mesorectal lymph node metastasis and local recurrence were independent risk factors for poor survival.

CONCLUSIONS

Although preoperative chemotherapy and TME with LLND are sufficient to control local recurrence, some cases will require more aggressive chemotherapy with radiation therapy.

Short-term outcomes of 47 selective laparoscopic lymph node dissection for rectal cancer: A retrospective study

This study aims to analyze the safety, feasibility, and short-term oncology outcomes of selective laparoscope lateral lymph node dissection (LLND) with total mesorectal excision surgery. Between December 2019 and May 2023, LLND with total mesorectal excision surgery was performed in 47 selected patients with advanced rectal cancer. Surgical complications and 2-year oncology survival outcomes were analyzed in the study. All 47 procedures were technically successful without converting conversion to open surgery. The mean operation time was 200.6 minutes (135-321 minutes), and the mean estimated blood loss was 92.9 mL (range 10-2000 mL). The most common postoperative complications were anastomotic (8.5%, n = 4), ileus (6.4%, n = 3), and chyle leakage (4.3%, n = 2). Lateral pelvic lymph node metastases were found in 19 (40.4%) patients. When divided into lateral pelvic lymph node positive and negative groups, there was no significant impact on overall survival (94.4% vs 100%, Log-rank P = .596) and local recurrence-free survival (LFRS) (76.7% vs 89.6%, Log-rank P = .210), except disease-free survival (DFS) (58.3% vs 90.2%, Log-rank P = .005). Subgroup analysis showed similar short-term survival outcomes between the pN+ group and the internal iliac metastasis group (Log-rank P of overall survival, LFRS, and DFS were all ˃.05). LRFS and DFS in the obturator or external iliac metastasis group were worse than those in the internal iliac metastasis group when the follow-up time was extended (Log-rank P of LFRS and DFS were .05 and .063). Selective laparoscopy LLND for rectal cancer is safety and feasibility, and its complications are manageable. Oncology survival outcomes for lateral pelvic lymph node metastases limited to the internal iliac are similar to the pN+ stage; therefore, it should be treated positively.

Lateral pelvic lymph node positivity (LPLNP) score: predictive clinic-radiological model of lateral pelvic lymph node involvement in rectal cancer patients

PURPOSE

The population in Western countries differs significantly from that in Eastern countries, and the prevalence of lateral pelvic lymph node (LPLN) involvement in Western populations remains largely unknown due to the limited application of LPLN dissection (LPLND). This discrepancy is primarily attributed to the higher body mass index commonly observed in Western populations, which increases the risk of intraoperative complications. Consequently, the aim of this study is to describe a specific Western clinico-radiological selection tool for LPLND, namely, the lateral pelvic lymph node positivity (LPLNP) score.

METHODS

This retrospective single center study was designed to elaborate the LPLNP score, which was further tested on a prospective cohort of patients. Clinical and MRI factors associated with LPLN involvement were identified, and logistic regression was used to establish the LPLNP score.

RESULTS

In the retrospective series, 120 patients underwent lateral pelvic lymph node dissection. After stepwise logistic regression, five parameters were ultimately included in the LPLNP score. When tested on 66 prospectively selected patients, 40 with an LPLNP score > 0.23 (corresponding to the highest sensitivity and specificity) underwent LPLND: 22 patients (55%) had pathologically confirmed positive LPLN. The negative predictive value of the LPLNP score was 96%, with a sensitivity of 95.7% and a specificity of 58.1%.

CONCLUSION

The LPLNP score was developed based on the largest group of Western patients with locally advanced rectal cancer. This scoring system demonstrated high sensitivity and specificity during validation on the prospective series, correctly identifying LPLN involvement in 55% of cases.

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.

Prediction of lateral lymph node metastasis in rectal cancer patients based on MRI using clinical, deep transfer learning, radiomic, and fusion models

Introduction

Lateral lymph node (LLN) metastasis in rectal cancer significantly affects patient treatment and prognosis. This study aimed to comprehensively compare the performance of various predictive models in predicting LLN metastasis.

Methods

In this retrospective study, data from 152 rectal cancer patients who underwent lateral lymph node (LLN) dissection were collected. The cohort was divided into a training set (n=86) from Tianjin Union Medical Center (TUMC), and two testing cohorts: testing cohort (TUMC) (n=37) and testing cohort from Gansu Provincial Hospital (GSPH) (n=29). A clinical model was established using clinical data; deep transfer learning models and radiomics models were developed using MRI images of the primary tumor (PT) and largest short-axis LLN (LLLN), visible LLN (VLLN) areas, along with a fusion model that integrates features from both deep transfer learning and radiomics. The diagnostic value of these models for LLN metastasis was analyzed based on postoperative LLN pathology.

Results

Models based on LLLN image information generally outperformed those based on PT image information. Rradiomics models based on LLLN demonstrated improved robustness on external testing cohorts compared to those based on VLLN. Specifically, the radiomics model based on LLLN imaging achieved an AUC of 0.741 in the testing cohort (TUMC) and 0.713 in the testing cohort (GSPH) with the extra trees algorithm.

Conclusion

Data from LLLN is a more reliable basis for predicting LLN metastasis in rectal cancer patients with suspicious LLN metastasis than data from PT. Among models performing adequately on the internal test set, all showed declines on the external test set, with LLLN_Rad_Models being less affected by scanning parameters and data sources.

Management of internal iliac and obturator lymph nodes in mid-low rectal cancer

In rectal cancer treatment, the diagnosis and management of lateral pelvic lymph nodes (LLN) are critical for preventing local recurrence. Over time, scholars have reached a consensus: when imaging suggests LLN metastasis, combining neoadjuvant chemoradiotherapy (nCRT) with selective LLN dissection (LLND) can mitigate the risk of recurrence. Selective LLND typically encompasses lymph nodes in the internal iliac and obturator regions. Recent studies emphasize distinctions between internal iliac and obturator lymph nodes regarding prognosis and treatment outcomes, prompting the need for differentiated diagnostic and treatment approaches.

Management of Surgically Accessible Lymph Nodes Beyond Normal Resection Planes

This article discusses the management of isolated metastatic lymph nodes for colon and rectal cancer. There are traditionally significant differences in how certain regions of lymph nodes for colon and rectal cancer are managed in the East and West. This has led to the development of the lateral lymph node dissection for rectal cancer and extended lymphadenectomy techniques for colon cancer. This article will evaluate the literature on these techniques and what the surgical and oncological outcomes are at this time. In addition, colon and rectal cancers can occasionally have isolated distant lymph node metastases. These would traditionally be treated as systemic disease with chemotherapy. There is consideration though that these could be treated as similar to isolated liver or lung metastases which have been shown to be able to be treated surgically with good oncological results. The literature for these isolated distant lymph node metastases will be reviewed and treatment options available will be discussed.

Feasibility, Indications, and Prognostic Significance of Selective Lateral Pelvic Lymph Node Dissection After Preoperative Chemoradiotherapy in Middle/Low Rectal Cancer: Results of a Multicenter Lateral Node Study in China

BACKGROUND

Lateral pelvic lymph node dissection after preoperative chemoradiotherapy can decrease local recurrence to lateral compartments, thereby providing survival benefits.

OBJECTIVE

The safety of lateral pelvic lymph node dissection after preoperative chemoradiotherapy was investigated, and the surgical indications and survival benefits of lateral pelvic lymph node dissection were established on the basis of preoperative characteristics.

DESIGN

A multicenter retrospective study.

SETTINGS

Three hospitals in China.

PATIENTS

Four hundred nine patients with clinical evidence of lateral pelvic lymph node metastasis.

INTERVENTIONS

Patients who received lateral pelvic lymph node dissection were divided into 2 groups depending on whether they received chemoradiotherapy (n = 139) or not (n = 270).

MAIN OUTCOME MEASURES

The safety, indications, and survival benefits of lateral pelvic lymph node dissection after preoperative chemoradiotherapy were investigated.

RESULTS

The surgery times were significantly prolonged by preoperative chemoradiotherapy (291.3 vs 265.5 min; p = 0.021). Multivariate analysis demonstrated that poor/mucinous/signet-ring adenocarcinoma (OR = 4.42, 95% CI, 2.24-11.27; p = 0.031) and postchemoradiotherapy lateral pelvic lymph node short-axis diameter ≥7 mm (OR = 15.2, 95% CI, 5.89-53.01; p < 0.001) were independent predictive factors for lateral pelvic lymph node metastasis. Multivariate prognostic analysis showed that swollen lateral pelvic lymph nodes beyond the obturator or internal iliac as well as the involvement of 3 or more lateral pelvic lymph nodes were independent adverse prognostic factors.

LIMITATIONS

The retrospective nature of the study and the small sample size were the limitations of this study.

CONCLUSIONS

Preoperative chemoradiotherapy combined with lateral pelvic lymph node dissection is a practicable procedure with acceptable morbidity. Postchemoradiotherapy lateral pelvic lymph node short-axis diameter ≥7 mm and poor/signet/mucinous adenocarcinoma could be used for predicting lateral pelvic lymph node metastasis after chemoradiotherapy. However, lateral pelvic lymph node dissection should be carefully considered in patients with swollen lateral pelvic lymph nodes beyond the obturator or internal iliac region or involvement of multiple lateral pelvic lymph nodes. See Video Abstract at http://links.lww.com/DCR/C133 .

VIABILIDAD, INDICACIONES E IMPORTANCIA PRONSTICA DE LA DISECCIN SELECTIVA DE GANGLIOS LINFTICOS PLVICOS LATERALES DESPUS DE QUIMIORRADIOTERAPIA PREOPERATORIA EN CNCER DE RECTO MEDIO/INFERIOR RESULTADOS DE UN ESTUDIO MULTICNTRICO DE GANGLIOS LATERALES EN CHINA

ANTECEDENTES:La disección de los ganglios linfáticos pélvicos laterales después de la quimiorradioterapia preoperatoria puede disminuir la recurrencia local en los compartimentos laterales, lo que brinda beneficios de supervivencia.OBJETIVO:Se investigó la seguridad de la disección de los ganglios linfáticos pélvicos laterales después de la quimiorradioterapia preoperatoria, y se establecieron las indicaciones quirúrgicas y los beneficios de supervivencia de la disección de los ganglios linfáticos pélvicos laterales en función de las características preoperatorias.DISEÑO:Estudio retrospectivo multicéntrico.ESCENARIO:Tres hospitales en China.PACIENTES:Cuatrocientos nueve pacientes con evidencia clínica de metástasis en los ganglios linfáticos pélvicos laterales.INTERVENCIONES:Los pacientes que recibieron disección de ganglios linfáticos pélvicos laterales se dividieron en dos grupos dependiendo de si recibieron quimiorradioterapia (n = 139) o no (n = 270).PRINCIPALES MEDIDAS DE RESULTADO:Se investigaron la seguridad, las indicaciones y los beneficios de supervivencia de la disección de los ganglios linfáticos pélvicos laterales después de la quimiorradioterapia preoperatoria.RESULTADOS:Los tiempos de cirugía se prolongaron significativamente con la quimiorradioterapia preoperatoria (291,3 vs 265,5 min, p = 0,021). El análisis multivariable demostró que el adenocarcinoma mal diferenciado/mucinoso/en anillo de sello (odds ratio = 4,42, intervalo de confianza del 95%, 2,24-11,27; p = 0,031) y el diámetro del eje corto de los ganglios linfáticos pélvicos laterales después de la quimiorradioterapia ≥7 mm (odds ratio = 15,2, intervalo de confianza del 95%, 5,89-53,01; p < 0,001) fueron factores predictivos independientes de metástasis en los ganglios linfáticos pélvicos laterales. El análisis pronóstico multivariable mostró que la inflamación de los ganglios linfáticos pélvicos laterales más allá del obturador o la ilíaca interna, así como la afectación de tres o más ganglios linfáticos pélvicos laterales, eran factores pronósticos adversos independientes.LIMITACIONES:La naturaleza retrospectiva del estudio y el pequeño tamaño de la muestra.CONCLUSIONES:La quimiorradioterapia preoperatoria combinada con la disección de los ganglios linfáticos pélvicos laterales es un procedimiento practicable con una morbilidad aceptable. Posterior a la quimiorradioterapia, el diámetro del eje corto de los ganglios linfáticos pélvicos laterales ≥7 mm y el adenocarcinoma pobre/en sello/mucinoso podrían usarse para predecir la metástasis en los ganglios linfáticos pélvicos laterales después de la quimiorradioterapia. Sin embargo, la disección de los ganglios linfáticos pélvicos laterales debe considerarse cuidadosamente en pacientes con ganglios linfáticos pélvicos laterales inflamados más allá del obturador o de la región ilíaca interna o compromiso de múltiples ganglios linfáticos pélvicos laterales. Consulte Video Resumen en http://links.lww.com/DCR/C133 . (Traducción-Dr. Felipe Bellolio ).

A radiomics model based on T2WI and clinical indexes for prediction of lateral lymph node metastasis in rectal cancer

OBJECTIVE

The aim of this study was to explore the clinical value of a radiomics prediction model based on T2-weighted imaging (T2WI) and clinical indexes in predicting lateral lymph node (LLN) metastasis in rectal cancer patients.

METHODS

This was a retrospective analysis of 106 rectal cancer patients who had undergone LLN dissection. The clinical risk factors for LLN metastasis were selected by multivariable logistic regression analysis of the clinical indicators of the patients. The LLN radiomics features were extracted from the pelvic T2WI of the patients. The least absolute shrinkage and selection operator algorithm and backward stepwise regression method were adopted for feature selection. Three LLN metastasis prediction models were established through logistic regression analysis based on the clinical risk factors and radiomics features. Model performance was assessed in terms of discriminability and decision curve analysis in the training, verification and test sets.

RESULTS

The model based on the combined T2WI radiomics features and clinical risk factors demonstrated the highest accuracy, surpassing the models based solely on either T2WI radiomics features or clinical risk factors. Specifically, the model achieved an AUC value of 0.836 in the test set. Decision curve analysis revealed that this model had the greatest clinical utility for the vast majority of the threshold probability range from 0.4 to 1.0.

CONCLUSION

Combining T2WI radiomics features with clinical risk factors holds promise for the noninvasive assessment of the biological characteristics of the LLNs in rectal cancer, potentially aiding in therapeutic decision-making and optimizing patient outcomes.

Lateral lymph node involvement presents another challenge in rectum cancer in the age of neoadjuvant chemoradiotherapy + total mesorectal excision: an evaluation of survival outcomes

PURPOSE

In the last decades, total mesorectal excision (TME) and neoadjuvant chemoradiotherapy (nCRT) have produced an undeniable improvement in the treatment of rectal cancer. However, local recurrence is still an important problem, and the effect of lateral lymph node (LLN) involvement on local recurrence is a controversial issue. The aim of this study was to investigate the effects of LLN status on local recurrence and survival in rectal cancers treated with nCRT + TME.

METHODS

Clinical features, pre- and post-nCRT lateral pelvic region imaging, long-term local recurrence, and the survival outcomes of 114 patients who underwent nCRT + TME for rectal cancer were evaluated.

RESULTS

On MRI before nCRT, 20 (17.5%) patients had lateral lymph nodes (LLN+), and 94 (82.5%) patients had no lymph nodes in the lateral pelvic compartments (LLN-). Local recurrences at 1 year in LLN+ and LLN- patients were 3 (15.8%) and 2 (2.3%), respectively (p=0.039). Five-year local recurrence-free survival rates and the mean duration of recurrence-free survival in LLN+ and LLN- patients were 56.2%, 42.6 months, and 87.3% 66.9 months, respectively (p=0.001). Disease-free survival and overall survival were shorter in LLN+ patients, but the difference was not statistically significant (p=0.096 and p=0.46, respectively). In the multivariate analysis, LLN involvement was determined to be an independent risk factor for local recurrence-free survival (Hazard Ratio 4.54, p=0.003).

CONCLUSION

Lateral lymph node involvement causes local recurrence to remain high after nCRT + TME. LLN status should be considered in treatment planning. Further studies are needed to define precise criteria for LLN involvement and the effect of LLND on local recurrence and survival.

Risk factors for lateral pelvic lymph node metastasis in patients with lower rectal cancer: a systematic review and meta-analysis

Background and objective

Lateral pelvic lymph node (LPLN) metastasis is one of the prominent reasons for local recurrence (LR) in patients with rectal cancer (RC). The evaluation criteria of lateral lymph node dissection (LLND) for patients in eastern (mainly in Japan) and western countries have been controversial. The aim of this study was to analyse the risk factors for LPLN metastasis in order to guide surgical methods.

Methods

We searched relevant databases (Embase (Ovid), Medline (Ovid), PubMed, Cochrane Library, and Web of Science) for articles published between 1 January 2000 and 05 October 2022 to evaluate the risk factors for LPLN metastasis in patients with RC in this meta-analysis.

Results

A total of 24 articles with 5843 patients were included in this study. The overall results showed that female sex, age <60 years, pretherapeutic CEA level >5 ng/ml, clinical T4 stage (cT4), clinical M1 stage (cM1), distance of the tumour from the anal verge (AV) <50 mm, tumour centre located below the peritoneal reflection (Rb), short axis (SA) of LPLN ≥8 mm before nCRT, short axis (SA) of LPLN ≥5 mm after nCRT, border irregularity of LPLN, tumour size ≥50 mm, pathological T3-4 stage (pT3-4), pathological N2 stage (pN2), mesorectal lymph node metastasis (MLNM), lymphatic invasion (LI), venous invasion (VI), CRM (+) and poor differentiation were significant risk factors for LPLN metastasis (P <0.05).

Conclusion

This study summarized almost all potential risk factors of LPLN metastasis and expected to provide effective treatment strategies for patients with LRC. According to the risk factors of lateral lymph node metastasis, we can adopt different comprehensive treatment strategies. High-risk patients can perform lateral lymph node dissection to effectively reduce local recurrence; In low-risk patients, we can avoid overtreatment, reduce complications and trauma caused by lateral lymph node dissection, and maximize patient survival and quality of life.

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 ).

Lateral Lymph Node Size and Tumor Distance From Anal Verge Accurately Predict Positive Lateral Pelvic Lymph Nodes in Rectal Cancer: A Multi-Institutional Retrospective Cohort Study

BACKGROUND

Lateral pelvic lymph node dissection improves oncological outcomes in rectal cancer patients with suspected lateral pelvic lymph node metastasis. However, the indication for this procedure remains unclear.

OBJECTIVE

This study aimed to identify the predictive factors for lateral lymph node metastasis and the indications for lateral pelvic lymph node dissection.

DESIGN

A multi-institutional retrospective study.

SETTINGS

This study was conducted at 3 university hospitals.

PATIENTS

This study involved 105 patients with locally advanced mid/low rectal cancer and clinically suspected lateral pelvic lymph node metastasis who underwent total mesorectal excision with lateral pelvic lymph node dissection between 2015 and 2020.

MAIN OUTCOME MEASURES

Indications were set using lateral pelvic lymph node metastasis-associated preoperative factors.

RESULTS

Among 105 patients, 36 (34.3%) had pathologically confirmed lateral pelvic lymph node metastasis and 77 (73.3%) underwent preoperative chemoradiation. Tumors located within 5 cm distance from the anal verge ( p = 0.02) and initial node size ≥ 6 mm ( p = 0.001) were significant predictors of lateral pelvic lymph node metastasis. The sensitivity was 100% (36/36) with a cutoff of 6 mm for the initial node size and 94.4% (34/36) with a cutoff of 8 mm for the initial node size. When using initial node size cutoffs of 8 mm for anal verge-to-tumor distance of >5 cm and 6 mm for anal verge-to-tumor distance of ≤5 cm, the sensitivity of lateral pelvic lymph node metastasis was found to be 100%.

LIMITATIONS

The retrospective design and small sample size were the limitations of this study.

CONCLUSION

Initial node size and tumor height were significant predictors of lateral pelvic lymph node metastasis. This study proposed that an initial node size of ≥8 mm with an anal verge-to-tumor distance of >5 cm and ≥6 mm with an anal verge-to-tumor distance of ≤5 cm are optimal indications for lateral pelvic lymph node dissection in rectal cancer. See Video Abstract at http://links.lww.com/DCR/C101 .

EL TAMAO DEL GANGLIO LINFTICO LATERAL Y LA DISTANCIA DEL TUMOR DESDE EL BORDE ANAL PREDICEN CON PRECISIN LOS GANGLIOS LINFTICOS PLVICOS LATERALES POSITIVOS EN EL CNCER DE RECTO UN ESTUDIO DE COHORTE RETROSPECTIVO MULTIINSTITUCIONAL

ANTECEDENTES:La disección de los ganglios linfáticos pélvicos laterales mejora los resultados oncológicos en pacientes con cáncer de recto con sospecha de metástasis en los ganglios linfáticos pélvicos laterales. Sin embargo, la indicación de este procedimiento sigue sin estar clara.OBJETIVO:Nuestro objetivo fue identificar los factores predictivos de la metástasis de los ganglios linfáticos laterales y las indicaciones para la disección de los ganglios linfáticos pélvicos laterales.DISEÑO:Estudio retrospectivo multiinstitucional.AJUSTES:Este estudio se realizó en tres hospitales universitarios.PACIENTES:Este estudio involucró a 105 pacientes con cáncer de recto medio/bajo localmente avanzado y sospecha clínica de metástasis en los ganglios linfáticos pélvicos laterales que se sometieron a una escisión mesorrectal total con disección de los ganglios linfáticos pélvicos laterales entre 2015 y 2020.PRINCIPALES MEDIDAS DE RESULTADO:Las indicaciones se establecieron utilizando los factores preoperatorios asociados con la metástasis de los ganglios linfáticos pélvicos laterales.RESULTADOS:Entre 105 pacientes, 36 (34,3%) tenían metástasis en los ganglios linfáticos pélvicos laterales confirmada patológicamente y 77 (73,3%) se sometieron a quimiorradiación preoperatoria. Los tumores ubicados dentro de los 5 cm desde el borde anal ( p = 0,02) y el tamaño inicial del ganglio ( p = 0,001) fueron predictores significativos de metástasis en los ganglios linfáticos pélvicos laterales. La sensibilidad fue del 100 % (36/36), con un punto de corte de 6 mm para el tamaño inicial del ganglio, seguido de 8 mm para el tamaño inicial del ganglio (94,4%, 34/36). Cuando se utilizó un tamaño de corte inicial del ganglio de 8 mm para una distancia entre el borde anal y el tumor >5 cm y 6 mm para una distancia entre el borde anal y el tumor ≤5 cm, la sensibilidad de la metástasis en los ganglios linfáticos pélvicos laterales fue del 100 %.LIMITACIONES:El diseño retrospectivo y el pequeño tamaño de la muestra.CONCLUSIONES:El tamaño inicial del ganglio y la altura del tumor fueron predictores significativos de metástasis en los ganglios linfáticos pélvicos laterales. Este estudio propuso que un tamaño de ganglio inicial de ≥8 mm con un tumor a >5 cm del margen anal y ≥6 mm con un tumor a ≤5 cm del margen anal son indicaciones óptimas para la disección de los ganglios linfáticos pélvicos laterales en el cáncer de recto. Consulte Video Resumen en http://links.lww.com/DCR/C101 . (Traducción-Dr. Yolanda Colorado ).

Robotic and laparoscopic salvage lateral pelvic node dissection for the treatment of recurrent rectal cancer

BACKGROUND

The lateral pelvic sidewall is a major site of local recurrence after radical resection of rectal cancer. Salvage lateral pelvic node dissection (LPND) may be the only way to eliminate recurrent lateral pelvic nodes (LPNs). This study aimed to describe the technical details of robotic and laparoscopic salvage LPND and assess the short-term clinical and oncological outcomes in patients with recurrent LPNs who underwent salvage LPND by a minimally invasive approach for curative intent.

METHODS

Between September 2010 and 2019, 36 patients who underwent salvage surgery for LPN recurrence were retrospectively analyzed from a prospectively maintained database. Patients' characteristics, index operation, MRI findings, and perioperative and pathological outcomes were analyzed.

RESULTS

Eleven and 14 patients underwent robotic and laparoscopic salvage LPND, respectively. Eight patients (32.0%) underwent a combined salvage operation for resectable extra-pelvic sidewall metastases. There were four cases of open-conversion during the laparoscopic approach due to uncontrolled bleeding of iliac vessels. In these patients, metastatic LPNs were suspected of iliac vessel invasion and were found to be larger in size (median 15 mm; range 12-20) than that in patients who underwent successful LPND using the minimally invasive approach (median 10 mm; range 5-20). The median number of metastatic LPNs and harvested LPNs was 1 (range 0-3) and 6 (range 1-16), respectively. Six patients (24.0%) experienced postoperative complications including lymphoceles and voiding difficulties. During the follow-up (median 44.6 months; range 24.0-87.7), eight patients developed recurrences, mainly the lung and para-aortic lymph nodes, and one patient developed pelvic sidewall recurrence after laparoscopic salvage LPND. The 3-year disease-free survival and overall survival after salvage LPND were 66.4% and 79.2%, respectively.

CONCLUSIONS

Robotic and laparoscopic salvage LPND for recurrent LPNs are safe and feasible with favorable short-term surgical outcomes. However, the surgical approach should be carefully chosen in patients with large-sized and invasive recurrent LPNs.

Total neoadjuvant treatment to increase the clinical complete response rate for distal locally advanced rectal cancer (TESS): A study protocol of a prospective, open-label, multicenter, single-arm, phase 2 trial

BACKGROUND

Standard treatment of locally advanced rectal cancer (LARC) was neoadjuvant chemoradiotherapy (CRT), followed by total mesorectal excision (TME). Total neoadjuvant treatment (TNT), a new concept, attempts to deliver both systemic chemotherapy and neoadjuvant CRT prior to surgery. Patients treated with neoadjuvant chemotherapy were more likely to show higher tumor regression. The objective of this trial was to increase complete clinical rate (cCR) for LARC patients by optimizing tumor response, using TNT regimen as compared to conventional chemoradiotherapy. TESS, a prospective, open-label, multicenter, single-arm, phase 2 study, is underway.

METHODS

Main inclusion criteria include cT3-4aNany or cT1-4aN+ rectal adenocarcinoma aged 18-70y; Eastern Cooperative Oncology Group (ECOG) performance 0-1; location ≤5 cm from anal verge. Ninety-eight patients will receive 2 cycles of neoadjuvant chemotherapy Capeox (capecitabine + oxaliplatin) before, during, and after radiotherapy 50Gy/25 fractions, before TME (or other treatment decisions, such as Watch and Wait strategy) and adjuvant chemotherapy capecitabine 2 cycles. Primary endpoint is the cCR rate. Secondary endpoints include ratio of sphincter preservation strategy; pathological complete response rate and tumor regression grade distribution; local recurrence or metastasis; disease-free survival; locoregional recurrence-free survival; acute toxicity; surgical complications; long-term anal function; late toxicity; adverse effect, ECOG standard score, and quality of life. Adverse events are graded per Common Terminology Criteria for Adverse Events V5.0. Acute toxicity will be monitored during antitumor treatment, and late toxicity will be monitored for 3 years from the end of the first course of antitumor treatment.

DISCUSSION

The TESS trial aims to explore a new TNT strategy, which is expected to increase the rate of cCR and sphincter preservation rate. This study will provide new options and evidence for a new sandwich TNT strategy in patients with distal LARC.

Establishing and validating predictive nomograms for lateral pelvic lymph node metastasis in patients with rectal cancer based on radiologic factors and clinicopathologic characteristics

INTRODUCTION

It is critical to accurately predict the occurrence of lateral pelvic lymph node (LPN) metastasis. Currently, verified predictive tools are unavailable. This study aims to establish nomograms for predicting LPN metastasis in patients with rectal cancer who received or did not receive neoadjuvant chemoradiotherapy (nCRT).

MATERIALS AND METHODS

We carried out a retrospective study of patients with rectal cancer and clinical LPN metastasis who underwent total mesorectal excision (TME) and LPN dissection (LPND) from January 2012 to December 2019 at 3 institutions. We collected and evaluated their clinicopathologic and radiologic features, and constructed nomograms based on the multivariable logistic regression models.

RESULTS

A total of 472 eligible patients were enrolled into the non-nCRT cohort (n = 312) and the nCRT cohort (n = 160). We established nomograms using variables from the multivariable logistic regression models in both cohorts. In the non-nCRT cohort, the variables included LPN short diameter, cT stage, cN stage, histologic grade, and malignant features, and the C-index was 0.930 in the training cohort and 0.913 in the validation cohort. In the nCRT cohort, the variables included post-nCRT LPN short diameter, ycT stage, ycN stage, histologic grade, and post-nCRT malignant features, and the C-index was 0.836 in the training dataset and 0.827 in the validation dataset. The nomograms in both cohorts were moderately calibrated and well-validated.

CONCLUSIONS

We established nomograms for patients with rectal cancer that accurately predict LPN metastasis. The performance of the nomograms in both cohorts was high and well-validated.

Clinical implication and management of rectal cancer with clinically suspicious lateral pelvic lymph node metastasis: A radiation oncologist's perspective

Rectal cancer is the eighth most common malignancy worldwide. With the introduction of total mesorectal excision (TME) and neoadjuvant chemoradiation (NCRT), intrapelvic local control has been remarkably improved. However, lateral pelvic recurrence remains problematic, especially in patients with clinically suspicious lateral pelvic lymph node (LPLN). LPLN dissection has been applied for the management of LPLN metastasis, mainly in Japan and other Eastern countries, while the role of NCRT is more emphasized and LPLN dissection is performed in very limited cases in Western countries. However, the optimal management strategy for patients with rectal cancer with suspicious LPLN metastasis has not been determined. Herein, we review the latest studies on the optimal management of LPLN metastasis to suggest the most appropriate treatment policies according to current evidence and discuss future research directions.

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.

Identification of patient subgroups with low risk of postoperative local recurrence for whom total mesorectal excision surgery alone is sufficient: a multicenter retrospective analysis

PURPOSE

For rectal cancer, a multimodality approach is mandatory including neoadjuvant chemoradiotherapy, neoadjuvant chemotherapy, and lateral pelvic lymph node (LPLN) dissection, in addition to the total mesorectal excision (TME). However, these treatments are associated with adverse events. It is important to select patients who do or do not need these treatments.

METHODS

We retrospectively analyzed patients with cStage II and III rectal cancer who underwent curative resection at three hospitals. Recurrence patterns were classified into three types; pelvic cavity, LPLN, and distant recurrences, and the risk factors for each pattern of recurrence were compared. We then analyzed the risk of recurrence in the patients who underwent TME alone.

RESULTS

In total, 506 patients were enrolled in this study. Pelvic cavity recurrence was significantly associated with clinical assumption of circumferential resection margin involvement (cCRM) (p < 0.001), distant recurrence was associated with cN positivity (p < 0.001), and LPLN recurrence was associated with pretreatment LPLN swelling ≥ 5 mm (p < 0.001), lower tumor location (p = 0.016), and serum CEA level > 5 ng/mL (p = 0.008). In patients without cCRM and swollen LPLN, the local recurrence rate was extremely low even if they underwent TME alone; the 5-year recurrence rates of pelvic cavity and LPLN were 2.2% and 1.9%, respectively.

CONCLUSION

Additional treatments to TME for rectal cancer need to be performed based on the risk factors for each recurrence pattern.

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.

Stepwise Improvement of Surgical Quality in Robotic Lateral Pelvic Node Dissection: Lessons From 100 Consecutive Patients With Locally Advanced Rectal Cancer

BACKGROUND

Lateral pelvic node dissection has significant technical difficulty and a high incidence of surgical morbidity. A steep learning curve is anticipated in performing lateral pelvic node dissection. However, no study has previously analyzed the learning curve and surgical skill acquisition for this complex procedure.

OBJECTIVES

We aimed to evaluate the learning process for performing robotic total mesorectal excision with lateral pelvic node dissection in patients with rectal cancer.

DESIGN

This is a retrospective analysis of a prospectively collected database.

SETTING

This study was conducted at a tertiary cancer center.

PATIENTS

A total of 100 patients who underwent robotic total mesorectal excision with lateral pelvic node dissection between 2011 and 2017 were included.

MAIN OUTCOME MEASURES

A cumulative sum analysis was calculated based on the number of unilateral retrieved lateral pelvic nodes. Operative time, estimated bloodloss, lateral pelvic node metastatic rate, postoperative morbidities, and local recurrence were also analyzed.

RESULTS

Cumulative sum modeling suggested 4 learning phases: learning I (33 patients), learning II (19 patients), consolidation (30 patients), and competence (18 patients). In the consolidation and competence phases, we adopted fluorescence imaging and standardized the surgical procedure on the basis of anatomical planes. The competence phase had the greatest number of unilateral retrieved lateral pelvic nodes (12.8 vs 4.9, 8.2, and 10.4; p < 0.001). Urinary complications, including urinary retention and postoperative α-blocker usage, were more frequently observed in learning phase I than in the competence phase (39.4% vs 16.7%, p = 0.034). During the median follow-up of 44.2 months, local recurrence in the pelvic sidewall was observed in 4 patients from learning phase I and in 1 patient from learning phase II.

LIMITATIONS

This study was limited by its retrospective design.

CONCLUSION

Completeness of the lateral pelvic node dissection procedure increased with the surgeon's experience and as new imaging systems and surgical technique standardization were implemented. Further studies are warranted to determine the oncologic outcomes associated with each phase. See Video Abstract at http://links.lww.com/DCR/B774.

MEJORA GRADUAL DE LA CALIDAD QUIRRGICA EN LA DISECCIN LINFTICA PLVICA LATERAL ROBTICA LECCIONES DE PACIENTES CONSECUTIVOS CON CNCER DE RECTO LOCALMENTE AVANZADO

ANTECEDENTES:La disección linfática pélvica lateral tiene una dificultad técnica significativa y una alta incidencia de morbilidad quirúrgica. Se prevé una curva de aprendizaje muy pronunciada al realizar la disección linfática pélvica lateral. Sin embargo, ningún estudio ha analizado previamente la curva de aprendizaje y la adquisición de habilidades quirúrgicas para este procedimiento.OBJETIVOS:Nuestro objetivo fue evaluar el proceso de aprendizaje para realizar la escisión total de mesorrecto robótica con disección linfática pélvica lateral en pacientes con cáncer de recto.DISEÑO:Este es un análisis retrospectivo de una base de datos recopilada prospectivamente.AJUSTE:Este estudio se realizó en un centro oncológico terciario.PACIENTES:Un total de 100 pacientes fueron sometidos a escisión total de mesorrecto robótica con disección linfática pélvica lateral entre 2011 y 2017.PRINCIPALES MEDIDAS DE DESENLACE:Se calculó un análisis de suma acumulativa basado en el número unilateral de ganglios pélvicos laterales recuperados. También se analizaron el tiempo operatorio, la pérdida de sangre estimada, la tasa de metástasis ganglionares pélvicas laterales, las morbilidades postoperatorias y la recidiva local.RESULTADOS:El modelado total acumulativo sugirió cuatro fases de aprendizaje: aprendizaje I (33 pacientes), aprendizaje II (19 pacientes), consolidación (30 pacientes) y competencia (18 pacientes). En las fases de consolidación y competencia, adoptamos imágenes de fluorescencia y estandarizamos el procedimiento quirúrgico basado en planos anatómicos, respectivamente. La fase de competencia tuvo el mayor número de ganglios pélvicos laterales recuperados unilateralmente (12,8 frente a 4,9, 8,2 y 10,4; p < 0,001). Las complicaciones urinarias, incluida la retención urinaria y el uso posoperatorio de bloqueadores beta, se observaron con más frecuencia en la fase de aprendizaje I que en la fase de competencia (39,4% frente a 16,7%, p = 0,034). Durante la mediana de seguimiento de 44,2 meses, se observó una recidiva local en la pared lateral pélvica en cuatro pacientes de la fase de aprendizaje I y en un paciente de la fase de aprendizaje II.LIMITACIONES:Este estudio estuvo limitado por su diseño retrospectivo.CONCLUSIÓNES:La completitud del procedimiento de disección linfática pélvica lateral aumentó con la experiencia del cirujano y a medida que se implementaron nuevos sistemas de imágenes y estandarización de técnicas quirúrgicas. Se necesitan más estudios para determinar los resultados oncológicos asociados con cada fase. Consulte Video Resumen en http://links.lww.com/DCR/B774.

Functional outcomes after lateral pelvic lymph node dissection for rectal cancer: a systematic review and meta-analysis

PURPOSE

Lateral pelvic lymph node dissection (LPLND) may improve oncological outcomes for select patients with rectal cancer, though functional outcomes may be adversely impacted. The aim of this study is to assess the functional outcomes associated with LPLND for rectal cancer and compare these outcomes with standard surgical resection.

METHODS

A systematic search was undertaken to identify relevant studies reporting on urinary dysfunction (UD), sexual dysfunction (SD), and defecatory dysfunction (DD) for patients who underwent LPLND for rectal cancer. Studies comparing functional outcomes in patients who underwent surgery with and without LPLND were assessed. In addition, a comparison of functional outcomes in patients who underwent LPLND before and after the year 2000 was performed.

RESULTS

Twenty-one studies of predominantly non-randomised observational data were included. Ten were comparative studies. Male SD was worse in patients who underwent LPLND compared with those who did not (RR 1.68 (95% CI 1.41-1.99, P < 0.001)). No difference was observed for the rate of UD between treatment groups. The rates of UD and male SD in patients who underwent LPLND after the year 2000 were significantly lower than those who underwent LPLND before the year 2000 ((UD) RR = 4.5, p value = 0.0034; male SD RR = 28.7, p value < 0.001).

CONCLUSION

Lateral pelvic lymph node dissection is associated with worse male sexual dysfunction compared to standard surgical resection. However, the rates of urine dysfunction and male sexual dysfunction are better in contemporary cohorts which may reflect improved surgical technique and autonomic nerve preservation.

Evaluation of the SYNAPSE VINCENT for lateral lymph node dissection in rectal cancer with robotic surgery: a preliminary report

Background

Even if 3D angiographic images of preoperative contrast-enhanced computed tomography (CT) are created, the coronal and axial sections can be unclear, and thus, it is difficult to achieve projection awareness similar to that of actual laparoscopic images. In recent years, the technology of analyzing and applying medical images has advanced, and surgical simulation and navigation have been widely used to improve the safety of surgical operations. It is important to understand pelvic anatomy in the area of rectal cancer, and use of the SYNAPSE VINCENT makes it possible to simulate the anatomy before surgery, which is very useful in educating surgeons and their assistants.

Materials and methods

An important objective in surgery is to understand the anatomy of the external/internal iliac arteries and lymph nodes in lateral lymph node dissection (LLD) for rectal cancer. In this study, we explored the accuracy and usefulness of SYNAPSE VINCENT images of pelvic anatomy (especially vascular anatomy) analyzed preoperatively in two cases of LLD for rectal cancer in our department.

Results

The patients were two men aged 73 and 57 years, respectively. Both patients underwent robotic abdominal perineal resection and LLD with neoadjuvant chemoradiotherapy. The operating times for LLD were 138 and 106 min, estimated blood loss was less than 10 mL and 20 mL, and the harvested lymph nodes were nos. 21 and 22, respectively. The SYNAPSE VINCENT could be used for simulation and navigation before and during surgery. For experienced surgeons, the system helped them carry out operations more accurately.

Conclusion

In the future, surgical support using virtual reality, augmented reality, and mixed reality based on medical images will be useful and is expected to improve the safety, accuracy, and efficiency of surgery, which is extremely useful for both young and skilled surgeons preparing for difficult operations.

A case report of the transanal lateral lymph node dissection with a combined abdominal assisted approach for the lower rectal cancer

Introduction

Low and mid rectal cancer cells have the tendency to spread in the lateral pelvic lymph node (LPLN). The Japanese guidelines recommend systematic lymph node dissection when a positive LPLN is suspected or in stages II–III rectal cancer. However, laparoscopic lymph node dissection is complex and challenging. We introduce transanal LPLN dissection using an abdominal approach.

Presentation of case

A 78-year-old man was diagnosed with advanced rectal cancer. Computed tomography and magnetic resonance imaging showed lower rectal wall thickening and bilateral lateral lymph node swelling. We performed laparoscopic abdominal peritoneal resection with combined bilateral LPLN dissection using abdominal and transanal approaches. He had an uneventful postoperative course with no signs of recurrence at the 5-month follow-up.

Discussion

LPLN metastases for low rectal cancer especially occur at the bottom of the deep pelvic spaces. As laparoscopic LPLND for low rectal cancer can be complicated, we adopted abdominal and transanal approaches, which provide the advantage of an anatomical view. This procedure may improve lateral pelvic anatomical structure viewing, and may offer advantages over laparoscopic abdominal approaches for visualizing and dissecting LPLNs.

Conclusion

Curative resection has become available for rectal cancer with transanal LPLN dissection. LPLN dissection with combined abdominal and transanal approaches is a feasible treatment for advanced rectal cancer.

•

Laparoscopic lymph node dissection for low rectal cancer is complex and challenging.

•

The surgical view around the distal internal lymph node (#263d) and the Alcock duct improved with the transanal approach.

•

Ta-LPLND combined with abdominal dissection is feasible and effective for rectal cancer.

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.

Risk factors and prognostic significance of lateral pelvic lymph node dissection after neoadjuvant chemoradiotherapy for rectal patients with clinically suspected lateral lymph node metastasis

AIM

It is still controversial whether the addition of lateral pelvic lymph node (LPN) dissection (LPND) to total mesorectal excision (TME) can provide a survival benefit after neoadjuvant chemoradiotherapy (nCRT) in rectal cancer patients with pathological lateral lymph node metastasis (LPNM).

METHODS

Patients with clinically suspected LPNM who underwent nCRT followed by TME + LPND were systematically reviewed and divided into the positive LPN group (n = 15) and the negative LPN group (n = 58). Baseline characteristics, clinicopathological data and survival outcomes were collected and analysed.

RESULTS

Of the 73 patients undergoing TME + LPND after nCRT, the pathological LPNM rate was 20.5% (15/73). Multivariate analysis showed that a post-nCRT LPN short diameter ≥ 7 mm (OR 49.65; 95% CI 3.98-619.1; P = 0.002) and lymphatic invasion (OR 9.23; 95% CI 1.28-66.35; P = 0.027) were independent risk factors for pathological LPNM. The overall recurrence rate of patients with LPNM was significantly higher than that of patients without LPNM (60.0% vs 27.6%, P = 0.018). Multivariate regression analysis identified that LPNM was an independent risk factor not only for overall survival (OS) (HR 3.82; 95% CI 1.19-12.25; P = 0.024) but also for disease-free survival (DFS) (HR 2.33; 95% CI 1.02-5.14; P = 0.044). Moreover, N1-N2 stage was another independent risk factor for OS (HR 7.41; 95% CI 1.63-33.75; P = 0.010).

CONCLUSIONS

Post-nCRT LPN short diameter ≥ 7 mm and lymphatic invasion were risk factors for pathological LPNM after nCRT. Furthermore, patients with pathological LPNM still show an elevated overall recurrence rate and poor prognosis after TME + LPND. Strict patient selection and intensive perioperative chemotherapy are crucial factors to ensure the efficacy of LPND.

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.

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.

The Addition of Preoperative Radiation Is Insufficient for Lateral Pelvic Control in a Subgroup of Patients With Low Locally Advanced Rectal Cancer: A Post Hoc Study of a Randomized Controlled Trial

BACKGROUND

The local recurrence of rectal cancer has been improved by total mesorectal excision following neoadjuvant chemoradiotherapy. However, in patients with low locally advanced rectal cancer, lateral pelvic recurrence remains to be addressed.

OBJECTIVE

This study aimed to determine the efficiency of neoadjuvant radiotherapy in addressing lateral pelvic recurrence and which subgroup of patients might be optimal to receive lateral lymph node dissection.

DESIGN

The MRI/CT images were reassessed for lateral lymph node status. The lateral lymph nodes with short axis ≥5 mm and ≥4 mm were considered positive in pretreatment and restaging MRI/CT.

SETTING

This was a post hoc analysis of a prospective randomized controlled trial (FOWARC, NCT01211210).

PATIENTS

A total of 495 patients with stage II or III rectal adenocarcinoma were included in the original trial. According to the excluding criteria, the finally included population consists of 253 patients; of these, 195 patients received neoadjuvant chemoradiotherapy and 94 received chemotherapy alone.

MAIN OUTCOMES AND MEASURES

The primary outcome was the 5-year lateral pelvic recurrence rate.

RESULTS

Compared with patients receiving chemotherapy alone, patients receiving additional radiotherapy had a marginal significance of lower lateral pelvic recurrence rate (6.6% vs 13.0%; p = 0.051). In the subset with pretreatment positive lateral lymph nodes, patients had a lateral pelvic recurrence rate of 22.6% and 45.1% after neoadjuvant chemoradiotherapy and chemotherapy alone. Of note, 34.9% of the pretreatment positive lateral lymph nodes were persistent after neoadjuvant chemoradiotherapy, culminating in a lateral pelvic recurrence rate of 63.3%.

LIMITATIONS

This is a post hoc analysis, and only the patients from the leading center were included, which limited the sample size. In addition, the lateral lymph node dissection was not performed in this cohort.

CONCLUSIONS

The addition of radiotherapy in neoadjuvant regimens could not address lateral pelvic recurrence adequately. Some subgroups of patients might need additional dissection. See Video Abstract at http://links.lww.com/DCR/B613.

LA INCLUSION DE LA RADIOTERAPIA PREOPERATORIA ES INSUFICIIENTE EN EL CONTROL PLVICO LATERAL EN UN SUBGRUPO DE PACIENTES CON CNCER DE RECTO INFERIOR LOCALMENTE AVANZADO UN ESTUDIO POSTHOC CONTROLADO Y RANDOMIZADO

ANTECEDENTES:La recurrencia local del cancer de recto ha disminuido al efectuar una excision mesorrectal total seguida de quimioradioterapia neoadyuvante. No obstante, en pacientes con cancer de tercio inferior de recto avanzado localmente, aún está por controlarse la recurrencia pélvicaOBJETIVOS:Determinar la eficacia de la radioterapia neoadyuvante en el control de la recurrencia pélvica lateral y en que subgrupo de pacientes sería conveniente efecutar una excisión lateral de las cadenas ganglionares.DISEÑO:Se reevaluaron las imágenes tomográficas y de resonancia magnética del status de las cadenas ganglionares linfáticas laterales. Los ganglios linfáticos laterales con un eje-corto > 5 mm y ≥ 4 mm se consideraron como positivos previo al tratamiento y reestadificados con RM y TAC respectivamente.ESCENARIO:Es un análisis post hoc de un studio prospectivo randomizado controlado (FOWARC, NCT01211210).PACIENTESSe incluyeron un total de 495 pacientes en estdio II o III con adenomcarcinoma rectal en el estudio original. De acuerdo a los criterios de exclusión, la población final incluida consistió en 253 pacientes; de estos, 195 recibieron quimioradioterapia neoadyuvante y 94 quimioterapia sola.EVALUACION DE LOS RESULTADOS PRINCIPALES:El parámetro mas importante fue la tasa de recurrencia pélvica lateral a cinco años.RESULTADOS:En comparación con los pacientes que recibieron quimioterapia sola, aquellos que además fueron sometidos a radioterapia adicional presentaron un margen significativo de menor tasa de recurrencia pélvica lateral (6.6% vs. 13.0%; p=0.051). En el grupo de pacientes con ganglios linfáticos laterales positivos, los enfermos presentaron una tasa de recurrencia pélvica lateral de 22.6% y 45.1% después de quimioradiaterapia neoadyuvante en comparación con quimioterapia sola respectivamente. Cabe mencionar que el 34.9% de los pacientes con ganglios linfáticos laterales positivos antes del tratamiento persistieron después de la quimioradioterapia neoadyuvante, reportándose finalmente una recurrencia pélvica lateral de un 63.3%.LIMITACIONES:Se trata de un análisis posthoc y solo los pacientes del hospital fueron incluidos, lo que limita el tamaño de la muestra. Además, no se efectuó la disección de los ganglios linfáticos laterales en este grupo.CONCLUSIONES:La radioterapia en los esquemas de neoadyuvancia no logran controlar la recurrencia pélvica lateral en forma adecuada. Algunos subgrupos de pacientes podría requerir de disección adicional. Consulte Video Resumen en http://links.lww.com/DCR/B613.

Lateral lymph node dissection in advanced low rectal cancer treatment

Lateral lymph node (LLN) metastasis is a determinant of local recurrence in advanced low rectal cancer. Lateral lymph node dissection (LLND) is effective in removing metastatic lymph nodes, and has been shown to have a decreased local recurrence rate. However, because of its complexity and complications it induces, there is still tremendous controversy about its usage. Neoadjuvant chemoradiotherapy (nCRT) and total mesorectal excision (TME) are recommended as a conventional treatment for advanced rectal cancer. However, LLN metastasis and local recurrence still occur despite nCRT with TME. In Japan, TME with LLND is the standard surgical treatment for Stage II/III of advanced low rectal cancer. Before surgery, a proper evaluation of LLN status should be performed. Laparoscopic LLND and robotic-assisted LLND are useful for this. More research is necessary to improve the oncological outcomes of LLND. In this review, we retrospectively examine previous reports about LLND, aiming to emphasize its application prospects to improve patient survival and life quality.

Lateral pelvic lymph nodes for rectal cancer: A review of diagnosis and management

The current status and future prospects for diagnosis and treatment of lateral pelvic lymph node (LPLN) metastasis of rectal cancer are described in this review. Magnetic resonance imaging (MRI) is recommended for the diagnosis of LPLN metastasis. A LPLN-positive status on MRI is a strong risk factor for metastasis, and evaluation by MRI is important for deciding treatment strategy. LPLN dissection (LPLD) has an advantage of reducing recurrence in the lateral pelvis but also has a disadvantage of complications; therefore, LPLD may not be appropriate for cases that are less likely to have LPLN metastasis. Radiation therapy (RT) and chemoradiation therapy (CRT) have limited effects in cases with suspected LPLN metastasis, but a combination of preoperative CRT and LPLD may improve the treatment outcome. Thus, RT and CRT plus selective LPLD may be a rational strategy to omit unnecessary LPLD and produce a favorable treatment outcome.

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.

Management of Clinically Involved Lateral Lymph Node Metastasis in Locally Advanced Rectal Cancer: A Radiation Dose Escalation Study

Background

Patients with lateral lymph nodes (LLNs) metastasis are not effectively treated with neoadjuvant chemoradiotherapy. This study aimed to compare the efficacy of three neoadjuvant therapeutic regimens, namely, chemotherapy, chemoradiotherapy, and chemoradiotherapy with a dose boost of LLNs, and to identify the optimal approach for treating LLNs metastasis of locally advanced rectal cancer.

Methods

A total of 202 patients with baseline LLNs metastasis (short axis ≥5 mm) and treated with neoadjuvant treatment, followed by radical surgery from 2011 to 2019, were enrolled. The short axis of the LLNs on baseline and restaging MRI were recorded. Survival outcomes were compared.

Results

In the booster subgroup, shrinkage of LLNs was significantly greater than in the neoadjuvant chemotherapy and chemoradiotherapy subgroups (P <0.001), without increasing radiation related side effects (P = 0.121). For patients with baseline LLNs of short axis ≥5 mm in the booster subgroup, the response rate (short axis <5 mm on restaging MRI) was 72.9%, significantly higher than patients in the neoadjuvant chemotherapy subgroup (48.9%, P = 0.007) and higher than for patients in the neoadjuvant chemoradiotherapy group (65.0%), but there was no statistical difference (P = 0.411). The 3-year local recurrence and lateral local recurrence rates were both 2.3% in the dose booster group, which were lower than those of the other two subgroups (local recurrence: P <0.001; lateral local recurrence: P <0.001). The short axis of lateral lymph nodes (≥5 and <5 mm) on restaging MRI was an independent risk factor for prognosis (P <0.05).

Conclusion

Radiation dose boost is an effective way of increasing the response rate and decreasing recurrence rates. The restaging LLNs with short axis ≥5 mm is a predictor of poor prognosis.

The Significance of Lateral Lymph Node Metastasis in Low Rectal Cancer: a Propensity Score Matching Study

BACKGROUND

The indications for lateral lymph node dissection (LLND) in rectal cancer have been controversial. The purpose of this study was to clarify the significance of lateral lymph node metastasis in low rectal cancer.

METHODS

This was a retrospective study at a high-volume cancer center in Japan. In this study, 40 patients with pathologically positive LLN (LLN+) were matched with 175 negative (LLN-) patients by propensity score matching (PSM). COX regression analysis was used to identify independent risk factors related to prognosis. The relapse-free survival rate (RFS) and overall survival rate (OS) of the 2 groups before and after matching were analyzed.

RESULTS

Of the 64 patients undergoing LLND, 40 (62.5%) patients had LLN+ disease. The LLN+ patients showed deeper infiltration of the primary tumor than the LLN- patients (T3-T4: 87.5% vs. 72.0%; p = 0.044), a greater number of metastatic lymph nodes (N2: 75.0% vs. 35.4%; p < 0.001), and a higher rate of local recurrence (30% vs. 9.1%; p < 0.001). Adjuvant chemotherapy was more common in the 40 LLN+ patients than in the 175 LLN- patients (70.0% vs. 46.8%; p = 0.008). After relapse, the rate of first-line chemotherapy administration for LLN+ patients was higher than that for the LLN- patients (62.5% vs. 29.5%; p = 0.005). The RFS of LLN+ patients was shorter than that of the LLN- patients (p = 0.005). After PSM, although more LLN+ patients received adjuvant chemotherapy than the LLN- patients (70.0% vs. 40.0%; p = 0.007), the local recurrence rate remained higher (30% vs. 10%; p = 0.025). The differences between RFS (p = 0.655) and OS rates (p = 0.164) of the 2 patient groups were not significant.

CONCLUSION

Even after LLND, patients with LLN+ low rectal cancer still showed an elevated local recurrence rate. Controlling local recurrence by adjuvant chemotherapy alone is difficult, and the additional strategic treatments are needed.

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

BACKGROUND

In the West, low rectal cancer patients with abnormal lateral lymph nodes (LLNs) are commonly treated with neoadjuvant (chemo)radiotherapy (nCRT) followed by total mesorectal excision (TME). Additionally, some perform a lateral lymph node dissection (LLND). To date, no comparative data (nCRT vs. nCRT + LLND) are available in Western patients.

METHODS

An international multi-centre cohort study was conducted at six centres from the Netherlands, US and Australia. Patients with low rectal cancers from the Netherlands and Australia with abnormal LLNs (≥5 mm short-axis in the obturator, internal iliac, external iliac and/or common iliac basin) who underwent nCRT and TME (LLND-group) were compared to similarly staged patients from the US who underwent a LLND in addition to nCRT and TME (LLND + group).

RESULTS

LLND + patients (n = 44) were younger with higher ASA-classifications and ypN-stages compared to LLND-patients (n = 115). LLND + patients had larger median LLNs short-axes and received more adjuvant chemotherapy (100 vs. 30%; p < 0.0001). Between groups, the local recurrence rate (LRR) was 3% for LLND + vs. 11% for LLND- (p = 0.13). Disease-free survival (DFS, p = 0.94) and overall survival (OS, p = 0.42) were similar. On multivariable analysis, LLND was an independent significant factor for local recurrences (p = 0.01). Sub-analysis of patients who underwent long-course nCRT and had adjuvant chemotherapy (LLND-n = 30, LLND + n = 44) demonstrated a lower LRR for LLND + patients (3% vs. 16% for LLND-; p = 0.04). DFS (p = 0.10) and OS (p = 0.11) were similar between groups.

CONCLUSION

A LLND in addition to nCRT may improve loco-regional control in Western patients with low rectal cancer and abnormal LLNs. Larger studies in Western patients are required to evaluate its contribution.

Effective dissection for rectal cancer with lateral lymph node metastasis based on prognostic factors and recurrence type

PURPOSE

There are no reports showing the significance and effective range of dissection for patients with lateral lymph node metastasis (LLNM). This study aimed to investigate the indications for lateral lymph node dissection (LLND) in patients with LLNM based on prognostic factors and recurrence types.

METHODS

We reviewed 379 patients with advanced rectal cancer who were treated with total mesorectal excision plus LLND. We analyzed background factors and survival times of patients who had LLNM to determine prognostic factors and recurrence types.

RESULTS

Pathological LLNM occurred in 44 (11.6%). Among patients with LLNM, the predictors of poor prognoses, according to univariate analysis, were > 3 node metastases, the presence of node metastasis on both sides, and spreading beyond the internal iliac lymph nodes. Moreover, LLNM beyond the internal iliac region was found to be an independent prognostic risk factor. Twenty-eight of the 44 patients with lateral lymph node metastasis (64%) relapsed, 22 of whom had distant metastases and 11 of whom experienced local recurrences. Among the latter group, nine (20%) and two (5%) had recurrences in the central and lateral pelvis, respectively.

CONCLUSION

The therapeutic benefit of resection was high, especially in patients with ≤ 3 positive lateral lymph nodes, one-sided bilateral lymph node areas, and positive nodes localized near the internal iliac artery.

Management of lateral pelvic lymph nodes by Australasian colorectal surgeons: An insight from the west

PURPOSE

Lateral pelvic lymph node dissection (LPLND) for locally advanced low rectal cancer is a common practice in Japan. However, it is not widely performed in western countries. The aim of this survey study is to assess the current practice and management of lateral pelvic lymph nodes by colorectal surgeons in Australasia.

METHODS

The authors developed a survey to assess surgeons' assessment and management of lateral pelvic lymph nodes in patients with rectal cancer. The survey was run through the online RedCap® platform in 2019. An electronic link and request to complete the survey was sent to specialist surgeons of the Colorectal Surgical Society of Australia and New Zealand (CSSANZ).

RESULTS

Ninety-two colorectal surgeons completed the online survey (32% response rate). Eighty percent of participants consider malignant lateral pelvic lymph nodes to represent locoregional and resectable disease. In patients with clinically malignant lateral pelvic lymph nodes on preoperative imaging the majority of respondents (92%) recommend neoadjuvant chemoradiotherapy and 86% would also recommend LPLND. Over half of the surgeons (57%) had no exposure to LPLND during fellowship training and approximately two thirds (62%) do not perform LPLND in their current practice.

CONCLUSION

This study highlights the challenges in the management of the lateral pelvic lymph nodes in a western context. The majority of the participating Australasian colorectal surgeons consider malignant lateral pelvic lymph nodes to represent locoregional and resectable disease. The majority also recommend LPLND for clinically malignant lateral pelvic nodes. However, adequate training and experience with LPLND is limited.

Lateral pelvic lymphadenectomy for low rectal cancer: a META-analysis of recurrence rates

BACKGROUND

Locoregional recurrence (LR) remains a problem for patients with lower rectal cancer despite standardized surgery and improved neoadjuvant treatment regimens. Lateral pelvic lymph node dissection (LPLND) has been routine practice for some time in the Orient/East, but other regions have concerns about morbidity. As perioperative care and surgical approaches are refined, this has been revisited for selected patients. The question as to whether LPLND improves oncological outcomes was explored here.

METHODS

A systematic review of patients who underwent TME with or without LPLND from 2000 to 2020 was performed. The primary endpoint was the rate of LR between the two groups.

RESULTS

Seven papers met the predefined search criteria in which 2000 patients underwent TME alone, while 1563 patients had TME and LPLND. The rate of LR was marginally higher with TME alone when compared with TME plus LPLND, but this result was not statistically significant (9.8 vs 9.4%, odds ratio 0.75, 95% CI 0.41-1.38, *p = 0.35). In addition, four studies reported on distant recurrence rates, with TME and LPLND showing a slight reduction in overall rates (27.3 vs 29.9%, respectively, OR 0.65, 95% CI 0.45-0.92, *p = 0.02).

CONCLUSION

The addition of LPLND to TME is not associated with a significantly lower risk of LR in patients who undergo surgery for lower rectal cancer.

Indications and oncological outcomes of selective dissection for clinically suspected lateral lymph node metastasis in patients with rectal cancer based on pretreatment imaging

BACKGROUND

The aim of this study was to identify the indications and oncological outcomes of selective lateral lymph node dissection (sLLND) in rectal cancer patients.

METHODS

A retrospective study was conducted on consecutive patients with rectal cancer who had standard total mesorectal excision and sLLND at our institution. Clinicopathological characteristics and oncological outcomes were analyzed. We performed subgroup analysis and multivariate analysis based on patients with or without preoperative chemoradiotherapy to identify the related risk factors.

RESULTS

A total of 77 consecutive patients with TME and sLLND were included. Twenty-two (28.6%) patients with pathological positive lateral lymph nodes metastasis (LLNM) were identified. Forty-seven (61%) patients accepted neoadjuvant chemoradiotherapy (nCRT). The pretreatment maximum short-axis diameters of LLN (≥ 8 mm) were the independent risk factors for LLNM among patients with LLN ≥ 5 mm. Lymph node metastasis were significantly higher in patients with pretreatment LLN ≥ 8 mm than in patients with LLN 5-8 mm (63% vs. 10%, p < 0.001). The receiver operating curve analysis suggested that the optimal cutoff value of LLN short-axis diameter for predicting LLNM was 8 mm. At a median follow-up of 42 months (range 6-140 months) 3 (3.9%) patients with lateral pelvic recurrence were observed. The 3-year cumulative overall survival in patients with LLNM and patients without LLNM was 76.7% and 89.8%, respectively (p = 0.01). The 3-year cumulative disease-free survival was 53.6% in patients with LLNM and 88.3% in patients without LLNM (p = 0.008).

CONCLUSION

Patients with LLNM had a worse prognosis. The pretreatment maximum short-axis diameter of LLN (≥ 8 mm) should be considered as an indication for sLLND.

Risk of nodal disease in patients with MRI-detected extramural vascular invasion in rectal cancer: a systematic review and meta-analysis

BACKGROUND

The impact of magnetic resonance imaging-detected extramural vascular invasion (mrEMVI) in distant metastasis is well known but its correlation with prevalence of lymph node metastasis is less studied. The aim of this systematic review and meta-analysis was to assess the prevalence of nodal disease in mrEMVI-positive and negative cases in rectal cancer.

METHODS

Following guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses, a systematic literature search in PubMed, Web of Science, Cochrane Library, and EMBase was carried out to identify relevant studies published up to May 2019.

RESULTS

Our literature search generated 10 studies (863 and 1212 mrEMVI-positive and negative patients, respectively). The two groups (mrEMVI-positive and negative) were significantly different in terms of nodal disease status (odds ratio [OR] 3.15; 95% confidence interval [CI] 2.12-4.67; p < 0.001). The prevalence of nodal disease was 75.90% vs 52.56% in the positive mrEMVI vs negative mrEMVI group, respectively (p < 0.001). The prevalence of positive lymph node in positive mrEMVI patients treated with neoadjuvant/adjuvant chemoradiotherapy (nCRT/CRT) (OR 2.47; 95% CI 1.65-3.69; p < 0.001) was less compared with the patients who underwent surgery alone (OR 6.25; 95% CI 3.74-10.44; p < 0.001).

CONCLUSION

The probability of positive lymph nodes in cases of positive mrEMVI is distinctly greater compared with negative cases in rectal cancer. Positive mrEMVI indicates risk of nodal disease prevalence increased by threefold in rectal cancer.

Neoadjuvant (chemo)radiotherapy and Lateral Node Dissection: Is It Mutually Exclusive?

The importance of total mesorectal excision (TME) has been the global standard of care in patients with rectal cancer. However, there is no universal strategy for lateral lymph nodes (LLN). The treatment of the lateral compartment remains controversial and has gone to the opposite directions between Eastern and Western countries in the past decades. In the East, mainly Japan, surgeons consider LLN metastases as regional disease and have performed TME with lateral lymph node dissection (LLND) without neoadjuvant (chemo)radiotherapy ([C]RT) in patients with clinical Stage II/III rectal cancer below the peritoneal reflection. In the West, neoadjuvant radiotherapy or has been the standard, and surgeons do not perform LLND assuming the (C)RT can sterilize most lateral lymph node metastasis (LLNM). Recent evidences show that lateral nodes are the major cause of local recurrence after (C)RT plus TME, and LLND reduces local recurrence particularly from the lateral compartment. Probably a combination of the two strategies, that is, neoadjuvant (C)RT plus LLND, would be needed to improve outcomes in patients with lateral nodal disease.