Staging error does not explain the relationship between the number of lymph nodes in a colon cancer specimen and survival

Prognostic and Predictive Determinants of Colorectal Cancer: A Comprehensive Review

Colorectal cancer (CRC) remains a significant global health burden, necessitating a thorough understanding of prognostic and predictive factors to enhance patient outcomes. This systematic review aims to comprehensively evaluate prognostic and predictive determinants in CRC, encompassing both traditional and emerging biomarkers. A systematic search of major electronic databases was conducted to identify relevant studies published from 1995 up to 2024. Eligible articles were critically appraised, and data extraction was performed according to predefined criteria. The prognostic determinants examined included clinicopathological features such as tumor stage, grade, and lymph node involvement, as well as molecular biomarkers including RAS, BRAF, and MSI status. Predictive determinants encompassed biomarkers influencing response to targeted therapies and immunotherapy, such as HER2 and Immunoscore. The review also explores novel prognostic and predictive markers, including tumor microenvironment characteristics and liquid biopsy-based biomarkers. Synthesizing evidence from diverse studies, this review provides insights into the prognostic and predictive landscape of CRC, highlighting the potential clinical implications of identified determinants. Understanding the multifaceted nature of prognostic and predictive factors in CRC is imperative for the advancement of personalized treatment strategies and improvement of patient outcomes.

Cancer spreading patterns based on epithelial-mesenchymal plasticity

Introduction: Metastasis is a major cause of cancer-related deaths, underscoring the necessity to discern the rules and patterns of cancer cell spreading. Epithelial-mesenchymal plasticity contributes to cancer aggressiveness and metastasis. Despite establishing key determinants of cancer aggressiveness and metastatic ability, a comprehensive understanding of the underlying mechanism is unknown. We aimed to propose a classification system for cancer cells based on epithelial-mesenchymal plasticity, focusing on hysteresis of the epithelial-mesenchymal transition and the hybrid epithelial/mesenchymal phenotype. Methods: We extensively reviewed the concept of epithelial-mesenchymal plasticity, specifically considering the hysteresis of the epithelial-mesenchymal transition and the hybrid epithelial/mesenchymal phenotype. Results: In this review and hypothesis article, based on epithelial-mesenchymal plasticity, especially the hysteresis of epithelial-mesenchymal transition and the hybrid epithelial/mesenchymal phenotype, we proposed a classification of cancer cells, indicating that cancer cells with epithelial-mesenchymal plasticity potential could be classified into four types: irreversible hysteresis, weak hysteresis, strong hysteresis, and hybrid epithelial/mesenchymal phenotype. These four types of cancer cells had varied biology, spreading features, and prognoses. Discussion: Our results highlight that the proposed classification system offers insights into the diverse behaviors of cancer cells, providing implications for cancer aggressiveness and metastasis.

Colon cancer: the 2023 Korean clinical practice guidelines for diagnosis and treatment

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients' values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Lymph node harvest as a predictor of survival for colon cancer: A systematic review and meta-analysis

Background and Objectives

The number of lymph nodes found harboring metastasis can be impacted by the extent of harvest. Guidelines recommend 12 lymph nodes for adequate lymphadenectomy to predict long-term oncologic outcomes, yet different cut-offs remain unevaluated. The aim of this review was to determine cut-offs that may predict survival outcomes.

Methods

Medline, Embase, and CENTRAL were systematically searched. Articles were included if they compared overall survival (OS) or disease-free survival (DFS) above and below a lymph node harvest cut-off. Studies solely examining rectal cancer or stage-IV disease were excluded. Pairwise meta-analyses using inverse variance random effects were performed.

Results

From 2587 citations, 20 studies with 854,359 patients (51.9% female, mean age: 68.9) were included, with 19 studies included in quantitative synthesis. A lymph node harvest cut-off of 12 predicted improved five-year OS (7 studies; OR 1.11, 95% CI 1.08-1.14, p<0.00001). A cut-off as low as 7 was associated with improved five-year OS (2 studies; OR 1.16, 95% CI 1.08-1.25, p<0.0001) and DFS (3 studies; OR 1.66, 95% CI 1.32-2.10, p<0.00001). All cut-offs greater than 12 demonstrated improved survival.

Conclusions

A lymph node cut-off of 12 distinguishes differences in five-year oncologic outcomes. Contrarily, lymph node harvests other than 12 have not been rigorously studied and thus lack the statistical power to derive meaningful conclusions compared to the 12-lymph node cut-off. Nonetheless, it is possible that a lymph node harvest cut-offs less than 12 may be adequate in predicting long-term survival. Further prospective study evaluating cut-offs below 12 are warranted.

Evaluation of lymph node adequacy in patients with colorectal cancer: Results from a referral center in Iran

Background

The presence of lymph node metastasis is one of the most important prognostic factors for long-term survival of patients with colorectal cancer. Therefore, thorough pathologic examination of at least 12 lymph nodes is essential for accurate staging of this disease, as well as for choosing the best adjuvant treatment. The aim of this study is to assess the adequacy of lymph node harvest in patients with colorectal cancer.

Methods

This observational, cross-sectional study was performed on 584 patients with colorectal adenocarcinoma who had undergone surgery from 2012 to 2017. Thereafter, the relevant demographic, pathological, and surgical data were extracted from the patients' medical records; and a relationship between the number of evaluated lymph nodes and other variables was also assessed.

Results

Among 584 studies cases in this study, 336 (57.5%) subjects had fewer than 12 evaluated lymph nodes. Mean and median number of the evaluated lymph nodes were calculated as 10.7 (±5.6) and 10, respectively. The patients aged 60 years old and older and the cases with tumors located in descending colon and rectum were observed to have a higher likelihood of inadequate lymph node retrieval. After an average follow-up of a 60-month period, 63% of the patients were alive. For the patients in whom fewer than 12 lymph nodes had been assessed, the median survival was estimated to be 48 months. For the patients in whom the number of evaluated lymph nodes was ≥12, median survival was calculated to be 54 months.

Conclusion

The number of lymph nodes evaluated in our study was less than the standard number in more than half of the patients. Among various other factors, older age and tumor location in descending colon and rectum are found to be associated with suboptimal assessment of lymph nodes. The number of lymph nodes dissected is also associated with survival.

Prognostic significance of lymph node count in high-risk node-negative colon carcinoma

BACKGROUND

the prognostic value of the number of lymph nodes isolated (< 12 versus ≥ 12) in the surgical specimen continues to be controversial. In this study, the impact of isolating fewer or more than 12 lymph nodes in stage II colon cancer with a high-risk biologic phenotype was analyzed, such as the presence of perineural invasion.

METHODS

all cases of stage II disease (T3-4N0M0) with perineural invasion (PNI+) were retrospectively identified from a prospective database of patients undergoing surgery for colon cancer. The cohort was divided into two groups depending on the number of lymph nodes isolated (< 12 vs ≥ 12). Apart from clinical and surgical data, the patterns of recurrence, overall (OS) and disease-free survival (DFS) at five and ten years were analyzed.

RESULTS

sixty patients met the inclusion criteria, 31.7 % had < 12 lymph nodes isolated and 68.3 % had more than 12 isolated. There were no clinical or surgical differences between the two groups. OS at five and ten years was significantly lower in the patients with < 12 lymph nodes isolated (84.2 %, 62.7 % vs 94.6 % and 91.6 %, p = 0.01). DFS at five and ten years was 51 % vs 86.5 %, respectively (p = 0.005).

CONCLUSION

the number of lymph nodes isolated (with a cutoff of 12) in stage II colon cancer with PNI+ has prognostic value and should therefore be borne in mind when planning adjuvant chemotherapy.

Determining the Risk Factors Affecting on Death Due to Colorectal Cancer Progression: Survival Analysis in the Presence of Competing Risks

PURPOSE

In survival analysis, some patients may be at risk of more than one event, for example cancer-related death and cancer-unrelated death. In this case, if the aim of study becomes to assess the impact of risk factors on different causes of death, the competing risk model should be used rather than classical survival model. The aim of the present study is to determine the risk factors for related and unrelated mortality in patients with colorectal cancer using competing risk regression models.

METHODS

The present retrospective cohort study was carried out on 310 CRC patients. Death due to cancer progression was considered as the interest event, and death due to unrelated cancer was considered as a competing event. Two most popular methods, cause-specific and subdistribution hazard regression model, were used to determine the effect of covariates on incidence and cause-specific hazard. Data analysis was performed using R3.6.2 software and cmprsk and survival packages.

RESULTS

The mean (SD) of patients' age was 55.84 ± 13.2 years and 53.9% of them were male. BMI, T and N stage had a significant effect on both incidence and cause specific hazard of cancer-related death.

CONCLUSION

The results of this study showed that cancer-related death is strongly correlated with under-weight (BMI < 18.5) and advanced clinical stage of the disease in patients with colorectal cancer. So, in the presence of competing events, both types of regression hazard models should be applied to permit a full understanding of the impact of covariates on the incidence and the rate of occurrence of each outcome.

Evaluation of the prognostic relevance of the recommended minimum number of lymph nodes in colorectal cancer-a propensity score analysis

PURPOSE

Nodal status in colorectal cancer (CRC) is an important prognostic factor, and adequate lymph node (LN) staging is crucial. Whether the number of resected and analysed LN has a direct impact on overall survival (OS), cancer-specific survival (CSS) and disease-free survival (DFS) is much discussed. Guidelines request a minimum number of 12 LN to be analysed. Whether that threshold marks a prognostic relevant cut-off remains unknown.

METHODS

Patients operated for stage I-III CRC were identified from a prospectively maintained database. The impact of the number of analysed LN on OS, CSS and DFS was assessed using Cox regression and propensity score analysis.

RESULTS

Of the 687 patients, 81.8% had ≥ 12 LN resected and analysed. Median LN yield was 17.0 (IQR 13.0-23.0). Resection and analysis of ≥ 12 LN was associated with improved OS (HR = 0.73, 95% CI: 0.56-0.95, p = 0.033), CSS (HR 0.52, 95% CI: 0.31-0.85, p = 0.030) and DFS (HR = 0.73, 95% CI: 0.57-0.95, p = 0.030) in multivariate Cox analysis. After adjusting for biasing factors with propensity score matching, resection of ≥ 12 LN was significantly associated with improved OS (HR = 0.59; 95% CI: 0.43-0.81; p = 0.002), CSS (HR = 0.34; 95% CI: 0.20-0.60; p < 0.001) and DFS (HR = 0.55; 95% CI: 0.41-0.74; p < 0.001) compared to patients with < 12 LN.

CONCLUSION

Eliminating biasing factors by a propensity score matching analysis underlines the prognostic importance of the number of analysed LN. The set threshold marks the minimum number of required LN but nevertheless represents a cut-off regarding outcome in stage I-III CRC. This analysis therefore highlights the significance and importance of adherence to surgical oncological standards.

Complete mesocolic excision for colon cancer: is it worth it?

Total mesorectal excision (TME) has been the miracle surgical technique which has since allowed the outcomes of rectal cancer to surpass that of colon cancer. Complete mesocolic excision (CME) attempts to adopt the same principles as that of TME and apply it to colon cancer surgery. Initial retrospective case series and comparative studies have shown promising oncological outcomes. CME entails the en bloc removal of a sufficient length of colonic specimen within an intact peritoneal envelop with extended lymphadenectomy through a high central ligation of vessels. This technique, standardizing the method for resection of right sided colon cancer, has witness promising perioperative and oncological data for both open and laparoscopic methods. However, most data available are mostly retrospective with a glaring lack of level 1 evidence. Despite the technique showing similar outcomes to that of conventional colectomy, parts of the procedure put the patient (and surgeon) at risk of potentially catastrophic complications. As promising as the initial results of CME has been, more well-designed randomized control trials are necessary to justify the increased risks taken and effort to mount the learning curve for CME.

Novel digital signatures of tissue phenotypes for predicting distant metastasis in colorectal cancer

Distant metastasis is the major cause of death in colorectal cancer (CRC). Patients at high risk of developing distant metastasis could benefit from appropriate adjuvant and follow-up treatments if stratified accurately at an early stage of the disease. Studies have increasingly recognized the role of diverse cellular components within the tumor microenvironment in the development and progression of CRC tumors. In this paper, we show that automated analysis of digitized images from locally advanced colorectal cancer tissue slides can provide estimate of risk of distant metastasis on the basis of novel tissue phenotypic signatures of the tumor microenvironment. Specifically, we determine what cell types are found in the vicinity of other cell types, and in what numbers, rather than concentrating exclusively on the cancerous cells. We then extract novel tissue phenotypic signatures using statistical measurements about tissue composition. Such signatures can underpin clinical decisions about the advisability of various types of adjuvant therapy.

Adjuvant chemotherapy for stage II colon cancer: who really needs it

Background

Although there is evidence that failure to reach the baseline of 12–13 lymph nodes in resected specimens is related to poor prognosis of patients with stage II colon cancer, and may be a marker of adjuvant therapy, the use of these markers remains controversial. The objective of this study was to determine the advantage of chemotherapy treatment in patients with stage II colon cancer on the basis of the number of lymph nodes examined in radical surgery.

Patients and methods

Using monitoring, epidemiology, and final outcome Medicare database, we authenticated 9,651 patients aged ≥66 years diagnosed with resected stage II colon cancer from 1999 to 2004. Medical insurance claims determined the adoption of chemotherapy within 3 months after radical operation. The relation between patient/tumor characteristics (including the number of lymph nodes examined) and the use of adjuvant chemotherapy was tested using chi-squared test and multiple logistic regression. Multivariate Cox model was used to compare survival rates between the treatment and untreated groups.

Results

Most patients (54.8%) had only 1–12 lymph nodes examined, while only 41.6% of the patients had >12 lymph nodes examined. Overall, 20.9% of patients received adjuvant chemotherapy; there was no relationship between chemotherapy and the number of lymph nodes examined (P=0.984). The presence of 12 or fewer lymph nodes in surgical specimens was related to poor overall survival (OS; adjusted hazard ratio [HR] 1.31, 95% CI 1.21–1.41). Although adjuvant chemotherapy was related to our cohort improvement, its beneficial effects on OS (HR: 0.73; 95% CI: 0.64–0.83) and disease-free survival (HR: 0.71; 95% CI: 0.60–0.85) only existed in patients with 0–12 lymph nodes examined.

Conclusion

The presence of 12 or fewer lymph nodes in surgical specimens is related to poor prognosis and survival benefit in adjuvant chemotherapy for stage II colon cancer patients. More attention should be paid to the implementation of recommendations for lymph node dissection to help identify patients who really benefit from adjuvant chemotherapy after colectomy.

Feasibility of Extended Dissection of Lateral Pelvic Lymph Nodes During Laparoscopic Total Mesorectal Excision in Patients with Locally Advanced Lower Rectal Cancer: A Single-Center Pilot Study After Neoadjuvant Chemotherapy

BACKGROUND The feasibility of additional dissection of the lateral pelvic lymph nodes (LPLNs) in patients undergoing total mesorectal excision (TME) combined with neoadjuvant chemotherapy (NAC) for locally advanced rectal cancer (LARC) is controversial. The use of laparoscopic surgery is also debated. In the present study, we evaluated the utility of laparoscopic dissection of LPLNs during TME for patients with LARC and metastatic LPLNs after NAC, based on our experience with 19 cases. MATERIAL AND METHODS Twenty-five patients with LARC with swollen LPLNs who underwent laparoscopic TME and LPLN dissection were enrolled in this pilot study. The patients were divided into 2 groups: those patients with NAC (n=19) and without NAC (n=6). Our NAC regimen involved 4 to 6 courses of FOLFOX plus panitumumab, cetuximab, or bevacizumab. RESULTS The operative duration was significantly longer in the NAC group than in the non-NAC group (648 vs. 558 minutes, respectively; P=0.022). The rate of major complications, defined as grade ≥3 according to the Clavien-Dindo classification, was similar between the 2 groups (15.8% vs. 33.3%, respectively; P=0.4016). No conversion to conventional laparotomy occurred in either group. In the NAC group, a histopathological complete response was obtained in 2 patients (10.5%), and a nearly complete response (Tis N0 M0) was observed in one patient (5.3%). Although the operation time was prolonged in the NAC group, the other perioperative factors showed no differences between the 2 groups. CONCLUSIONS Laparoscopic LPLN dissection is feasible in patients with LARC and clinically swollen LPLNs, even after NAC.

Rectal cancer and the pathologist

Examination of the rectum by pathologists is instrumental in the management of patients affected by rectal carcinoma. That role includes evaluation of multiple gross and microscopic features that convey prognostic implications. The analysis is based on the authors' experience handling rectal specimens along with review of the pertinent literature in these areas: margins of excision, quality of the mesorectum, diligence and techniques to sample lymph nodes, tumor budding, grading of residual amount of carcinoma after preoperative therapy, vascular/perineural invasion, and staging the tumor. Pathologists must communicate the findings in a clear manner. Evaluation of margins and completeness of mesorectum are markers of the quality of surgical excision. The number of lymph nodes obtained and examined is dependent in great part on the diligence of the pathologist finding them in the mesenteric adipose tissue. There are grades for budding and response to prior chemoradiation therapy. The location of vascular invasion (extramural vs. intramural) may predict aggressive behavior. Pathologists proactively are to choose sections of tumor for molecular testing. Meticulous macro- and microscopic evaluation of specimens for rectal carcinoma by pathologist is needed to determine an accurate assessment of staging and other prognostic factors. The modern pathologists play a pivotal part in the care and management of patients suffering from rectal adenocarcinoma. That role goes from the initial histological diagnosis to the gross and microscopic examination of the excised specimens. Based on that examination pathologists issue statements that not only evaluate the quality of the surgical procedure, but also through the application of molecular tests they give light on prognostic factors and information for therapeutic purposes.

Complete mesocolic excision in right hemicolectomy: comparison between hand-assisted laparoscopic and open approaches

Purpose

To demonstrate the feasibility, safety, and technical strategies of hand-assisted laparoscopic complete mesocolic excision (HAL-CME) and to compare oncological outcomes between HAL-CME and the open approach (O-CME) for right colon cancers.

Methods

Patients who were scheduled to undergo a right hemicolectomy were divided into HAL-CME and O-CME groups. Measured outcomes included demographic variables, perioperative parameters, and follow-up data. Demographic variables included age, sex distribution, body mass index (BMI), American Society of Anesthesiologists (ASA) physical status classification, previous abdominal surgery, tumor localization, and potential comorbidities. Perioperative parameters included incision length, operative time, blood loss, conversion rate, postoperative pain score, postoperative first passage of flatus, duration of hospital stay, total cost, number of lymph nodes retrieved, TNM classification, and postoperative complications. Follow-up data included follow-up time, use of chemotherapy, local recurrence rate, distant metastasis rate, and short-term survival rate.

Results

In total, 150 patients (HAL-CME, 78; O-CME, 72) were included. The groups were similar in age, sex distribution, BMI, ASA classification, history of previous abdominal surgeries, tumor localization, and potential comorbidities. Patients in the HAL-CME group had shorter incision lengths, longer operative times, less operative blood loss, lower pain scores, earlier first passage of flatus, shorter hospital stay, higher total costs, similar numbers of lymph nodes retrieved, similar TNM classifications, and a comparable incidence of postoperative complications. The 2 groups were also similar in local recurrence rate, distant metastasis rate, and short-term survival rate.

Conclusion

The results demonstrate that the HAL-CME procedure is a safe, valid, and feasible surgical method for right hemicolon cancers.

Lymph node retrieval in colorectal cancer: determining factors and prognostic significance

PURPOSE

The study aimed to analyze clinicopathological factors that determine the extent of lymph node retrieval and to evaluate its prognostic impact in patients with colorectal cancer (CRC).

METHODS

The number of retrieved lymph nodes was analyzed in 381 CRC specimens. Lymph node count was related to different clinicopathological variables by binary logistic regression. Progression-free survival (PFS) and cancer-specific survival (CSS) were determined using the Kaplan-Meier method and Cox regression models.

RESULTS

The median number of retrieved lymph nodes was 20 (mean 21 ± 10, range 1-65) in right-sided, 13 (16 ± 10, 1-66) in left-sided, and 15 (18 ± 11, 3-64) in rectal tumors. The number of retrieved lymph nodes was independently associated with T-classification (p < 0.001), N-classification (p = 0.014), and tumor size (p = 0.005) as well as right-sided tumor location (p = 0.012). There was no association with age, sex, tumor grade, mismatch-repair status, and lymph or blood vessel invasion. The longer the surgical specimen, the higher were the numbers of retrieved and positive lymph nodes (p < 0.001, respectively). In patients with locally advanced (T3/T4) tumors (n = 283), analysis of more than 12 lymph nodes was independently associated with PFS (HR = 0.63, p = 0.025) and CSS (HR = 0.54, p = 0.004). In the subset of T3/T4 N0 patients (n = 130), analysis of more than 12 lymph nodes similarly proved to be an independent predictor of outcome (PFS, HR = 0.48, p = 0.046; OS, HR = 0.41, p = 0.026).

CONCLUSION

The number of retrieved lymph nodes is associated with higher tumor stage, tumor size, and right-sided location. Low lymph node count indicates adverse outcome in patients with locally advanced (T3/T4) disease.

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.

Surgery along the embryological planes for colon cancer: a systematic review of complete mesocolic excision

BACKGROUND

Complete mesocolic excision (CME) for colonic cancer offers a surgical specimen of higher quality, with higher number of lymph nodes compared to conventional colectomy. However, evidence on oncological outcomes is limited. The aim of the present study is to review recent literature and provide more information regarding the effect of CME colectomy on short- and long-term outcomes.

METHOD

PubMed and MEDLINE databases were searched, and articles in English reporting data on CME were reviewed. Intraoperative events; postoperative morbidity and mortality; histopathological characteristics, including macroscopic assessment, number, and status of retrieved lymph nodes; and oncological outcomes were the end-points.

RESULTS

Thirty-two studies were analyzed. As regards the macroscopic assessment, a larger specimen (p = 0.02) that contains a higher number of lymph nodes (p < 0.00001) is acquired after CME. Two studies report a higher disease-free survival, in stage I and II and particularly in stage III disease after CME. CME by laparoscopy offers comparable outcomes, as regards intraoperative blood loss and immediate postoperative morbidity and mortality rates. Specimen quality is similar after either approach, for cancers located at the right and left colon, but not at the transverse colon.

CONCLUSION

There is strong evidence that CME offers a longer central pedicle that contains more lymph nodes than conventional surgery for colon cancer. CME represents the surgical background for the maximum lymph node harvest, an important quality marker for the surgical outcome. However, and according to present data, there is limited evidence that colectomy in terms of CME leads to improved long-term oncological outcomes.

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.

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 count and prognosis in colorectal cancer: the influence of examination quality

Colorectal cancer guidelines recommend adjuvant chemotherapy in stage II disease when less than 12 lymph nodes are assessed. The recommendation bases on previous studies showing an association of a low lymph node count and adverse outcome. Compared to current standards, however, the quality of lymph node examination in the studies was low. We, therefore, investigated the prognostic role of <12 lymph nodes in cancers diagnosed adherent to current quality measures. Stage I-IV colorectal cancers from 1,899 patients enrolled into a population-based cohort study were investigated for the prognostic impact of a lymph node count <12. The stage specific share of patients diagnosed with ≥12 nodes (stage I-IV: 62, 85, 85, 78%, respectively) was used to compare lymph node examination quality to other studies. We found no impact of a lymph node count <12 on overall, cancer-specific or recurrence-free survival for any tumour stage. Compared to studies reporting an adverse prognostic impact of a low lymph node count in stages II and III the stage-specific shares of patients with ≥12 nodes were markedly higher in this study (85% vs. 24-58% in previous analyses) and this correlated with increased rates of stage III compared to stage II cancers. In conclusion our data indicate, that the previously reported effect of a low lymph node count on the patients' outcomes is eliminated by improved lymph node examination quality and thus question the general applicability of a 12 lymph node cut off for adjuvant chemotherapy decision making in stage II disease.

Controversies in the pathological assessment of colorectal cancer

Pathologic assessment of colorectal cancer specimens plays an essential role in patient management, informing prognosis and contributing to therapeutic decision making. The tumor-node-metastasis (TNM) staging system is a key component of the colorectal cancer pathology report and provides important prognostic information. However there is significant variation in outcome of patients within the same tumor stage. Many other histological features such as tumor budding, vascular invasion, perineural invasion, tumor grade and rectal tumor regression grade that may be of prognostic value are not part of TNM staging. Assessment of extramural tumor deposits and peritoneal involvement contributes to TNM staging but there are some difficulties with the definition of both of these features. Controversies in colorectal cancer pathology reporting include the subjective nature of some of the elements assessed, poor reporting rates and reproducibility and the need for standardized examination protocols and reporting. Molecular pathology is becoming increasingly important in prognostication and prediction of response to targeted therapies but accurate morphology still has a key role to play in colorectal cancer pathology reporting.

Colorectal cancer and lymph nodes: The obsession with the number 12

Lymphadenectomy of colorectal cancer is a decisive factor for the prognostic and therapeutic staging of the patient. For over 15 years, we have asked ourselves if the minimum number of 12 examined lymph nodes (LNs) was sufficient for the prevention of understaging. The debate is certainly still open if we consider that a limit of 12 LNs is still not the gold standard mainly because the research methodology of the first studies has been criticized. Moreover many authors report that to date both in the United States and Europe the number “12” target is uncommon, not adequate, or accessible only in highly specialised centres. It should however be noted that both the pressing nature of the debate and the dissemination of guidelines have been responsible for a trend that has allowed for a general increase in the number of LNs examined. There are different variables that can affect the retrieval of LNs. Some, like the surgeon, the surgery, and the pathology exam, are without question modifiable; however, other both patient and disease-related variables are non-modifiable and pose the question of whether the minimum number of examined LNs must be individually assigned. The lymph nodal ratio, the sentinel LNs and the study of the biological aspects of the tumor could find valid application in this field in the near future.

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.

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.

Does senescence affect lymph node number and morphology? A systematic review

BACKGROUND

Immunosenescence may contribute to an observed increase in infections and specific cancers in the elderly. Lymph nodes play a key role in the body's immune system. A systematic review was undertaken to investigate the effects of senescence on lymph node number and morphology.

METHODS

Electronic databases Ovid MEDLINE, Embase and Google Scholar were searched for relevant articles examining normal lymph node number and morphology with senescence. Data on lymph node number, gross anatomy and histo-architecture were collated and analysed.

RESULTS

A total of 20 articles (15 human and 5 animal studies) were eligible for inclusion; many were limited by poorly standardized methods and relatively small sample sizes. However, there is evidence to suggest both a decrease in lymph node number and histological lymph node degeneration with senescence, at least in some lymph node basins. Degenerative changes include loss of lymphoid tissue from both the cortex and the medulla of lymph nodes, a reduction in the number and size of germinal centres, and changes such as hyalinization, fibrosis, fat deposition, a decrease in high endothelial venules and 'transparency'.

CONCLUSION

In this first systematic review to examine changes in lymph nodes with senescence, evidence was accrued to suggest a decline in lymph node number and morphological degeneration in older age groups. These changes might adversely affect immune function and the prognosis of infections and selected cancers in the elderly. Further research is required to confirm these morphological changes and to explore their potential immunological and functional effects.

Effect of metabolic syndrome and its components on recurrence and survival in colon cancer patients

BACKGROUND

Although epidemiologic studies suggest that metabolic syndrome (MetS) increases the risk of colorectal cancer, its effect on cancer mortality remains controversial.

METHODS

The authors used the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database (1998-2006) to conduct a retrospective cohort study of 36,079 patients with colon cancer to determine the independent effect of MetS and its components on overall survival (OS) and recurrence-free rates (RFRs). Data on MetS and its components were ascertained from Medicare claims. OS and RFRs in patients with and without MetS and its components were compared using multivariate Cox models.

RESULTS

MetS had no apparent effect on OS or RFR. Both elevated glucose/diabetes mellitus (DM) and elevated hypertension were associated with worse OS (adjusted hazard ratio [aHR], 1.17 [95% confidence interval, 1.13-1.21] and 1.08 [95% confidence interval, 1.03-1.12], respectively) and worse RFRs (aHR, 1.25 [95% confidence interval, 1.16-1.34] and 1.22 [95% confidence interval, 1.12-1.33], respectively). In contrast, dyslipidemia was associated with improved survival (aHR, 0.77; 95% confidence interval, 0.75-0.80) and reduced recurrence (aHR, 0.71; 95% confidence interval, 0.66-0.75). These effects were consistent for both men and women and were more pronounced in patients with early stage disease.

CONCLUSIONS

MetS had no apparent effect on colon cancer outcomes, probably because of the combined adverse effects of elevated glucose/DM and hypertension and the protective effect of dyslipidemia in patients with nonmetastatic disease. The authors concluded that patients who have early stage colon cancer with elevated glucose/DM and/or hypertension may benefit from more intensive surveillance and/or broader use of adjuvant therapy and that trials to define the benefits of low-fat diets, insulin-lowering agents, and statins on recurrence/survival in patients with nonmetastatic colon cancer are warranted.

Complete mesocolic excision in colon cancer surgery: a comparison between open and laparoscopic approach

BACKGROUND

Complete mesocolic excision (CME) with central vessel ligation (CVL) as performed in Erlangen offers the best long-term outcome for colon cancer. The aim of this study was to assess specimens after laparoscopic vs open CME-CVL macroscopically and morphometrically in patients with left and right colon cancers.

METHOD

All specimens were freshly photographed. Precise tumour morphometry and grading of the surgical plane were performed as described by pathologists in Leeds, UK.

RESULTS

Thirty-four specimens from right-sided cancers were divided into 18 transverse colon cancers (nine laparoscopic vs nine open) and 16 caecum-ascending colon cancers (seven laparoscopic vs nine open) and 56 specimens from left-sided cancers (33 laparoscopic vs 23 open). There was no difference between laparoscopically and open acquired left- and right-sided specimens. Specimens of transverse colon displayed differences in length of central ligation to tumour (open 11.67 cm vs laparoscopic 8.72 cm, P = 0.049), length of central ligation to bowel wall (open 9.11 cm vs laparoscopic 6.5 cm, P = 0.015) and lymph node clearance (open 46.33 vs laparoscopic 39.33, P = 0.033).

CONCLUSION

Laparoscopy seems to offer specimens of similar quality after CME-CVL surgery for colon cancer to the open approach. Issues of completeness of excision from laparoscopy are raised for tumours located in the transverse colon.

Should quality measures for lymph node dissection in colon cancer be extrapolated to rectal cancer?

BACKGROUND

A minimum of 12 lymph nodes has been endorsed as a quality measure to confirm node-negative colon cancer, but its relevance to early-stage rectal cancer is unclear.

METHODS

Patients with stage I or II rectal cancer from the Surveillance, Epidemiology and End Results tumor registries from 1998 to 2002 were identified. Patients were grouped by the number of lymph nodes sampled. Groups were compared for patient demographics, tumor characteristics, and 5-year overall survival.

RESULTS

Of the 6,214 patients (57% men) identified, only 33% had ≥12 lymph nodes examined in the surgical specimen. Multivariate analysis identified sex, race, age, T stage, and number of lymph nodes examined as independent predictors of 5-year overall survival.

CONCLUSIONS

Five-year overall survival improved as the number of sampled nodes increased. A thorough lymphadenectomy should routinely be performed to optimize staging and to improve survival of patients with early-stage rectal cancer.

High lymph node yield is related to microsatellite instability in colon cancer

BACKGROUND

Lymph node (LN) yield in colon cancer resection specimens is an important indicator of treatment quality and has especially in early-stage patients therapeutic implications. However, underlying disease mechanisms, such as microsatellite instability (MSI), may also influence LN yield, as MSI tumors are known to exhibit more prominent lymphocytic antitumor reactions. The aim of the present study was to investigate the association of LN yield, MSI status, and recurrence rate in colon cancer.

METHODS

Clinicopathological data and tumor samples were collected from 332 stage II and III colon cancer patients. DNA was isolated and PCR-based MSI analysis performed. LN yield was defined as "high" when 10 or more LNs were retrieved and "low" in case of fewer than 10 LNs.

RESULTS

Tumors with high LN yield were significantly associated with the MSI phenotype (high LN yield: 26.3% MSI tumors vs low LN yield: 15.1% MSI tumors; P=.01), mainly in stage III disease. Stage II patients with high LN yield had a lower recurrence rate compared with those with low LN yield. Patients with MSI tumors tended to develop fewer recurrences compared with those with MSS tumors, mainly in stage II disease.

CONCLUSIONS

In the present study, high LN yield was associated with MSI tumors, mainly in stage III patients. Besides adequate surgery and pathology, high LN yield is possibly a feature caused by biologic behavior of MSI tumors.

Can the quality of colonic surgery be improved by standardization of surgical technique with complete mesocolic excision?

AIM

we analysed the influence of standardization of colon cancer surgery with complete mesocolic excision (CME) on the quality of surgery measured by the pathological end-points of number of harvested lymph nodes, high tie of supplying vessels, plane of mesocolic resection and rate of R0 resection.

METHOD

One hundred and ninety-eight patients with colonic carcinoma who underwent radical surgery between September 2007 and February 2009 were divided into two groups, including those undergoing surgery before (93) or after (105) 1 June 2008, when complete mesocolic excision (CME) was introduced as standard in our hospital.

RESULTS

The overall mean high tie increased from 7.1 (CI, 6.5-7.6) to 9.6 (8.9-10.3) cm (P<0.0001) and the mean number of harvested lymph nodes from 24.5 (22.8-26.2) to 26.7 (24.6-28.8) (P=0.0095). There were no significant increases in these end-points in open right hemicolectomy, and in laparoscopic sigmoid resection the number of lymph nodes did not increase significantly. The plane of mesocolic resection, the rate of R0 resection and the risk of complications did not change significantly. The median (range) length of hospital stay increased from 4 (2-62) to 5 (2-71) days (P=0.04).

CONCLUSION

Standardization of colonic cancer surgery with CME seems to improve the quality of surgery without increasing the risk of complications.

The impact of surgical guidelines and periodic quality assessment on the staging of endometrial cancer

OBJECTIVE

To determine the impact of surgical guidelines and transparent periodic assessment of surgical quality on endometrial cancer (EC) staging by gynecologic oncologists in a single institution and to identify process-of-care, patient-specific, and disease-specific risk factors that influence surgical quality.

METHODS

In January 2004, a prospective treatment algorithm was implemented for EC at our institution. The number of nodes harvested was a surrogate, and staging quality from 2004 to 2008 (quality assessment [QA] interval) was compared with the previous 5 years (pre-QA interval). Since 2004, low-risk cases based on frozen section examination had not undergone lymphadenectomy and were excluded. Independent patient-specific, disease-specific, and surgery-related risk factors influencing lymphadenectomy quality during both intervals were identified with multivariable logistic regression analysis.

RESULTS

Pelvic and para-aortic lymph node dissection (LND) in surgical EC management before QA (n=420) were 77.9% and 48.8% vs 89.3% and 83.4% during the QA (n=561) (P<.001). The median number of pelvic and para-aortic nodes harvested in LND was 29 and 10 before QA vs 34 and 16 during the QA interval (P<.001). With acceptance of stringent criteria for defining systematic LND (mean node count-1 SD) during the QA, systematic pelvic (≥22 nodes) and para-aortic (≥10 nodes) LNDs occurred in 57.4% and 25.7% of cases before QA vs 77.9% and 70.7% during the QA interval (P<.001). In patients with LND, rates of systematic pelvic and para-aortic LND were 73.7% and 53.0% before vs 87.2% and 84.8% after QA (P<.001). Multivariable logistic regression analysis showed independent factors influencing systematic pelvic and para-aortic LND (P<.01): surgeon and stage during the pre-QA interval vs surgical approach; intraoperative ascites; body mass index; surgeon; patient age; and myometrial invasion after QA implementation.

CONCLUSION

Inclusion of detailed surgical guidelines and transparent periodic assessment of surgical quality translated to dramatic improvement in quality of surgical EC staging. This implementation was associated with a transition to more patient-specific risk factors influencing systematic LND. Although surgical quality metrics were markedly enhanced during QA, persistent variability observed among surgeons and the change in surgical approach render continuous QA and improvement obligatory.

The impact of age on quality measure adherence in colon cancer

BACKGROUND

Recently lymph node yield (LNY) has been endorsed as a quality measure of colon cancer resection adequacy. It is unclear whether this measure is relevant to all ages. We hypothesized that total lymph node yield (LNY) is negatively correlated with increasing age and overall survival (OS).

STUDY DESIGN

The Surveillance, Epidemiology and End Results (SEER) database was queried for all nonmetastatic colon cancer patients diagnosed from 1992 to 2004 (n = 101,767), grouped by age (<40, 41 to 45, 46 to 50, and in 5-year increments until 86+ years). Proportions of patients meeting the 12 LNY minimum criterion were determined in each age group and analyzed with multivariate linear regression adjusting for demographics and American Joint Committee on Cancer (AJCC) 6(th) Edition stage. OS comparisons in each age category were based on the guideline of 12 LNY.

RESULTS

Mean LNY decreased with increasing age (18.7 vs 11.4 nodes/patient, youngest vs oldest group, p < 0.001). The proportion of patients meeting the 12 LNY criterion also declined with each incremental age group (61.9% vs 35.2% compliance, youngest vs oldest, p < 0.001). Multivariate regression demonstrated a negative effect of each additional year in age and log (LNY) with coefficient of -0.003 (95% CI -0.003 to -0.002). When stratified by age and nodal yield using the 12 LNY criterion, OS was lower for all age groups in stage II colon cancer with less than 12 LNY, and each age group over 60 years with less than 12 LNY for stage III colon cancer (p < 0.05).

CONCLUSIONS

Every attempt to adhere to proper oncologic principles should be made at the time of colon cancer resection regardless of age. The prognostic significance of the 12 LN minimum criterion should be applied even to elderly colon cancer patients.

Clinicopathological staging of colorectal cancer: Evolution and consensus-an Australian perspective

In 1991 this journal published the report of an international working party to the World Congress of Gastroenterology regarding the clinicopathological staging of colorectal cancer. Since that time staging has continued to evolve as further prognostic factors in colorectal cancer have been elucidated in studies of increasingly large databases in several countries. This review summarizes several of the key issues that have arisen during this evolutionary process and raises matters which still remain controversial in staging at the present time.