Prognostic significance of lateral lymph node dissection in node positive low rectal carcinoma

Management of inguinal lymph node metastases from rectal and anal canal adenocarcinoma

AIM

The surgical treatment of inguinal lymph node (ILN) metastases secondary to anorectal adenocarcinoma remains controversial. This study aimed to clarify the surgical treatment and management of ILN metastasis according to its classification.

METHODS

This retrospective, multi-centre, observational study included patients with synchronous or metachronous ILN metastases who were diagnosed with rectal or anal canal adenocarcinoma between January 1997 and December 2011. Treatment outcomes were analysed according to recurrence and prognosis.

RESULTS

Among 1181 consecutively enrolled patients who received treatment for rectal or anal canal adenocarcinoma at 20 referral hospitals, 76 (6.4%) and 65 (5.5%) had synchronous and metachronous ILN metastases, respectively. Among 141 patients with ILN metastasis, differentiated carcinoma, solitary ILN metastasis and ILN dissection were identified as independent predictive factors associated with a favourable prognosis. No significant difference was found in the frequency of recurrence after ILN dissection between patients with synchronous (80.6%) or metachronous (81.0%) ILN metastases. Patients who underwent R0 resection of the primary tumour and ILN dissection had a 5-year survival rate of 41.3% after ILN dissection (34.1% and 53.1% for patients with synchronous and metachronous ILN metastases, respectively, P = 0.55).

CONCLUSION

The ILN can be appropriately classified as a regional lymph node in rectal and anal canal adenocarcinoma. Moreover, aggressive ILN dissection might be effective in improving the prognosis of low rectal and anal canal adenocarcinoma with ILN metastases; thus, prophylactic ILN dissection is unnecessary.

Effect of lateral lymph nodes without malignant characteristics on the prognosis of patients with rectal cancer

Background: Lateral lymph node (LLN) metastasis is a poor prognostic factor for rectal cancer patients. However, the effect of LLNs without malignant characteristics on the prognosis of rectal cancer patients has been uncertain. Methods: Consecutive patients who underwent laparoscopic-assisted low anterior resection were included. Patients with MRI-detected LLNs, but without malignant characteristics, were compared with patients with no MRI-detected LLNs. Results: The local recurrence rate was higher in the LLN-present group than in the LLN-absent group (9.8% vs 2.5%; p = 0.056). The overall survival of patients with no MRI-detected LLNs was significantly better than that of patients with MRI-detected LLNs (p = 0.021). Conclusion: The presence of LLNs, even without malignant features, may lead to worse local control and overall survival.

Mesorectal excision with lateral lymph node dissection for mid-low rectal cancer with lateral lymph node metastasis: efficacy and prognostic analysis

Background

The aim of this study was to evaluate the efficacy of lateral pelvic lymph node (LPN) dissection (LPND) for rectal cancer patients with LPN metastasis (LPNM) and investigate the impact of LPNM on prognosis.

Methods

One hundred twenty-five matched pairs were selected and divided into the total mesorectal excision (TME) group and TME + LPND group for evaluation after propensity matching.

Results

No significant difference was observed in the 3-year local recurrence rate between the TME group and the TME + LPND group (10.7% vs 8.8%, P = 0.817); however, the rate of distant metastasis after TME + LPND was significantly higher (15.2% vs 7.2%, P = 0.044). When the mesorectal LN and LPN groups were subdivided, 3-year RFS was not significantly different between the internal LPN and N2 groups (57.1% vs. 55.3%, P = 0.613). There was no significant difference in RFS between the external group and the stage IV group (49.1% vs. 22.5%, P = 0.302), but RFS in the former group was significantly worse than that in the N2 group (49.1% vs. 55.3%, P = 0.044).

Conclusion

Although patients with suspected LPNM can achieve satisfactory local control after TME + LPND, systemic metastases are more likely to develop after surgery. Patients limited to internal iliac and obturator LN metastasis appear to achieve a survival benefit from LPND and can be regarded as regional LN metastasis. However, patients with LPNM in the external and common iliac LN metastasis have a poor prognosis that is significantly worse than that of N2 and slightly better than that of stage IV, and LPND should be carefully selected.

Fluorescence Imaging in Colorectal Surgery: An Updated Review and Future Trends

Fluorescence imaging in colorectal surgery is considered a novel predominantly intraoperative method of ensuring a greater surgical success. The use of fluorescence is linked to advanced tumor visualization and projection of its lymphatics, both vessels and nodes, which results in a higher chance of achieving a total excision. Additionally, iatrogenic complications prove to be reduced using fluorescence during the surgical excision. The combination of fluorescence and artificial intelligence to better facilitate oncological surgery will soon become an established approach in operating rooms worldwide.

Prognostic significance of lateral pelvic lymph node dissection for middle-low rectal cancer patients with lateral pelvic lymph node metastasis: a propensity score matching study

Background

There is still controversy regarding the clinical value and significance of lateral pelvic lymph node (LPN) dissection (LPND). The present study aimed to investigate whether the addition of LPND to total mesorectal excision (TME) confers survival benefits in rectal cancer patients with clinical lateral pelvic node metastasis (LPNM).

Methods

From January 2015 to January 2021, a total of 141 rectal cancer patients with clinical evidence of LPNM who underwent TME + LPND were retrospectively analysed and divided into the LPNM group (n = 29) and the non-LPNM group (n = 112). The LPNM group was further subdivided into a high-risk LPNM group (n = 14) and a low-risk LPNM group (n = 15). Propensity score matching (PSM) was performed to minimize selection bias. The primary outcomes of this study were 3-year overall survival (OS) and disease-free survival (DFS).

Results

Of the 141 patients undergoing LPND, the local recurrence rate of patients with LPNM was significantly higher than that of patients without LPNM both before (27.6% vs. 4.5%, P = 0.001) and after (27.6% vs. 3.4%, P = 0.025) PSM. Multivariate analysis revealed that LPNM was an independent risk factor for not only OS (HR: 3.06; 95% CI, 1.15–8.17; P = 0.025) but also DFS (HR: 2.39; 95% CI, 1.18–4.87; P = 0.016) in patients with LPNM after TME + LPND. When the LPNM group was further subdivided, multivariate logistic regression analysis showed that OS and DFS were significantly better in the low-risk group (obturator/internal iliac artery region and < 2 positive LPNs).

Conclusion

Even after LPND, LPNM patients have a poor prognosis. Moreover, LPNM is an independent poor prognostic factor affecting OS and DFS after TME + LPND. However, LPND appears to confer survival benefits to specific patients with single LPN involvement in the obturator region or internal iliac vessel region. Furthermore, LPND may have no indication in stage IV patients and should be selected carefully.

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.

The expression of carcinoembryonic antigen mRNA in the lavage of the dissected area of the lateral lymph nodes influences the lateral recurrence of lower rectal cancer

PURPOSE

To determine whether or not migrating cancer cells are present on the surgical plane after lateral lymph node dissection (LLND) for lower rectal cancer and related to lateral recurrence (LR), we evaluated the lavage of LLND areas by reverse-transcription polymerase chain reaction (RT-PCR) to check the expression of CEA mRNA in the residual cancer cells.

METHODS

Thirty patients who underwent curative LLND were enrolled. Lavage was collected after LLND and subjected to RT-PCR to detect CEA mRNA. The median follow-up to check for recurrence was 31.4 months.

RESULTS

CEA mRNA was detected in 9 of the 46 dissected areas. Based on the receiver operating characteristic curves, the cut-off value of PCR was set at 0.025. This cut-off point classified five patients into the high-expression group for CEA mRNA. During follow-up, LR developed in 1 of 40 low-expression areas of CEA mRNA and 3 of 6 high-expression areas. The LR rate was higher in the high-expression group than in the low-expression group (p = 0.015). A multivariate analysis showed that the high expression of CEA mRNA was likely an independent prognostic factor of LR.

CONCLUSION

The expression of CEA mRNA in the lavage of LLND areas indicates the presence of residual cancer cells that cause LR.

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)

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Robotic Surgery for Rectal Cancer: Operative Technique and Review of the Literature

The number of patients undergoing robotic surgery for rectal cancer has rapidly increased in Japan, since the government approved the procedure for national insurance coverage in April 2018. Robotic surgery has the potential to overcome some limitations of laparoscopic surgery, especially in the narrow pelvis, providing a three-dimensional view, articulated instruments, and a stable camera platform. Although meta-analyses and randomized controlled trials have failed to demonstrate the superiority of robotic surgery over laparoscopic surgery with respect to the short-term clinical outcomes, the published findings suggest that robotic surgery may be potentially beneficial for patients who are obese, male, or patients undergoing sphincter-preserving surgery for rectal cancer. The safety and feasibility of robotic surgery for lateral lymph node dissection, the standard procedure for locally advanced lower rectal cancer in Japan, have been demonstrated in some retrospective studies. However, additional prospective, randomized trials are required to determine the actual benefits of robotic surgery to ameliorate the urogenital and oncological outcomes. The cost of this approach is a long-standing principal concern. A literature search showed that the cost of robotic surgery for rectal cancer was 1.3-2.5 times higher per patient than that for the laparoscopic approach. We herein describe our surgical technique using a da Vinci Surgical System (S/Si/Xi) with 10 years of experience in performing robotic surgery. We also review current evidence regarding short-term clinical and long-term oncological outcomes, lateral lymph node dissection, and the cost of the procedure.

Short- and long-term outcomes of robotic surgery for rectal cancer: a single-center retrospective cohort study

PURPOSE

This study aimed to clarify the short- and long-term outcomes of robotic surgery with or without lateral lymph node dissection (LLND) for rectal cancer at Fujita Health University Hospital, Aichi, Japan, during a self-pay period.

METHODS

We retrospectively evaluated 115 consecutive patients who underwent robotic surgery for rectal cancer between September 2009 and March 2018, with a median follow-up period of 48 months. Total mesorectal excision was completed by two certified surgeons using a da Vinci S, Si, or Xi Surgical System with an entirely robotic single-docking technique. The surgical and pathological outcomes, morbidity, and oncological results were examined.

RESULTS

Lateral lymph node dissection was performed in 26 patients (22.6%). Neither conversion to open surgery nor perioperative blood transfusion occurred. Ten patients (8.7%) experienced Clavien-Dindo grade III postoperative complications. Pathologically, both the distal and radial margins were negative in all cases. The 5-year relapse-free survival rates for stages I, II, III, and IV were 93.5%, 100%, 83.8%, and not reached, respectively.

CONCLUSIONS

Even in the period before coverage by the health insurance system, robotic surgery for rectal cancer performed by experienced surgeons was safe and technically feasible, with favorable perioperative results and long-term oncological outcomes, including rates of the relapse-free survival.

Application of indocyanine green-enhanced near-infrared fluorescence-guided imaging in laparoscopic lateral pelvic lymph node dissection for middle-low rectal cancer

BACKGROUND

As one effective treatment for lateral pelvic lymph node (LPLN) metastasis (LPNM), laparoscopic LPLN dissection (LPND) is limited due to the complicated anatomy of the pelvic sidewall and various complications after surgery. With regard to improving the accuracy and completeness of LPND as well as safety, we tried an innovative method using indocyanine green (ICG) visualized with a near-infrared (NIR) camera system to guide the detection of LPLNs in patients with middle-low rectal cancer.

AIM

To investigate whether ICG-enhanced NIR fluorescence-guided imaging is a better technique for LPND in patients with rectal cancer.

METHODS

A total of 42 middle-low rectal cancer patients with clinical LPNM who underwent total mesorectal excision (TME) and LPND between October 2017 and March 2019 at our institution were assessed and divided into an ICG group and a non-ICG group. Clinical characteristics, operative outcomes, pathological outcomes, and postoperative complication information were compared and analysed between the two groups.

RESULTS

Compared to the non-ICG group, the ICG group had significantly lower intraoperative blood loss (55.8 ± 37.5 mL vs 108.0 ± 52.7 mL, P = 0.003) and a significantly larger number of LPLNs harvested (11.5 ± 5.9 vs 7.1 ± 4.8, P = 0.017). The LPLNs of two patients in the non-IVG group were residual during LPND. In addition, no significant difference was found in terms of LPND, LPNM, operative time, conversion to laparotomy, preoperative complication, or hospital stay (P > 0.05).

CONCLUSION

ICG-enhanced NIR fluorescence-guided imaging could be a feasible and convenient technique to guide LPND because it could bring specific advantages regarding the accuracy and completeness of surgery as well as safety.

Evaluating predictive factors for determining the presence of lateral pelvic node metastasis in rectal cancer patients following neoadjuvant chemoradiotherapy

AIM

The need or otherwise for lateral pelvic node dissection (LPND) in rectal cancer patients with clinical lateral pelvic node metastasis (LPNM) after neoadjuvant chemoradiotherapy (nCRT) is controversial. This study was designed to explore the predictive factors for pathological LPNM in rectal cancer patients with clinical LPNM after nCRT.

METHOD

From January 2010 to February 2018, a consecutive series of patients with rectal cancer and clinical LPNM after nCRT who underwent total mesorectal excision and LPND were reviewed. Patient demographics, operative and pathological outcomes were collected and analysed.

RESULTS

A total of 76 consecutive cases were included in this study: 53 (69.7%) patients underwent unilateral LPND and 23 (30.3%) bilateral LPND. The pathological results showed that LPNM was found in 13 (17.1%) patients. Multivariate logistic regression analysis showed that the post-nCRT lateral pelvic node size ≥ 5 mm (OR = 7.67, 95% CI = 1.45-40.63, P = 0.017) and mucinous/signet-ring adenocarcinoma (OR = 4.60, 95% CI = 1.11-19.08, P = 0.035) were independent risk factors for pathological LPNM.

CONCLUSION

Post-nCRT lateral pelvic node size ≥ 5 mm and mucinous/signet-ring adenocarcinoma were independent predictive factors of pathological LPNM for rectal cancer patients with clinical LPNM after nCRT, and patients with these characteristics may benefit from LPND.

Effect of preoperative injection of carbon nanoparticle suspension on the outcomes of selected patients with mid-low rectal cancer

BACKGROUND

Carbon nanoparticles show significant lymphatic tropism and can be used to identify lymph nodes surrounding mid-low rectal tumors. In this study, we analyzed the effect of trans anal injection of a carbon nanoparticle suspension on the outcomes of patients with mid-low rectal cancer who underwent laparoscopic resection.

METHODS

We collected the data of 87 patients with mid-low rectal cancer who underwent laparoscopic resection between November 2014 and March 2015 at Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College. For 35 patients in the experimental group, the carbon nanoparticle suspension was injected transanally into the submucosa of the rectum around the tumor 30 min before the operation; 52 patients in the control group underwent the operation directly without the injection of carbon nanoparticle suspension. We then compared the operation outcomes between the two groups.

RESULTS

In the experimental group, the rate of incomplete mesorectal excision was lower than that in the control group, but no significant difference was found (2.9% vs. 7.7%, P = 0.342). The distance between the tumor and the circumferential resection margin was 5.8 ± 1.4 mm in the experimental group and 4.8 ± 1.1 mm in the control group (P = 0.001). The mean number of lymph nodes removed was 28.2 ± 9.4 in the experimental group and 22.7 ± 7.3 in the control group (P = 0.003); the mean number of lymph nodes smaller than 5 mm in diameter was 10.1 ± 7.5 and 4.5 ± 3.7, respectively (P < 0.001). Three patients in the experimental group received lateral lymph node resection. Among the three patients, we retrieved three nodes (one stained node) from the first patient, three nodes (two stained nodes) from the second patient, and two nodes (no stained nodes) from the third patient.

CONCLUSIONS

Injecting a carbon nanoparticle suspension improved the outcomes of patients who underwent laparoscopic resection for mid-low rectal cancer; it also improved the accuracy of pathologic staging. Moreover, for selected patients, this technique narrowed the scope of lateral lymph node dissection.

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.