Lymphatic spread, nodal count and the extent of lymphadenectomy in cancer of the colon

Immune microenvironment and lymph node yield in colorectal cancer

BACKGROUND

Lymph node (LN) harvesting is associated with outcomes in colonic cancer. We sought to interrogate whether a distinctive immune milieu of the primary tumour is associated with LN yield.

METHODS

A total of 926 treatment-naive patients with colorectal adenocarcinoma with more than 12 LNs (LN-high) were compared with patients with 12 or fewer LNs (LN-low). We performed immunohistochemistry and quantification on tissue microarrays for HLA class I/II proteins, beta-2-microglobulin (B2MG), CD8, CD163, LAG3, PD-L1, FoxP3, and BRAF V600E.

RESULTS

The LN-high group was comprised of younger patients, longer resections, larger tumours, right-sided location, and tumours with deficient mismatch repair (dMMR). The tumour microenvironment showed higher CD8+ cells infiltration and B2MG expression on tumour cells in the LN-high group compared to the LN-low group. The estimated mean disease-specific survival was higher in the LN-high group than LN-low group. On multivariate analysis for prognosis, LN yield, CD8+ cells, extramural venous invasion, perineural invasion, and AJCC stage were independent prognostic factors.

CONCLUSION

Our findings corroborate that higher LN yield is associated with a survival benefit. LN yield is associated with an immune high microenvironment, suggesting that tumour immune milieu influences the LN yield.

Speculation on optimal numbers of examined lymph node for early-stage epithelial ovarian cancer from the perspective of stage migration

Introduction

In early-stage epithelial ovarian cancer (EOC), how to perform lymphadenectomy to avoid stage migration and achieve reliable targeted excision has not been explored in depth. This study comprehensively considered the stage migration and survival to determine appropriate numbers of examined lymph node (ELN) for early-stage EOC and high-grade serous ovarian cancer (HGSOC).

Methods

From the Surveillance, Epidemiology, and End Results database, we obtained 10372 EOC cases with stage T1M0 and ELN ≥ 2, including 2849 HGSOC cases. Generalized linear models with multivariable adjustment were used to analyze associations between ELN numbers and lymph node stage migration, survival and positive lymph node (PLN). LOESS regression characterized dynamic trends of above associations followed by Chow test to determine structural breakpoints of ELN numbers. Survival curves were plotted using Kaplan-Meier method.

Results

More ELNs were associated with more node-positive diseases, more PLNs and better prognosis. ELN structural breakpoints were different in subgroups of early-stage EOC, which for node stage migration or PLN were more than those for improving outcomes. The meaning of ELN structural breakpoint varied with its location and the morphology of LOESS curve. To avoid stage migration, the optimal ELN for early-stage EOC was 29 and the minimal ELN for HGSOC was 24. For better survival, appropriate ELN number were 13 and 8 respectively. More ELNs explained better prognosis only at a certain range.

Discussion

Neither too many nor too few numbers of ELN were ideal for early-stage EOC and HGSOC. Excision with appropriate numbers of lymph node draining the affected ovary may be more reasonable than traditional sentinel lymph node resection and systematic lymphadenectomy.

Potassium voltage‑gated channel subfamily E member 4 facilitates the malignant progression of colon cancer by enhancing EGF containing fibulin extracellular matrix protein 2 expression

Colon cancer is a highly invasive and metastatic cancer with a poor prognosis. The University of Alabama at Birmingham Cancer data analysis portal (UALCAN) database indicates that potassium voltage-gated channel subfamily E member 4 (KCNE4) is highly expressed in colon cancer tissues. UALCAN data also show that KCNE4 expression is positively associated with individual cancer stages and negatively associated with patient survival. Therefore, the aim of the current study was to elucidate the functional role of KCNE4 in the biological behaviors of colon cancer cells and to investigate the underlying molecular mechanism. The gene EGF containing fibulin extracellular matrix protein 2 (EFEMP2) was found to be positively correlated with KCNE4 in colon cancer based on analysis performed using the LinkedOmics database; notably, upregulated EFEMP2 expression has been reported to be closely associated with the malignant phenotypes of colon cancer cells. The differences in the expression levels of KCNE4 and EFEMP2 between human colon cancer and normal colonic mucosa cell lines were assessed via reverse transcription-quantitative PCR and western blot assays. In addition, the proliferation, migration and invasion of colon cancer cells were determined using Cell Counting kit-8, colony formation, would healing and Transwell assays, and a co-immunoprecipitation assay was performed to confirm the interaction between KCNE4 and EFEMP2. The results of the study demonstrated that KCNE4 and EFEMP2 are markedly upregulated in colon cancer cells. In addition, KCNE4 interacted with and bound to EFEMP2. The suppressive effects of KCNE4 knockdown on the proliferation, colony formation, migration and invasion of colon cancer cells were attenuated by EFEMP2 overexpression. On the basis of these findings, it may be concluded that KCNE4 acts as an oncogene in colon cancer via the promotion of EFEMP2 expression.

Contrast enhanced magneto-motive ultrasound in lymph nodes - modelling and pre-clinical imaging using magnetic microbubbles

Despite advances in MRI, the detection and characterisation of lymph nodes in rectal cancer remains complex, especially when assessing the response to neo-adjuvant treatment. An alternative approach is functional imaging, previously shown to aid characterization of cancer tissues. We report proof-of-concept of the novel technique Contrast-Enhanced Magneto-Motive Ultrasound (CE-MMUS) to recover information relating to local perfusion and lymphatic drainage, and interrogate tissue mechanical properties through magnetically induced tissue deformations. The feasibility of the proposed application was explored using a combination of pre-clinical ultrasound imaging and finite element analysis. First, contrast enhanced ultrasound imaging on one wild type mouse recorded lymphatic drainage of magnetic microbubbles after bolus injection. Second, preliminary CE-MMUS data were acquired as a proof of concept. Third, the magneto-mechanical interactions of a magnetic microbubble with an elastic solid were simulated using finite element software. Accumulation of magnetic microbubbles in the inguinal lymph node was verified using contrast enhanced ultrasound, with peak enhancement occurring 3.7 s post-injection. Preliminary CE-MMUS indicates the presence of magnetic contrast agent in the lymph node. The finite element analysis explores how the magnetic force is transferred to motion of the solid, which depends on elasticity and bubble radius, indicating an inverse relation with displacement. Combining magnetic microbubbles with MMUS could harness the advantages of both techniques, to provide perfusion information, robust lymph node delineation and characterisation based on mechanical properties. Clinical Relevance- Robust detection and characterisation of lymph nodes could be aided by visualising lymphatic drainage of magnetic microbubbles using contrast enhanced ultrasound imaging and magneto-motion, which is dependent on tissue mechanical properties.

Modelling of magnetic microbubbles to evaluate contrast enhanced magnetomotive ultrasound in lymph nodes - a pre-clinical study

OBJECTIVES

Despite advances in MRI the detection and characterisation of lymph nodes in rectal cancer remains complex, especially when assessing the response to neoadjuvant treatment. An alternative approach is functional imaging, previously shown to aid characterisation of cancer tissues. We report proof of concept of the novel technique Contrast-Enhanced Magneto-Motive Ultrasound (CE-MMUS) to recover information relating to local perfusion and lymphatic drainage, and interrogate tissue mechanical properties through magnetically induced deformations.

METHODS

The feasibility of the proposed application was explored using a combination of experimental animal and phantom ultrasound imaging, along with finite element analysis. First, contrast-enhanced ultrasound imaging on one wild type mouse recorded lymphatic drainage of magnetic microbubbles after bolus injection. Second, tissue phantoms were imaged using MMUS to illustrate the force- and elasticity dependence of the magnetomotion. Third, the magnetomechanical interactions of a magnetic microbubble with an elastic solid were simulated using finite element software.

RESULTS

Accumulation of magnetic microbubbles in the inguinal lymph node was verified using contrast enhanced ultrasound, with peak enhancement occurring 3.7 s post-injection. The magnetic microbubble gave rise to displacements depending on force, elasticity, and bubble radius, indicating an inverse relation between displacement and the latter two.

CONCLUSION

Combining magnetic microbubbles with MMUS could harness the advantages of both techniques, to provide perfusion information, robust lymph node delineation and characterisation based on mechanical properties.

ADVANCES IN KNOWLEDGE

(a) Lymphatic drainage of magnetic microbubbles visualised using contrast-enhanced ultrasound imaging and (b) magnetomechanical interactions between such bubbles and surrounding tissue could both contribute to (c) robust detection and characterisation of lymph nodes.

Is Laparoscopic Complete Mesocolic Excision and Central Vascular Ligation Really Necessary for All Patients With Right-Sided Colon Cancer?

Colon cancer treatment is on the way to evolution over several decades. The minimally invasive surgery has improved postoperative short-term outcomes. Adjuvant chemotherapy has prolonged the survival of advanced colon cancer patients. Hohenberger proposed the noble concept of complete mesocolic excision (CME) which consists of 3 components: plane surgery, sufficient longitudinal bowel resection, and central vascular ligation (CVL). Mesocolic plane surgery shares the same surgical principle of total mesorectal excision, which is maintaining the intact mesothelial envelope. However, there remain debates about the extent of bowel resection and the level of CVL for maximizing lymph node dissection. There is no solid clinical evidence for the oncological necessity and benefit of extended radical dissection in right hemicolectomy. CME with CVL based on open surgery has been adopted in laparoscopic surgery. So, it is also necessary to look at how the CME could be transformed and successfully implanted in the laparoscopic era. Recent rapid advances in surgical technology and cancer biology are preparing for fundamental changes in cancer surgery. In this study, we reviewed the history, oncological necessity, and compatibility of CME for the right hemicolectomy in the laparoscopic era and outline the new perspectives on the evolution of cancer surgery.

Association of MACC1 expression with lymphatic metastasis in colorectal cancer: A nested case-control study

MACC1 gene is a newly discovered gene and plays an important role in the metastasis of colorectal cancer (CRC). The objective of this study was to investigate whether MACC1 is an independent factor associated with lymphatic metastasis in CRC patients. We analyzed the association between MACC1 expression and lymphatic metastasis in a nested case-control study including 99 cases and 198 matched controls in CRC patients, assessed from August 2001 to March 2015. Cases were defined as lymphatic metastasis and non-lymphatic metastasis according to AJCC TNM stages; for each case, two age-matched control without lymphatic and distant metastasis was randomly selected from the study participants. Demographic, variables about metastasis and MACC1 expression were collected. In multivariate analysis, the OR (95% CI) of MACC1 expression was 1.5 (1.1 to 2.0) in patients with lymphatic metastasis versus non-lymphatic metastasis after adjusting all variables. After adjustment for all variables and age stratification, MACC1 expression was found to be an independent risk factor for lymph node metastasis in the middle-aged group (OR 2.1, 95%CI 1.1–4.0). A nonlinear relationship between MACC1 expression and 64–75 age group was observed. The probability of metastasis slightly increased with the MACC1 level lower than turning point 1.4. At the same time, the probability of lymphatic metastasis was obviously increased even after adjusting all variables when MACC1 level higher than 1.4 (OR 11.2, 95% CI 1.5–81.5; p = 0.017) in the middle age group. The expression of MACC1 was not associated with lymphatic metastasis in populations younger than 64 or older than 75. The results demonstrates that increased MACC1 level in 64–75 age group might be associated with lymphatic metastasis in CRC patients.

Aquaporin: targets for dietary nutrients to regulate intestinal health

Aquaporins (AQP) are a class of water channel membrane proteins that are widely expressed in the gut. The biological functions of aquaporins, which regulate the absorption and secretion of water molecules and small solutes, maintain the stable state of the intestine, regulate cell proliferation and migration, participate in the process of intestinal inflammation, and mediate tumorigenesis, demonstrate the physiological significance of these channels in intestinal health. The pathology of many intestinal diseases is associated with changes in the location and expression of aquaporins, such as intestinal infection, which can change the expression and distribution of AQPs in intestinal tissues/cells by affecting cytokines and chemokines. This can lead to various intestinal diseases such as diarrhoea, which also suggests the importance of aquaporins in the prevention and treatment of intestinal diseases. This review summarizes the relationship between aquaporins and intestinal physiology and diseases and focuses on drugs (such as plant extracts) or diets that can regulate intestinal health by regulating aquaporins. It provides a basis for establishing aquaporins as biomarkers and therapeutic targets for intestinal health.

Does transverse colon cancer spread to the extramesocolic lymph node stations?

BACKGROUND

Transverse colon cancers show behavioral differences in terms of the involvement of extramesocolic lymph nodes since they are closely related to all three embryological planes. These tumors have also been observed in the gastroepiploic-omental (GEOM) region, outside their usual regional areas. We will evaluate this new metastatic route in our own cases.

METHODS

Thirty-four patients (16 female, 18 male) that presented to our clinic with hepatic flexure, transverse colon, and splenic flexure cancer between October 2011 and May 2017 were included in the study. Type of surgery, histopathology, and factors causing metastasis, morbidity, and mortality were evaluated.

RESULTS

Cancer was located in the transverse colon in 20 patients (58.8%), hepatic flexure in 10 (29.4%), and splenic flexure in four (11.7%). Lymph node positivity in the GEOM region was present in four patients: in the infrapyloric region and pancreatic head, close to the hepatic flexure in three patients; and the midline of GEOM, close to the inferior body of the pancreas in one patient. Perineural invasion (p < .05) and N stage (p < .05) were associated with GEOM region metastasis. Tumor localization and age significantly increased pleural effusion.

CONCLUSIONS

In transverse colon and both flexural tumors, we recommend planning the surgery according to the localization of the tumor and including the GEOM, infrapyloric and infrapancreatic areas. It is possible to discuss whether to perform extended excision for all or only selected patients. The best approach seems to be to evaluate the co-factors to manage these patients.

The impact of molecular profile on the lymphatic spread pattern in stage III colon cancer

The anatomical spread of lymph node (LN) metastasis is of practical importance in the surgical management of colon cancer (CC). We examined the effect of KRAS, BRAF, and microsatellite instability (MSI) on LN count and anatomical spread pattern in stage III CC. We determined KRAS, BRAF, and MSI status from stage III CC patients. Biomarker status was correlated with LN count and anatomical spread pattern, which was classified as sequential or skipped. Relapse-free survival (RFS) was estimated using Kaplan-Meier method, and correlations were assessed using log-rank and Cox regression analyses. We analyzed 369 stage III CC patients. The proportion of KRAS mutant (mt), BRAF mt, and MSI-high (H) were 44.2% (163/344), 6.8% (25/344), and 6.8% (25/344), respectively. The mean number of metastatic LN was higher in microsatellite-stable (MSS) compared with MSI patients (3.5 vs. 2.7, P = .0406), although no differences were observed in accordance with KRAS or BRAF status. Interestingly, patients with BRAF mt and MSI-H were less likely to harbor skipped metastatic LN (9.3% vs 20% and 4% vs 10.5% compared with BRAF wild-type (wt) and MSS, respectively), but KRAS status did not predict anatomical spread pattern. Patients with KRAS wt and MSI-H showed superior RFS compared with KRAS mt and MSS patients, respectively, whereas BRAF status did not affect RFS. Differences exist in the anatomical pattern of invaded LN in accordance with the molecular status of stage III CC. Patients with MSI-H CC have less invaded and skipped LN, suggesting that a tailored surgical approach is possible.

Incidence of and Risk Factors for Gastroepiploic Lymph Node Involvement in Patients with Cancer of the Transverse Colon Including the Hepatic Flexure

BACKGROUND

To define the incidence of gastroepiploic lymph node (GLN) metastasis in patients with cancer of the transverse colon, including the hepatic flexure, and to identify the preoperative predictors of GLN involvement in a large-volume center in China.

METHODS

This retrospective monocentric cross-sectional study respected the STROBE statement. Of 3208 consecutive patients who underwent colon cancer resection, a total of 371 patients with cancer of the transverse colon including the hepatic flexure who underwent complete mesocolic excision and GLN resection in our center were retrospectively reviewed between November 2010 and November 2017. Logistic regression was performed to identify predictors of GLN metastasis. Endoscopic obstruction was defined as a luminal obstruction of the colon severe enough to prevent the colonoscope from passing beyond the tumor regardless of the presenting symptoms.

RESULTS

The GLN involvement rate was 4.0 (2.0-6.1)%. Patients who had GLN involvement had a significantly higher rate of endoscopic obstruction (P = 0.030), higher rate of signet ring adenocarcinoma or lymphovascular invasion (P < 0.05), higher preoperative CEA level (P = 0.037), more advanced pN stage (P < 0.001) and more advanced M stage (P = 0.003) than the patients without GLN involvement. ROC curve analyses showed that the cutoff value for CEA was 17.0 ng/ml (46.7% sensitivity, 84.3% specificity, P = 0.037) for the prediction of GLN metastasis. Multivariate analysis showed that endoscopic obstruction, signet ring adenocarcinoma, a CEA level ≥17 ng/ml and M1 stage were independently correlated with the GLN metastasis.

CONCLUSION

The incidence rate of GLN metastasis was low. To the best of our knowledge, the present study was the first to evaluate the preoperative predictors of GLN metastasis. Combinations of predictive factors may be useful for stratifying patients at high risk of GLN metastasis.

Distribution of Lymph Node Metastases in Esophageal Carcinoma Patients Undergoing Upfront Surgery: A Systematic Review

Metastatic lymphatic mapping in esophageal cancer is important to determine the optimal extent of the radiation field in case of neoadjuvant chemoradiotherapy and lymphadenectomy when esophagectomy is indicated. The objective of this review is to identify the distribution pattern of metastatic lymphatic spread in relation to histology, tumor location, and T-stage in patients with esophageal cancer. Embase and Medline databases were searched by two independent researchers. Studies were included if published before July 2019 and if a transthoracic esophagectomy with a complete 2- or 3-field lymphadenectomy was performed without neoadjuvant therapy. The prevalence of lymph node metastases was described per histologic subtype and primary tumor location. Fourteen studies were included in this review with a total of 8952 patients. We found that both squamous cell carcinoma and adenocarcinoma metastasize to cervical, thoracic, and abdominal lymph node stations, regardless of the primary tumor location. In patients with an upper, middle, and lower thoracic squamous cell carcinoma, the lymph nodes along the right recurrent nerve are often affected (34%, 24% and 10%, respectively). Few studies describe the metastatic pattern of adenocarcinoma. The current literature is heterogeneous in the classification and reporting of lymph node metastases. This complicates evidence-based strategies in neoadjuvant and surgical treatment.

Should there be a specific length of the colon-rectum segment to be resected for an adequate number of lymph nodes in cases of colorectal cancers? A retrospective multi-center study

OBJECTIVES

This study aimed to evaluate the question as to whether there should be a certain length of the colon-rectum segment to be resected for correct lymph node staging in cases with colorectal cancer.

MATERIAL AND METHODS

The files and electronic datas of the patients had been undergone surgery for colorectal cancer between January 2011 and June 2016 were evaluated. The patients were divided into two groups; Group I= ≥ 12 lymph nodes, and Group II= lymph nodes less than 12 ( <12) lymph nodes.

RESULTS

Mean age of the 327 participants in this study was 64.30 ± 12.20. Mean length of resected colon-rectum segment was 25.61 (± 14.07) cm; mean number of dissected lymph nodes was 20.63 ± 12.30. Median length of the resected colon was 24 cm (range: 145-6) in Group I and 20 cm (range: 52-9) in Group II; a significant difference was found between the groups (p= 0.002). Factors associated with adequate lymph node dissection included type of the operation (p= 0.001), tumor location (p= 0.005), tumor T stage (p= 0.001), condition of metastasis in the lymph node (p= 0.008) and stage of the disease (p= 0.031). Overall survival was 62.4 ± 1.31 months, and Group I and Group II survival was 61.4 ± 1.39 months and 66.7 ± 3.25 months, respectively (p= 0.449).

CONCLUSION

Results of the study showed that ≥ 12 lymph nodes would likely be dissected when the length of the resected colon-rectum segment is > 21 cm. We conclude that the removed colonic size can be significant when performed with oncological surgical standardization.

Resection of isolated distant nodal metastasis in metastatic colorectal cancer

BACKGROUND

Little is known regarding the role of resection in patients with colorectal cancer (CRC) who present with isolated non-regional lymph node metastasis (NRLNM).

METHODS

Using the Surveillance, Epidemiology and End Results database, we identified patients diagnosed with CRC and NRLNM from 2004 to 2013.

RESULTS

A total of 849 patients presented with CRC and isolated NRLNM. Of these, 90 (10.6%) underwent resection of NRLNM. Median overall survival (OS) did not differ for patients who underwent resection of NRLNM compared to those who did not (33 versus 29 months, p = 0.68). Subgroup analysis by primary tumor site, also did not demonstrate a difference in median OS. Cox proportional hazard model revealed older age (Hazard ratio [HR] 1.34, 95% Confidence Interval [CI] 1.17-1.53, p < 0.0001), higher tumor grade (HR 1.81, 95% CI 1.52-2.16, p < 0.0001), and earlier year of diagnosis (HR 1.34, 95% CI 1.17-1.53, p < 0.0001) were associated with decreased OS. There was no survival difference between those who underwent resection of NRLNM compared to those who had not (HR 0.997, p = 0.28).

CONCLUSION

Resection of NRLNM in patients with CRC is not associated with an OS benefit. Further studies are needed to determine if there is a subset of patients who could potentially benefit from this resection strategy.

The adequacy of lymph node clearance in colon cancer surgery performed in a non-specialist centre; implications for practice

BACKGROUND

Despite recent medical advances, surgery remains the mainstay treatment in colon cancer. It is well established that better patient outcomes are achieved when complex surgery including pancreatic, oesophageal and rectal surgeries are carried out in high-volume centres. However, it is unclear as to whether or not colon cancer patients receive the same benefit. Lymph node adequacy is a key performance indicator of successful oncological colonic resection which impacts on patient outcome.

AIM

To assess the adequacy of lymph node clearance during colonic resection performed with curative intent in a non-specialist centre post introduction of the National Cancer Strategy.

METHODS

Retrospective analysis was performed of a prospectively maintained database examining the lymph node clearance of all oncological resections for colon cancer over a 7-year period (Nov 2010-Dec 2017) at a satellite unit with links to a regional specialist centre. Primary outcome measured was the number of lymph nodes retrieved. Secondary outcomes included resection margins, 30-day complication rate and survival at 1 year. Statistical analysis was performed using SPSS Statistics for Windows, version 24.0 (IBM Corp, Armonk, N.Y., USA).

RESULTS

One hundred sixty-seven patients were included. Mean age was 71.0 ± 11.6 years. Majority were male (n = 90, 53.6%). The majority of resections was right sided (n = 112.66.7%) with 78.6% of all resections being undertaken electively. All margins were free of tumour. The average lymph node count was 19.93 ± 8.63 (4.62) with only 17 (10.2%) of specimens containing < 12 nodes. The anastomotic leak rate was 3.3%. There was no association between surgeon or pathologist volume, nor emergent status and achieving oncological lymph node count (p = 0.14, 0.29, 0.97). 90.5% of patients were alive at 1 year.

CONCLUSIONS

This study demonstrates that colonic cancer surgery can be safely performed in a non- specialist centre with technical outcomes comparable to nationally reported figures.

Prognostic significance of number versus location of positive mesenteric nodes in stage iii colon cancer

INTRODUCTION

Debate persists on the ideal extent of lymphadenectomy for colon cancer (CC). Specifically, it is unknown whether the anatomical location of positive lymph nodes (LN) has any independent prognostic significance. We assessed the prognostic value of positive LN location in stage III CC patients who underwent extensive (D3) lymphadenectomy.

METHODS

Patients from Kanagawa Cancer Center, Japan, who underwent D3 dissection for CC from 2000 to 16 were analyzed. Mesenteric LN were classified according to location as paracolic (L1), intermediate (L2), or central (L3). Recurrence-free survival (RFS) and the corresponding hazard function were evaluated with their trends over the L groups. Multivariate Cox models were used to evaluate the association of LN location with RFS.

RESULTS

Four hundred forty-six stage III patients were analyzed. The mean number of examined/positive nodes per patient was 42.5/2.6 in L1 (n = 310), 40.9/4.8 in L2 (n = 111), and 44.0/9.8 in L3 (n = 25). RFS was worse for L3 vs. L2 (HR: 2.00, 95%CI [1.05-3.75], p = 0.034) and for L3 vs. L1 (2.62 [1.45-4.71], p = 0.001), but not significantly different between L2 and L1 (1.32 [0.89-1.5], p = 0.17). In a multivariate model adjusting for age, tumor size, and number of lymph nodes harvested T-stage (p < 0.001), adjuvant therapy (p < 0.0038), lymphatic invasion (p = 0.023), and LNR (p = 0.038) were significantly associated with RFS, but not L level or tumor location.

CONCLUSION

The anatomical location of invaded LN does not significantly correlate with RFS in CC, after adjusting for potential confounders. Central LN are infrequently invaded and confer a worse RFS.

Modified American Joint Committee on Cancer Tumor-Node-Metastasis Staging System Based on the Node Ratio Can Further Improve the Capacity of Prognosis Assessment for Gastric Cancer Patients

Background and Objectives: Our aim was to investigate whether the modified American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) staging system based on the node ratio can further improve the capacity of prognosis assessment for gastric cancer (GC) patients regardless of the number of lymph nodes examined (eLNs).

Methods: A total of 17,187 GC patients in the Surveillance, Epidemiology, and End Results (SEER) database were included. On the basis of a training set of 7,660 GC patients, we built the tumor-node ratio-metastasis (TNrM) staging system, which was then externally validated with a validation set of 9,527 GC patients.

Results: For the training set, the C-index value of the TNrM staging system was significantly higher than that of the AJCC 8th TNM staging system to predict survival for GC patients (C-index: 0.688 vs. 0.671, P < 0.001). Moreover, the C-index value of the TNrM staging system was significantly higher than that of the 8th TNM staging system to predict survival for GC patients with ≤15 eLNs (C-index: 0.682 vs. 0.673, P < 0.001), as well as for GC patients with >15 eLNs (C-index: 0.700 vs. 0.694, P < 0.001). Similar results were found in the validation set.

Conclusions: The TNrM staging system predicted survival more accurately and discriminatively than the AJCC 8th TNM staging system for GC patients regardless of the number of eLNs.

Prognostic Implication of Negative Lymph Node Count in ypN+ Rectal Cancer after Neoadjuvant Chemoradiotherapy and Construction of a Prediction Nomogram

PURPOSE

This study aimed to investigate the prognostic significance of negative lymph nodes (NLNs) for ypN+ rectal cancer after neoadjuvant chemoradiotherapy (nCRT) and radical surgery and to construct a nomogram predicting disease-free survival (DFS).

METHOD

One hundred fifty-eight eligible patients were included. X-tile analysis was performed to determine cutoff values of NLNs. Clinicopathological and survival outcomes were compared. A Cox regression analysis was performed to identify prognostic factors of DFS. A nomogram was constructed and validated internally.

RESULTS

X-tile analysis identified cutoff values of 4 and 16 in terms of DFS (χ² = 8.129, p = 0.017). The 3-year DFS rates for low (≤ 4), middle (5-16), and high (≥ 17) NLNs group was 15.2, 55.5, and 73.1%, respectively (P = 0.017). NLN count (NLNs ≥ 17, HR = 0.400, P = 0.022), IMA nodal metastasis (HR = 1.944, P = 0.025), tumor differentiation (poor/anaplastic, HR = 1.805, P = 0.021), and ypT4 stage (HR = 7.787, P = 0.047) were independent prognostic factors of DFS. A predicting nomogram incorporating the four significant predictors was developed with a C-index of 0.64.

CONCLUSION

NLN count was an independent prognostic factor of DFS in patients with ypN+ rectal cancer following nCRT. A nomogram incorporating NLN count, IMA nodal metastasis, tumor differentiation, and ypT stage could stratify rectal cancer patients with different DFS and might be helpful during clinical decision-making.

Protocol for a multicentre randomized clinical trial comparing oncological outcomes of D2 versus D3 lymph node dissection in colonic cancer (COLD trial)

Background

The extent of lymph node dissection in colonic cancer surgery remains arguable, and evidence from RCTs regarding extended lymph node dissection outcomes is lacking. This study aimed to compare the long‐term results of D3 lymph node dissection with those of D2 dissection.

Methods

This is a multicentre RCT. The aim is to enrol 768 patients with primary colonic cancer assigned randomly to D2 or D3 lymph node dissection. The trial is assessing the superiority of 5‐year overall survival as the primary endpoint in patients undergoing D3 lymph node dissection versus D2 dissection. Secondary endpoints include disease‐free survival, short‐term outcomes (30‐day morbidity and mortality), quality of complete mesocolic excision and lymph node dissection, pattern of lymph node metastasis and quality of life in patients following D2 and D3 lymph node dissection. Experience of 20 D3 and 20 D2 lymph node dissections is required for surgeons to participate in the trial. For surgical accreditation four non‐edited videos of procedures will be assessed. Patients will be followed up for 5 years after last patient enrolment. Intention‐to‐treat analysis will be performed.

Discussion

The results of this study will demonstrate whether extended lymph node dissection is superior to standard dissection in terms of oncological outcomes, and will also assess the impact of more extensive surgery on short‐term outcomes and quality of life.

Prognostic Value of the Number of Lymph Nodes Examined in Patients with Node-Negative Gastric Cancer

BACKGROUND

Our aim was to evaluate the prognostic value of the number of lymph nodes examined (eLNs) in patients with node-negative gastric cancer (GC) and further to adjust the American Joint Committee on Cancer (AJCC) 8th staging system based on the number of eLNs.

METHODS

Node-negative GC patients diagnosed during 1988-2015 from the Surveillance, Epidemiology, and End Results (SEER) database were included. On the basis of a primary cohort of 4159 node-negative GC patients, we built the adjusted AJCC 8th staging system, which was then internally validated by a bootstrap method, and externally validated with an independent cohort of 5565 node-negative GC patients.

RESULTS

The median number of eLNs was 10. For the training set, the optimal eLNs thresholds were determined to be 9 for node-negative GC patients. The adjusted AJCC 8th staging system for node-negative GC patients based on the number of eLNs had a significantly higher Harrell's concordance index than the initial AJCC 8th staging system (C-index, 0.635 versus 0.616; P < 0.001). Thus, the adjusted AJCC 8th staging system had superior prognostic stratification. Similar results were found in the validation set.

CONCLUSIONS

For node-negative GC patients in the United States, the adjusted AJCC 8th staging system based on the number of eLNs predicted survival more accurately and discriminatively.

A Review of Current Challenges in Colorectal Cancer Reporting

Context.—

Pathologic assessment of colorectal cancer resection specimens plays an important role in postsurgical management and prognostication in patients with colorectal cancer. Challenges exist in the evaluation and reporting of these specimens, either because of difficulties in applying existing guidelines or related to newer concepts.

Objective.—

To address challenging areas in colorectal cancer pathology and to provide an overview of the literature, current guidelines, and expert recommendations for the handling of colorectal cancer resection specimens in everyday practice.

Data Sources.—

PubMed (US National Library of Medicine, Bethesda, Maryland) literature review; reporting protocols of the College of American Pathologists, the Royal College of Pathologists of the United Kingdom, and the Japanese Society for Cancer of the Colon and Rectum; and classification manuals of the American Joint Committee on Cancer and the Union for International Cancer Control.

Conclusions.—

This review has addressed issues and challenges affecting quality of colorectal cancer pathology reporting. High-quality pathology reporting is essential for prognostication and management of patients with colorectal cancer.

Biology-Based Surgery: The Extent of Lymphadenectomy in Cancer of the Colon

The progression of colon cancer (CC) involves hematogenous and lymphatic spread to locoregional lymph nodes (LN), distant LN, and metastatic sites including the liver. The biological mechanisms that govern CC progression remain elusive. The Halsted model assumes an orderly, stepwise progression from the primary tumor to nearby nodes, henceforth to anatomically more distant nodes, and ultimately to distant organs. The Fisher model, on the other hand, regards the release of metastatic cells as early and essentially random events. The underlying biology has important implications for the ideal extent of surgery: when the Fisher model is correct, efforts to remove apical (central), extramesenteric, or para-aortic LN are unlikely to affect the oncological outcome. Recent data from phylogenetic studies suggest that cancer cell populations differ genetically among different LN stations and from distant metastases. Circulating tumor cells and other liquid biomarkers can be detected in the circulation of patients with early-stage disease. Local recurrence in CC is uncommon, and it is associated with a high risk of systemic progression and poor survival. Clinical studies comparing standard colectomy with extensive surgery (high ligation of the inferior mesenteric artery, complete mesocolic excision, D3 dissection, and para-aortic or extramesenteric node dissection) show that these techniques increase the LN count, while any beneficial effect on the risk of local recurrence or disease-free survival is at present uncertain due to the lack of controlled trials. Ongoing randomized trials comparing extensive vs. standard surgery for CC will generate important answers.

Effects of radiation on the metastatic process

Radiotherapy remains one of the corner stones in the treatment of various malignancies and often leads to an improvement in overall survival. Nonetheless, pre-clinical evidence indicates that radiation can entail pro-metastatic effects via multiple pathways. Via direct actions on cancer cells and indirect actions on the tumor microenvironment, radiation has the potential to enhance epithelial-to-mesenchymal transition, invasion, migration, angiogenesis and metastasis. However, the data remains ambiguous and clinical observations that unequivocally prove these findings are lacking. In this review we discuss the pre-clinical and clinical data on the local and systemic effect of irradiation on the metastatic process with an emphasis on the molecular pathways involved.

Lymph node evaluation for colon cancer in routine clinical practice: a population-based study

BACKGROUND

Guidelines recommend that 12 or more lymph nodes (lns) be evaluated during surgical resection of colon cancer. Here, we report ln yield and its association with survival in routine practice.

METHODS

Electronic records of treatment were linked to the population-based Ontario Cancer Registry to identify all patients with colon cancer treated during 2002-2008. The study population (n = 5508) included a 25% random sample of patients with stage ii or iii disease. Modified Poisson regression was used to identify factors associated with ln yield; Cox models were used to explore the association between ln yield and overall (os) and cancer-specific survival (css).

RESULTS

During 2002-2008, median ln yield increased to 17 from 11 nodes (p < 0.001), and the proportion of patients with 12 or more nodes evaluated increased to 86% from 45% (p < 0.001). Lymph node positivity did not change over time (to 53% from 54%, p = 0.357). Greater ln yield was associated with younger age (p < 0.001), less comorbidity (p = 0.004), higher socioeconomic status (p = 0.001), right-sided tumours (p < 0.001), and higher hospital volume (p < 0.001). In adjusted analyses, a ln yield of less than 12 nodes was associated with inferior os and css for stages ii and iii disease [stage ii os hazard ratio (hr): 1.36; 95% confidence interval (ci): 1.19 to 1.56; stage ii css hr: 1.52; 95% ci: 1.26 to 1.83; and stage iii os hr: 1.45; 95% ci: 1.30 to 1.61; stage iii css hr: 1.54; 95% ci: 1.36 to 1.75].

CONCLUSIONS

Despite a temporal increase in ln yield, the proportion of cases with ln positivity has not changed. Lymph node yield is associated with survival in patients with stages ii and iii colon cancer. The association between ln yield and survival is unlikely to be a result of stage migration.

Robotic right hemicolectomy: Analysis of 108 consecutive procedures and multidimensional assessment of the learning curve

PURPOSE

Surgeons tend to view the robotic right colectomy (RRC) as an ideal beginning procedure to gain proficiency in robotic general and colorectal surgery. Nevertheless, oncological RRC, especially if performed with intracorporeal ileocolic anastomosis confectioning, cannot be considered a technically easier procedure. The aim of this study was to assess the learning curve of the RRC performed for oncological purposes and to evaluate its safety and efficacy investigating the perioperative and pathology outcomes in the different learning phases.

METHODS

Data on a consecutive series of 108 patients undergoing RRC with intracorporeal anastomosis between June 2011 and September 2015 at our institution were prospectively collected to evaluate surgical and short-term oncological outcomes. CUSUM (Cumulative Sum) and Risk-Adjusted (RA) CUSUM analysis were performed in order to perform a multidimensional assessment of the learning curve for the RRC surgical procedure. Intraoperative, postoperative and pathological outcomes were compared among the learning curve phases.

RESULTS

Based on the CUSUM and RA-CUSUM analyses, the learning curve for RRC could be divided into 3 different phases: phase 1, the initial learning period (1st-44th case); phase 2, the consolidation period (45th-90th case); and phase 3, the mastery period (91th-108th case). Operation time, conversion to open surgery rate and the number of harvested lymph nodes significantly improve through the three learning phases.

CONCLUSIONS

The learning curve for oncological RRC with intracorporeal anastomosis is composed of 3 phases. Our data indicate that the performance of RRC is safe from an oncological point of view in all of the three phases of the learning curve. However, the technical skills necessary to significantly reduce operative time, conversion to open surgery rate and to significantly improve the number of harvested lymph nodes were achieved after 44 procedures. These data suggest that it might be prudent to start the RRC learning curve by treating only benign diseases and to reserve the performance of oncological resection to when at least the initial learning phase has been completed.

A Nomogram to Predict Adequate Lymph Node Recovery before Resection of Colorectal Cancer

Increased lymph node count (LNC) has been associated with prolonged survival in colorectal cancer (CRC), but the underlying mechanisms are still poorly understood. The study aims to identify new predictors and develop a preoperative nomogram for predicting the probability of adequate LNC (≥ 12). 501 eligible patients were retrospectively selected to identify clinical-pathological factors associated with LNC ≥ 12 through univariate and multivariate logistic regression analyses. The nomogram was built according to multivariate analyses of preoperative factors. Model performance was assessed with concordance index (c-index) and area under the receiver operating characteristic curve (AUC), followed by internal validation and calibration using 1000-resample bootstrapping. Clinical validity of the nomogram and LNC impact on stage migration were also evaluated. Multivariate analyses showed patient age, CA19-9, circulating lymphocytes, neutrophils, platelets, tumor diameter, histology and deposit significantly correlated with LNC (P < 0.05). The effects were marginal for CEA, anemia and CRC location (0.05 < P < 0.1). The multivariate analyses of preoperative factors suggested decreased age, CEA, CA19-9, neutrophils, proximal location, and increased platelets and diameter were significantly associated with increased probability of LNC ≥ 12 (P < 0.05). The nomogram achieved c-indexes of 0.75 and 0.73 before and after correction for overfitting. The AUC was 0.75 (95% CI, 0.70–0.79) and the clinically valid threshold probabilities were between 10% and 60% for the nomogram to predict LNC < 12. Additionally, increased probability of adequate LNC before surgery was associated with increased LNC and negative lymph nodes rather than increased positive lymph nodes, lymph node ratio, pN stages or AJCC stages. Collectively, the results indicate the LNC is multifactorial and irrelevant to stage migration. The significant correlations with preoperative circulating markers may provide new explanations for LNC-related survival advantage which is reflected by the implication of regional and systemic antitumor immune responses.

A nomogram improves AJCC stages for colorectal cancers by introducing CEA, modified lymph node ratio and negative lymph node count

Lymph node stages (pN stages) are primary contributors to survival heterogeneity of the 7^th AJCC staging system for colorectal cancer (CRC), indicating spaces for modifications. To implement the modifications, we selected eligible CRC patients from the Surveillance Epidemiology and End Results (SEER) database as participants in a training (n = 6675) and a test cohort (n = 6760), and verified tumor deposits to be metastatic lymph nodes to derive modified lymph node count (mLNC), lymph node ratio (mLNR), and positive lymph node count (mPLNC). After multivariate Cox regression analyses with forward stepwise elimination of the mLNC and mPLNC for the training cohort, a nomogram was constructed to predict overall survival (OS) via incorporating preoperative carcinoembryonic antigen, pT stages, negative lymph node count, mLNR and metastasis. Internal validations of the nomogram showed concordance indexes (c-index) of 0.750 (95% CI, 0.736-0.764) and 0.749 before and after corrections for overfitting. Serial performance evaluations indicated that the nomogram outperformed the AJCC stages (c-index = 0.725) with increased accuracy, net benefits, risk assessment ability, but comparable complexity and clinical validity. All the results were reproducible in the test cohort. In summary, the proposed nomogram may serve as an alternative to the AJCC stages. However, validations with longer follow-up periods are required.

Laparoscopic Wide Mesocolic Excision and Central Vascular Ligation for Carcinoma of the Colon

Background and Aims:

The principle of complete mesocolic excision for colon cancer has been introduced to improve oncologic outcome. However, this approach is scantily discussed for laparoscopic surgery and there is a lack of randomized trials. This study examined oncologic and clinical outcome after laparoscopic wide mesocolic excision and central vascular ligation for colon cancer.

Material and Methods:

This is a review of prospectively gathered data from a single-institution colorectal cancer database. This study was conducted in the Central Hospital of Central Finland. From January 2003 to December 2011, 222 patients underwent laparoscopic colonic resections with wide mesocolic excision and central vascular ligation in the multimodal setting. The main measures of outcome were cancer recurrence and survival, with early recovery, 30d-mortality and morbidity, reoperation, readmission, and late complications as secondary outcomes.

Results:

The median follow-up was 5.5 (interquartile range (IQR) = 3.7–8.0) years. The 5-year overall survival for all 222 patients was 80.2% and disease-specific survival was 87.5%, and for those 210 R0-patients with stage I–III disease, 83.9% and 91.3%, respectively. The 5-year disease-free survival was 85.8%: stage I was 94.7%, stage II was 90.8%, and stage III was 75.6% ( p = 0.004). Increasing lymph node ratio significantly decreased the 5-year disease-free survival. Conversion rate to open surgery was 12.2%. Thirty-day mortality was 1.3% and morbidity, 19.7%. Median postoperative hospital stay was 5 (IQR = 3–7) days.

Conclusion:

Laparoscopic wide mesocolic excision and central vascular ligation for colon cancer resulted in good long-term oncologic outcome. Randomized trials are needed to show that laparoscopic complete mesocolic excision technique would become the standard of care for the carcinoma of the colon.

Trends in pathology and long-term outcomes after resection of colorectal cancer: 1971-2013

BACKGROUND

The aim of this study was to describe temporal trends in tumour pathology and long-term outcomes in 5217 patients recorded in a registry of colorectal cancer resections initiated at Concord Hospital, Sydney, Australia, in 1971.

METHODS

This report is based on consecutive resections up to December 2013, with no exclusions. Categories in variables examined were expressed as percentages over annual totals of relevant patients or annual mean values. The statistical significance of temporal trends was examined by least squares regression.

RESULTS

The percentages of patients with local spread beyond the muscularis propria, nodal metastasis, distant metastasis and tumour in a line of resection all declined significantly. In consequence, the percentage of stage D patients fell, whereas the percentage in stage A rose. Other tumour variables that increased significantly were polypoid morphology, contiguous adenoma and invasion of a free serosal surface. Tumours in which an adherent adjacent structure was partly or completely removed also increased. There were significant declines in high-grade malignancy, venous invasion and tumour size. The recurrence rate for rectal cancers declined significantly, whereas for rectal and colonic cancers combined, both the overall 5-year survival rate and the 5-year cancer-specific survival rate increased markedly.

CONCLUSION

These results show a reduction in adverse pathology findings and favourable trends in recurrence and survival after colorectal cancer resections in a high-incidence country over a period of 43 years.

Nomograms to predict survival after colorectal cancer resection without preoperative therapy

Background

The predictive accuracy of the American Joint Committee on Cancer (AJCC) stages of colorectal cancer (CRC) is mediocre. This study aimed to develop postoperative nomograms to predict cancer-specific survival (CSS) and overall survival (OS) after CRC resection without preoperative therapy.

Methods

Eligible patients with stage I to IV CRC (n = 56072) diagnosed from 2004 to 2010 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. The patients were allocated into training (n = 27,700), contemporary (n = 3158), and prospective (n = 25,214) validation cohorts. Clinically important variables were incorporated and selected using the Akaike information criterion in multivariate Cox regressions to derive nomograms with the training cohort. The performance of the nomograms was assessed and externally testified using the concordance index (c-index), bootstrap validation, calibration, time-dependent receiver-operating characteristic curves, Kaplan–Meier curves, mosaic plots, and decision curve analysis (DCA). Performance of the conventional AJCC stages was also compared with the nomograms using similar statistics.

Results

The nomograms for CSS and OS shared common predictors: sex, age, race, marital status, preoperative carcinoembryonic antigen status, surgical extent, tumor size, location, histology, differentiation, infiltration depth, lymph node count, lymph node ratio, and metastasis. The c-indexes of the nomograms for CSS and OS were 0.816 (95 % CI 0.810–0.822) and 0.777 (95 % CI 0.772–0.782), respectively. Performance evaluations showed that the nomograms achieved considerable predictive accuracy, appreciable reliability, and significant clinical validity with wide practical threshold probabilities, while the results remained reproducible when applied to the validation cohorts. Additionally, model comparisons and DCA proved that the nomograms excelled in stratifying each AJCC stage into three significant prognostic subgroups, allowing for more robust risk classification with an improved net benefit.

Conclusions

We propose two prognostic nomograms that exhibit improved predictive accuracy and net benefit for patients who have undergone CRC resection. The established nomograms are intended for risk assessment and selection of suitable patients who may benefit from adjuvant therapy and intensified follow-up after surgery. Independent external validations may still be required.

Effect of Neoadjuvant Radiation Dose and Schedule on Nodal Count and Its Prognostic Impact in Stage II-III Rectal Cancer

BACKGROUND

It is unknown how neoadjuvant treatment schedule affects lymph node count (LNC) and lymph node ratio (LNR) and how these correlate with overall survival (OS) in rectal cancer (RC).

METHODS

Data were used from the Belgian PROCARE rectal cancer registry on RC patients treated with surgery alone, short-term radiotherapy with immediate surgery (SRT), or chemoradiation with deferred surgery (CRT). The effect of neoadjuvant therapy on LNC was examined using Poisson log-linear analysis. The association of LNC and LNR with overall survival (OS) was studied using Cox proportional hazards models.

RESULTS

Data from 4037 patients were available. Compared with surgery alone, LNC was reduced by 12.3 % after SRT and by 31.3 % after CRT (p < 0.001). In patients with surgery alone, the probability of finding node-positive disease increased with LNC, while after SRT and CRT no increase was noted for more than 12 and 18 examined nodes, respectively. Per node examined, we found a decrease in hazard of death of 2.7 % after surgery alone and 1.5 % after SRT, but no effect after CRT. In stage III patients, the LNR but not (y)pN stage was significantly correlated with OS regardless of neoadjuvant therapy. Specifically, a LNR > 0.4 was associated with a significantly worse outcome.

CONCLUSIONS

Nodal counts are reduced in a schedule-dependent manner by neoadjuvant treatment in RC. After chemoradiation, the LNC does not confer any prognostic information. A LNR of >0.4 is associated with a significantly worse outcome in stage III disease, regardless of neoadjuvant therapy type.

A high lymph node yield in colon cancer is associated with age, tumour stage, tumour sub-site and priority of surgery. Results from a prospective national cohort study

AIM

To determine the relation between patient-related and histopathological factors, as well as the influence of national programs for diagnosing and treatment of colon cancer and a lymph node yield (LNY) ≥ 12.

METHOD

An analysis was carried out of the LNY in a nationwide Danish cohort treated by curative resection of stage I-III colon cancer in the period 2003-2011. The association between a LNY ≥ 12 and age, sex, body mass index, open vs. laparoscopic surgery, acute vs. elective surgery, pT stage, tumour sub-site and year of diagnosis was analysed.

RESULTS

A total of 13,766 patients were eligible for the analysis. In total, 71.4 % of the patients had a LNY ≥ 12. In multivariate analysis, age, pT stage, tumour sub-site and priority of surgery were independently associated with the probability of a LNY ≥ 12. Odds ratios (ORs) were as follows: age <65 1, 65-75 0.685 (confidence interval (CI) 0.586-0.800), >75 0.517 (CI 0.439-0.609); T1 1, T2 2.750 (CI 2.168-3.487), T3 6.016 (CI 4.879-7.418), T4 6.317 (CI 4.950-8.063); right colon 1, left colon 0.568 (0.511-0.633); elective surgery 1, acute surgery 0.748 (CI 0.625-0.894). Moreover, year of diagnosis was associated with the probability of a LNY ≥ 12: OR 1.480 (CI 1.445-1.516) for each increasing year in the study period.

CONCLUSION

A LNY ≥ 12 is significantly associated with age, pT stage, tumour sub-site and priority of surgery. A significant increase in the LNY over the period of the study was observed, probably reflecting the effect of national programmes initiated by the Danish Colorectal Cancer Group.

Lymph node ratio and surgical quality are strong prognostic factors of rectal cancer: results from a single referral centre

AIM

Nodal stage is a strong prognostic factor of oncological outcome of rectal cancer. To compensate for the variation in total number of harvested nodes, calculation of the lymph node ratio (LNR) has been advocated. The aim of the study was to compare the impact, on the long-term oncological outcome, of the LNR with other predictive factors, including the quality of total mesorectal excision (TME) and the state of the circumferential resection margin.

METHOD

Consecutive patients having elective surgery for nonmetastatic rectal cancer were extracted from a prospectively maintained database. Retrospective uni- and multivariate analyses were performed based on patient-, surgical- and tumour-related factors. The prognostic value of the LNR on overall survival (OS) and on overall recurrence-free survival (ORFS) was assessed and a cut-off value was determined.

RESULTS

From 1998 to 2013, out of 456 patients, 357 with nonmetastatic disease were operated on for rectal cancer. Neoadjuvant radiochemotherapy was administered to 66.7% of the patients. The mean number of lymph nodes retrieved was 12.8 ± 8.78 per surgical specimen. A lower lymph node yield was obtained in patients who received neoadjuvant chemoradiotherapy (11.8 vs 14.2; P = 0.014). The 5-year ORFS was 71.8% and the 5-year OS was 80.1%. Multivariate analysis confirmed LNR, the quality of TME and age to be independent prognostic factors of OS. LNR, age and perineural infiltration were independently associated with ORFS. Low- and high-risk patients could be discriminated using an LNR cut-off value of 0.2.

CONCLUSION

LNR is an independent prognostic factor of OS and ORFS. In line with the principles of optimal surgical management, the quality of TME and lymph node yield are essential technical requirements.

Complete mesocolic excision and central vascular ligation for colon cancer: Principle, anatomy, surgical technique, and outcomes

Classic colon cancer surgery refers to a wide resection of the tumor-bearing segment and the lymphatics draining along the named artery. The concept of TME has been applied to colon cancer and complete mesocolic excision (CME) in conjuction with central vascular ligation (CVL) has been introduced as the surgical treatment for colon cancer. Here, we discuss appropriate CME procedure with regard to the oncologic backgrounds, essential components, applied anatomy, laparoscopic technique, short-term, and oncologic outcomes. The introduction of CME has improved oncologic outcomes greatly in patients with colon cancer. The improved outcomes with CME can be attributed to underlying sound oncologic principles such as dissection through the proper plane of mesocolic excision, central vascular ligation, and sufficient length of proximal and distal margins. Thereby, CME technique can achieve en bloc removal of the diseased lesion with the increased amount of the colonic mesentery even though the length of for both bowel and mesentery resection remains a matter of debate. CME is a technically demanding operation thus, comprehensive understanding of the applied vascular anatomy is essential for successful CME. Favorable outcomes of open CME have been replicated with a laparoscopic approach. In future perspective, incorporating a structured education program on minimally invasive (laparoscopy or robot) CME would be beneficial.

Laparoscopic Complete Mesocolic Excision for Stage II/III Left-Sided Colon Cancers: A Prospective Study and Comparison with D3 Lymph Node Dissection

BACKGROUND

To investigate the similarities and differences of laparoscopic complete mesocolic excision (CME) to a colon resection with a D3 lymphadenectomy for the stage II/III left-sided colon carcinoma.

METHODS

Patients between July 2011 and August 2014 were randomized into D3 and CME groups. Mesenteric area, log odds of positive lymph nodes (LODDS), and other operative parameters were collected and assessed.

RESULTS

The average specimen sizes were 5730 ± 828 mm(2) in superior rectal artery (SRA)-preserving D3, 8145 ± 1022 mm(2) in SRA-nonpreserving D3, and 8745 ± 1039 mm(2) in the CME group; the differences were significant (P < .0001). The number of lymph nodes collected from CME specimens was larger, but the CME specimens did not contain an elevated value of LODDS or positive nodes or lymph node ratio (LNR). There were also no significant differences between recovery times of bowel function. Although it took more operation time in D3 approach, especially in SRA-preserving D3 operation, the difference was not significant. Concerning the leakage rate (P = .34) and vessel-related complications (P = .64), there were no significant differences either.

CONCLUSIONS

Both standard D3 resection and CME could achieve a high quality of mesocolic plane grade for stage II/III colon cancer. The LODDS and LNR were comparable, and those were not relevant to mesenteric size.

Complete mesocolic excision and extended (D3) lymphadenectomy for colonic cancer: is it worth that extra effort? A review of the literature

PURPOSE

Recent interest in complete mesocolic excision (CME) with central vascular ligation (CVL) or extended (D3) lymphadenectomy (EL) for curative resection of colon cancer has been driven by published series from experienced practitioners showing excellent survival outcomes and low recurrence rates. In this article, we attempt to clarify the role of CME or EL in modern colorectal surgery.

METHODS

A narrative review of the evidence for CME and EL in the curative treatment of colon cancer.

RESULTS

The principal of CME surgery, similar to total mesorectal excision (TME) for rectal cancer, is the removal of all lymphatic, vascular, and neural tissue in the drainage area of the tumour in a complete mesocolic envelope with intact mesentery, peritoneum and encasing fascia. Extended (D3) lymphadenectomy (EL) is based on similar principles. Sound anatomical and oncological arguments are made to support the principles of removing the tumor contained within an intact mesocolic facial envelope together with an extended lymph node harvest. Excellent oncological outcomes with minimal morbidity and mortality have been reported. This has led to calls for the standardisation of surgery for colon cancer using CME. However, there is conflicting evidence regarding the prognostic benefit of greater lymph node harvests and the evidence for an oncological benefit of CME is limited by methodology flaws and several potential confounding factors.

CONCLUSIONS

Although there is a reasonable anatomical and oncological basis for these techniques, there are no randomised controlled trials from which to draw confident conclusions and there is insufficient consistent high quality evidence to recommend widespread adoption of CME.

Complete mesocolic excision: Lessons from anatomy translating to better oncologic outcome

Since the introduction of complete mesocolic excision (CME) for colon cancer, the oncologic outcome of patients has been greatly improved, which has led to a longer survival and a lower recurrence, just like the total mesorectum excision for rectal cancer. Despite the fact that the exact anatomy of the organ is one of the most vital things for surgeons to conduct surgery, no team has really studied the exact structure of the mesocolon and related attachments for CME, until the mesocolonic anatomy was first formally characterized in 2012. Therefore, this article mainly focuses on the anatomy development of the mesocolon and the achievement in this field. Meanwhile, we introduce the latest progress in laparoscopic surgery for colon cancer achieved by our team.

Lymph node hypoplasia is associated with adverse outcomes in node-negative colon cancer using advanced lymph node dissection methods

PURPOSE

Lymph node size as a prognostic parameter has not been investigated well in the past. Recent data, however, have indicated that this parameter could be even more important than the lymph node count.

METHODS

Based on the results of earlier studies, we analyzed the lymph node size and number of node-negative colon cancer patients with regard to survival. Data from 115 node-negative cases of colon cancer were analyzed. Lymph nodes with diameters ≤5 mm were defined as small, and all other lymph nodes were classified as intermediate/large in size and labeled LN5. All of the cases were categorized according to the number of LN5s. The LN5 very low (LN5vl) group included cases with less than two LN5s. All of the other cases were assigned to the LN5 low/high (LN5l/h) group.

RESULTS

The overall survival analysis revealed significantly worse outcomes for the LN5vl group, with a mean survival of 34 months compared to the LN5l/h group, with a mean survival of 40 months (P = 0.022). After adjusting for the pT1/2 and pT3/4 stages, we still found a significant outcome difference (P = 0.012). Multivariate analysis identified LN5vl and T-stage as being independently correlated with the outcome. The vast majority of LN5vl cases (91 %) were located in the left colon. The location itself, however, was not prognostic (P = 0.478).

CONCLUSION

LN5 count, as a marker of immune response, could be shown as being prognostic in node-negative colon cancer. Patients with low LN5 counts showed poor outcomes. These patients could perhaps profit from adjuvant chemotherapy.

Linking surgical specimen length and examined lymph nodes in colorectal cancer patients

AIM

The number of examined lymph nodes (NLN) was associated with survival of stages II and III colorectal cancer (CRC) patients. Guidelines recommend examining at least 12 lymph nodes. This study investigated the influence of surgical specimen length on lymph node harvest and compliance with international guidelines.

MATERIALS AND METHODS

This population-based study included 4,724 cases of surgically treated CRC that were diagnosed from 2002 to 2008. Multivariate analyses were performed for the main study variables (age, gender, diagnosis at screening or in symptomatic patients, cancer site, staging, grading, number of positive nodes, neo-adjuvant treatment for rectal cancer, hospital were surgery was performed). Fractional polynomial models investigated the relationship between continuous variables and outcomes.

RESULTS

The NLN increased over time reaching ≥12 NLN in 64% of cases at the end of the study period. More NLN were associated with young age, right colon cancer, pT3-T4 disease, stages II and III and high grade. Fewer NLN were associated with short surgical specimen length and neo-adjuvant treatment in rectal cancer patients. Use of laparoscopy increased sharply over time.

CONCLUSIONS

NLN increased over time in accordance with international guidelines. Surgical specimen length correlated with NLN which may determine therapeutic choices, particularly in stage II colon cancer. When harvested lymph nodes are under 10 in number and all are negative, chemotherapy is always recommended. As specimen lengths <20 cm were associated with a high risk of inadequate NLN counts, patients are at risk of over-treatment.

Management of nodal disease from colon cancer in the laparoscopic era

PURPOSE

In colon cancer (CC), nodal involvement is the main prognostic factor following potentially curative (R0) resection. The purpose of this study was to examine data from the literature to provide an up-to-date analysis of the management of nodal disease with special reference to laparoscopic treatment.

METHODS

MEDLINE and EMBASE databases were searched for potentially eligible studies published in English up to July 15, 2014.

RESULTS

In CC, nodal involvement is a frequent event and represents the main risk of cancer recurrence. Node negative patients recur in 10-30 % of cases most likely due to underdiagnosed or undertreated nodal disease. Extended colonic resections (complete mesocolic excision with central vascular ligation; D3 lymphadenectomy) provides a survival benefit and better local control. Sentinel lymph node mapping in addition to standard surgical resection represents an option for improving staging of clinical node negative patients. Both extended resection and sentinel lymph node mapping are feasible in a laparoscopic setting.

CONCLUSIONS

Both extended colonic resection and sentinel lymph node mapping should play a role in the laparoscopic treatment of CC with the purpose of improving control and staging of nodal disease.

Expression of aquaporin-1, aquaporin-3, and aquaporin-5 correlates with nodal metastasis in colon cancer

OBJECTIVES

The clinical significance of aquaporin-1 (AQP1), aquaporin-3 (AQP3), and aquaporin-5 (AQP5) expression was analyzed in a large number of patients with colon cancer.

METHODS

AQP1, AQP3, and AQP5 expression was investigated based on the immunohistochemistry of tissue microarray specimens from 486 colon cancer patients who underwent curative surgery. Scores were given to the staining intensity and percentage of positive cells, and the staining score was defined as the sum of these scores then used to categorize the AQP expression as negative, weakly AQP-positive, or strongly AQP-positive.

RESULTS

A total of 298 (61.3%) patients were identified as strongly AQP1-positive (staining score ≥ 6), while 38 (7.8%) were strongly AQP3-positive and 145 (29.8%) were strongly AQP5-positive. The overexpression of AQP1, AQP3, and AQP5 was significantly correlated with lymph node metastasis in a multivariate logistic analysis (AQP1, p = 0.026; AQP3, p = 0.023; AQP5, p = 0.003). While the multivariate survival analysis, which included age, histology, TNM stage, and CEA level showed that the expression of AQP1, AQP3, and AQP5 had no effect on the overall survival and disease-free survival.

CONCLUSIONS

The current study found a significant correlation between AQP1, AQP3, and AQP5 expression and lymph node metastasis in patients with surgically resected colon cancer.

Clinico-pathological factors influencing lymph node yield in colorectal cancer and impact on survival: analysis of New Zealand Cancer Registry data

BACKGROUND

Lymph node yield (LNY) and lymph node ratio (LNR) are recognized as independent prognostic factors in colorectal cancer (CRC).

OBJECTIVES

To examine the relationship between LNY and other clinico-pathological variables, and the prognostic value of LNY and LNR on patient survival in CRC.

METHODS

The clinico-pathological and survival data for patients diagnosed from January 2000 to July 2012 were retrieved from the New Zealand Cancer Registry. Multiple linear regression was used to identify clinico-pathological factors influencing LNY, and Cox regression was used to determine the association between LNY and LNR and patient survival.

RESULTS

14,646 patients were included in the study (mean age 70.3 years, 50.1% male). Mean LNY was 17.4. Younger age, right-sided disease, higher T stage, female sex and no neoadjuvant radiotherapy (rectal cancer) were all associated with higher LNY (P ≤ 0.001). Overall survival in Stage I-III disease increased with higher LNY (for LNY ≥ 12, HR = 0.67, 95% CI 0.64-0.72; P < 0.001). Survival in Stage III-IV disease was inversely related to LNR (HR = 0.56, 95% CI 0.51-0.62; P < 0.001).

CONCLUSION

LNY is influenced by patient age, site of disease and T stage. LNY (Stage I-II) and LNR (Stage III-IV) have independent prognostic value in CRC.

Extent of surgery in cancer of the colon: Is more better?

Since the introduction of total mesorectal excision as the standard approach in mid and low rectal cancer, the incidence of local recurrence has sharply declined. Similar attention to surgical technique in colon cancer (CC) has resulted in the concept of complete mesocolic excision (CME), which consists of complete removal of the intact mesentery and high ligation of the vascular supply at its origin. Although renewed attention to meticulous surgical technique certainly has its merits, routine implementation of CME is currently unfounded. Firstly, in contrast to rectal cancer, local recurrence originating from an incompletely removed mesentery is rare in CC and usually a manifestation of systemic disease. Secondly, although CME may increase nodal counts and therefore staging accuracy, this is unlikely to affect survival since the observed relationship between nodal counts and outcome in CC is most probably not causal but confounded by a range of clinical variables. Thirdly, several lines of evidence suggest that metastasis to locoregional nodes occurs early and is a stochastic rather than a stepwise phenomenon in CC, in essence reflecting the tumor-host-metastasis relationship. Unsurprisingly, therefore, comparative studies in CC as well as in other digestive cancers have failed to demonstrate any survival benefit associated with extensive, additional or extra-mesenteric lymphadenectomy. Finally, routine implementation of CME may cause patient harm by longer operating times, major vascular damage and autonomic nerve injury. Therefore, data from randomized trials reporting relevant endpoints are required before CME can be recommended as a standard approach in CC surgery.