Lymph node harvest in colon cancer specimens depends on tumour factors, patients and doctors, but foremost on specimen handling

How Many Lymph Nodes are Enough in Paratesticular Rhabdomyosarcoma?

BACKGROUND

Treatment strategies for paratesticular rhabdomyosarcoma (PT RMS) are based on stage, which requires accurate lymph node (LN) evaluation. Previous methodology for determining quantity of LN for negative nodal status is based on LN positivity rates, without accounting for the relationship between LNs or amongst patients. This study aims to quantify the chance of missing involved LNs based on LN yield (LNY) using a previously established methodology in comparison to current recommendations.

METHODS

Using the National Cancer Database, patients with a diagnosis of PT RMS were queried from 2004 to 2018. Patients >10 years and those ≤10 years with cN1 disease were included, based on COG guidelines for who should undergo retroperitoneal LN sampling (RPLNS). The beta-binomial model was used to calculate the rate of false negative RPLNS and identified the LNY threshold to reduce the risk of a missing an involved LN node to <10 %.

RESULTS

Sixty-two patients were included for analysis over the study period. Median LNY was 17 (IQR 9-28.75), and the median number of involved LNs was 2.5 (IQR 2-5). The median LN density was 0.27 (IQR 0.10-0.34). Application of the beta-binomial model identified that a LNY of 26 LNs corresponds to a <10 % chance of missing occult disease (Fig. 3).

CONCLUSION

Previous models estimate that sampling of 7-12 LN is adequate for accurate staging. However, the beta binomial model quantifies sampling at least 26 LNs to reduce the chance of missing occult metastatic disease to <10 % in the majority of patients. Surgeons should consider this false negative rate during RPLNS for patients with PT RMS.

LEVEL OF EVIDENCE

III.

Quality of Life of Young Gastric Cancer Survivors: An Interpretation in the Context of Our Society

Background and Objectives: This retrospective case-control study aimed to investigate the quality of life (QoL) of young gastric cancer survivors and determine what should be pursued to obtain the best QoL for them after surgery. Materials and Methods: Patients with stage I gastric cancer who underwent distal subtotal gastrectomy were included. The European Organization for Research and Treatment of Cancer Quality of Life questionnaires were used to assess QoL. The QoL outcomes of younger (age 30-49 years, n = 76) and older (age 50-69 years, n = 232) groups were compared preoperatively, 3 months, and 1 year postoperatively. Results: There was no statistically significant difference in the preoperative QoL except for the physical functioning scale, which favored the younger group (p = 0.020). This difference remained significant throughout the postoperative periods (3 months, p = 0.002; 1 year, p = 0.004). Better QoL was found for the younger group according to the body image scale (p = 0.031). However, it was limited to the 3-month postoperative assessment. Persistent QoL disadvantages for the younger group were revealed by the diarrhea scale at the 3-month (p = 0.007) and 1-year (p = 0.005) postoperative assessments. Conclusions: While young gastric cancer survivors enjoyed better QoL in physical functioning and body image, worse QoL was related to diarrhea after surgery. Despite ever-rising concerns about QoL deterioration in elderly patients in our aged society, young gastric cancer survivors also need QoL support.

How many lymph nodes are enough? Assessing the adequacy of lymph node yield for staging in favorable histology wilms tumor

PURPOSE

Current investigational priorities in the treatment of favorable histology Wilms tumor (FHWT) center on accurate staging and risk-stratification. The extent of lymph node (LN) sampling has not been clearly defined; its importance cannot be overstated as it guides adjuvant therapy. The identification of a minimum LN yield to minimize the risk of harboring occult metastatic disease could help development of surgical guidelines. This study focuses on using the beta-binomial distribution to estimate the risk of occult metastatic disease in patients with FHWT.

MATERIALS & METHODS

The National Cancer Database was queried for patients with unilateral FHWT from 2004 to 2013. Data were used to characterize nodal positivity for patients who underwent surgery and had ≥1 positive LN and ≥2 LNs examined. The probability of missing a positive LN (i.e., false negative) for a given LN yield was calculated using an empirical estimation and the beta-binomial model. Patients were then stratified by tumor size.

RESULTS

422 patients met study criteria. To limit the chance of missing a positive LN to ≤10%, the empirical estimation and beta-binomial model estimated that 6 and 10 LNs needed to be sampled, respectively. Tumor size did not influence the result. Internal validation showed little variation to maintain a false negative rate ≤ 10%.

CONCLUSIONS

Using mathematical modeling, it appears that the desired LN yield in FHWT to reduce the risk of false-negative LN sampling to ≤10% is between 6 and 10. The current analysis represents an objective attempt to determine the desired surgical approach to LN sampling to accurately stage patients with FHWT.

LEVEL OF EVIDENCE

II.

Patterns of lymph node sampling and the impact of lymph node density in favorable histology Wilms tumor: An analysis of the national cancer database

INTRODUCTION

There is controversy about the role of lymph node (LN) sampling or dissection in the management of favorable histology (FH) Wilms tumor (WT), specifically how it performed and how it may impact survival.

OBJECTIVE

The objective of this study was to analyze factors affecting LN sampling patterns and the impact of LN yield and density (number of positive LNs/LNs examined) on overall survival (OS) in patients with advanced-stage favorable histology Wilms tumor (FHWT).

METHODS

The National Cancer Database (NCDB) was queried for patients with FHWT during 2004-2013. Demographic, clinical and OS data were abstracted for those who underwent surgical resection. Poisson regression was performed to analyze how factors influenced LN yield. Patients with positive LNs had LN density calculated and were further analyzed.

RESULTS

A total of 2340 patients met criteria, with a median age at diagnosis of 3 years (range 0-78 years). The median number of LNs examined was three (range 0-87). Lymph node yield was affected by age, race, insurance, tumor size, laterality, advanced stage, LN positivity, and institutional volume. A total of 390 (16.6%) patients had LN-positive disease. Median LN density for these LN-positive patients was 0.38 (range 0.02-1) (Summary Figure). Estimated 5-year OS was significantly improved for those with LN density ≤0.38 vs. >0.38 (94% vs. 84.6%, P = 0.012). In this population, on multivariate analysis, age and LN density were significant predictors of OS.

DISCUSSION

It is difficult to compile large numbers of cases in rare diseases like WT, and fortunately a large administrative database such as the NCDB can serve as a great resource. However, administrative data come with inherent limitations such as missing data and inability to account for a variety of factors that may influence LN yield and/or OS (specimen designation, pathologist experience, surgeon experience/volume, institutional Children's Oncology Group (COG) association, etc.). In this specific disease, the American Joint Committee on Cancer staging (captured by the NCDB) is different than the COG WT staging system that is used clinically, and the NCDB does not capture oncologic outcomes beyond OS.

CONCLUSIONS

In a review of the NCDB, various factors associated with LN yield and observed LN density were identified to be significantly associated with OS in patients with LN-positive FHWT. This reinforces the need for adequate LN sampling at the time of WT surgery, to maximize surgical disease control. It was proposed that LN density as a metric may allow for improved risk-stratification, and possibly allow for therapeutic reduction in a sub-set of patients with low LN density.

Procedural difficulty differences according to tumor location do not compromise the clinical outcome of laparoscopic complete mesocolic excision for colon cancer: a retrospective analysis

Laparoscopic colectomy procedures and their corresponding difficulty levels may vary depending on the tumor location within the colon, and a laparoscopic complete mesocolic excision (CME) with central vascular ligation (CVL) would require more proficiency than a conventional laparoscopic colectomy. We aimed to report our laparoscopic CME with CVL data and to investigate the clinical outcome differences of laparoscopic CME with CVL by various tumor sub-site locations. Prospectively collected clinical data of consecutive patients who received laparoscopic colectomy for primary colon cancer between April 1995 and December 2010 from single surgeon were retrospectively reviewed. All of the included surgery was performed on the basis of CME with CVL principle with no-touch isolation technique. Data were analyzed and compared among three groups; patients who received right or extended right hemicolectomy (group A, n = 142), transverse colectomy or left or extended left hemicolectomy (group B, n = 59), and sigmoidectomy or anterior resection (group C, n = 210). Female patients were more common in group A (53.5% vs. 37.3% vs. 39.5%, p = 0.020). Other baseline characteristics were comparable. Operative time was shorter in group C than the other groups (309.0 ± 74.7 vs. 324.3 ± 89.1 vs. 280.1 ± 93.1 min, p = 0.000). There was no significant difference among groups in perioperative complication and patient recovery. Five-year overall survival, disease-free survival and local recurrence rate showed no difference for a median follow up period of 73 (1–120) months. In conclusion, laparoscopic tumor-specific CME and CVL for colon cancer can be performed with comparable short- and long-term outcomes regardless of tumor sub-site location except for the operative time.

Laparoscopic Surgery for Transverse Colon Cancer: Short- and Long-Term Outcomes in Comparison with Conventional Open Surgery

BACKGROUND

Published studies on laparoscopic surgery for transverse colon cancer are scarce. More studies are necessary to evaluate the feasibility, safety, and long-term oncologic outcomes of laparoscopic surgery for transverse colon cancer.

SUBJECTS AND METHODS

From April 1996 to December 2010, 102 consecutive patients with stage II or III disease who had undergone curative resection for transverse colon cancer were enrolled. Seventy-nine patients underwent laparoscopy-assisted colectomy (LAC), whereas 23 patients underwent conventional open colectomy (OC). Short- and long-term outcomes of the two groups were compared.

RESULTS

The OC group had a larger tumor size (7.6 ± 3.4 cm versus 5.2 ± 2.3 cm, P = .004) and more retrieved lymph nodes (26.4 ± 11.6 versus 17.5 ± 9.4, P = .002), without differences in resection margins. In the LAC group, return to diet was faster (4.5 ± 1.2 days versus 5.4 ± 1.8 days, P = .013), and postoperative hospital stay was shorter (12.1 ± 4.2 days versus 15.9 ± 4.8 days, P = .000). There were no differences in occurrence of intra- or postoperative complications. There were no statistically significant differences in overall survival rate (OS) or disease-free survival rate (DFS) between the two groups (5-year OS, 90.4% versus 90.5%, P = .670; 5-year DFS, 84.2% versus 90.7%, P = .463).

CONCLUSIONS

Laparoscopic surgery for transverse colon cancer has better short-term outcomes compared with open surgery, with acceptable long-term outcomes. As in colorectal cancer of other sites, laparoscopic surgery can be a feasible alternative to conventional surgery for transverse colon cancer.

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.

Increased lymph node yield in colorectal cancer is not necessarily associated with a greater number of lymph node positive cancers

The presence of lymph node metastasis is a key prognostic factor in colorectal cancer and lymph node yield is an important parameter in assessing the quality of histopathology reporting of colorectal cancer excision specimens. This study assesses the trend in lymph node evaluation over time in a single institution and the relationship with the identification of lymph node positive tumours. It compares the lymph node yield of a contemporary dataset compiled from the histopathology reports of 2178 patients who underwent surgery for primary colorectal cancer between 2005 and 2012 with that of a historic dataset compiled from the histopathology reports of 1038 patients who underwent surgery for colorectal cancer at 5 yearly intervals from 1975 to 2000. The mean lymph node yield was 14.91 in 2005 rising to 21.38 in 2012. In 2012 92.9% of all cases had at least 12 lymph nodes examined. Comparison of the mean lymph node yield and proportion of Dukes C cases shows a significant increase (Pearson correlation = 0.927, p = 0.001) in lymph node yield while there is no corresponding significant trend in the proportion of Dukes C cases (Pearson correlation =  -0.138, p = 0.745). This study shows that there is increasing yield of lymph nodes from colorectal cancer excision specimens. However, this is not necessarily associated with an increase number of lymph node positive cancers. Further risk stratifying of colorectal cancer requires consideration of other pathological parameters especially the presence of extramural venous invasion and relevant biomarkers.

The rationale behind complete mesocolic excision (CME) and a central vascular ligation for colon cancer in open and laparoscopic surgery : proceedings of a consensus conference

BACKGROUND

It has been evident for a while that the result after resection for colon cancer may not have been optimal. Several years ago, this was showed by some leading surgeons in the USA but a concept of improving results was not consistently pursued. Later, surgeons in Europe and Japan have increasingly adopted the more radical principle of complete mesocolic excision (CME) as the optimal approach for colon cancer. The concept of CME is a similar philosophy to that of total mesorectal excision for rectal cancer and precise terminology and optimal surgery are key factors.

METHOD

There are three essential components to CME. The main component involves a dissection between the mesenteric plane and the parietal fascia and removal of the mesentery within a complete envelope of mesenteric fascia and visceral peritoneum that contains all lymph nodes draining the tumour area (Hohenberger et al., Colorectal Disease 11:354-365, 2009; West et al., J Clin Oncol 28:272-278, 2009). The second component is a central vascular tie to completely remove all lymph nodes in the central (vertical) direction. The third component is resection of an adequate length of bowel to remove involved pericolic lymph nodes in the longitudinal direction.

RESULT

The oncological rationale for CME and various technical aspects of the surgical management will be explored.

CONCLUSION

The consensus conference agreed that there are sound oncological hypotheses for a more radical approach than has been common up to now. However, this may not necessarily apply in early stages of the tumour stage. Laparoscopic resection appears to be equally well suited for resection as open surgery.

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.

A survey of reporting of colorectal cancer in Scotland: compliance with guidelines and effect of proforma reporting

AIMS

The main purpose of the study was to present a baseline audit of reporting of colorectal cancers resection specimens in Scotland, audited against the Royal College of Pathologists (RCPath) standards (2007) and NHS Quality Improvement Scotland (NHS QIS) standards.

METHODS

50 consecutive rectal and 50 consecutive colonic cancer cases from 2011 were audited from 10 Scottish health boards involved in colorectal cancer reporting (n=953). The rates of reporting of serosal involvement, extramural venous invasion (EMVI) and the mean numbers of lymph nodes found were audited against RCPath standards and compared between units that routinely used a reporting proforma versus those that did not.

RESULTS

The performance in reporting of rectal cancer was generally worse than for colonic cancer, with only three units meeting the RCPath standards for reporting of rectal cancer. There were significant differences between units that routinely used a proforma, with the non-proforma group failing to meet the minimum standards for both serosal involvement (6%) and EMVI (24%). In the non-proforma group, 56% of rectal cases had a mean lymph node count of 12 or more compared with 81% in the proforma group.

CONCLUSIONS

Significant differences exist in the frequencies with which important adverse prognostic features are reported by pathologists across 10 Scottish health boards. This has potential implications for patient care. Health boards that make routine use of reporting proformas are more likely to meet RCPath guidelines for reporting of these important pathological parameters.

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.

Small bowel carcinoid: Location isn’t everything!

AIM: To investigate the prognostic significance of the primary site of disease for small bowel carcinoid (SBC) using a population-based analysis.

METHODS: The Surveillance, Epidemiology and End Results (SEER) database was queried for histologically confirmed SBC between the years 1988 and 2009. Overall survival (OS) and disease-specific survival (DSS) were analyzed using the Kaplan-Meier method and compared using Log rank testing. Log rank and multivariate Cox regression analyses were used to identify predictors of survival using age, year of diagnosis, race, gender, tumor histology/size/location, tumor-node-metastasis stage, number of lymph nodes (LNs) examined and percent of LNs with metastases.

RESULTS: Of the 3763 patients, 51.2% were male with a mean age of 62.13 years. Median follow-up was 50 mo. The 10-year OS and DSS for duodenal primaries were significantly better when compared to jejunal and ileal primaries (P = 0.02 and < 0.0001, respectively). On multivariate Cox regression analysis, after adjusting for multiple factors, primary site location was not a significant predictor of survival (P = 0.752 for OS and P = 0.966 DSS) while age, number of primaries, number of LNs examined, T-stage and M-stage were independent predictors of survival.

CONCLUSION: This 21-year, population-based study of SBC challenges the concept that location of the primary lesion alone is a significant predictor of survival.

Clinical and pathologic factors affecting lymph node yields in colorectal cancer

OBJECTIVE

Lymph node yield is recommended as a benchmark of quality care in colorectal cancer. The objective of this study was to evaluate the impact of various factors upon lymph node yield and to identify independent factors associated with lymph node harvest.

MATERIALS AND METHODS

The records of 162 patients with Stage I to Stage III colorectal cancers seen in one institution were reviewed. These patients underwent radical surgery as definitive therapy; high-risk patients then received adjuvant treatment. Pathologic and demographic data were recorded and analyzed. The subgroup analysis of lymph node yields was determined using a t-test and analysis of variants. Linear regression model and multivariable analysis were used to perform potential confounding and predicting variables.

RESULTS

Five variables had significant association with lymph node yield after adjustment for other factors in a multiple linear regression model. These variables were: tumor size, surgical method, specimen length, and individual surgeon and pathologist. The model with these five significant variables interpreted 44.4% of the variation.

CONCLUSIONS

Patients, tumor characteristics and surgical variables all influence the number of lymph nodes retrieved. Physicians are the main gatekeepers. Adequate training and optimized guidelines could greatly improve the quality of lymph node yields.

Adequate lymph node recovery improves survival in colorectal cancer patients

INTRODUCTION

Current recommendations suggest recovery of 12 lymph nodes during surgical resection for colorectal cancer (CRC) for proper staging and prognostication. Adequate lymph node recovery has been associated with improved patient survival, with results inconsistent.

METHODS

We examined factors for association with adequate lymph node recovery and used findings to adjust survival analyses to clarify whether adequate lymph node examination is associated with CRC survival or associated with a subset of characteristics that biases lymph node recovery.

RESULTS

In 74% of subjects (1,036/1,397) an adequate number of lymph nodes was examined. A stepwise multivariate regression analysis showed procedure year, cancer stage, tumor size, and age at diagnosis were significantly associated with lymph node recovery. These and other factors associated with survival status were adjusted for in further analyses, revealing no difference in unadjusted overall survival by adequacy of lymph node recovery (HR = 0.90, 95% CI: 0.75-1.08, P = 0.239). However, in adjusted Cox proportional hazards analysis, adequate lymph node recovery was associated with reduced risk for death (HR = 0.71, 95% CI: 0.57-0.89, P = 0.002).

CONCLUSION

The current recommendation for retrieval and examination of at least 12 lymph nodes is appropriate for proper treatment and prognostication in patients undergoing surgical resection for CRC.

Predictors of lymph node count in colorectal cancer resections: data from US nationwide prospective cohort studies

OBJECTIVE

To identify factors that influence the total and negative lymph node counts in colorectal cancer resection specimens independent of pathologists and surgeons.

DESIGN

We used multivariate negative binomial regression. Covariates included age, sex, body mass index, family history of colorectal carcinoma, year of diagnosis, hospital setting, tumor location, resected colorectal length (specimen length), tumor size, circumferential growth, TNM stage, lymphocytic reactions and other pathological features, and tumor molecular features (microsatellite instability, CpG island methylator phenotype, long interspersed nucleotide element 1 [LINE-1] methylation, and BRAF, KRAS, and PIK3CA mutations).

SETTING

Two US nationwide prospective cohort studies.

PATIENTS

Patients with rectal and colon cancer (N=918).

MAIN OUTCOME MEASURES

The negative and total node counts (continuous).

RESULTS

Specimen length, tumor size, ascending colon location, T3N0M0 stage, and year of diagnosis were positively associated with the negative node count (all P.002). Mutation of KRAS might also be positively associated with the negative node count (P=.03; borderline significance considering multiple hypothesis testing). Among node-negative (stages I and II) cases, specimen length, tumor size, and ascending colon location remained significantly associated with the node count (all P.002), and PIK3CA and KRAS mutations might also be positively associated (P=.03 and P=.049, respectively, with borderline significance).

CONCLUSIONS

This molecular pathological epidemiology study shows that specimen length, tumor size, tumor location, TNM stage, and year of diagnosis are operator-independent predictors of the lymph node count. These crucial variables should be examined in any future evaluation of the adequacy of lymph node harvest and nodal staging when devising individualized treatment plans for patients with colorectal cancer.

Reliability and Effectiveness of GEWF Solution in the Identification of Lymph Nodes in Specimens of Colorectal Carcinoma

Lymph node status is pivotal in the staging process of cancer. With regards to colorectal cancer, lymph node retrieval is always laborious. Sometimes, it is also a challenge to recover a minimum of 12 lymph nodes from the pericolorectal tissue. Among many proposed adjunctive solutions, GEWF solution (glacial acetic acid, ethanol, distilled water, and formaldehyde) has been introduced recently and suggested to be superior. To further evaluate its efficiency, the pericolorectal tissue, which has been reexamined extensively in the conventional condition, was refixed into GEWF solution in this study. More lymph nodes were found in 75% (n = 6) of the 8 experimental cases, and 50% (n = 4) of them had 12 or more yielded lymph nodes eventually. In addition, no adverse influences on the expressions of immunohistochemical and special stains were seen. These data support the reliability and effectiveness of GEWF solution in improvement of lymph node yield.

Improved lymph node harvest from resected colon cancer specimens did not cause upstaging from TNM stage II to III

BACKGROUND

The number of lymph nodes retrieved and examined from a resected colon cancer specimen may be crucial for correct staging. We examined if efforts to increase the lymph node harvest to more than 12 lymph nodes per specimen would upstage some patients from TNM stage II to III.

METHODS

Three hospitals compared results from 2000 with those of 2007 in 421 resected patients with stage II and III colon cancer. Hospital A endeavored to improve the surgical procedure while the pathologists enhanced the quality of lymph node sampling. Hospital B did not make any marked changes, while hospital C introduced the GEWF lymph node solvent (glacial acetic acid, ethanol, distilled water, and formaldehyde) in their pathology method.

RESULTS

In 2000, 12 or more lymph nodes were harvested in 39.6, 45.0, and 21.1% of the specimens from the three hospitals, while the figures for 2007 were 85.7, 42.0, and 90.3%, respectively. The significant increase in lymph node harvest in two of the hospitals in 2007 compared to 2000 (p < 0.001) did not affect the share of patients with stage III in 2007 (38.7%) compared to 2000 (44.1%) (p = 0.260). The number of positive lymph nodes and the lymph node ratio (LNR) decreased from 2000 to 2007. A lymph node yield of 12 or more was not associated with an increased probability of positive lymph nodes in a multivariable logistic regression analysis.

CONCLUSION

More radical surgery and dedicated pathologists and the use of the GEWF solvent significantly increased the lymph node yield but did not upstage patients from TNM stage II to III.

Prognostic impact of lymph node harvest and lymph node ratio in patients with colon cancer

BACKGROUND

The prognostic impact of the number of lymph nodes and ratio in colon cancer is still debated.

OBJECTIVES

The aim of this study was to evaluate lymph node harvest in patients with colon cancer over time, and to test the hypotheses that investigation of more lymph nodes, and low lymph node ratio in stage III patients, has positive prognostic impact.

DESIGN

This is a prospective, observational study.

SETTINGS

This study was conducted in a single institution treating all patients with colon cancer in a defined catchment area.

PATIENTS

All patients admitted in the period 1993 to 2009 (n = 1481) were included.

MAIN OUTCOME MEASURES

The primary outcomes measured were the number of examined regional lymph nodes according to treatment period, 5-year overall survival and time to recurrence, and univariate (Kaplan-Meier) and multivariate (Cox regression) analyses of prognostic factors.

RESULTS

Nine hundred fifty (65%) patients underwent curative resection. Median number of examined lymph nodes increased from 7 to 15 (p < 0.001), and the proportion of patients with stage III disease increased from 25% to 33% (p = 0.02) during the study period. In patients with stage I to III disease, time to recurrence (proportion of patients without recurrence or death of colon cancer) improved from 65% to 82% during the period (p < 0.001). An association between lymph node count (<8 compared with ≥ 12) and overall survival was found for patients with stage II disease (57% vs 71%, p = 0.004). Hazard ratio for death within 5 years was 0.7 (p = 0.043) when 8 to 11 nodes were examined and 0.6 (p = 0.001) when ≥ 12 nodes were examined (<8 reference). In patients with stage III disease, increasing lymph node ratio was associated with reduced overall survival and time to recurrence in uni- and multivariate analyses.

LIMITATIONS

This study was limited by the small number of patients in each stage.

CONCLUSIONS

The number of examined lymph nodes increased in the study period. A stage migration was observed, and time to recurrence improved in patients with stage I to III disease. In patients with stage III disease, lymph node ratio was a stronger prognostic factor than the total number of lymph nodes examined.

Factors affecting lymph node yield from patients undergoing colectomy for cancer

PURPOSE

Lymph node (LN) yield is a critical component of colon cancer staging and is often a surrogate for quality assessment in surgery. We investigated the impact of pathologists' training on LN harvest.

METHODS

This is a retrospective review on 137 patients undergoing elective colectomy for adenocarcinoma at a single institution from 2008 to 2009. We studied surgeon-, patient- and pathologist-derived factors, and identified independent variables affecting LN yield using logistic regression.

RESULTS

LN yield was similar between open and laparoscopic resections (21 versus 23, p = 0.54). Similarly, nodal counts were independent of tumor location (p = 0.08) and no difference was noted between colorectal and general surgeons (24 versus 21, p = 0.31). Strikingly, the number of LNs reported by PGY-1 pathology residents was significantly higher than those with two or more years of training (24 versus 19, p = 0.02). On logistic regression, only the reporting pathologists' year in training remained a significant predictor of the number of nodes reported (OR = 5.28, p = 0.0001).

CONCLUSIONS

LN retrieval in patients with colon cancer is inversely related to the interpreting pathologists' level of training.

A natural orifice transrectal approach for oncologic resection of the rectosigmoid: an experimental study and comparison with conventional laparoscopy

BACKGROUND

A transrectal (TR) approach for natural orifice translumenal endoscopic surgery (NOTES) makes sense for colorectal surgery because the colotomy can be incorporated into subsequent anastomosis. Because cancer is a primary indication for left-sided colon resection, oncologic standards will have to be met by a NOTES procedure. This study aimed to assess whether pure TR rectosigmoidectomy can be performed with strict adherence to oncologic principles compared with a conventional laparoscopically assisted approach (LAP).

METHODS

Human male cadavers were allocated to either TR (n = 4) or LAP (n = 2). A simulated sigmoid lesion was created at 25 cm. Transrectal retrograde mobilization of the rectosigmoid was performed using conventional transanal endoscopic microsurgery (TEM) instrumentation. After ligation of the superior hemorrhoidal artery and further mobilization, the specimen was delivered transanally and divided extracorporeally. Using a circular stapler, NOTES colorectal anastomosis was performed. Lymph node yield, adequate resection margins, and operative time were compared with LAP.

RESULTS

Transrectal retrograde rectosigmoid dissection was achieved in all attempts (4/4) and showed numbers of lymph nodes (median, 5; range, 3-6) similar to the LAP group (median, 4.5; range, 2-7). One pure TR approach failed to resect the lesion. Three TR procedures required additional mobilization via an abdominal approach to provide adequate margins. The mean length of TR specimens was 16 ± 4 cm compared with 31 ± 9 cm achieved by LAP (p < 0.01). The TR operative time was significantly longer (247 ± 15 vs 110 ± 14 min).

CONCLUSION

Lymph node yield during TR rectosigmoidectomy was similar to that achieved by the LAP approach. However, conventional TEM instrumentation alone did not permit adequate colon mobilization. This indicates a need for flexible instrumentation or other technical solutions to perform true NOTES colectomies.

Lymph node harvest in colorectal adenocarcinoma specimens: the impact of improved fixation and examination procedures

A review of 1050 pathology reports from colorectal adenocarcinoma specimens examined at the Department of Pathology, Sørlandet sykehus HF, Kristiansand, Norway during the period 1995-2006 revealed a poor performance of most doctors concerning lymph node harvest. A mean of 8.1 nodes per specimen (range 12.3-2.1) and a mean proportion of 22.3% of specimens with ≥12 lymph nodes (range 47.1-0%) were found. A small pilot study was undertaken in 2007 to evaluate the effect of prolonged formalin fixation and the use of a special lymph node fixative [glacial acetic acid, ethanol, water and formaldehyde (GEWF) solution] with regard to the number of retrieved nodes. This showed that one extra day formalin fixation and the use of GEWF solution considerably enhanced the detection of lymph nodes, particularly those of smaller size. Based on these findings, our routines concerning handling of colorectal cancer specimens were changed during 2007. After this time all specimens have been fixed in a mixture of GEWF solution and formalin for at least 48 h and the doctors have been encouraged to find as many lymph nodes as possible. In cases revealing <12 nodes after microscopical examination, the specimens have been re-examined and searched for additional nodes. A review of lymph node retrieval in 423 cases of colorectal cancer during the period 2008-2010 showed that the mean number of nodes per specimen had increased to 16.8 (range 29.0-13.3) and the proportion of specimens with ≥12 nodes to 78.0% (range 96.8-63.6%). Thus, these changes of routines which were easy to implement without significant extra costs have considerably improved lymph node harvest at our department. The use of a special lymph node fixative (e.g. GEWF solution) is highly recommended not only for detection of nodes in colorectal specimens, but also for retrieval of lymph nodes embedded in fat tissue generally.