Meta-analysis of survival and functional outcomes after total mesorectal excision with or without lateral pelvic lymph node dissection in rectal cancer surgery

Role of Lateral Pelvic Node Dissection in Rectal Cancer Surgery

The role of lateral pelvic lymph node dissection in the treatment of patients with locally advanced rectal cancer is a matter of controversy. Surgical practices in Korea and Japan have accepted this approach and are widely utilized; however, it is not routinely incorporated in the practice of countries in the Western hemisphere. This review will examine the role of lateral pelvic lymph node dissection.

Feasibility and limitations of combined treatment for lateral pelvic lymph node metastases in rectal cancer

Colorectal cancer ranks among the most commonly diagnosed cancers globally, and is associated with a high rate of pelvic recurrence after surgery. In efforts to mitigate recurrence, pelvic lymph node dissection (PLND) is commonly advocated as an adjunct to radical surgery. Neoadjuvant chemoradiotherapy (NACRT) is a therapeutic approach employed in managing locally advanced rectal cancer, and has been found to increase the survival rates. Chua et al have proposed a combination of NACRT with selective PLND for addressing lateral pelvic lymph node metastases in rectal cancer patients, with the aim of reducing recurrence and improving survival outcomes. Nevertheless, certain studies have indicated that the addition of PLND to NACRT and total mesorectal excision did not yield a significant reduction in local recurrence rates or improvement in survival. Consequently, meticulous patient selection and perioperative chemotherapy may prove indispensable in ensuring the efficacy of PLND.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Total Mesorectal Excision with or without Lateral Pelvic Lymph Node Dissection in Rectal Cancer

Results

Incidence of local recurrence was slightly higher in Group A (8.7%) than in Group B (4.3%) but was not statistically significant. There was no statistical significance between both groups regarding distant metastasis (8.7% in Group A and 13% in Group B). Urinary and sexual dysfunctions were higher in Group B (26.1%) compared to those in Group A (21.7%) but were not statistically significant. The incidence of lateral pelvic lymph node metastasis was 30.4%. Also, intraoperative blood loss was higher and operative time was longer in Group B which was statistically significant (P value <0.001).

Conclusion

Our conclusion was that prophylactic addition of LPLD to TME was not associated with a statistically significant decrease in the risk of local recurrence or distant metastasis in patients with rectal cancer, although it was numerically better. LPLD is associated with longer operative time and higher intraoperative blood loss.

The Incidence and Prognosis Value of Perineural Invasion in Rectal Carcinoma: From Meta-Analyses and Real-World Clinical Pathological Features

AIMS

Perineural invasion (PNI) is a special type of metastasis of several cancers and has been reported as being a factor for poor prognosis in colorectal carcinoma. However, investigations of PNI in only rectal cancer and a comprehensive analysis combining meta-analyses with real-world case studies remain lacking.

MATERIALS AND METHODS

First, articles from 2000 to 2020 concerning the relationship between PNI and rectal cancer prognoses and clinical features were meta-analysed. Subsequently, we carried out a retrospective analysis of 312 rectal cancer cases that underwent radical surgery in the real world. The incidence of PNI and the relationship between PNI and prognosis, as well as clinicopathological factors, were investigated.

RESULTS

The incidence of PNI was 23.09% and 33.01% in the meta-analysis and clinical cases, respectively. PNI occurred as early as stage I (2.94%). Moreover, neoadjuvant therapy significantly reduced the PNI-positive rate (20.34% versus 26.54%). Both meta-analysis and real-world clinical case studies suggested that PNI-positive patients had poorer prognoses than PNI-negative patients. We established an effective risk model consisting of T stage, differentiation and lymphovascular invasion to predict PNI in rectal cancer.

CONCLUSION

PNI is a poor prognostic factor for rectal cancer and could occur even in stage I. Additionally, neoadjuvant therapy could sufficiently reduce the PNI-positive rate. T stage, lymphovascular invasion and differentiation grade were independent risk factors for PNI and the risk model that included these factors could predict the probability of PNI.

Feasibility and safety of lateral pelvic lymph node dissection for elderly patients with middle-low rectal cancer: results of a large multicenter lateral node collaborative group study in China

BACKGROUND

Lateral pelvic lymph node (LPN) dissection can improve local control in certain rectal cancer patients with LPN metastasis. However, the effects of this technically complex procedure on perioperative safety and long-term survival of elderly patients (≥ 70 years) remain unclear.

METHODS

Locally advanced middle-low rectal cancer patients diagnosed with LPN metastasis who underwent total mesorectal excision (TME) with LPN dissection at three institutions from January 2012 to December 2019 were included in this study. Additionally patients who had neoadjuvant chemoradiotherapy (nCRT) and those who did not were compared.

RESULTS

In total there were 407 patients, including 49 elderly and 358 non-elderly patients, of which 249 were male, with a median age of 58 years (range:18-85 years). In the whole cohort, operation time (280.7 vs. 292.0 min, p = 0.498) and estimated blood loss (100 vs. 100 ml, p = 0.384) were comparable in the elderly and non-elderly groups. There was no significant difference in the incidences of overall complications (24.5% vs. 19.8%, p = 0.448) and severe (Clavien-Dindo grade 3-5) surgical complications (8.2% vs. 7.5%, p = 0.778) between the two groups. However, the incidence of urinary retention (14.3% vs. 5.6%, p = 0.032) and intensive care unit admission (16.3% vs. 6.1%, p = 0.018) was significantly higher in the elderly group compared with those in the non-elderly group. The 3-year overall survival (88.7% vs. 82.1%, p = 0.516) and disease-free survival (81.2% vs. 70.7%, p = 0.352) were comparable between the two groups. Moreover, results in the nCRT cohort were comparable to those in the overall cohort.

CONCLUSIONS

Even with nCRT, TME combined with LPN dissection is safe and feasible for elderly patients, demonstrating low mortality and acceptable morbidity. Elderly and non-elderly patients with LPN metastasis who undergo LPN dissection can achieve comparable 3-year survival outcomes.

TRAIL REGISTRATION

ClinicalTrials.gov Identifier: NCT04850027.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A nomogram and risk classification system forecasting the cancer-specific survival of lymph- node- positive rectal cancer patient after radical proctectomy

Background

The aim of the study was to develop and validate a nomogram for predicting cancer-specific survival (CSS) in lymph- node- positive rectal cancer patients after radical proctectomy.

Methods

In this study, we analyzed data collected from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. In addition, in a 7:3 randomized design, all patients were split into two groups (development and validation cohorts). CSS predictors were selected via univariate and multivariate Cox regressions. The nomogram was constructed by analyzing univariate and multivariate predictors. The effectiveness of this nomogram was evaluated by concordance index (C-index), calibration plots, and receiver operating characteristic (ROC) curve. Based on the total score of each patient in the development cohort in the nomogram, a risk stratification system was developed. In order to analyze the survival outcomes among different risk groups, Kaplan-Meier method was used.

Results

We selected 4,310 lymph- node- positive rectal cancer patients after radical proctectomy, including a development cohort (70%, 3,017) and a validation cohort (30%, 1,293). The nomogram correlation C-index for the development cohort and the validation cohort was 0.702 (95% CI, 0.687-0.717) and 0.690 (95% CI, 0.665-0.715), respectively. The calibration curves for 3- and 5-year CSS showed great concordance. The 3- and 5-year areas under the curve (AUC) of ROC curves in the development cohort were 0.758 and 0.740, respectively, and 0.735 and 0.730 in the validation cohort, respectively. Following the establishment of the nomogram, we also established a risk stratification system. According to their nomogram total points, patients were divided into three risk groups. There were significant differences between the low-, intermediate-, and high-risk groups (p< 0.05).

Conclusions

As a result of our research, we developed a highly discriminatory and accurate nomogram and associated risk classification system to predict CSS in lymph-node- positive rectal cancer patients after radical proctectomy. This model can help predict the prognosis of patients with lymph- node- positive rectal cancer.

Robotic pelvic side-wall lymph node dissection for rectal cancer: a systematic review of videos and application of the IDEAL 2A framework

Lateral pelvic lymph node dissection (LPLND) in rectal cancer has gained increasing traction worldwide. Robotic LPLND is an emerging technique. Utilising the IDEAL (idea, development, exploration, assessment and long-term follow-up) framework for surgical innovation, robotic LPLND is currently at the IDEAL 2A stage (development) mainly limited to case reports, case series and videos. A systematic literature review was performed for videographic robotic LPLND. Pubmed, Ovid and Web of Science were searched with a predefined search strategy. The LapVEGAS score for peer review of video surgery was adapted for the robotic approach (RoVEGAS) and applied to measure video quality. Two reviewers independently reviewed videos and consensus reached on technical steps and learning points. Data are presented as a narrative synthesis of results. The IDEAL 2A framework was applied to videos to assess their content at the present stage of innovation. A total of 83 abstracts were identified. In accordance with the PRISMA statement, nine videos were analysed. Adherence to the complete IDEAL 2a framework was low. All videos demonstrated LPLND; however, reporting of clinical outcomes was heterogeneous and completed in six of nine videos. Histopathology was reported in six videos, with other outcomes variably reported. No videos presented patient-reported outcome measures. Two videos reported presence or absence of recurrence on follow-up. Video articles provide a valuable educational resource in dissemination and adoption of robotic techniques. Standardisation of reporting objectives are needed. Complete reporting of pathology and oncologic outcomes is required in videographic procedural-based publications to meet the IDEAL 2A framework criteria.

Oncological outcome after lateral pelvic lymphadenectomy for low rectal carcinoma: not only an N-status matter

Tumour deposits (TDs), novel pathological entities, should be considered when estimating the regional and systemic spread of rectal carcinoma and formulating treatment strategies. In fact, TDs may have more severe prognostic impact than lymph node positivity or the lymph node ratio. The assessment of the presence of TDs can be performed only through accurate postoperative pathological examination; however, the detection of TDs is not part of any of the procedures currently used to assess preoperative or intraoperative staging. This review aims to analyse and discuss the impact of TDs on the oncological outcome of patients who undergo surgery for advanced low rectal carcinoma. No prospective study has evaluated the impact of lateral pelvic TDs on oncological outcomes following total mesorectal excision with lateral pelvic lymphadenectomy. Although adequate total mesorectal excision allows for the excision of intramesorectal TDs, lateral pelvic lymph node dissection cannot guarantee the removal of lateral pelvic TDs; moreover, it remains to be determined whether surgical excision of lateral pelvic TDs can impact long-term outcomes. However, the identification of lateral pelvic TDs strengthens the 'staging effect' and limits the 'therapeutic effect' of lateral pelvic lymphadenectomy, supporting the rationale for the use of neoadjuvant chemoradiotherapy for rectal cancer. When evaluating the oncological outcomes after total mesorectal excision with lateral pelvic lymphadenectomy, the impact of lateral pelvic TDs should be considered.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

How to do a robotic lateral pelvic side wall dissection for rectal cancer

Our article describes the anatomy, technical steps, common pitfalls, and our recommendations for performing a successful robotic lateral pelvic side wall dissection for rectal cancer. This is supplemented with videos and an image to clearly demonstrate our technique.

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.

Two-Team Lateral Pelvic Lymph Node Dissection Assisted By the Transanal Approach

INTRODUCTION

Although lateral pelvic lymph node dissection is considered as a treatment option for advanced rectal cancer, it is technically demanding. Recently, the transanal approach for total mesorectal excision has become increasingly used. In this Technical Note, we describe lateral pelvic lymph node dissection using a 2-team method that was assisted by the transanal approach.

TECHNIQUE

First, the lateral pelvic area was entered from the anal side by dissection between the S4 sacral splanchnic nerve and levator ani muscle. Then, the fatty tissues including the obturator compartment and the distal part of the internal iliac compartment were separated from the inferior and superior vesical vessels and the bladder wall. Next, the fatty tissues were separated from the lateral pelvic wall. The obturator nerve was isolated and preserved, whereas the obturator vessels were resected at their peripheral end. Then, the fatty tissues were dissected from the bottom plane. Finally, the fatty tissues were dissected from the ventral bladder wall and were completely isolated from the obturator nerve in cooperation with the transabdominal team.

RESULTS

The 2-team method shortened the operative time dramatically and decreased mental and physical burden on the operators during lateral dissection. Assistance with the transanal approach helped with a secure and effective dissection, especially of the most distal parts, such as around the internal pudendal and inferior vesical arteries, because substantial skill is required for the transabdominal approach alone.

CONCLUSIONS

This procedure is useful for the safe and effective performance of lateral pelvic lymph node dissection for patients with rectal cancer.

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.

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.

Complete mesocolic excision and central vascular ligation in colorectal cancer in the era of minimally invasive surgery

Since the 19^th century, appropriate lymphadenectomy has been considered a cornerstone of oncologic surgery and one of the most important prognostic factors. This approach can be applied to any surgery for gastrointestinal cancer. During surgery for colon and rectal cancer, an adequate portion of the mesentery is removed together with the segment of bowel affected by the disease. The adequate number of lymph nodes to be removed is standardized and reported by several guidelines. It is mandatory to determine the appropriate extent of lymphadenectomy and to balance its oncological benefits with the increased morbidity associated with its execution in cancer patients. Our review focuses on the concept of “complete mesenteric excision (CME) with central vascular ligation (CVL),” a radical lymphadenectomy for colorectal cancer that has gained increasing interest in recent years. The aim of this study was to evaluate the evolution of this approach over the years, its potential oncologic benefits and potential risks, and the improvements offered by laparoscopic techniques. Theoretical advantages of CME are improved local-relapse rates due to complete removal of the intact mesocolic fascia and improved distance recurrence rates due to ligation of vessels at their origin (CVL) which guarantees removal of a larger number of lymph nodes. The development and worldwide diffusion of laparoscopic techniques minimized postoperative trauma in oncologic surgery, providing the same oncologic results as open surgery. This has been widely applied to colorectal cancer surgery; however, CME entails a technical complexity that can limit its wide minimally-invasive application. This review analyzes results of these procedures in terms of oncological outcomes, technical feasibility and complexity, especially within the context of minimally invasive surgery.

Central vascular ligation and mesentery based abdominal surgery

In the nineteenth century the idea of a correct surgical approach in oncologic surgery moved towards a good lymphadenectomy. In colon cancer the segment is removed with adjacent mesentery, in gastric cancer or pancreatic cancer a good oncologic resection is obtained with adequate lymphadenectomy. Many guidelines propose a minimal lymph node count that the surgeon must obtain. Therefore, it is essential to understand the adequate extent of lymphadenectomy to be performed in cancer surgery. In this review of the current literature, the focus is on "central vascular ligation", understood as radical lymphadenectomy in upper and lower gastrointestinal cancer, the evolution of this approach during the years and the improvement of laparoscopic techniques. For what concerns laparoscopic surgery, the main goal is to minimize post-operative trauma introducing the "less is more" concept whilst preserving attention for oncological outcomes. This review will demonstrate the importance of a scientifically based standardization of oncologic gastrointestinal surgery, especially in relation to the expansion of minimally invasive surgery and underlines the importance to further investigate through new randomized trials the role of extended lymphadenectomy in the new era of a multimodal approach, and most importantly, an era where minimally invasive techniques and the idea of "less is more" are becoming the standard thought for the surgical approach.

The additional diagnostic impact of positron emission tomography-computed tomography for lymph node metastasis from colorectal cancer: A prospective lymph node level analysis

BACKGROUND

We conducted a prospective study to determine the diagnostic performance of positron emission tomography-computed tomography (PET-CT) for lymph node metastasis in colorectal cancer patients.

METHODS

We enrolled patients scheduled to receive curative surgery with lymph node dissection for colorectal adenocarcinoma who underwent contrast-enhanced abdominopelvic CT and PET-CT before surgery and who had primary lesions of cT2 or deeper. A radiologist determined the fluorodeoxyglucose uptake and the standardized uptake value (SUV) and metabolic volume (MV) to diagnose metastasis in cases with enlarged lymph nodes (≥7 mm long in minor diameter) on contrast-enhanced CT. Two gastrointestinal surgeons intraoperatively identified target lymph nodes to assess the association between images and pathological findings. The diagnostic performance (i.e., sensitivity, specificity, and positive and negative predictive values) for lymph node metastasis was determined using multilevel logistic modeling.

RESULTS

A total of 205 colorectal cancer patients were enrolled from February 2018 to April 2020 and 194 patients were analyzed in this study. The sensitivity, specificity, and positive and negative predictive values of PET-CT were 15.3% (13.4%-17.5%), 100.0% (99.0%-100.0%), 100.0% (51.2%-100.0%), and 98.7% (98.5%-99.0%), respectively.

CONCLUSION

PET-CT is a useful modality for determining the presence of metastasis in swollen lymph nodes on contrast-enhanced CT in colorectal cancer patients.

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.