Systematic review of sentinel lymph node mapping procedure in colorectal cancer

Laparoscopic complete mesocolic excision with central vascular ligation in right colon cancer: Long-term oncologic outcome between mesocolic and non-mesocolic planes of surgery

AIM

To analyze our experience in translating the concept of total mesorectal excision to "no-touch" complete removal of an intact mesocolonic envelope (complete mesocolic excision), along with central vascular ligation and apical node dissection, in the surgical treatment of right-sided colonic cancers, comparing "mesocolic" to less radical "non-mesocolic" planes of surgery in respect to quality of the surgical specimen and long-term oncologic outcome.

METHOD

A total of 115 patients with right-sided colonic cancers were retrospectively enrolled from 2008 to 2013 and operated on following the intent of minimally invasive complete mesocolic excision with central vascular ligation.

RESULTS

Morbidity and mortality were 22.6% and 1.7%, respectively. Mesocolic, intramesocolic, and muscularis propria planes of resection were achieved in 65.2%, 21.7%, and 13% of cases, respectively, with significant impact for mesenteric plane of surgery on R0 resection rate (97.3%), circumferential resection margin <1 mm (2.6%), and consequent survival advantage (82.6% at 5 years) when compared to muscularis propria plane of surgery, with R0 resection rate and overall survival falling to 72% and 60%, respectively, and with circumferential resection margin <1 mm raising to 33.3%, all being statistically significant. Stratifying patients for stage of disease, laparoscopic complete mesocolic excision with central vascular ligation significantly impacted survival in patients with stage II, IIIA/B, and in a subgroup of IIIC patients with negative apical nodes.

CONCLUSION

In our experience, minimally invasive complete mesocolic excision with central vascular ligation allows for both safety and higher quality of surgical specimens when compared to less radical intramesocolic or muscularis propria planes of "standard" surgery, significantly impacting loco-regional control and thus overall survival.

Intra-arterial methylene blue injection into ex vivo colorectal cancer specimens improves lymph node staging accuracy: a randomized controlled trial

AIM

A randomized controlled trial was carried out to study the effect of a recently proposed technique of ex vivo intra-arterial methylene blue injection of the surgical specimen removed for colorectal cancer on lymph node harvest and staging.

METHOD

Between May 2012 and February 2013, 100 consecutive colorectal cancer resection specimens in a single institution were randomly assigned to intervention (methylene blue injection) and control (standard manual palpation technique) groups before formalin fixation. The specimen was then examined by the histopathologist for lymph nodes.

RESULTS

Both groups were similar for age, sex, site of tumour, operation and tumour stage. In the intervention group, a higher number of nodes was found [median 23 (5-92) vs. 15 (5-37), P < 0.001], with only one specimen not achieving the recommended minimum standard of 12 nodes [1/50 (2%) vs. 8/50 (16%), P = 0.014]. However, there was no upstaging effect in the intervention group [23/50 (46.0%) vs. 20/50 (40.0%); P = 0.686]. With a significantly lower number of nodes harvested in rectal cancer, the positive effect of the intervention was particularly observed in the patients who underwent preoperative neoadjuvant radiotherapy [median 30 nodes (12-57) vs. 11 (7-15); P = 0.011; proportion of cases with < 12 nodes 0/5 vs. 5/8 (62.5%), P = 0.024].

CONCLUSION

Ex vivo intra-arterial methylene blue injection increases lymph node yield and can help to reduce the number of cases with a lower-than-recommended number of nodes, particularly in patients with rectal cancer having neoadjuvant treatment. The technique is easy to perform, cheap and saves time.

Impact of D3 lymph node dissection on survival for patients with T3 and T4 colon cancer

PURPOSE

The clinical significance of D3 lymph node dissection for patients with colon cancer remains controversial. This study aims to clarify the impact of D3 lymph node dissection on survival in patients with colon cancer.

METHODS

This is a retrospective cohort study from a prospectively registered multi-institutional database of colorectal cancer in Japan. Propensity score matching method was applied to balance potential confounders of the treatment. A cohort of 10,098 patients who underwent radical colectomy for pT3 and pT4 colon cancer between 1985 and 1994 were identified. A total of 3,425 propensity score matched pairs were extracted from the entire cohort. The primary outcome measure was overall survival (OS).

RESULTS

In the entire cohort, there was a statistically significant difference in overall survival (OS) between the patients who had D3 and D2 lymph node dissection (p = 0.00003). The estimated hazard ratio (HR) for OS of patients who had D3 versus D2 lymph node dissection was 0.827 (95 % confidence interval, 0.757 to 0.904). In the matched cohort, there was also a significant difference in OS between the two groups (p = 0.0001), and the estimated HR for OS was 0.814 (95 % confidence interval, 0.734 to 0.904).

CONCLUSIONS

We found D3 lymph node dissection for pT3 and pT4 colon cancer to be associated with a significant survival advantage in a large-scale database, even after adjusting potential confounders of lymph node dissection. This finding may provide a rationale for D3 lymph node dissection in radical surgery for pT3 and pT4 colon cancer.

Mapping lymph nodes in cancer management - role of (99m)Tc-tilmanocept injection

Two decades ago, lymphatic mapping of sentinel lymph nodes (SLN) was introduced into surgical cancer management and was termed sentinel node navigated surgery. Although this technique is now routinely performed in the management of breast cancer and malignant melanoma, it is still under investigation for use in other cancers. The radioisotope technetium (^99mTc) and vital blue dyes are among the most widely used enhancers for SLN mapping, although near-infrared fluorescence imaging of indocyanine green is also becoming more commonly used. ^99mTc-tilmanocept is a new synthetic radioisotope with a relatively small molecular size that was specifically developed for lymphatic mapping. Because of its small size, ^99mTc-tilmanocept quickly migrates from its site of injection and rapidly accumulates in the SLN. The mannose moieties of ^99mTc-tilmanosept facilitate its binding to mannose receptors (CD206) expressed in reticuloendothelial cells of the SLN. This binding prevents transit to second-echelon lymph nodes. In Phase III trials of breast cancer and malignant melanoma, and Phase II trials of other malignancies, ^99mTc-tilmanocept had superior identification rates and sensitivity compared with blue dye. Trials comparing ^99mTc-tilmanocept with other ^99mTc-based agents are required before it can be routinely used in clinical settings.

What should we intend for minimally invasive treatment of colorectal cancer?

Non-inferiority of laparoscopic treatment of colorectal cancer (CRC) has been demonstrated in randomized controlled trials although operative and perioperative management varies widely among centers. Literature data in English language published up to April 15, 2014 were analyzed in order to give an up to date analysis that would highlights the key aspects of a modern and factual minimally invasive treatment of CRC. Laparoscopic resection is the first choice treatment of colon cancer. Laparoscopic resection of rectal cancer should be considered an investigational procedure to be performed in high volume centers with special interest in laparoscopy and colorectal surgery. Less invasive approaches should be taken into account with the aim of reducing surgical stress. The adoption of ERAS programs has demonstrated to optimize short-term results. Future research should be directed to prove possible long-term advantages, in terms of overall and disease-free survival, of minimally invasive treatment of CRC.

Blue dye injection does not induce dissemination of epithelial cells during SLN procedure in colon cancer patients

INTRODUCTION

The sentinel lymph node (SLN) procedure for colon cancer patients has been increasingly performed over the past decade and has shown advantages regarding lymph node staging. However, there are concerns that the manipulation of the colon, particularly the blue dye injection, results in isolated tumor cell dissemination to lymph nodes. Therefore, the objective of the present study was to evaluate whether the blue dye injection during the SLN procedure for colon cancer induces epithelial cell dissemination to the regional lymph nodes using a fake SLN procedure as a model.

METHODS

One hundred seventy-four colon cancer patients underwent open oncologic colon resection and SLN procedure according to a standardized protocol. For the fake SLN procedure, blue dye was injected ex vivo, into the subserosa of a nontumor-bearing segment of the resected colon in 37 unselected patients. Three levels of each SLN were stained with H&E and with the pancytokeratin marker AE1/AE3 and were analyzed for the presence of cytokeratin positive cells.

RESULTS

Identification of fake SLN was successful in 32 of the 37 patients (86 %). Seventy fake SLN were histologically confirmed. The median number of fake SLN was 2 per patient (range 1-8). None of the fake SLN showed any disseminated epithelial cells.

CONCLUSIONS

The present prospective study provides compelling evidence that blue dye injection during sentinel lymph node procedure for colon cancer does not induce epithelial cell dissemination to the sentinel lymph nodes. Therefore, isolated tumor cells in sentinel lymph nodes result from a true metastatic process.

The role of sentinel lymph node in colon cancer evolution

INTRODUCTION

The aim of this study is to evaluate the sentinel lymph node mapping (SLNM) with methylene blue staining "ex vivo" in colon cancer, as well as calculate the upstaging obtained by the determination of micrometastases and its correlation with the evolution of the disease.

METHODS

Between 2008 and 2011, 101 patients with colon cancer undergoing resection were studied prospectively with SLNM and detection of micrometastases. The correlation of SLN micrometastases with the disease evolution was evaluated in patients with a follow-up of more than one year.

RESULTS

The SLNM rate was 92 cases (91%). Only SLN was positive for micrometastases in 9 cases, with a 14% upstaging. The incidence of false negatives was 9 patients (10%). Mean follow of N0 patients (n=74) was 38 months. The SLN- (negative) group (65 patients) had a recurrence rate of 4 patients (7%), whereas this rate was 2 patients (22%) in the group of SLN+(positive) (9 patients), but without significant differences. No differences in survival were observed.

CONCLUSIONS

SLNM is a reproducible technique without significant increase in time and costs. Upstaging was obtained in 14% of patients staged as N0 by conventional technique. At follow-up of N0 patients with SLN+there seems to be a higher rate of recurrence, which could change the guidelines of adjuvant treatment, but we must interpret the results it with caution because the sample is small.

[The intraoperative study of the sentinel lymph node was made possible through molecular analysis: a new concept and new applications for colon cancer?]

Sentinel lymph node (SLN) is a concept but also a technical possibility that can be studied and applied to almost all organs with cancer. For colorectal cancer surgery, some possibilities of using the SLN are possible, other implausible and some completely new especially aware of possible analysis of SLN by a molecular biology technique. The orientation of dissection or "lymph road mapping" can be designed for this case or the surgeon may want to limit his actions, particularly in patients with a history of colonic surgical resection, to keep the digestive function in maintaining vascular axes considered not involved in the metastatic process. The use of the single analysis of SLN to determine the positive or negative status of the cleaning has failed because of the frequency of false negatives in part to the size of colic advanced cancers at diagnosis. The use of "ultra-stading" by multiple section or exhaustion of the block, can lead to reconsider a stage N0 to N1 as a point, if the analysis technique remains in HES. Unlike the "ultra-stading" by RT- PCR or immunohistochemistry was even more discussed and seems not equivalent in terms of prognosis and therefore no giving formally justification for adjuvant therapy. Currently, a new technique for molecular biology, named "OSNA", allows an analysis of all the SLN in less than 45 minutes. It is therefore possible to obtain during surgery analysis of a node with the same level of information than traditional analysis using HES. If this node is positive and if the strategy in case of positive lymph nodes was determined prior for this patient, it is possible to anticipate this strategy and place after colectomy during the same anesthesia, venous access quickly to start postoperative chemotherapy. This new technique for analyzing lymph applied to the SLN opens a new potential application of this concept in digestive oncology.

Micrometastatic cancer cells in lymph nodes, bone marrow, and blood: Clinical significance and biologic implications

Cancer metastasis may be regarded as a progressive process from its inception in the primary tumor microenvironment to distant sites by way of the lymphovascular system. Although this type of tumor dissemination often occurs in an orderly fashion via the sentinel lymph node (SLN), acting as a possible gateway to the regional lymph nodes, bone marrow, and peripheral blood and ultimately to distant metastatic sites, this is not a general rule as tumor cells may enter the blood and spread to distant sites, bypassing the SLN. Methods of detecting micrometastatic cancer cells in the SLN, bone marrow, and peripheral blood of patients have been established. Patients with cancer cells in their SLN, bone marrow, or peripheral blood have worse clinical outcomes than patients with no evidence of spread to these compartments. The presence of these cells also has important biologic implications for disease progression and the clinician's understanding of the process of cancer metastasis. Further characterization of these micrometastatic cancer cells at each stage and site of metastasis is needed to design novel selective therapies for a more "personalized" treatment.

Colon resection: is standard technique adequate?

The traditional approach to surgical resection of colonic cancer involves removal of the primary tumor together with the associated lymphovascular pedicle. In an attempt to improve oncological outcomes, several groups have recently published data describing improved outcomes with a more radical surgical approach termed complete mesocolic excision (CME) with central vessel ligation (CVL). Here we critically appraise this new surgical advance and discuss other surgical options suggested to offer improvements over current best practice.

Digestive cancer surgery in the era of sentinel node and epithelial-mesenchymal transition

Lymph node involvement is one of the most important prognostic indicators of carcinoma of the digestive tract. Although the therapeutic impact of lymphadenectomy has not been proven and the number of retrieved nodes cannot be considered a measure of successful cancer surgery, an adequate lymph node count should be guaranteed to accurately assess the N-stage through the number of involved nodes, lymph node ratio, number of negative nodes, ratio of negative to positive nodes, and log odds, i.e., the log of the ratio between the number of positive lymph nodes and the number of negative lymph nodes in digestive carcinomas. As lymphadenectomy is not without complications, sentinel node mapping has been used as the rational procedure to select patients with early digestive carcinoma in whom nodal dissection may be omitted or a more limited nodal dissection may be preferred. However, due to anatomical and technical issues, sentinel node mapping and nodal basin dissection are not yet the standard of care in early digestive cancer. Moreover, in light of the biological, prognostic and therapeutic impact of tumor budding and tumor deposits, two epithelial-mesenchymal transition-related phenomena that are involved in tumor progression, the role of staging and surgical procedures in digestive carcinomas could be redefined.

Lymph node staging in colorectal cancer: Old controversies and recent advances

Outcome prediction based on tumor stage reflected by the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) tumor node metastasis (TNM) system is currently regarded as the strongest prognostic parameter for patients with colorectal cancer. For affected patients, the indication for adjuvant therapy is mainly guided by the presence of regional lymph node metastasis. In addition to the extent of surgical lymph node removal and the thoroughness of the pathologist in dissecting the resection specimen, several parameters that are related to the pathological work-up of the dissected nodes may affect the clinical significance of lymph node staging. These include changing definitions of lymph nodes, involved lymph nodes, and tumor deposits in different editions of the AJCC/UICC TNM system as well as the minimum number of nodes to be dissected. Methods to increase the lymph node yield in the fatty tissue include methylene blue injection and acetone compression. Outcome prediction based on the lymph node ratio, defined as the number of positive lymph nodes divided by the total number of retrieved nodes, may be superior to the absolute numbers of involved nodes. Extracapsular invasion has been identified as additional prognostic factor. Adding step sectioning and immunohistochemistry to the pathological work-up may result in higher accuracy of histological diagnosis. The clinical value of more recent technical advances, such as sentinel lymph node biopsy and molecular analysis of lymph nodes tissue still remains to be defined.

Survival outcome of local excision versus radical resection of colon or rectal carcinoma: a Surveillance, Epidemiology, and End Results (SEER) population-based study

OBJECTIVE

To compare cancer-specific results of local excision with major resection.

BACKGROUND

Technological advances have enabled endoscopic and local excision techniques to be applied in the treatment of early colorectal cancer in preference to radical surgery.

METHOD

Patients with stage 0 (carcinoma in situ) or stage I (T1/2N0M0) adenocarcinoma of the colon or rectum undergoing surgery between 1998 and 2009 were included from the SEER (Surveillance, Epidemiology, and End Results) database. Local excision (endoscopic or surgical) was compared with major surgical resection using adjusted hazard ratios (HRs) for 5-year cancer-specific survival (CSS).

RESULTS

This study included 7378 local excisions and 36,116 major resections. There were 3553 patients with carcinoma in situ and 39,941 with clinical stage I cancer. Local tumor excision for carcinoma in situ was associated with equivalent CSS compared to major resection (HRs = 1.06, P = 0.814, for colon and 0.78, P = 0.494, for rectum). Local excision of T1 and T2 colon cancer was associated with reduced CSS (HR = 1.31, P = 0.020, and 2.89, P < 0.001, respectively). Local excision of T1 rectal cancer did not affect CSS (HR = 1.16, P = 0.236), but it significantly reduced CSS for T2 cancer (HR = 1.71, P < 0.001). Subgroup analysis of T1 and T2 rectal cancer after neoadjuvant therapy and local excision showed oncological equivalence to major resection (HR = 1.12, P = 0.802, and 1.23, P = 0.802).

CONCLUSIONS

Local excision for early colorectal cancer was oncologically equivalent to major surgery for carcinoma in situ and T1 rectal cancer, but inferior for T1-2 colon and T2 rectal cancer. Exploratory data suggest local excision of T1-2 rectal cancer after neoadjuvant therapy may be safe.

D3 Lymph Node Dissection in Right Hemicolectomy with a No-touch Isolation Technique in Patients With Colon Cancer

BACKGROUND

The role of lymph node dissection in the management of right-sided colon cancer remains controversial.

OBJECTIVE

The aim of this study was to investigate the surgical treatment of curable right-sided colon cancer by using D3 lymphadenectomy with a no-touch isolation technique and to determine the extent of lymph node dissection optimal for the prognosis of right-sided colon cancer.

DESIGN

This research is a retrospective cohort study from a prospectively collected database.

SETTING

The investigation took place in a specialized colorectal surgery department.

PATIENTS

: Data on 370 consecutive patients who underwent D3 lymph node dissection for right-sided colon cancer with a no-touch isolation technique were identified.

MAIN OUTCOME MEASURES

The survival of patients with involvement of main nodes at the roots of colonic arterial trunks along superior mesenteric vessels through intermediate nodes in the right mesocolon was determined.

RESULTS

The 5-year overall survival of patients with stage I (n = 73, 19.7%), II (n = 155, 41.9%), and III (n = 142, 38.4%) cancer were 94.5%, 87.6%, and 79.2%. The 5-year disease-specific survival of patients with stages I, II, and III cancer were 100.0%, 94.5%, and 85.0%. Eleven patients (3.0%) had metastatic involvement of main lymph nodes, whereas 49 (13.2%) had metastases to intermediate lymph nodes. The 5-year overall survival and disease-specific survival of patients with metastases to main lymph nodes were 36.4% for both, and 5-year overall survival and disease-specific survival of patients with metastases to intermediate lymph nodes were 77.6% and 83.5%.

LIMITATIONS

This study was limited by its nonrandomized retrospective design.

CONCLUSIONS

D3 lymphadenectomy with a no-touch isolation technique allows curative resection and long-term survival in a cohort of patients with cancer of the right colon.

Qualitative and quantitative issues of lymph nodes as prognostic factor in colon cancer

For patients undergoing curative resections for colon cancer, the nodal status represents the strongest prognostic factor, yet at the same time the most disputed issue as well. Consequently, the qualitative and quantitative aspects of lymph node evaluation are thus being scrutinized beyond the blunt distinction between 'node positive' (pN+) and 'node negative' (pN0) disease. Controversy ranges from a minimal or 'least-unit' strategy as exemplified by the 'sentinel node' to a maximally invasive or 'all inclusive' approach by extensive surgery. Ranging between these two extremes of node sampling strategies are factors of quantitative and qualitative value, which may be subject to modification. Qualitative issues may include aspects of lymph node harvest reflected by surgeon, pathologist and even hospital performance, which all may be subject to modification. However, patient's age, gender and genotype may be non-modifiable, yet influence node sample. Quantitative issues may reflect the balance between absolute numbers and models investigating the relationships of positive to negative nodes (lymph node ratio; log odds of positive lymph nodes). This review provides an updated overview of the current controversies and a state-of-the-art perspective on the qualitative and quantitative aspects of using lymph nodes as a prognostic marker in colon cancer.