Improving prediction of lateral node spread in low rectal cancers—multivariate analysis of clinicopathological factors in 1,046 cases

Post-hoc analysis of clinicopathological factors affecting lateral lymph node metastasis based on STELLAR study for rectal cancer

PURPOSE

In post-hoc analyses of phaseIII randomized controlled study(STELLAR), to analyzethe prognostic impact oflateral pelvic lymph node (LPLN)metastasis in locally advanced rectal cancer (LARC).

METHODS

LPLN metastasis was defined as a short diameter > 7 mm on magnetic resonance imaging (MRI).The studyincluded 591 patients with LARC.All patients received neoadjuvant (chemo)radiotherapy combined withradical resection.

RESULTS

Among 591 patients, 99 (16.8 %) were diagnosed with LPLN metastasis, mostly with unilateral metastasis (79.8 %), with internal iliac lymph node metastasis being more common (81.8 %).Significant differences were found among with and without LPLN metastasis in rectal segmentation (P=0.001),N disease (P<0.001), mesenteric LN metastasis or not (P=0.030). The median follow-up timewas 34.0 months, three-year disease-free survival (DFS),overall survival (OS), andmetastasis-free survival (MFS)were significantly lower in LPLN metastaticgroup than those in LPLN non-metastaticgroup (51.4 % vs. 68.2 %, P<0.001; 71.8 % vs. 84.2 %, P=0.006; 60.8 % vs. 80.1 %,P<0.001), respectively; while there were no significant differences in locoregional recurrence(11.4 % vs. 8.5 %, P=0.564). Multivariate analysis found that LPLN metastasis was an independent prognostic factor affecting DFS (P=0.005), OS (P=0.036),MFS (P=0.001).No significantly survival benefit was observed for the short-term radiotherapy based total neoadjuvant therapy compared to long-term concurrent chemoradiotherapy.

CONCLUSIONS

LPLN metastasis observed byMRI should be considered in LARC patients, especially in populations with lowrectal cancer, N2 disease, and mesenteric LN metastasis. LPLN metastasis diagnosed by MRI is a significant and independent risk factor and is associated with worse DFS, OS, MFS.

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.

Development and External Validation of a Preoperative Nomogram for Predicting Lateral Pelvic Lymph Node Metastasis in Patients With Advanced Lower Rectal Cancer

Background

The preoperative prediction of lateral pelvic lymph node (LPLN) metastasis is crucial in determining further treatment strategies for advanced lower rectal cancer patients. In this study, we established a nomogram model to preoperatively predict LPLN metastasis and then externally validated the accuracy of this model.

Methods

A total of 287 rectal cancer patients who underwent LPLN dissection were included in this study. Among them, 200 patients from the Peking University First Hospital were included in the development set, and 87 patients from the First Affiliated Hospital of Xi’an Jiaotong University were included in the independent external validation set. Multivariate logistic regression analysis was used to develop the nomogram. The performance of the nomogram was assessed based on its calibration, discrimination, and clinical utility.

Results

Five factors (differentiation grade, extramural vascular invasion, distance of the tumor from the anal verge, perirectal lymph node status, and largest short-axis diameter of LPLN) were identified and included in the nomogram. The nomogram developed based on the analysis showed robust discrimination with an area under the receiver operating characteristic curve (AUC) of 0.878 (95% CI, 0.824–0.932). The validation set showed good discrimination with an AUC of 0.863 (95% CI, 0.779–0.948). Decision curve analysis showed that the nomogram was clinically useful.

Conclusions

The present study proposed a clinical-imaging nomogram with a combination of clinicopathological risk factors and imaging features. After external verification, the predictive power of the nomogram model was satisfactory, and it is expected to be a convenient, visual, and personalized clinical tool for assessing the risk of LPLN metastasis in advanced lower rectal cancer patients.

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.

Is prophylactic lateral lymph node dissection needed for lower rectal cancer? A single-center retrospective study

Background

The effectiveness of prophylactic lateral lymph node dissection (LLND) in treating patients with lower rectal cancer remains controversial and has not been clearly established. Therefore, we aimed to retrospectively analyze the survival impact of prophylactic LLND in patients with lower rectal cancer.

Methods

Data of 301 patients with lower rectal cancer (tumor’s lower edge on the anal side of the peritoneal reflexion) with clinical T3 disease and negative preoperative lateral lymph node metastasis, who underwent radical resection (R0) at our hospital between April 2007 and March 2017, were included in this study. Patients who received preoperative chemotherapy or radiotherapy were excluded. The relapse-free survival (RFS) and overall survival (OS) rates were compared between the dissection (prophylactic LLND, n = 37) and non-dissection (no prophylactic LLND, n = 264) groups.

Results

Significantly fewer men and younger patients were noted in the dissection group than in the non-dissection group. Post-surgery 3- and 5-year RFS rates were 69.6% and 66.8% in the dissection group and 75.1% and 72.5% in the non-dissection group, respectively (5-year post-surgery RFS, p = 0.58). In the dissection and non-dissection groups, the 5-year OS rates were 86.5% and 79.7%, respectively (p = 0.29), and the 5-year cancer-specific survival rates were 88.9% and 86.0%, respectively (p = 0.29), with no significant differences. Lateral lymph node recurrence was observed in one (2.7%) and 10 patients (3.8%) in the dissection and non-dissection groups, respectively, and there was no significant difference between the groups.

Conclusions

In this study, the effectiveness of prophylactic LLND was limited in patients with > T3 lower rectal cancer with no evidence of preoperative lymph node metastasis. Prophylactic LLND may not be necessary if there is no preoperative lymph node metastasis, even if the invasion depth is T3 or higher.

Prevalence of Metastatic Lateral Lymph Nodes in Asian Patients with Lateral Lymph Node Dissection for Rectal Cancer: A Meta-analysis

Importance

Rectal cancers occupy the eighth position worldwide for new cases and deaths for both men and women. These cancers have a high tendency to form metastases in the mesorectum but also in the lateral lymph nodes. The therapeutic approach for the involved lateral lymph nodes remains controversial.

Objective

We performed a systematic review and meta-analysis to assess the prevalence of metastatic lateral lymph nodes in patients with lateral lymph node dissection (LLND) for rectal cancer, which seems to be a fundamental and necessary criterion to discuss any possible indications for LLND.

Methods

Data sources–study selection–data extraction and synthesis–main outcome and measures. We searched MEDLINE, EMBASE and COCHRANE from November 1, 2018, to November 19, 2018, for studies reporting the presence of metastatic lateral lymph nodes (iliac, obturator and middle sacral nodes) among patients undergoing rectal surgery with LLND. Pooled prevalence values were obtained by random effects models, and the robustness was tested by leave-one-out sensitivity analyses. Heterogeneity was assessed using the Q-test, quantified based on the I2 value and explored by subgroup analyses.

Results

Our final analysis included 31 studies from Asian countries, comprising 7599 patients. The pooled prevalence of metastatic lateral lymph nodes was 17.3% (95% CI: 14.6–20.5). The inter-study variability (heterogeneity) was high (I² = 89%). The pooled prevalence was, however, robust and varied between 16.6% and 17.9% according to leave-one-out sensitivity analysis. The pooled prevalence of metastatic lymph nodes was not significantly different when pooling only studies including patients who received neoadjuvant treatment or those without neoadjuvant treatment (p = 0.44). Meta-regression showed that the pooled prevalence was associated with the sample size of studies (p < 0.05), as the prevalence decreased when the sample size increased.

Conclusion

The pooled prevalence of metastatic lateral lymph nodes was 17.3% among patients who underwent rectal surgery with LLND in Asian countries. Further studies are necessary to determine whether this finding could impact the therapeutic strategy (total mesorectal excision with LLND versus total mesorectal excision with neoadjuvant radiochemotherapy).

Supplementary Information

The online version contains supplementary material available at(10.1007/s00268-021-05956-1)

Controversies in the Management of Lateral Pelvic Lymph Nodes in Patients With Advanced Rectal Cancer: East or West?

The presence of lateral pelvic lymph nodes (LPLN) in advanced rectal cancer entails challenges with ongoing debate regarding the role of prophylactic dissection vs. neoadjuvant radiation treatment. This article highlights the most recent data of both approaches: bilateral LPLN dissection in every patient with low rectal cancer (Rb) as per the Japanese guidelines, vs. the developing approach of neoadjuvant radiotherapy as per Eastern countries. In addition, we also accentuate the importance of a combined approach published by Sammour et al. where a simple "one-size-fits-all" strategy should be abandoned. Rectal cancer treatment is well-established in Western countries. Patients with advanced rectal cancer will undergo radiation ± chemo neoadjuvant therapy followed by TME. In the Dutch TME trial, TME plus radiotherapy showed that the presacral area was the most frequent site of recurrence and not the lateral pelvic wall. Supporting this data, the Swedish study also concluded that LPLN metastasis is not an important cause of local recurrence in patients with low rectal cancer. Therefore, Western approach is CRM-orientated and prophylactic LPLN dissection is not performed routinely as the NCCN guideline does not recommend its surgical removal unless metastases are clinically suspicious. The paradigm in Eastern countries differs somewhat. The Korean study demonstrated that adjuvant radiotherapy without lateral lymph node dissection was not enough to control local recurrence and LPLN metastases. The Japanese Trial JCOG 0212 demonstrated the effects of LPLN dissection in reducing local recurrence in the lateral pelvic compartment. We agree with Sammour and Chang on the fact that rather than a mutual exclusivity approach, we should claim for an approach where all available modalities are considered and used to optimize treatment outcomes, classifying patients into 3 categories of LPLN: low risk cT1/T2/earlyT3 (and Ra) with clinically negative LPLN on MRI; Moderate risk (cT3+/T4 with negative LPLN on MRI) and high risk (clinically abnormal LPLN on MRI). Treatment modality should be based on detailed pretreatment workup and an individualized approach that considers all options to optimize the treatment of patients with rectal cancer in the West or the East.

Does lateral lymph node dissection for low rectal cancer improve overall survival? Protocol for a systematic review and meta-analysis

•

We aim determining if lateral lymphadenectomy increases survival in patients with rectal cancer.

•

We will perform a systematic review and meta-analysis of the literature.

•

Hazard ratios of overall and recurrence-free survivals will be combined and compared.

Introduction

The best therapeutic strategy for treating lateral lymph nodes in patients with advanced mid to low rectal cancer remains unknown. Our objective is to determine which therapeutic strategy – lateral lymph node dissection versus radiochemotherapy – offers the best overall and recurrence-free survivals for these patients.

Methods and analysis

We will perform a systematic review and meta-analysis aiming at determining the overall and recurrence-free survivals of patients with total mesorectum excision with and without lateral lymph node dissection, in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. MEDLINE, Embase, Cochrane and Web of Science will be searched from inception to the 16th of January 2019 for original studies written in English or in French including patients who benefited from lateral lymph node dissection for low rectal cancer and reporting overall survival for patients with and without lateral lymph node dissection. Hazard ratios of overall and recurrence-free survivals extracted from included studies will be combined and compared between patients with and without lateral lymph node dissection. Risk of bias will be assessed by using the Newcastle-Ottawa scale.

The systematic review and meta-analysis protocol is registered in the International Prospective Register of Ongoing Systematic Reviews (PROSPERO) with number CRD42019123181.

Ethics and dissemination

No ethical clearance is required for this study. This review will be published in a peer- reviewed journal and will be presented at various national and international conferences.

A systematic review and meta-analysis of pT2 rectal cancer spread and recurrence pattern: Implications for target design in radiation therapy for organ preservation

BACKGROUND

There are no guidelines on clinical target volume (CTV) delineation for cT2 rectal cancer treated with organ preservation.

MATERIALS AND METHODS

A systematic review and meta-analysis were performed to determine the extent of distal mesorectal (DMS) and distal intramural spread (DIS), the risk of lateral lymph node (LLN) metastases in pT2 tumours, and regional recurrence pattern after organ preservation.

RESULTS

The rate of DMS > 1 cm was 1.9% (95% CI: 0.4-5.4%), maximum extent: 1.3 cm. The rate of DIS > 0.5 cm was 4.7% (95% CI: 1.3-11.5%), maximum extent: 0.8 cm. The rate of LLN metastases was 8.2% (95% CI: 6.7-9.9%) for tumours below or at peritoneal reflexion and 0% for higher tumours. Regional nodal recurrences alone were recorded in 1.0% (95% CI: 0.5-1.7%) of patients after watch-and-wait and in 2.1% (95% CI: 1.2-3.4%) after preoperative radiotherapy and local excision. Thus, the following rules for CTV delineation are proposed: caudal border 1.5 cm from the tumour to account for DMS or 1 cm to account for DIS, whichever is more caudal; cranial border at S2/S3 interspace; inclusion of LLN for tumours at or below peritoneal reflexion. A planning study was performed in eight patients to compare dose-volume parameters obtained using these rules to that obtained using current guidelines for advanced cancers. The proposed rules led to a mean 18% relative reduction of planning target volume, which resulted in better sparing of organs-at-risk.

CONCLUSION

This meta-analysis suggests a smaller CTV for cT2 tumours than the current guidelines designed for advanced cancers.

Predictive factors of pathological lateral pelvic lymph node metastasis in patients without clinical lateral pelvic lymph node metastasis (clinical stage II/III): The analysis of data from the clinical trial (JCOG0212)

BACKGROUND

Mesorectal excision (ME) is the standard surgical procedure for lower rectal cancer. However, in Japan, total or tumor-specific ME with lateral pelvic lymph node dissection (LLND) is the standard surgical procedure for patients with clinical stages II or III lower rectal cancer, because lateral pelvic lymph node metastasis occasionally occurs in these patients. The aim of study was to elucidate the predictive factors of pathological lateral pelvic lymph node metastasis in patients without clinical lateral pelvic lymph node metastasis.

METHODS

Data form the clinical trial (JCOG0212) was analyzed. The JCOG0212 was a randomized controlled trial to confirm the non-inferiority of mesorectal excision alone to mesorectal excision with lateral lymph node dissection for clinical stage II/III patients who don't have clinical lateral pelvic lymph node metastasis in terms of relapse free survival. This study was conducted at a multitude of institution33 major hospitals in Japan. Among the 351 patients who underwent lateral lymph node dissection in the JCOG0212 study, 328 patients were included in this study. Associations between pathological lateral pelvic lymph node metastasis and preoperative and postoperative factors were investigated. The preoperative factors were age, sex, clinical stage, tumor location, distance from anal verge, tumor size, and short-axis diameter of lateral pelvic lymph node on computed tomography and the postoperative factors were pathological T, pathological N, and histological grade.

RESULTS

Among the 328 patients, 24 (7.3%) had pathological lateral pelvic lymph node metastasis. In multivariable analysis of the preoperative factors, patient age (p = 0.067), tumor location (p = 0.025), and short-axis diameter of lateral pelvic lymph node (p = 0.002) were significantly associated with pathological lateral pelvic lymph node metastasis.

CONCLUSIONS

Patient age, tumor location, and short-axis diameter of lateral pelvic lymph node were predictive factors of pathological lateral pelvic lymph node metastasis.

Preoperative chemoradiotherapy changes the size criterion for predicting lateral lymph node metastasis in lower rectal cancer

PURPOSE

The purpose of this study was to identify the size criteria of lateral lymph node metastasis in lower rectal cancer both in patients who underwent preoperative CRT and those who did not.

METHODS

This study enrolled 150 patients who underwent resection for primary lower rectal adenocarcinoma with lateral lymph node dissection between 2013 and 2015. Patients were divided into two groups: the CRT group, treated with preoperative chemoradiotherapy before surgery, and the non-CRT group, treated with surgery alone. The short-axis diameter of each dissected lateral lymph node was measured. Receiver-operating characteristic curves were generated to reveal the optimal cutoff values for determining lateral lymph node metastasis in both groups.

RESULTS

In the non-CRT group (n = 131), the ROC curve demonstrated that the optimal cutoff value for determining metastasis was 6.0 mm, with a sensitivity of 78.5% and specificity of 82.9%, and the AUC was 0.845. In comparison, in the CRT group (n = 19), the optimal cutoff value was 5.0 mm, with a sensitivity of 71.4% and specificity of 85.3% and an AUC of 0.836.

CONCLUSION

The cutoff size for determining lateral lymph node metastasis was smaller in the CRT group than in the non-CRT group.

Prediction of lateral pelvic lymph node metastasis from lower rectal cancer using magnetic resonance imaging and risk factors for metastasis: Multicenter study of the Lymph Node Committee of the Japanese Society for Cancer of the Colon and Rectum

PURPOSE

The goal of the study was to examine prediction of lateral pelvic lymph node (LPLN) metastasis from lower rectal cancer using a logistic model including risk factors for LPLN metastasis and magnetic resonance imaging (MRI) clinical LPLN (cLPLN) status, compared to prediction based on MRI alone.

METHODS

The subjects were 272 patients with lower rectal cancer who underwent MRI prior to mesorectal excision combined with LPLN dissection (LPLD) at six institutes. No patients received neoadjuvant therapy. Prediction models for right and left pathological LPLN (pLPLN) metastasis were developed using cLPLN status, histopathological grade, and perirectal lymph node (PRLN) status. For evaluation, data for patients with left LPLD were substituted into the right-side equation and vice versa.

RESULTS

Left LPLN metastasis was predicted using the right-side model with accuracy of 86.5%, sensitivity 56.4%, specificity 92.7%, positive predictive value (PPV) 61.1%, and negative predictive value (NPV) 91.2%, while these data using MRI cLPLN status alone were 80.4, 76.9, 81.2, 45.5, and 94.5%, respectively. Similarly, right LPLN metastasis was predicted using the left-side equation with accuracy of 83.8%, sensitivity 57.8%, specificity 90.4%, PPV 60.5%, and NPV 89.4%, and the equivalent data using MRI alone were 78.4, 68.9, 80.8, 47.7, and 91.1%, respectively. The AUCs for the right- and left-side equations were significantly higher than the equivalent AUCs for MRI cLPLN status alone.

CONCLUSIONS

A logistic model including risk factors for LPLN metastasis and MRI findings had significantly better performance for prediction of LPLN metastasis compared with a model based on MRI findings alone.

Inspection of Perirectal Lymph Nodes by One-Step Nucleic Acid Amplification Predicts Lateral Lymph Node Metastasis in Advanced Rectal Cancer

BACKGROUND

Lateral lymph node dissection (LLND) is performed for advanced rectal cancers in Japan; however, it can cause sexual and urinary dysfunction. The incidence of lateral LN metastasis is estimated at 7-13.9%; therefore, excessive rectal surgery with LLND should be avoided, especially for prophylactic purposes. To identify the patients who require LLND, we examined metastases in perirectal LNs by using a one-step nucleic acid amplification (OSNA) assay to predict lateral LN metastases.

METHODS

Twenty-five patients who underwent surgery with bilateral LN dissection due to T3-T4 rectal cancers were prospectively included in this study. Twenty-two patients (88.0%) received preoperative chemotherapy. Among 1052 LNs from 25 patients (median 40 per case), 135 perirectal LNs (median 6 per patient) were divided into three pieces and analyzed by OSNA, reverse transcriptase-polymerase chain reaction for carcinoembryonic antigen mRNA, and pathological examination after surgery. These results were compared with the pathological diagnosis of lateral LNs.

RESULTS

Lateral LN metastases were present in 4 of 25 patients (16.0%). All of these patients were positive by OSNA for perirectal LN metastases. The OSNA assay had a sensitivity of 100%, specificity of 86%, positive predictive value of 57%, and negative predictive value (NPV) of 100% for predicting lateral LN metastases.

CONCLUSIONS

The findings from this prospective study suggest that the OSNA assay of perirectal LNs may be useful for determining when LLND is necessary because of its high NPV, even in patients treated with preoperative chemotherapy.

The important risk factor for lateral pelvic lymph node metastasis of lower rectal cancer is node-positive status on magnetic resonance imaging: study of the Lymph Node Committee of Japanese Society for Cancer of the Colon and Rectum

PURPOSE

This study seeks to evaluate lateral pelvic lymph node (LPLN) and perirectal lymph node (PRLN) status on magnetic resonance imaging (MRI) as potential risk factors for lymph node metastasis.

METHODS

The subjects were 394 patients with lower rectal cancer who underwent MRI prior to mesorectal excision (combined with lateral pelvic lymph node dissection in 272 patients) at 6 institutes. No patients received neoadjuvant therapy. Cases were classified as cN(+) and cN(-) based on the short axis of the largest lymph node ≥5 and <5 mm, respectively. LPLN and PRLN status and other clinicopathologic factors were analyzed by multivariate logistic regression. The importance of identified risk factors for lymph node metastasis was examined using the area under the curve (AUC).

RESULTS

Independent risk factors for right LPLN metastasis included histopathological grade (G3 + G4), pPRLN(+), M1, cLPLN(+) [odds ratio (OR) 10.73, 95 % confidence interval (CI) 4.59-27.1], and those for left LPLN metastasis were age (<64), histopathological grade (G3 + G4), pPRLN(+), and cLPLN(+) (OR 24.53, 95 % CI 9.16-77.7). ORs for cLPLN(+) were highest. The AUCs for right and left cLPLN status of 0.7484 (95 % CI 0.6672-0.8153) and 0.7904 (95 % CI 0.7088-0.8538), respectively, were significantly higher than those for other risk factors. In contrast, the ORs for cPRLN(+) and cPRLN status of 2.46 (95 % CI 1.47-4.18) and 0.6396 (95 % CI 0.5917-0.6848) were not much higher than for other factors.

CONCLUSIONS

An LPLN-positive status with a short axis ≥5 mm on MRI is an important predictor of LPLN metastasis, but PRLN status is not a strong predictor of PRLN metastasis.

Indications for Lateral Pelvic Lymph Node Dissection Based on Magnetic Resonance Imaging Before and After Preoperative Chemoradiotherapy in Patients with Advanced Low-Rectal Cancer

BACKGROUND

We assessed the magnetic resonance imaging (MRI) findings of lateral pelvic lymph node (LPLN) metastasis in patients with advanced low-rectal cancer treated with preoperative chemoradiotherapy (CRT) and LPLN dissection (LPLD) for clinically suspected LPLN metastasis. Our aim was to identify the optimal indications for LPLD.

METHODS

The study population consisted of 77 patients with advanced low-rectal cancer who underwent LPLD for clinically suspicious LPLN metastasis after preoperative CRT. MRI findings before/after CRT, clinical factors, and LPLN metastasis were evaluated.

RESULTS

LPLN metastasis was confirmed in 31 patients (40.3 %). Metastasis was significantly higher in patients with LPLNs with a short-axis diameter ≥8 mm than in patients with LPLNs with a short-axis diameter <8 mm before CRT (75 vs. 20 %, P < 0.0001). LPLN metastasis was also significantly higher in patients with LPLNs with a short-axis diameter >5 mm than in patients with LPLNs with a short-axis diameter ≤5 mm after CRT (75 vs. 20 %, P < 0.0001). Multivariate analysis showed the independent association of female sex [P = 0.0192; odds ratio (OR) 5.616; 95 % confidence interval (CI) 1.315-28.942], pre-CRT short-axis diameter of the LPLN ≥8 mm (P = 0.0047; OR 9.188; 95 % CI 1.948-54.366), and CRT without induction systemic chemotherapy (P = 0.0285; OR 9.235; 95 % CI 1.241-106.947) with LPLN metastasis.

CONCLUSIONS

MRI before CRT is useful to predict LPLN metastasis and to determine the indications for LPLD.

Factors associated with lateral pelvic recurrence after curative resection following neoadjuvant chemoradiotherapy in rectal cancer patients

PURPOSE

This study aims to determine the risk factors for lateral pelvic recurrence (LPR) in rectal cancer patients treated with neoadjuvant chemoradiotherapy (CRT) and curative surgery.

METHODS

Four hundred forty-three patients treated with neoadjuvant CRT and curative surgery from October 1999 through June 2009 were analyzed. All patients underwent total mesorectal resection without lateral pelvic lymph node (LPLN) dissection. Recurrence patterns and lateral pelvic recurrence-free survival (LPFS) were evaluated relative to clinicopathologic parameters including pelvic LN status.

RESULTS

Median follow-up was 52 months, with locoregional recurrence in 53 patients (11.9 %). Of the 53 patients, 28 (52.8 %) developed LPR, of which eight had both central and lateral PR. Multivariate analysis showed a significant relationship between LPFS and the number of lateral pelvic LN (p = 0.010) as well as the ratio of the number of positive LN/number of dissected LN (p = 0.038). The relationship between LPFS and LPLN size had a marginal trend (p = 0.085). Logistic regression analysis showed positive relationships between LPR probability and the number of LPLN (odds ratio [OR] 1.507; 95 % confidence interval [CI] 1.177-1.929; p = 0.001) as well as LPLN size (OR 1.124; CI 1.029-1.227, p = 0.009).

CONCLUSIONS

LPLN ≥ 2 and a ratio of the number of positive LN/number of dissected LN > 0.3 were prognostic of poor LPFS. The prediction curve of LPR according to the number and size of LPLN could be useful for determining the benefit of additional lateral pelvic treatment.

The role of lateral lymph node dissection in the management of lower rectal cancer

INTRODUCTION

Lateral lymph node involvement is a problem encountered in patients with low rectal cancers. This has been documented in both anatomical and pathological studies. Currently, the vast majority of centers have concentrated on the use of chemoradiation to obtain better local control and manage these nodes indirectly. In Japan, extended nodal dissection for the control of pelvic nodal disease has seen further advancement. This paper discusses the key issues involved in the management of pelvic lateral nodes in low rectal cancers.

METHODS

A review of available literature and critical appraisal of the entity of lateral nodes in low rectal cancers, the treatment options, and oncological and functional results were performed.

RESULTS

There are good data showing that the entity of pelvic lateral nodes in low rectal cancers should not be ignored. Recent data have emerged showing that radiotherapy is associated with significant long-term functional side effects. Refinement of the technique, lateral node dissection, has led to good local control as well as good functional outcomes.

CONCLUSION

In this context, there needs to be a reevaluation of the role of chemoradiation as the sole treatment for lateral nodal disease in centers outside of Japan. Individualization of the treatment of rectal cancer may require all centers to be able to offer both modalities.

Extended resections for colorectal cancer - indications for supraradical lymphadenectomy

The laparoscopic approach to standard resections in colorectal cancer has proven that it may provide equal rates of R0 resections and adequate retrieval of lymph nodes as open procedures if performed by experienced hands. There might be difficulties in more advanced tumors or those with lymphatic spread beyond typical drainage areas and more extensive operations might be required. An atypical pattern of lymphatic spread often is associated with other adverse factors such as multifocality of primary cancers and adverse tumorbiological factors such as grade. Such patient subgroups may be defined beforehand and include particularly patients with underlying ulcerative colitis. Repetitively, extended lymph node dissection approaches have been advocated, however neither in randomised trails nor in meta-analysis has a more favourable outcome of patients undergoing such extended lymphatic dissections been demonstrated. Sticking to the rules of classical dissection of lymphatic drainage basins with removal of adequate lymph node numbers is one corner stone for successful treatment of colorectal cancer. The other one refers to a detailed description of the procedure performed in order to make the surgical procedure trackable.

EUS-FNA assessment of extramesenteric lymph node status in primary rectal cancer

BACKGROUND

Preoperative staging is an essential factor in the multidisciplinary management of rectal cancer. The accuracy of imaging alone with CT, magnetic resonance imaging, or rigid endorectal US is poor. The addition of EUS-FNA may enhance extramesenteric lymph node metastases detection (M1 disease) and overall staging accuracy.

OBJECTIVE

To evaluate the frequency of extramesenteric lymph node visualization by EUS and the rate of extramesenteric lymph node metastases by FNA. Secondary goals were to evaluate the clinical, endoscopic, and sonographic features associated with extramesenteric lymph node metastases, disease progression, and overall mortality.

DESIGN

Retrospective cohort study.

SETTINGS

Tertiary referral center.

RESULTS

Forty-one of 316 patients (13%) with primary rectal cancer over a 6-year period had M1 disease by EUS-FNA. Significant clinical, endoscopic, and sonographic features associated with extramesenteric lymph node metastases included the serum carcinoembryonic antigen level, tumor length 4 cm and longer, annularity 50% or more, sessile morphology, and lymph node size. The sensitivity and specificity of CT for extramesenteric lymph node metastases were 44% and 89%, respectively. Twenty-three of 316 rectal cancer endosonographic procedures (7.3%) were up-staged by FNA, which established extramesenteric lymph node metastases. Over a 4-year follow-up, disease progression and overall mortality of patients with extramesenteric lymph node metastases was observed in 6 patients (14.6%) and 14 patients (34%), respectively.

CONCLUSIONS

Preoperative EUS-FNA identification of extramesenteric lymph node metastases outside of standard radiation fields or total mesorectal excision resection margins could affect medical and surgical planning.

Clinical impact of lymph node status in rectal cancer

Lymph node status at the time of diagnosis remains one of the principal indicators of prognosis in patients with rectal cancer. Involvement of loco-regional lymph nodes is relevant to surgical and clinical oncologists and continues to impact significantly upon local and systemic management strategies, in both neo-adjuvant and adjuvant settings. In this review, the clinical impact of lymph node status in the surgical management of rectal cancer is considered, with particular reference to the significance of lymphadenectomy and the potential implications for rectal tumours amenable to trans-anal excision. Current standards of care are reviewed and the extent to which the determination of lymph node status influences oncological decisions regarding neo-adjuvant and adjuvant therapies are discussed with areas of controversy highlighted.