Increasing negative lymph node count is independently associated with improved long-term survival in stage IIIB and IIIC colon cancer

Negative lymph node count is an independent prognostic factor for patients with rectal cancer who received preoperative radiotherapy

Background

Negative lymph node (NLN) count has been reported to provide more accurate prognostic information than the N stage alone in patients with rectal cancer (RC). Since preoperative radiotherapy (Pre-RT) can significantly affect the LN status, it is unclear whether NLN count still has prognostic value count on survival of patients with RC who received Pre-RT.

Methods

In this study, clinicopathological characteristics, number of positive LNs and survival time were collected from Surveillance, Epidemiology, and End Results Program (SEER)-registered RC patients. Univariate and multivariate Cox proportional hazards models were used to assess the risk factors for survival.

Results

X-tile plots identified 9 (P < 0.001) as the optimal cutoff NLN value to divide the patients into high and low risk subsets in terms of cause specific survival (CSS). NLN count was validated as independently prognostic factor in univariate and multivariate analysis (P < 0.001). Subgroup analysis showed that NLN count was an independently prognostic factor for patients with stage ypII (P = 0.002) and ypIII (P < 0.001).

Conclusions

Our results firmly demonstrated that NLN count provides accurate prognostic information for RC patients with Pre-RT.

Variations in the Vascular Anatomy of the Right Colon and Implications for Right-Sided Colon Surgery

BACKGROUND

Knowledge of the normal pattern and variations of the blood supply of the right colon is crucial for better outcomes after colon surgery.

OBJECTIVE

The purpose of this study was to describe the precise vascular anatomy of the right colon according to surgical perspective.

DESIGN

Adult fresh cadavers were dissected between January 2013 and October 2015, focusing on the venous and arterial anatomy of the right side of the colon.

SETTINGS

Macroscopic anatomical dissections were performed on 111 adult fresh cadavers with emphasis on the vascular anatomy of the right colon. The colic tributaries of the superior mesenteric artery and vein were documented in writing. Furthermore, the dissections were recorded with a video camera.

RESULTS

The incidence of colic arteries arising from the superior mesenteric artery included ileocolic artery, 100%; right colic artery, 33.3%; middle colic artery, 100%; and accessory middle colic artery, 11,7%. All 111 cadavers had a single ileocolic vein, which drained into the superior mesenteric vein in 103 cases (92.8%), into the gastro-pancreatico-colic trunk in 7 cases (6.3%), and into the jejunal trunk in 1 case (0.9%). The drainage site of the ileocolic vein to the superior mesenteric vein varied, and in 9% of cases the ileocolic vein did not accompany the ileocolic artery. The gastro-pancreatico-colic trunk was detected in 87 cases (78.4%); with several forms of the origin of the respective branches, the gastropancreatic trunk was detected in 24 cases (21.6), and the classic gastrocolic trunk of Henle was not detected. Variations were found in the formation and drainage routes of other venous colic tributaries of the superior mesenteric vein.

LIMITATIONS

This study is limited by its use of cadavers in that it is impossible to trace each vessel to its origin in live surgery.

CONCLUSIONS

Surgeons must watch, observe, and bear in mind that vascular variations can occur. Awareness of these complex variations may improve the quality of surgery and may prevent devastating complications during right-sided colon resections.

Supraclavicular lymph node incisional biopsies have no influence on the prognosis of advanced non-small cell lung cancer patients: a retrospective study

BACKGROUND

Supraclavicular lymph node (SCLN) biopsies play an important role in diagnosing and staging lung cancer. However, not all patients with SCLN metastasis can have a complete resection. It is still unknown whether SCLN incisional biopsies affect the prognosis of non-small cell lung cancer (NSCLC) patients.

METHODS

Patients who were histologically confirmed to have NSCLC with SCLN metastasis were enrolled in the study from January 2007 to December 2012 at Guangdong Lung Cancer Institute. The primary endpoint was OS, and the secondary endpoints were complications and local recurrence/progression.

RESULTS

Two hundred two consecutive patients who had histologically confirmed NSCLC with SCLN metastasis were identified, 163 with excisional and 39 with incisional biopsies. The median OS was not significantly different between the excisional (10.9 months, 95% CI 8.7-13.2) and incisional biopsy groups (10.1 months, 95% CI 6.3-13.9), P = 0.569. Multivariable analysis showed that an Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≥2 (HR = 2.75, 95% CI 1.71-4.38, P < 0.001) indicated a worse prognosis. Having an epidermal growth factor receptor (EGFR) mutation (HR = 0.58, 95% CI 0.40-0.84, P = 0.004) and receiving systemic treatment (HR = 0.36, 95% CI 0.25-0.53, P < 0.001) were associated with a favorable OS. Neither the number (multiple vs. single) nor site (bilateral vs. unilateral) of SCLNs was associated with an unfavorable OS, and SCLN size or fixed SCLNs did not affect OS.

CONCLUSIONS

SCLN incisional biopsies did not negatively influence the prognosis of NSCLC patients. It was safe and feasible to partly remove a metastatic SCLN as a last resort in advanced NSCLC.

Cohort Research in "Omics" and Preventive Medicine

Cohort studies are observational studies in which the investigator determines the exposure status of subjects and then follows them for subsequent outcomes. The incidence of outcomes is observed in the exposed group and compared with that in a nonexposed group. Recently, new epidemiologic strategies have encouraged cohort research information exchange and cooperation to improve the cognition of disease etiology, such as case-cohort design and nested case-control study, which is available for "omics" data. Meanwhile, large-scale cohort studies using a prospective multiple design and long follow-ups have explored some of the challenges in preventive medicine. Cohort study can bridge the gap between the micro and macro research.This chapter is divided into three parts: 1. Basic knowledge of cohort study, which included the definition of cohort study and different types of cohort study, how to design the cohort study, data analysis for the cohort study, sources of bias in cohort studies, tools and software for cohort studies, and strengths and limitations of cohort study 2. Cohort study for "omics" data analysis, which introduced three related methodologically distinct study designs, case-cohort design for genomic cohort study, nested case-control design for transcriptomics cohort data, and population-based design for integrative "omics" cohort 3. Perspectives on cohort study including data-driven medicine and cohort research, cohort research for healthcare medicine, and cohort research for preventive medicine.

Better survival in PMRT of female breast cancer patients with >5 negative lymph nodes: A population-based study

Many studies have confirmed the role of postmastectomy radiotherapy (PMRT) for breast cancer patients with at least 4 lymph nodes invasion in the postoperative therapy. Recently, the number of negative lymph nodes (NLNs) has been increasingly paid attention to and recognized as a prognostic indicator in different kinds of caners. Therefore, it is very necessary to study the association between the number of NLNs and the prognosis of PMRT in breast cancer patients. In our study, we used Surveillance, Epidemiology, and End Results (SEER) population-based data and identified 16,686 breast cancer patients to explore their correlation. The ROC curve and the log-rank χ test were applied to determine the appropriate cutoff point of the number of NLNs and 5 was selected as the cutoff point. Furthermore, the cutoff point 5 was validated as an independent prognostic factor affecting cancer-specific survival (CSS) and overall survival (OS) in breast cancer patients, as confirmed by both univariate and multivariate analysis (P < 0.001). In addition, subgroup analysis showed that the number of NLNs >5 can be a prognostic indicator in patients with PMRT according to different clinical variables (all, P < 0.001). Importantly, our results showed that PMRT obviously improved CSS and OS in patients regardless of the number of NLNs (P < 0.001). In conclusion, our study showed the number of NLNs is an independent prognostic factor for breast cancer patients with PMRT, and those who have higher number of NLNs have an increased CSS and OS.

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.

Less than 12 lymph nodes in the surgical specimen after neoadjuvant chemo-radiotherapy: an indicator of tumor regression in locally advanced rectal cancer?

BACKGROUND

The number of lymph node retrieved in the surgical specimen is important for tumor staging and has paramount impact on prognosis in colorectal cancer and imitates the adequacy of lymph node surgical clearance. The paucity of lymph node yields in patients undergoing resection after preoperative chemo radiotherapy (CRT) in rectal cancer has seen. Lower total number of lymph nodes in the total mesoractal excision (TME) specimen after CRT, could a marker of better tumor response.

METHODS

We retrospectively reviewed the prospectively managed data of patients underwent excision for rectal cancer, who treated by neoadjuvant radiotherapy with or without chemotherapy in locally advanced rectal cancer. From 2010 to 2014, 364 patients underwent rectal cancer surgery, of which ninety-one treated with neoadjuvant treatment. Standard surgical and pathological protocols were followed. Patients were categorized into two groups based on the number of total harvested lymph nodes with group 1, having 12 or more nodes harvested, and group 2 including patients who had <12 lymph nodes harvested. The total number of lymph nodes retrieved from the surgical specimen was correlated with grade of tumor regression with neoadjuvant treatment.

RESULTS

Out of 91 patients, 38 patients (42%) had less than 12 lymph nodes examined in specimen. The difference in median number of lymph nodes was observed significantly as 9 (range, 2-11) versus 16 (range, 12-32), in group 2 and 1, respectively (P<0.01). Patients with fewer lymph node group were comparable with respect to age, BMI, pre-operative staging, neoadjuvant treatment. Pathological complete response in tumor pCR was seen with significantly higher rate (40% vs. 26%, P<0.05) in group 2. As per Mandard criteria, there was significant difference in tumor regression grade (TRG) between both the groups (P<0.05). Among patients with metastatic lymph nodes, median LNR was lower in <12 lymph nodes group at 0.167 (range, 0.09-0.45) versus 0.187 (range, 0.05-0.54), difference was not statistically significant (P=0.81).

CONCLUSIONS

Retrieval of fewer than 12 lymph nodes in surgical specimen of rectal cancer who had received neo-adjuvant radiotherapy with or without chemotherapy should be considered as a good indicator of tumor response with better local disease control, and a good prognostic factor, rather than as a pointer of poor diligence of the surgical and pathological assessment.

Ex Vivo Intra-arterial Methylene Blue Injection in Rectal Cancer Specimens Increases the Lymph-Node Harvest, Especially After Preoperative Radiation

BACKGROUND

The examination of as large a number of lymph nodes as possible in rectal carcinoma resectates is important for exact staging. However, after neoadjuvant radiochemotherapy (RCT), it can be difficult to obtain a sufficient number of lymph nodes. We therefore investigated whether staining with methylene blue via the inferior mesenteric artery can lead to an increase in the yield of lymph nodes in rectal carcinoma tissue after neoadjuvant RCT.

METHODS

In a prospective, unicentric study rectal carcinoma resectates from three consecutive groups of patients were examined (Group I, no staining; Group II, staining with methylene blue; Group III, again no staining). The numbers of lymph nodes examined were compared (a) between the groups and (b) between patients who had not, or who had, received neoadjuvant RCT.

RESULTS

In all, 75 rectal carcinoma preparations were assessed. The yield of lymph nodes investigated before the use of staining (Group I) increased when staining was introduced (Group II), both for the patients without neoadjuvant RCT (20.9 vs. 31.3, p = 0.018) and for those who did receive this (15.0 vs. 35.1; p = 0.003). After withdrawal of the staining procedure (Group III), the lymph-node yield remained high for the patients without neoadjuvant RCT (31.3 vs. 30.4; p = 0.882), but it reverted to a lower value for those who did receive neoadjuvant RCT (35.1 vs. 24.2; p = 0.029). Before the introduction of staining (Group I), significantly fewer lymph nodes were examined for patients who received neoadjuvant RCT (15.0 vs. 20.9; p = 0.039). However, with staining (Group II), no difference was found associated with the use or non-use of neoadjuvant RCT (31.3 vs. 35.1; p = 0.520).

CONCLUSION

The use of methylene blue staining of rectal carcinoma preparations leads to a significant increase in the number of lymph nodes examined after neoadjuvant RCT. This can be expected to improve the accuracy of lymph-node staging of neoadjuvant-treated rectal carcinoma.

The association between institution at orchiectomy and outcomes on active surveillance for clinical stage I germ cell tumours

INTRODUCTION

Institutional experience has been associated with improved outcomes for various malignancies, including testicular cancer. The present study evaluated whether institution at orchiectomy was associated with outcomes on active surveillance (AS) for clinical stage (CS) I germ cell tumours (GCT).

METHODS

815 patients with CSI GCT managed with AS at the Princess Margaret Cancer Centre were identified. Princess Margaret is a tertiary academic institution with a multidisciplinary testicular cancer clinic involving radiation oncologists, medical oncologists, and urologists, and has research experience in testicular cancer care. The association between institution of orchiectomy (Princess Margaret vs. Other) and time to progression on AS was analyzed using multivariable Cox proportional hazards models. Academic vs. non-academic institutions were compared in a sensitivity analysis.

RESULTS

Patients undergoing orchiectomy at Princess Margaret for non-seminoma GCT were significantly less likely to have pure embryonal carcinoma (EC) in orchiectomy pathology (odds ratio [OR] 0.33; p=0.008) and CSIB disease (OR 0.47; p=0.014). Seminoma characteristics did not differ significantly between institution groups. In non-seminoma GCT, median followup was 5.4 years, 27% progressed on AS, and institution of orchiectomy was not associated with time to progression in either univariate (hazard ratio [HR] 0.79; p=0.33) or multivariable analyses (HR 1.01; p=0.97). In seminoma, median followup was 4.7 years, 12% progressed on AS, and institution of orchiectomy was not associated with progression (univariate: HR 0.87; p=0.73; multivariable: HR 0.98; p=0.96). Sensitivity analyses demonstrated similar results.

CONCLUSIONS

Among CSI GCT patients managed on AS at a specialized cancer centre, there appears to be no difference in oncologic outcomes based upon the institution where orchiectomy was performed.

Different lymph node staging systems in patients with gastric cancer from Korean: What is the best prognostic assessment tool?

To investigate whether the log odds of positive lymph nodes (LODDS) system is a more accurate prognostic tool than the number-based (pN) or ratio-based (rN) lymph node staging system in Korean patients with gastric cancer (GC).The LODDS is a recently proposed staging modality in surgical oncology. However, it is unclear whether LODDS is superior to the pN or rN system in terms of predicting the prognosis of GC patients who underwent radical gastrectomy with extended lymphadenectomy and had a greater number of retrieved lymph nodes.Clinicopathological data from 3929 patients who had undergone curative gastrectomy for GC were reviewed. In addition, overall survival rates according to pN and rN classification stratified by the LODDS were analyzed. A multivariate analysis of survival rate was performed using a Cox proportional hazard model.pN, rN, and LODDS were significantly correlated with 5-year survival rate. Spearman correlation test showed no correlation between LODDS and number of lymph nodes retrieved. The receiver operating characteristic (ROC) curves showed that the 3 staging systems had comparable prognostic accuracy (P < 0.05). Survival analysis according to pN and rN classification stratified by the LODDS staging system demonstrated that LODDS is superior to pN and rN.The LODDS is independently and significantly associated with the OS of Korean patients with GC, and its prognostic value is superior to that of the other lymph node staging systems in Korean patients.

Factors affecting number of lymph nodes harvested and the impact of examining a minimum of 12 lymph nodes in stage I-III colorectal cancer patients: a retrospective single institution cohort study of 1167 consecutive patients

BACKGROUND

To identify factors affecting the harvest of lymph nodes (LNs) and to investigate the association between examining a minimum of 12 LNs and clinical outcomes in stage I-III colorectal cancer (CRC) patients.

METHODS

The clinicopathologic features and the number of examined LNs for 1167 stage I-III CRC patients were analyzed to identify factors affecting the number of LNs harvested and the correlations between clinical outcomes and high harvests (≧12 LNs) and low harvests (<12 LNs).

RESULTS

A multivariate analysis showed that age (P = 0.007), tumor size (P = 0.030), and higher T stage (P = 0.001) were independent factors affecting the examinations of LNs in colon cancer and that tumor size (P = 0.015) was the only independent factor in rectal cancer. Patients with low harvests had poorer overall survival with stage II and stage III CRC (stage II: P < 0.0001; III: P = 0.001) and poorer disease-free survival for stages I-III (stage I: P = 0.023; II: P < 0.0001; III: P = 0.001).

CONCLUSIONS

The factors influencing nodal harvest are multifactorial, and an adequate number of examined LNs (≧12) is associated with a survival benefit. Removal of at least 12 LNs will determine the lymph node status reliably.

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.

Stage migration vs immunology: The lymph node count story in colon cancer

Lymph node staging is of crucial importance for the therapy stratification and prognosis estimation in colon cancer. Beside the detection of metastases, the number of harvested lymph nodes itself has prognostic relevance in stage II/III cancers. A stage migration effect caused by missed lymph node metastases has been postulated as most likely explanation for that. In order to avoid false negative node staging reporting of at least 12 lymph nodes is recommended. However, this threshold is met only in a minority of cases in daily practice. Due to quality initiatives the situation has improved in the past. This, however, had no influence on staging in several studies. While the numbers of evaluated lymph nodes increased continuously during the last decades the rate of node positive cases remained relatively constant. This fact together with other indications raised doubts that understaging is indeed the correct explanation for the prognostic impact of lymph node harvest. Several authors assume that immune response could play a major role in this context influencing both the lymph node detectability and the tumor’s behavior. Further studies addressing this issue are need. Based on the findings the recommendations concerning minimal lymph node numbers and adjuvant chemotherapy should be reconsidered.

Sentinel lymph node biopsy and nodal ultrastaging in colorectal cancer

The tumor status of the regional lymph nodes is the most important prognostic indicator in colorectal cancer (CRC), as it is in other solid tumors. Sentinel lymph node biopsy (SLNB), which has profoundly impacted the treatment of melanoma and breast cancer, has been applied in CRC in an attempt to improve nodal staging accuracy. The challenge lies in identifying patients who have tumor-negative nodes but are at high risk of regional or distant failure and therefore may benefit from adjuvant chemotherapy. Because standard pathological analysis of lymph nodes may incorrectly stage colon cancer, multiple studies have investigated nodal ultrastaging based on identification and immunohistochemical and/or molecular assessment of the sentinel node. This review focuses on the technique of SNLB, its feasibility and validity, and the controversies that remain regarding the clinical significance of nodal ultrastaging in CRC.

Increased number of negative lymph nodes is associated with improved cancer specific survival in pathological IIIB and IIIC rectal cancer treated with preoperative radiotherapy

Preoperative radiation significantly decreases the number of retrieved lymph nodes (LNs) in rectal cancer, but little is known with respect to the prognostic significance of negative LN (NLN) counts under these circumstances. In this study, Surveillance, Epidemiology, and End Results Program (SEER)-registered ypIII stage rectal cancer patients, and patients from Fudan University Shanghai Cancer Center (FDSCC) were combined and analyzed. The results showed that the survival rate of patients with n (cutoff) or more NLNs increased gradually when n ranged from two to nine. After n reached 10 or greater, survival rates were approximately equivalent. Furthermore, the optimal cutoff value of 10 was validated as an independent prognostic factor in stage ypIIIB and ypIIIC patients by both univariate and multivariate analysis (P < 0.001); the number of NLNs could also stratify the prognosis of ypN(+) patients in more detail. Patients in the FDSCC set validated these findings and confirmed that NLN count was not decreased in the good tumor regression group relative to the poor tumor regression group. These results suggest that NLN count is an independent prognostic factor for ypIIIB and ypIIIC rectal cancer patients, and, together with the number of positive LNs, this will provide better prognostic information than the number of positive LNs alone.

Lymph Node Yield in Colon Cancer: Individuals Can Make the Difference

AIM

To investigate the influence of individual surgeons and pathologists on examining an adequate (i.e. ≥10) number of lymph nodes in colon cancer resection specimens.

PATIENTS AND METHODS

The number of lymph nodes was evaluated in surgically treated patients for colon cancer at our hospital from 2008 through 2010, excluding patients who had received neo-adjuvant treatment. The patient group consisted of 156 patients with a median age of 73 (interquartile range (IQR) 63-82 years) and a median of 12 lymph nodes per patient (IQR 8-15). In 106 patients (67.9%), 10 or more nodes were histopathologically examined.

RESULTS

At univariate analysis, the examination of ≥10 nodes was influenced by tumour size (p = 0.05), tumour location (p = 0.015), type of resection (p = 0.034), individual surgeon (p = 0.023), and pathologist (p = 0.005). Neither individual surgeons nor pathologists did statistically and significantly influence the chance of finding an N+ status. Age (p = 0.044), type of resection (p = 0.007), individual surgeon (p = 0.012) and pathologist (p = 0.004) were independent prognostic factors in a multivariate model for finding ≥10 nodes.

CONCLUSION

Though cancer staging was not affected in this study, individual efforts by surgeons and pathologists play a critical role in achieving optimal lymph node yield through conventional methods.

Novel Methods of Lymph Node Evaluation for Predicting the Prognosis of Colorectal Cancer Patients with Inadequate Lymph Node Harvest

Purpose

Lymph node metastasis is an important factor for predicting the prognosis of colorectal cancer patients. However, approximately 60% of patients do not receive adequate lymph node evaluation (less than 12 lymph nodes). In this study, we identified a more effective tool for predicting the prognosis of patients who received inadequate lymph node evaluation.

Materials and Methods

The number of metastatic lymph nodes, total number of lymph nodes examined, number of negative metastatic lymph nodes (NL), lymph node ratio (LR), and the number of apical lymph nodes (APL) were examined, and the prognostic impact of these parameters was examined in patients with colorectal cancer who underwent surgery from January 2004 to December 2011. In total, 806 people were analyzed retrospectively.

Results

In comparison of different lymph node analysis methods for rectal cancer patients who did not receive adequate lymph node dissection, the LR showed a significant difference in overall survival (OS) and the APL predicted a significant difference in disease-free survival (DFS). In the case of colon cancer patients who did not receive adequate lymph node dissection, LR predicted a significant difference in DFS and OS, and the APL predicted a significant difference in DFS.

Conclusion

If patients did not receive adequate lymph node evaluation, the LR and NL were useful parameters to complement N stage for predicting OS in colon cancer, whereas LR was complementary for rectal cancer. The APL could be used for prediction of DFS in all patients.

Lymph node yield after colectomy for cancer: is absence of mismatch repair a factor?

BACKGROUND

Nodal staging is crucial in determining the use of adjuvant chemotherapy for colon cancer. The number of metastatic lymph nodes has been positively correlated with the number of lymph nodes examined. Current guidelines recommend that at minimum 12 to 14 lymph nodes be assessed. In some studies, mismatch repair deficiency has been associated with lymph node yield.

OBJECTIVE

The purpose of this work was to determine whether mismatch repair-deficient colorectal tumors are associated with increased lymph node yield.

DESIGN

We queried an institutional database to analyze colectomy specimens with immunohistochemistry for mismatch repair genes in patients treated for colorectal cancer between 1999 and 2012. Before 2006, immunohistochemistry was performed at the request of an oncologist or surgeon. After 2006, it was routinely performed for patients <50 years of age. We measured the association of clinical and pathologic features with lymph node quantity. Fourteen predictors and confounders were jointly analyzed in a multivariable linear regression model.

SETTINGS

The study was conducted at a single tertiary care institution.

PATIENTS

Tissue specimens from 256 patients were reviewed.

MAIN OUTCOME MEASURES

The correlation of tumor, patient, and operative variables to the yield of mesenteric lymph nodes was measured.

RESULTS

Of 256 colectomy specimens reviewed, 94 had mismatch repair deficiency. On univariate analysis, mismatch repair deficiency was associated with lower lymph node yield, older patient age, right-sided tumors, and poor differentiation. The linear regression model identified 5 variables with independent relationships to lymph node yield, including patient age, specimen length, lymph node ratio, perineural invasion, and tumor size. A positive correlation was observed with tumor size, specimen length, and perineural invasion. Tumor location had a more complex, nonlinear, quadratic relationship with lymph node yield; proximal tumors were associated with a higher yield than more distal lesions. Mismatch repair deficiency was not independently associated with lymph node yield.

LIMITATIONS

Mismatch repair immunohistochemistry based on patient age, family history, and pathologic features may reduce the generalizability of these results. Our sample size was too small to identify variables with small measures of effect. The retrospective nature of the study did not permit a true assessment of the extent of mesenteric resection.

CONCLUSIONS

Patient age, length of bowel resected, lymph node ratio, perineural invasion, tumor size, and tumor location were significant predictors of lymph node yield. However, when controlling for surgical and pathologic factors, mismatch repair protein expression did not predict lymph node yield.

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.

Number of negative lymph nodes is associated with disease-free survival in patients with breast cancer

BACKGROUND

The aim of this study was to evaluate the prognostic value of the number of negative lymph nodes (NLNs) in breast cancer patients after mastectomy.

METHODS

2,455 breast cancer patients who received a mastectomy between January 1998 and December 2007 were retrospectively reviewed. The prognostic impact of the number of NLNs with respect to disease-free survival (DFS) was analyzed.

RESULTS

The median follow-up time was 62.0 months, and the 5-year and 10-year DFS was 87.1% and 74.3%, respectively. The DFS of patients with >10 NLNs was significantly higher than that of patents with ≤10 NLNs, and the 5-year DFS rates were 87.5% and 69.5%, respectively (P < 0.001). Univariate Cox analysis showed that the NLN count (continuous variable) was a prognostic factor of DFS (hazard ratio [HR] = 0.913, 95% confidence interval [CI]: 0.896-0.930, P < 0.001). In multivariate Cox analysis, patients with a higher number of NLNs had a better DFS (HR = 0.977, 95% CI: 0.958-0.997, P = 0.022). Subgroup analysis showed that the NLN count had a prognostic value in patients at different pT stages and pN positive patients (log-rank P < 0.001). However, it had no prognostic value in pN0 patients (log-rank P = 0.684).

CONCLUSIONS

The number of NLNs is an independent prognostic factor of DFS in breast cancer patients after mastectomy, and patients with a higher number of NLNs have a better DFS.

The size of retrieved lymph nodes correlates with the number of retrieved lymph nodes and is an independent prognostic factor in patients with stage II colon cancer

PURPOSE

In stage II colon cancer, patients with many retrieved lymph nodes (LNs) have been reported to have better oncological outcomes. We tested the hypothesis that the greater number of retrieved LNs is related to a larger LN size.

METHODS

The subjects comprised 320 patients with stage II colon cancer who underwent curative resection. All operations were elective and were performed by the same surgeons. The maximum long axis and short axis diameters of LNs were measured on hematoxylin-eosin-stained specimens.

RESULTS

A total of 4,744 LNs were evaluated. The number of retrieved LNs was 14.8 ± 10.1 (mean ± SD). The long axis diameter was 4.8 ± 2.6 mm, with a median value of 4.3 mm, a maximum value of 20.4 mm, and a minimum value of 0.6 mm. The corresponding short axis diameters were 3.4 ± 1.7, 3.0, 15.1, and 0.5 mm, respectively. The highest correlation coefficient for the association with the number of LNs was obtained for the maximum value of the long axis diameter (0.59). Multivariate analysis revealed that age, tumor location, pathological T stage, and the maximum long axis diameter were independent prognostic factors. The number of LNs was not a significant factor. Patients with less than 12 LNs and a maximum long axis diameter of less than 10 mm had significantly poorer outcomes (p < 0.001).

CONCLUSION

In patients with stage II colon cancer, the maximum long axis diameter of LNs correlated with the number of LNs and was an independent prognostic factor.

Number of negative lymph nodes can predict survival of breast cancer patients with four or more positive lymph nodes after postmastectomy radiotherapy

Background

This study was conducted to assess the prognostic value of the number of negative lymph nodes (NLNs) in breast cancer patients with four or more positive lymph nodes after postmastectomy radiotherapy (PMRT).

Methods

This retrospective study examined 605 breast cancer patients with four or more positive lymph nodes who underwent mastectomy. A total of 371 patients underwent PMRT. The prognostic value of the NLN count in patients with and without PMRT was analyzed. The log-rank test was used to compare survival curves, and Cox regression analysis was performed to identify prognostic factors.

Results

The median follow-up was 54 months, and the overall 8-year locoregional recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS) were 79.8%, 50.0%, 46.8%, and 57.9%, respectively. The optimal cut-off points for NLN count was 12. Univariate analysis showed that the number of NLNs, lymph node ratio (LNR) and pN stage predicted the LRFS of non-PMRT patients (p < 0.05 for all). Multivariate analysis showed that the number of NLNs was an independent prognostic factor affecting the LRFS, patients with a higher number of NLNs had a better LRFS (hazard ratio = 0.132, 95% confidence interval = 0.032-0.547, p =0.005). LNR and pN stage had no effect on LRFS. PMRT improved the LRFS (p < 0.001), DMFS (p = 0.018), DFS (p = 0.001), and OS (p = 0.008) of patients with 12 or fewer NLNs, but it did not any effect on survival of patients with more than 12 NLNs. PMRT improved the regional lymph node recurrence-free survival (p < 0.001) but not the chest wall recurrence-free survival (p = 0.221) in patients with 12 or fewer NLNs.

Conclusions

The number of NLNs can predict the survival of breast cancer patients with four or more positive lymph nodes after PMRT.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-014-0284-5) contains supplementary material, which is available to authorized users.

Prognostic value of different lymph node staging methods in esophageal squamous cell carcinoma after esophagectomy

BACKGROUND

This study aimed to investigate the prognostic value of number of involved lymph nodes, number of removed lymph nodes, ratio of involved to removed nodes (lymph node ratio), and number of negative lymph nodes in esophageal squamous cell carcinoma (ESCC) patients after esophagectomy.

METHODS

A retrospective review of 603 patients receiving esophagectomy for ESCC was made. Cox regression analysis was performed to identify significant prognostic factors.

RESULTS

The median follow-up time was 36.7 months, and the 5-year overall survival (OS) was 43.5%. Patients with negative lymph node count ≥ 14 had better survival (p < 0.001). Univariate Cox analysis showed that the number of involved lymph nodes, number of removed lymph nodes, lymph node ratio, and number of negative lymph nodes influenced OS (p < 0.05 for all). Multivariate Cox analysis indicated that the number of involved lymph nodes and number of negative lymph nodes were independent prognostic factors for OS, and a higher number of negative lymph nodes was associated with lower mortality. The number of removed lymph nodes and lymph node ratio had no significant effect on OS. The number of negative lymph nodes had prognostic value in different lymph node stages and in two-field or three-field lymphadenectomy.

CONCLUSIONS

For ESCC patients after esophagectomy, the number of involved lymph nodes and the number of negative lymph nodes had a better prognostic value than did the number of removed lymph nodes and lymph node ratio.

The prognostic impact of the log odds of positive lymph nodes in colon cancer

AIM

This study aimed to investigate the prognostic impact of the log odds of positive lymph nodes (LODDS) in colon cancer.

METHOD

Four hundred and forty patients with colon cancer were divided into three each groups according to their lymph node ratio (LNR) and LODDS. Survival analysis was performed.

RESULTS

The 5-year overall survival (OS) rate was 70.2%. In univariate analysis age, pT and pN stage, tumour grade, lymphatic, venous and perineural invasion, surgical margin clearance, LNR and LODDS were significantly associated with OS. In multivariate analysis age, surgical margins, perineural invasion and LODDS were found to be independent prognostic factors. In subgroup analysis of patients with an inadequate number of examined lymph nodes (NELN) (n = 76) and node-negative patients (n = 210), LODDS retained its prognostic value, whereas the impact of LNR was not statistically significant (P = 0.063). The overall survival rates of node-negative patients in the LODDS groups 0, 1 and 2 were 81%, 74.2% and 50%, respectively (P = 0.020). LNR and LODDS classifications were both significantly associated with survival in Stage III colon cancer, but only LODDS was an independent prognostic factor.

CONCLUSION

Conventional TNM staging for nodes (pN) and LNR status cannot reliably classify node-negative patients into homogeneous groups. LODDS provides more valuable information than LNR independently of the NELN.

Alcohol Fat Clearing Increases Lymph Node Yield after Surgery for Colorectal Cancer

Lymph node (LN) yield is associated with oncologic outcome in patients who undergo surgery for colorectal adenocarcinoma (CRC). Standards to maximize LN yield have been initiated to enhance treatment of patients with CRC. This study evaluates the impact of a simple alcohol-based preparation protocol on LN yield. Surgical specimens from patients with CRC were prepared using either the alcohol protocol or standard formalin fixation and LN yield was compared. In total, 80 consecutive patients (n = 40 formalin, n = 40 alcohol) were examined. Overall, median LN yield increased from 17 to 29 ( P < 0.01) with the alcohol fat clearance protocol. For patients with rectal adenocarcinoma who underwent proctectomy after neoadjuvant chemoradiotherapy, LN yield increased from 15 to 23 ( P = 0.02). The frequency of need for additional sampling to achieve a minimum 12 LN count was also reduced. Initiation of a standardized alcohol fat-clearing protocol increased LN yield after surgery for CRC. This simple, cost-effective measure may improve the efficiency of LN assessment and accurate staging, which may impact oncologic outcomes.

Lymph node metastasis of carcinomas of transverse colon including flexures. Consideration of the extramesocolic lymph node stations

PURPOSE

Complete mesocolic excision (CME) is nowadays state of the art in the treatment of colon cancer. In cases of carcinoma of transverse colon and of both flexures an extramesocolic lymph node metastasis can be found in the infrapancreatic lymph node region (ILR) and across the gastroepiploic arcade (GLR). These direct metastatic routes were not previously systematically considered. In order to validate our hypothesis of these direct metastatic pathways and to obtain evidence of our approach of including dissection of these areas as part of CME, we initiated a prospective study evaluating these lymph node regions during surgery.

METHODS

Forty-five consecutive patients with primary tumour manifestation in transverse colon and both flexures between May 2010 and January 2013 were prospectively analyzed. Patients were followed up for at least 6 months. Mode of surgery, histopathology, morbidity and mortality were evaluated.

RESULTS

Twenty-six patients had a carcinoma of transverse colon, 16 patients one of hepatic flexure and four patients one of splenic flexure. The median lymph node yield was 40. Occurrence of lymph node metastasis in ILR was registered in five patients and in GLR in four patients. The mean lymph node ratio was 0.085. Postoperative complications occurred in nine patients, and postoperative mortality was 2 %.

CONCLUSIONS

We were able to demonstrate this novel metastatic route of carcinomas of the transverse colon and of both flexures in ILR and GLR. These could be considered as regional lymph node regions and have to be included into surgery for cancer of the transverse colon including both flexures.

High Ligation of Inferior Mesenteric Artery in Left Colonic and Rectal Cancers: Lymph Node Yield and Survival Benefit

During surgery for colorectal cancer, the inferior mesenteric artery (IMA) may be ligated either directly at the origin of the IMA from the aorta (high ligation) or at a point just below the origin of the left colic artery (low ligation). Sixty patients of left colonic and rectal cancer undergoing elective curative surgery in 2007 and 2008 were selected for this observational study. The resected lymph nodes were grouped into three levels: along the bowel wall (D1), along IMA below left colic (D2), and along the IMA and its root (D3). Statistical analysis was performed with SPSS version 20.0. D2 level was involved pathologically in 20 (33.3 %) and D3 in six out of 44 (13.6 %) patients. The median nodal yield with high and low ligation were 33 and 25, respectively (p = 0.048). Median overall survival for high ligation was 62 months versus 42 months for low ligation (p = 0.190). High ligation of the IMA for rectal and left colonic cancers can improve lymph node yield, thus facilitating accurate tumor staging and thus better disease prognostication, but the survival benefit is not significant.

Does reevaluation of colorectal cancers with inadequate nodal yield lead to stage migration or the identification of metastatic lymph nodes?

BACKGROUND

The National Comprehensive Cancer Network recommends routine reevaluation of all stage II colon cancer specimens with fewer than 12 lymph nodes. However, there are few data demonstrating the effect of reevaluation on stage.

OBJECTIVE

The aim of this study was to demonstrate the effect of pathologic reevaluation for colorectal cancers with fewer than 12 lymph nodes on stage.

DESIGN

This study entailed a retrospective review of pathology reports.

SETTINGS

This study was conducted at 2 large multispecialty referral centers.

INTERVENTIONS

Pathologic reevaluation was performed to look for additional lymph nodes.

PATIENTS

All patients with stage I through III colorectal cancers with inadequate lymph node yields who underwent reevaluation from January 1, 2007 through March 31, 2011 were identified.

MAIN OUTCOME MEASURES

We recorded initial pathologic stage and new stage following reevaluation. The following variables before and after reevaluation were also recorded: 1) total lymph node count, 2) metastatic node count, 3) negative node count, and 4) lymph node ratio.

RESULTS

Eighty-three patients underwent pathologic reevaluation from a total of 1682 cancer specimens. Mean nodal yields were 7.2 ± 2.6 on the first pathologic review. On reevaluation, 80% of patients had one or more newly identified nodes. On average, 6.9 ± 9.6 more lymph nodes were identified with a metastatic node detected in 4 of 83 patients (4.8%). After pathologic reevaluation, 1 patient (1.2%) had a change in TNM stage from N1 to N2 disease. The lymph node ratio changed in 13 of 15 patients (87% of stage III cancers). Only 4 of these had a change in lymph node quartile.

LIMITATIONS

The study was limited by its retrospective nature and small sample size.

CONCLUSION

Few patients have a newly discovered metastatic node or stage change following pathologic reevaluation. The effect of pathologic reevaluation on treatment and outcome should be further investigated.

Extended lymphadenectomy in colon cancer is crucial

No one doubts that lymph node dissection in colon cancer is necessary, it is just the extent of that dissection that is still under debate. As the individual steps of an oncologic operation cannot be separated from each other, analysis of the significance of lymph node dissection alone is difficult. It has been proven that the T category is directly related to the number and central spread of lymph node metastases. Micrometastases and isolated tumor cells may be detected in lymph nodes by using special staining techniques; their presence may worsen prognosis significantly and approximate it to UICC stage III. The numbers of dissected lymph nodes and the ratio of involved versus dissected lymph nodes have been used as markers for quality of surgery and histopathological evaluation. Recent results underscore the importance of technique and extent of dissection. Dissection must be performed along the embryologic planes of the mesocolon and leave them intact. A high vascular tie with preservation of the central hypogastric nerves must be applied in order to achieve the best oncologic results while preserving quality of life. Extended lymphadenectomy is oncologically relevant only when it is combined with removal of the primary tumor with adequate longitudinal clearance, an intact complete mesocolon, and high vascular tie. It is part of a concept in which the tumor-bearing specimen is harvested as an enveloped package to minimize the risk of tumor cell spillage and local recurrence.

Prognostic biomarkers in colorectal cancer: where do we stand?

Colorectal cancer remains a major cause of cancer-related death worldwide. One way to reduce its staggering mortality rate and socio-economic burden is to predict outcome based on the aggressiveness of the tumor biology in order to treat patients accordingly to their risk profile. As such, it comes as no surprise that prognostic biomarker discovery is a hot topic in colorectal cancer research. The last two decades have literally produced tons of new data and an avalanche of potential clinically applicable biomarkers. This review explores and summarizes data concerning the prognostic strength and clinical utility of current and future tissue biomarkers in the diagnosis and treatment of colorectal cancer.

Short term results of complete (D3) vs. standard (D2) mesenteric excision in colon cancer shows improved outcome of complete mesenteric excision in patients with TNM stages I-II

BACKGROUND

The aim of the present study was to investigate whether the new method of complete mesocolic excision (CME) with a high (apical) vascular tie (D3 resection) had an immediate effect compared with a conventional (standard) approach even in those patients without lymph node metastases.

METHODS

A cohort of 189 consecutive patients with tumour-nodal-metastasis (TNM) stages I-II and a mean age of 73 years were operated on in the period from January 2007 to December 2008 in three community teaching hospitals. The CME approach (n = 89), used in hospital A, was compared to the standard technique used (n = 105) in two other hospitals, B and C. Lymph node yields from the specimens were used as a surrogate measure of radical resections. Outcome was analysed after a median follow-up of 50.2 months.

RESULTS

In-hospital mortality rate was 2.8 % in the CME group and 8.6 % in the standard group. The 3-year overall survival (OS) in the CME group was 88.1 versus 79.0 % (p = 0.003) in the standard group, and the corresponding disease-free survival (DFS) was 82.1 versus 74.3 % (p = 0.026). Cancer-specific survival was 95.2 % in the CME group versus 90.5 % in the standard group (p = 0.067). Age, operative technique, and T category were significant in multiple Cox regressions of OS and DFS.

CONCLUSIONS

Compared with the standard (D2) approach, introduction of CME surgical management of colon cancer resulted in a significant immediate improvement of 3-year survival for patients with TNM stage I-II tumours as assessed by OS and DFS.

Negative node count improvement prognostic prediction of the seventh edition of the TNM classification for gastric cancer

OBJECTIVE

To demonstrate that the seventh edition of the tumor-node-metastasis (TNM) classification for gastric cancer (GC) should be updated with the number of negative lymph nodes for the improvement of its prognostic prediction accuracy.

METHODS

Clinicopathological data of 769 GC patients who underwent curative gastrectomy with lymphadenectomy between 1997 and 2006 were retrospectively analyzed to demonstrate the superiority of prognostic efficiency of the seventh edition of the TNM classification, which can be improved by combining the number of negative lymph nodes.

RESULTS

With the Cox regression multivariate analysis, the seventh edition of the TNM classification, the number of negative nodes, the type of gastrectomy, and the depth of tumor invasion (T stage) were identified as independent factors for predicting the overall survival of GC patients. Furthermore, we confirmed that the T stage-N stage-number of negative lymph nodes-metastasis (TNnM) classification is the most appropriate prognostic predictor of GC patients by using case-control matched fashion and multinominal logistic regression. Finally, we were able to clarify that TNnM classification may provide more precise survival differences among the different TNM sub-stages of GC by using the measure of agreement (Kappa coefficient), the McNemar value, the Akaike information criterion, and the Bayesian Information Criterion compared with the seventh edition of the TNM classification.

CONCLUSION

The number of negative nodes, as an important prognostic predictor of GC, can improve the prognostic prediction efficiency of the seventh edition of the TNM classification for GC, which should be recommended for conventional clinical applications.

The total number of lymph nodes in resected colon cancer specimens is affected by several factors but the lymph node ratio is independent of these

The number of lymph nodes retrieved from the specimen may be a surrogate measure of the adequacy of extensive colon cancer surgery, but many variables may influence the total lymph node yield of any specimen. We examined which variables would be influential both for negative and positive node sampling.The combined results from 428 patients from three hospitals A to C treated in 2007-2009 with single colon cancers having R0 segmental resections were analysed. The surgical technique and pathology staining methods were slightly different between the hospitals.The mean number of lymph nodes was 15.8 (range 1-60). Twelve or more lymph nodes were harvested in 78% of the specimens. In the multivariate Poisson regression analysis of all TNM stages, the factors associated with the total lymph node harvest were age, pathology handling, tumour location and size (p < 0.001), whereas for TNM stage III alone the pathology handling (p < 0.001) and a radical operating technique (p = 0.003) were highly significant. The total number of lymph nodes was the only significant factor for the number of positive lymph nodes (Posln) according to the multivariate negative regression analysis (p = 0.02) but the analysis of the lymph node ratio (LNR) detected no statistically significant variable.Several factors, and especially the specimen processing technique, were important for the total number of harvested lymph nodes. The number of Posln varied between segments and increased with the total number of harvested lymph nodes, but for LNR no variable was important. LNR seemed to abolish the combined effect of tumour location and the total lymph node yield in prognosis assessment.

Nodal status, number of lymph nodes examined, and lymph node ratio: what defines prognosis after resection of colon adenocarcinoma?

BACKGROUND

Lymph node ratio (LNR) has been proposed as an optimal staging variable for colorectal cancer. However, the interactive effect of total number of lymph nodes examined (TNLE) and the number of metastatic lymph nodes (NMLN) on survival has not been well characterized.

STUDY DESIGN

Patients operated on for colon cancer between 1998 and 2007 were identified from the Surveillance, Epidemiology, and End Results database (n = 154,208) and randomly divided into development (75%) and validation (25%) datasets. The association of the TNLE and NMLN on survival was assessed using the Cox proportional hazards model with terms for interaction and nonlinearity with restricted cubic spline functions. Findings were confirmed in the validation dataset.

RESULTS

Both TNLE and NMLN were nonlinearly associated with survival. Patients with no lymph node metastasis had a decrease in the risk of death for each lymph node examined up to approximately 25 lymph nodes, while the effect of TNLE was negligible after approximately 10 negative lymph nodes (NNLN) in those with lymph node metastasis. The hazard ratio varied considerably according to the TNLE for a given LNR when LNR ≥ 0.5, ranging from 2.88 to 7.16 in those with an LNR = 1. The independent effects of NMLN and NNLN on survival were summarized in a model-based score, the N score. When patients in the validation set were categorized according to the N stage, the LNR, and the N score, only the N score was unaffected by differences in the TNLE.

CONCLUSIONS

The effect of the TNLE on survival does not have a unique, strong threshold (ie, 12 lymph nodes). The combined effect of NMLN and TNLE is complex and is not appropriately represented by the LNR. The N score may be an alternative to the N stage for prognostication of patients with colon cancer because it accounts for differences in nodal samples.

The number of resected lymph nodes (nLNs) combined with tumor size as a prognostic factor in patients with pathologic N0 and Nx non-small cell lung cancer

Background

The prognostic role of the number of resected lymph nodes (nLNs) in pathologic N0 (lymph node negative) and Nx (no lymph node examined) non-small cell lung cancer (NSCLC) patients remains uncertain. Guidelines for optimal nLNs have not been established. In the current study, we evaluated whether a higher number of resected lymph nodes (LNs) results in better survival in different tumor size categories among NSCLC patients without metastatic LNs.

Method

A retrospective study was conducted. Based on nLNs (LN = 0, 1–7, >7) and tumor size (T_a: ≤3.5cm, T_b: >3.5cm) during surgery, patients were categorized into 6 groups (LN₀T_a, LN₀T_b, LN_1–7T_a, LN_1–7T_b, LN_7-T_a and LN_7-T_b). Survival and multivariate analyses were carried out to determine whether nLNs combined with tumor size was significant for overall survival (OS) or disease free survival (DFS) after adjusting for potential confounders.

Results

A total of 428 patients were enrolled in the study. Multivariate analysis demonstrated that nLNs, tumor size and pathological stage were the independent prognosticators for OS and DFS. Data from our study suggested that lung cancer lymphadenectomy with more than 7 LNs removed should be considered a benchmark for surgery or pathology at an early stage. Survival was significantly better in the LN_7-T_a group, compared with other 5 groups (p<0.001).

Conclusions

The combined predictor (nLNs combined with tumor size) is an independent prognostic factor and a reasonable stratification criterion in patients with pathologic N0 and Nx NSCLC. The validation of our finding is warranted in further investigation.

Impact of Schwartz enhanced visualization solution on staging colorectal cancer and clinicopathological features associated with lymph node count

BACKGROUND

Stage-specific survival for colon cancer improves when more lymph nodes are reported in the surgical specimen. This has led to a minimum standard of identifying 12 lymph nodes as a quality indicator.

OBJECTIVE

The aim of this study was to determine whether the addition of Schwartz solution increases node yield and impacts pathologic staging.

DESIGN

This is a prospective cohort study.

SETTING

The study was conducted in an academic medical center.

PATIENTS

Included were 104 consecutive patients with colorectal cancer.

MAIN OUTCOME MEASURES

Lymph node counts before and after specimen treatment with Schwartz solution and incidence of upstaging were measured.

RESULTS

An additional 20 minutes (interquartile range, 15-40 minutes) was spent searching for lymph nodes, increasing the median number of nodes from 22.5 to 29.0 nodes. However, only 1 patient was upstaged. Schwartz solution decreased the number of specimens with less than 12 lymph nodes from 15 to 6. The following factors were associated with Schwartz solution leading to the detection of additional nodes: number of nodes detected initially with formalin only (p < 0.000), mesenteric fat volume (p < 0.000), mesenteric fat weight (p < 0.000), length of specimen (p < 0.016), tumor greatest dimension (p < 0.016), patient body surface area (p < 0.034), and patient age (p < 0.003).

LIMITATIONS

Clinical data for this study were obtained retrospectively and were not available for all of the patients.

CONCLUSIONS

Although Schwartz solution increased the number of nodes detected in 95% of patients and improved compliance with the 12-node standard for colon resection, there was minimal impact on cancer staging. Upstaging is unlikely to explain the increase in overall survival in patients with higher lymph node counts, casting doubt on the validity of this process measure as a meaningful quality indicator. Rather, the lymph node count may be a reflection of inherent tumor biology or host-related factors.

A nodal positivity constant: new perspectives in lymph node evaluation and colorectal cancer

PURPOSE

To date, associations between the number of lymph nodes evaluated, staging, and survival have been examined in the context of large population-based studies conducted by a small number of investigators. Therefore, although high-quality data are available, perspective is lacking.

METHODS

Studies for this paper were identified by searches of Medline, Scopus, PubMed, and manual searching of references from articles, using the search terms ''colorectal cancer'', ''nodal status'' and ''lymph node''.

RESULTS

It is clear that survival benefit increases with the increasing number of lymph nodes harvested. Despite this observation, there has been no significant increase in the proportion of node-positive cancers over the past two decades.

CONCLUSION

The nodal positivity rate for colorectal cancer consistently approximates 40 % across a wide range of studies internationally, a phenomenon that has not previously been recognized in the literature. We review the evidence and introduce the concept of a nodal positivity constant.

Lack of relationships between FGF19 staining pattern, lymph node metastasis and locally invasive characteristics of the tumor in colorectal cancers

INTRODUCTION

Colorectal cancers are in the top of the cancer-related causes of death in the world and lymph node metastasis is accepted as the primary prognostic factor. In this study, correlations of FGF19 staining pattern with local invasion and lymph node metastasis in a series of colorectal cancers were investigated.

METHODS

This studyincluded 81 colorectal cancer patients who underwent surgery in our hospital with no evidence of preoperative radiological distant metastasis. Routine pathological examination of the resection material was performed in order to identify vascular, perineural and serosal infiltration, regional lymph node metastasis and the degree of differentiation. Tumor tissue samples were stained with an immunohistochemistry method for FGF 19 evaluation and the staining pattern was statistically compared with the above mentioned characteristics of the tumors.

RESULTS

The patient population consisted of 47 females and 34 males with a median age of 70 years. In 40 patients regional lymph nodes were positive and 51%, 32% and 38% had serosal, perineural and vascular invasion. While 64 cases were moderately-differentiated, 11 cases were well-differentiated and 6 poorly- differentiated, there was no association with FGF 19 staining, including intensity.

CONCLUSION

No evidence of significant statistically correlation was found between FGF 19 staining pattern and serosal, perineural, vascular invasion, lymph node involvement and degree of differentiation.

AJCC Cancer Staging Manual 7th edition criteria for colon cancer: do the complex modifications improve prognostic assessment?

BACKGROUND

The 7th edition of the AJCC Cancer Staging Manual (AJCC-7) includes substantial changes for colon cancer (CC), which are particularly complex in patients with stage II and III disease. We used a national cancer database to determine if these changes improved prediction of survival.

STUDY DESIGN

The database of the Surveillance, Epidemiology and End Results Program was queried to identify patients with pathologically confirmed stage I to III CC diagnosed between 1988 and 2008. Colon cancer was staged by the 6(th) edition of the AJCC Cancer Staging Manual (AJCC-6) and then restaged by AJCC-7. Five-year disease-specific survival and overall survival were compared.

RESULTS

After all exclusion criteria were applied, AJCC-6 and AJCC-7 staging was possible in 157,588 patients (68.9%). Bowker's test of symmetry showed that the number of patients per substage was different for AJCC-6 and AJCC-7 (p < 0.001). The Akaike information criteria comparison showed superior fit with the AJCC-7 model (p < 0.001). However, although AJCC-7 staging yielded a progressive decrease in disease-specific survival and overall survival of patients with stage IIA (86.3% and 72.4%, respectively), IIB (79.4% and 63.2%, respectively), and IIC (64.9% and 54.6%, respectively) CC, disease-specific survival and overall survival of patients with stage IIIA disease increased (89% and 79%, respectively). Subset analysis of patients with >12 lymph nodes examined did not affect this observation.

CONCLUSIONS

The AJCC-7 staging of CC does not address all survival discrepancies, regardless of the number of lymph nodes examined. Consideration of other prognostic factors is critical for decisions about therapy, particularly for patients with stage II CC.