Factors influencing lymph node harvest in colorectal surgery

Advanced Preoperative Clinical Stage Is Associated With More Lymph Node Harvest in Patients With Right Colon Cancer

PURPOSE

The adequacy of lymph node (LN) harvest is important in oncological colon cancer resections. While several studies have suggested factors influencing LN yield in colon cancer, limited data are available only regarding right hemicolectomies with complete mesocolic excision (CME) and central vessel ligation (CVL).

METHODS

A retrospective analysis was conducted on 169 patients who underwent right hemicolectomies with CME and CVL for right-sided colon cancer between February 2019 and March 2023. The patients were divided into 2 groups: groups with ≤24 LN yield and >24 LN yield, and the patient, surgical, and pathologic factors, which could potentially influence the LN yield, were analyzed.

RESULTS

Younger age, lower American Society of Anesthesiologists (ASA) classification, and advanced clinical TNM (cTNM) stage among patient factors, the presence of obstructions regarding the surgical factors, and the presence of desmoplastic tumor reaction in the pathologic factors were more likely to harvest >24 LNs. In a multivariate analysis, younger age, lower ASA classification, advanced cTNM stage, and an ileocolic artery (ICA) crossing pattern posterior to the superior mesenteric vein (SMV) were independently associated with a >24 LN harvest. Patients with cTNM 3,4 showed the tendency of > 24 LN yield consistently within each subgroup, irrespective of the age, ASA classification, and ileocolic artery crossing pattern.

CONCLUSIONS

Our investigation revealed a significant correlation between the advanced preoperative clinical stage and an increased number of harvested lymph nodes (LNs) in patients undergoing right hemicolectomies with CME a CVL. The observed association is potentially influenced by tumor aggressiveness and the extent of surgical resection performed by the surgeon. To elucidate the intricate relationship between surgical outcomes and the quantity of LN harvest in patients subjected to standardized CME and CVL for right-sided colon cancer, further dedicated research is warranted.

Importance of Arterial Vessel Length for Metastatic Lymph Node Retrieval and Survival in Standardized Left- and Right-Sided Colon Cancer Surgery

BACKGROUND

We investigated the localization of lymph node metastases, and the role of arterial vessel and specimen lengths in left- and right-sided colon cancer surgery, for survival.

METHODS

This was a prospective cross-sectional population-based study of specimens from patients who underwent standardized surgical resection for colon cancer in 2012-2015. The mesocolon of the specimens was divided into four sections for pathological analysis of lymph nodes. Multiple linear regression analysis was used to explore the relationship between lymph node counts and patient- and surgery-related factors. For survival analysis, a multivariable Cox regression method was used.

RESULTS

A total of 317 patients (160 females) were included. Median (range) age was 74 (30-95) years. Median number of lymph node retrieval was 32 (8-198) and was associated with increased specimen length but not to arterial vessel length. One hundred and thirty-three (42%) patients had lymph node metastases. All patients had these located < 5 cm from the tumour. Ten, two, and three specimens had lymph node metastases around the central and peripheral ligation of the ileocolic artery and at the central ligation of the inferior mesenteric artery, respectively. The tumour stages in these specimens were T3-4N2M0-1. No statistically significant survival benefit was associated with longer arterial vessel length (p = 0.429).

CONCLUSIONS

Neither retrieval of lymph nodes nor statistically significant survival was affected by vessel length in standardized left- and right-sided colon cancer surgery.

Influence of colonic mesenteric area on the number of lymph node retrieval for colon cancer: a prospective cohort study

PURPOSE

The minimum harvested 12 lymph nodes (LNs) is regarded as the limit for accurate staging of nodal status in colorectal cancer patients. Besides the association of the lengths of resected intestinal segments and vascular pedicles, the mesocolic mesenteric area's impact on LN count has not been studied. We aimed to evaluate the associations between metric variables, including the mesocolic mesentery area on the nodal harvest.

METHODS

All consecutive patients who underwent elective colectomy with a curative intention for colon adenocarcinoma were prospectively included. The metric variables included the lengths of resected intestinal segments, vascular pedicle, and colonic mesenteric area. The variables influencing the LN count and the correlation between the total LN count and the specimens' relevant metric measurements were analyzed.

RESULTS

There were 46 patients with a median age of 64 years. The median count for total LNs was 22, and the LN positivity was 59.2%. There was an inadequate LN yield (<12) in 3 patients (6.1%). No significant associations were found between the adequacy of nodal harvest and the demographic, clinical, and tumoral features (P>0.05). There were significant positive correlations between total LN number and length of vascular pedicle and mesenteric area (r=0.576, P<0.001 and r=0.566, P<0.001).

CONCLUSION

The length of the vascular pedicle and mesenteric area were significantly correlated with total LN counts. Although there was no significant impact on the length of resected segments, the colonic mesenteric area can be used alone as a measure for the assessment of the nodal yield in colon cancer.

Adequacy of lymph node harvest following colectomy for obstructed and nonobstructed colon cancer

BACKGROUND

Technical and clinical differences in resection of obstructed and non-obstructed colon cancers may result in differences in lymph node retrieval. The objective of this study is to compare the lymph node harvest following resection of obstructed and nonobstructed colon cancer patients.

METHODS

A retrospective analysis utilizing the 2014-2018 NSQIP colectomy targeted data set was conducted. One-to-one coarsened exact matching (CEM) was utilized between patients undergoing resection for obstructed and non-obstructed colon cancer. The primary outcome was the adequacy of lymph node retrieval (LNR, ≥12 nodes).

RESULTS

CEM resulted in 9412 patients. Patients with obstructed tumors were more likely to have inadequate LNR (13.3% vs 8.2%, p < .001) compared to those with nonobstructed tumors. Multivariate analysis demonstrated that patients with obstructing tumors had worse LNR compared to non-obstructed tumors (odds ratio [OR]: 0.74, 95% confidence interval [CI]: 0.62-0.87; p < .005). Increased age (OR: 0.99, 95% CI: 0.098-0.99), presence of preoperative sepsis (OR: 0.70, 95% CI: 0.055-0.90), left-sided and sigmoid tumors compared to right-sided (OR: 0.64, 95% CI: 0.51-0.81; OR: 0.69, 95% CI: 0.58-0.82, respectively), and open surgical resection compared to an minimally invasive surgical approach were associated with inadequate LNR (p < .05).

CONCLUSION

This study demonstrated that resection for obstructing colon cancer compared to non-obstructed colon cancer is associated with increased odds of inadequate lymph node harvest.

A Preoperative Risk Prediction Model for Lymph Node Examination of Stage I-III Colon Cancer Patients: A Population-Based Study

Background: Lymph node examination is a prognostic indicator for colon cancer (CC) patients. The aim of this study was to develop and validate a preoperative risk prediction model for inadequate lymph node examination. Methods: 24284 patients diagnosed as stage I-III CC between 2010-2014 were extracted from SEER database and randomly divided into development cohort (N=12142) and internal validation cohort (N=12142). 680 patients diagnosed as stage I-III CC between 2012-2014 were extracted from our hospital as external validation cohort. Logistic regression analysis was performed and risk score of each factor was calculated according to model formula. Model discrimination was assessed using C-statistics. Results: Preoperative risk factors were identified as gender, age, tumor site and tumor size. Patients with total risk score of 0-6 were considered as low risk group while patients scored ≥13 were considered as high risk group. The model had good discrimination and calibration in all cohorts and could apply to patients in the SEER database (American population) and patients in our hospital (Chinese population). Conclusions: The model could accurately predict the risk of inadequate lymph node examination before surgery and might provide useful reference for surgeons and pathologists.

Factors affecting the number of lymph nodes retrieved after colo-rectal cancer surgery: A prospective single-centre study

BACKGROUND

The number of harvested lymph nodes (LNs) in colorectal cancer surgery relates to oncologic radicality and accuracy of staging. In addition, it affects the choice of adjuvant therapy, as well as prognosis. The American Joint Committee on Cancer defines at least 12 LNs harvested as adequate in colorectal cancer resections. Despite the importance of the topic, even in high-volume colorectal centres the rate of adequacy never reaches 100%. The aim of this study was to identify factors that affect the number of harvested LNs in oncologic colorectal surgery.

MATERIALS AND METHODS

We prospectively collected all consecutive patients who underwent colorectal cancer resection from January 1st 2013 to December 31st 2017 at Emergency Surgery Unit St Orsola University Hospital of Bologna.

RESULTS

Six hundred and forty-three consecutive patients (382 elective, 261 emergency) met the study inclusion criteria. Emergency surgery and laparoscopic approach did not have a significant influence on the number of harvested LNs. The adequacy of lymphadenectomy was negatively affected by age >80 (OR 3.47, p < 0.001), ASA score ≥3 (OR 3.48, p < 0.001), Hartmann's or rectal resection (OR 3.6, p < 0.001) and R1-R2 resection margins (OR 3.9, p = 0.006), while it was positively affected by T-status ≥3 (OR 0.33 p < 0.001).

CONCLUSION

Both the surgical technique and procedure regimen did not affect the number of lymphnodes retrieved. Age >80 and ASA score ≥3 and Hartmann's procedure or rectal resection showed to be risk factors related to inadequate lymphadenectomy in colorectal cancer surgery.

Factors affecting retrieval of 12 or more lymph nodes in pT1 colorectal cancers

Objective

The aim of this study was to identify clinicopathological factors that affect the number of lymph nodes (LNs) (12 or more) retrieved from patients with colorectal cancer (CRC), particularly those with pathologic T1 (pT1) disease.

Methods

From 429 CRC patients, 75 pT1 cancers were identified and digitally scanned. Binary logistic regression analysis was performed to identify the clinicopathological factors affecting the number of LNs retrieved from all 429 patients and from the subset of patients with pT1 CRC.

Results

For the 429 patients, the mean number of harvested LNs per specimen was 20 (median, 19). The number of retrieved LNs was independently associated with maximum tumor diameter > 2.3 cm and right-sided tumor location. The mean number of LNs retrieved from the 75 patients with pT1 CRC was 14 (median, 15); retrieval of 12 or more LNs from this group was independently associated with maximum tumor diameter > 14.1 mm.

Conclusion

The number of LNs retrieved from patients with CRC was associated with maximum tumor diameter and right-sided tumor location. For patients with pT1 CRC, maximum tumor diameter was independently associated with the harvesting of 12 or more LNs.

Clinicopathological Factors Influencing Lymph Node Yield in Colorectal Cancer: A Retrospective Study

Many colorectal resections do not meet the minimum of 12 lymph nodes (LNs) recommended by the American Joint Committee on Cancer for accurate staging of colorectal cancer. The aim of this study was to investigate factors affecting the number of the adequate nodal yield in colorectal specimens subject to routine pathological assessment. We have retrospectively analysed the data of 2319 curatively resected colorectal cancer patients in San Raffaele Scientific Institute, Milan, between 1993 and 2017 (1259 colon cancer patients and 675 rectal cancer patients plus 385 rectal cancer patients who underwent neoadjuvant therapy). The factors influencing lymph node retrieval were subjected to uni- and multivariate analyses. Moreover, a survival analysis was carried out to verify the prognostic implications of nodal counts. The mean number of evaluated nodes was 24.08 ± 11.4, 20.34 ± 11.8, and 15.33 ± 9.64 in surgically treated right-sided colon cancer, left-sided colon cancer, and rectal tumors, respectively. More than 12 lymph nodes were reported in surgical specimens in 1094 (86.9%) cases in the colon cohort and in 425 (63%) cases in the rectal cohort, and patients who underwent neoadjuvant chemoradiation were analysed separately. On univariate analysis of the colon cancer group, higher LNs counts were associated with female sex, right colon cancer, emergency surgery, pT3-T4 diseases, higher tumor size, and resected specimen length. On multivariate analysis right colon tumors, larger mean size of tumor, length of specimen, pT3-T4 disease, and female sex were found to significantly affect lymph node retrieval. Colon cancer patients with 12 or more lymph nodes removed had a significantly better long-term survival than those with 11 or fewer nodes (P = 0.002, log-rank test). Rectal cancer patients with 12 or more lymph nodes removed approached but did not reach a statistically different survival (P = 0.055, log-rank test). Multiple tumor and patients' factors are associated with lymph node yield, but only the removal of at least 12 lymph nodes will reliably determine lymph node status.

D2 VS D3 LYMPH NODE DISSECTION FOR RIGHT COLON CANCER (review)

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Predictors of adequate lymph node harvest during colectomy for colon cancer

BACKGROUND

Consensus guidelines recommend a yield of 12 lymph nodes in resections for colon cancer. Factors affecting this yield are not well defined.

METHODS

Retrospective study using the colectomy-targeted American College of Surgeons National Surgical Quality Improvement Program for years 2014-2016. Primary outcome was resection of at least 12 nodes. Univariate and multivariate analyses determined factors associated with ≥12 LN yield.

RESULTS

17,612 colectomies for colon cancer were extracted from the NSQIP database. 7.26% of cases did not reach a 12 LN harvest. Harvesting ≥12 LN was 74% more likely (p = 0.001) if the resection was laparoscopic and 72% more likely (p < 0.0001) if hand-assisted. Advanced T and N stage had a higher likelihood of reaching 12 LN harvest. Older age, female gender and smoking history decreased the likelihood of ≥12 LN harvest.

CONCLUSIONS

Laparoscopic and robotic colectomies were 1.5-2.5 times more likely to achieve adequate LN harvest compared to open surgery. Several non-modifiable patient and disease related factors may render adequate LN yield challenging.

Reconsideration of the optimal minimum lymph node count for young colon cancer patients: a population-based study

BACKGROUND

Currently, young colon cancer (CC) patients continue to increase and represent a heterogeneous patient group. The aim of this study was to explore the optimal minimum lymph node count after CC resection for young patients.

METHODS

We performed a comprehensive search of the Surveillance, Epidemiology, and End Results (SEER) database, 2360 CC patients aged from 20 to 40 were analyzed. X-tile was used to determine the optimal cut-off point of lymph node based on survival outcomes of young patients. The cancer specific survival (CSS) was estimated with Kaplan-Meier method, the Cox proportional hazards regression model was used to analyse independent prognostic factors and exact 95% confidence intervals (CIs).

RESULTS

Using X-tile analysis, 22-node measure was identified as the optimal choice for CC patients aged < 40. The 5-year CSS were 85.8% and 80.9% for patients examining ≥22 nodes and < 22 nodes. Furthermore, we identified that examining < 22 nodes was an independent adverse prognostic factor in patients aged < 40. In addition, the revised 22-node measure could examine more positive nodes than the standard 12-node measure in young patients.

CONCLUSIONS

For young colon cancer patients, the lymph node examination should be differently evaluated. We suggest that 22-node measure may be more suitable for CC patients aged < 40.

TRIAL REGISTRATION

Retrospectively registered.

Radiological and pathological evaluation of the level of arterial division after colon cancer surgery

AIM

In aiming to cure patients with colorectal cancer surgery, the surgeon must carefully dissect the mesocolon and mesorectum and divide the vascular pedicle near to its origin so as to include all local lymph nodes. This has been termed complete mesocolic excision. The distance from the distal vascular tie to the bowel wall in the fixed specimen is an indication as to the quality of surgery but this does not assess the length of the residual vascular pedicle and, by implication, residual lymph nodes. The aim of this study was to establish if our surgeons were carrying out complete mesocolic excision by assessing the length of the proximal arterial pedicle and relating this to arterial length in the fixed specimen.

METHOD

This was a single centre prospective study of patients undergoing elective surgery for locally advanced colorectal cancer. An abdominal and pelvic CT scan was performed 2 days postoperatively and a radiologist blinded to the operative procedure measured the length of the residual arterial stump. Similarly, the length of the vessel in the fixed resected specimen and lymph node yield were also recorded.

RESULTS

Fifty-two patients were recruited. The mean length of the residual arterial stump was 38 mm (95% CI: 33-43), which was significantly longer than the < 10 mm recommended in guidelines (P < 0.0001). The mean length was 31 mm (95% CI: 25-37) and 49 mm (95% CI: 40-57) for left and right sided resections respectively. There was no correlation between the residual arterial stump and the pathology.

CONCLUSIONS

The residual arterial length was greater than suggested by guidelines and may indicate that our surgery is less radical than we planned. Caution should be taken when using pathological measurements of vascular ligation as it may not reflect the height of the pedicle division.

Tumor size, tumor location, and antitumor inflammatory response are associated with lymph node size in colorectal cancer patients

Lymph node size affects lymph node retrieval in surgical specimen and is used as criterion for pre-operative radiological estimation of metastatic disease. However, factors determining lymph node size remain to be established. Therefore, the association between lymph node size and presence of metastatic cancer deposits as well as different primary tumor characteristics was analyzed in a prospective cross-sectional study. Visible and palpable nodes were harvested, and conventional histology, immunohistochemistry, and molecular analysis were performed. The study cohort comprised 148 patients (median age 69 years, range 36-92). Lymph node dissection rendered 4167 nodes. Mean lymph node count was 28 (median 26, range 9-67). Metastatic disease was detected in 320 (8%) nodes and was associated with lymph node size (P<0.001). Positive nodes measuring ≤2 mm caused upstaging within the N category in one third of cases, but did not identify patients as node-positive as all patients also had positive larger nodes. Large tumor size (P=0.001), right tumor location (P<0.001), and deep tumor penetration (P=0.024) were all independently associated with lymph node size, whereas high lymphocytic antitumor reaction just missed statistical significance (P=0.053) in multivariable analysis. Microsatellite instability had no influence on lymph node size when analysis was restricted to right-sided tumors. In conclusion, analysis of small lymph nodes may lead to upstaging within the N category, but they do not identify a patient as node-positive and do therefore not influence clinical decision-making in the adjuvant setting. The majority of enlarged lymph nodes, including those measuring >1 cm, are not involved by cancer. Different tumor characteristics, such as large primary tumor size, right tumor location, and deep tumor penetration are independently associated with lymph node size and need to be considered when interpreting enlarged nodes detected by radiological imaging.

T1 colon cancer in the era of screening: risk factors and treatment

BACKGROUND

The aim of this study was to identify risk factors for lymph node positivity in T1 colon cancer and to carry out a surgical quality assurance audit.

METHODS

The sample consisted of consecutive patients treated for early-stage colon lesions in 15 colorectal referral centres between 2011 and 2014. The study investigated 38 factors grouped into four categories: demographic information, preoperative data, indications for surgery and post-operative data. A univariate and multivariate logistic regression analysis was performed to analyze the significance of each factor both in terms of lymph node (LN) harvesting and LN metastases.

RESULTS

Out of 507 patients enrolled, 394 patients were considered for analysis. Thirty-five (8.91%) patients had positive LN. Statistically significant differences related to total LN harvesting were found in relation to central vessel ligation and segmental resections. Cumulative distribution demonstrated that the rate of positive LN increased starting at 12 LN harvested and reached a plateau at 25 LN.

CONCLUSIONS

Some factors associated with an increase in detection of positive LN were identified. However, further studies are needed to identify more sensitive markers and avoid surgical overtreatment. There is a need to raise the minimum LN count and to use the LN count as an indicator of surgical quality.

Non-surgical factors influencing lymph node yield in colon cancer

There are numerous factors which can affect the lymph node (LN) yield in colon cancer specimens. The aim of this paper was to identify both modifiable and non-modifiable factors that have been demonstrated to affect colonic resection specimen LN yield and to summarise the pertinent literature on these topics. A literature review of PubMed was performed to identify the potential factors which may influence the LN yield in colon cancer resection specimens. The terms used for the search were: LN, lymphadenectomy, LN yield, LN harvest, LN number, colon cancer and colorectal cancer. Both non-modifiable and modifiable factors were identified. The review identified fifteen non-surgical factors: (13 non-modifiable, 2 modifiable) which may influence LN yield. LN yield is frequently reduced in older, obese patients and those with male sex and increased in patients with right sided, large, and poorly differentiated tumours. Patient ethnicity and lower socioeconomic class may negatively influence LN yield. Pre-operative tumour tattooing appears to increase LN yield. There are many factors that potentially influence the LN yield, although the strength of the association between the two varies greatly. Perfecting oncological resection and pathological analysis remain the cornerstones to achieving good quality and quantity LN yields in patients with colon cancer.

Surgery has a key role for quality assurance of colorectal cancer screening programs: impact of the third level multidisciplinary team on lymph nodal staging

PURPOSE

From 2011 to 2013 in the area of the Naples 3 public health district (ASL-NA3), a colorectal cancer screening program (CCSP) was developed. In order to stress the need of quality assurance procedures for surgery and pathology, a third level oncologic pathway was added and set up at a referral colorectal cancer center (RC). Lymph nodal (LN) harvesting, as a process indicator, and nodal positivity were adopted for an interim analysis.

METHODS

The program was implemented by a series of audit meetings and a double type of multidisciplinary team (MDT): "horizontal" and "vertical." Three hundred and forty colorectal cancer (CRC) patients underwent surgery: 119 chose to be operated at the RC (Gr In), 65 were operated at 22 district hospitals (DH) (Gr Out), and 156 symptomatic not screened patients were operated at the RC (Gr Sym).

RESULTS

Statistical analysis revealed differences between Gr In and Gr Out colon groups both for LN harvesting (median of 26 and 11, respectively, P = 0.0001), and for nodal positivity after the first screening round (34.78 and 19.45%, respectively, P = 0.0169). Results were all the more significant in a subset analysis on early T stage colon subgroups (In vs Out) both for LN harvesting (P < 0.0001) and nodal positivity (P < 0.0001).

CONCLUSION

xSignificant differences between RC and DHs were found, particularly for early-stage CRC patients. LN harvesting should be considered as a surrogate marker of quality assurance for at least screening hospitals for "minimum best" standard of care. This should lead to set up a third level in any CCSP.

Laparoscopic surgery for patients with colorectal cancer produces better short-term outcomes with similar survival outcomes in elderly patients compared to open surgery

The number of operations on elderly colorectal cancer (CRC) patients has increased with the aging of the population. The aim of this study was to evaluate surgical outcomes in elderly patients who underwent laparoscopic or open surgery for CRC. We analyzed the data of 280 patients aged 80 or over who underwent surgery for CRC between January 2001 and December 2010. Seventy-one pairs were selected after propensity score matching for laparoscopic or open surgery. Operative time, return to normal bowel function, length of hospital stay, postoperative complications, overall survival (OS), recurrence-free survival (RFS), and prognostic factors affecting survival were investigated. In matched cohorts, operative time in the laparoscopic group was longer than in the open group (P < 0.001). In the laparoscopic group, time to flatus passage (P < 0.001) and length of postoperative hospital stay (P = 0.037) were shorter than in the open group. The rate of operation-related morbidity was higher in the open group (P = 0.019). There was no difference in OS and RFS between two groups. This study suggests that laparoscopic surgery for CRC in elderly patients may be safe and feasible, with better short-term outcomes. OS and RFS, however, were not different in both groups.

Lymph node retrieval for colorectal cancer: Estimation of the minimum resection length to achieve at least 12 lymph nodes for the pathological analysis

INTRODUCTION

Adequate lymph node retrieval is important in colorectal cancer staging for the selection of patients that necessitate adjuvant treatments. The minimum number of 12 lymph nodes is one of the premises and is dependent, among the other factors, from the length of bowel resected. We have reviewed our specimens to identify the high-risk operations for inadequate nodal sampling and estimate the minimum length of bowel needed to resect to achieve this purpose.

MATERIALS AND METHODS

A retrospective review of colorectal specimens over 10 years of activity looking at data including location of the tumor, type of operation performed, length of bowel resected and number of lymph nodes retrieved.

RESULTS

Abdominoperineal and Hartmann's resections produced significant lower adequate retrievals compared to other colorectal operations, corresponding to 45.4% and 59.1% of cases respectively. The measured average length of bowel was 30 cm and 25 cm respectively, increasing the length to 36 cm and 42 cm would increase the adequacy rate to 90%.

CONCLUSIONS

Abdominoperineal and Hartmann's resections are, in our series, high-risk operations that frequently do not produce the minimum number of lymph nodes necessary. These operations may require additional maneuvers such as mobilization of the splenic flexure to achieve the minimum length of bowel to resect.

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

AIM

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Practice parameters for early colon cancer management: Italian Society of Colorectal Surgery (Società Italiana di Chirurgia Colo-Rettale; SICCR) guidelines

Early colon cancer (ECC) has been defined as a carcinoma with invasion limited to the submucosa regardless of lymph node status and according to the Royal College of Pathologists as TNM stage T1 NX M0. As the potential risk of lymph node metastasis ranges from 6 to 17% and the preoperative assessment of lymph node metastasis is not reliable, the management of ECC is still controversial, varying from endoscopic to radical resection. A meeting on recent advances on the management of colorectal polyps endorsed by the Italian Society of Colorectal Surgery (SICCR) took place in April 2014, in Genoa (Italy). Based on this material the SICCR decided to issue guidelines updating the evidence and to write a position statement paper in order to define the diagnostic and therapeutic strategy for ECC treatment in context of the Italian healthcare system.

Factors related to lymph node harvest: does a recovery of more than 12 improve the outcome of colorectal cancer?

AIM

The nodal harvest was studied to identify factors that affected the number of lymph nodes (LNs) retrieved in patients undergoing curative surgery for colorectal cancer. The influence of predictive factors on overall and disease-free 5-year survival was analysed.

METHOD

All patients diagnosed with colorectal cancer who underwent oncological resection consecutively from January 1996 to December 2011 in a single institution have been studied. Factors influencing LN retrieval were analysed. A logistic regression analysis was performed to determine the factors that predicted a recovery of more than 12 LNs. A Cox regression analysis was made to identify the predictive factors of overall and disease-free 5-year survival.

RESULTS

A total of 1166 patients were included in the study. The factors associated with the number of LNs harvested in surgical resections were age, colorectal surgeon, right colectomy, total colectomy, year of surgery, number of LN metastases and lymphocyte response. The factors that predicted a recovery of ≥ 12 LNs were age < 60 years, right colectomy, year of surgery and expert pathologist. A recovery of ≥ 12 LNs did not show significant differences in overall and disease-free 5-year survival, but the factor of colorectal surgeon did.

CONCLUSION

Number of LN metastases, lymphocyte response, type of surgical resection, age of patient and colorectal surgeon can predict the LN harvest. Survival in colorectal cancer, however, is probably more influenced by the performance of the operation by an expert surgeon than by recovery of more than 12 LNs.

Modified methylene blue injection improves lymph node harvest in rectal cancer

BACKGROUND

The presence of nodal metastases in rectal cancer plays an important role in accurate staging and prognosis, which depends on adequate lymph node harvest. The aim of this prospective study is to investigate the feasibility and survival benefit of improving lymph node harvest by a modified method with methylene blue injection in rectal cancer specimens.

METHODS

One hundred and thirty-one patients with rectal cancer were randomly assigned to the control group in which lymph nodes were harvested by palpation and sight, or to the methylene blue group using a modified method of injection into the superior rectal artery with methylene blue. Analysis of clinicopathologic records, including a long-term follow-up, was performed.

RESULTS

In the methylene blue group, 678 lymph nodes were harvested by simple palpation and sight. Methylene blue injection added 853 lymph nodes to the total harvest as well as 32 additional metastatic lymph nodes, causing a shift to node-positive stage in four patients. The average number of lymph nodes harvested was 11.7 ± 3.4 in the control group and 23.2 ± 4.7 in the methylene blue group, respectively. The harvest of small lymph nodes (<5 mm) and the average number of metastatic nodes were both significantly higher in the methylene blue group. The modified method of injection with methylene blue had no impact on overall survival.

DISCUSSION

The modified method with methylene blue injection improved lymph node harvest in rectal cancer, especially small node and metastatic node retrieval, which provided more accurate staging. However, it was not associated with overall survival.

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.

Totally laparoscopic versus laparoscopic-assisted right colectomy for colon cancer: is there any advantage in short-term outcomes? A prospective comparative assessment in our center

BACKGROUND

Several techniques are described in the literature about laparoscopic treatment of the right colon. Among them, laparoscopic-assisted colectomy (LAC) with creation of an extracorporeal ileocolonic anastomosis remains the favourite approach in most centers. So far, total laparoscopic colectomy (TLC) with intracorporeal anastomosis is not widely performed, because it requires adequate skills and competence in the use of mechanical linear staplers and laparoscopic manual sutures. The purpose of this study was to determine prospectively if TLC offers some advantages in short-term outcomes over LAC.

METHODS

A prospective comparative study was designed for 80 consecutive patients who were alternatively treated with TLC and LAC for right colon neoplasms. The following data were collected: operative time, intra- and postoperative complication rate, time to bowel movement, hospitalization time, length of minilaparotomy, number of harvested lymph nodes, and specimen length.

RESULTS

Operative time in TLC resulted significantly longer than in LAC (230 vs. 203 min), complication rate was similar in both groups, with no case of anastomotic dehiscence, two anastomotic bleedings in TLC vs. three in LAC and one case of postoperative ileus for each group. One case of death occurred in LAC patient developing a postoperative severe cardiopulmonary syndrome. Time to first flatus was in favour of TLC (2.2 vs. 2.6 days), whereas hospitalization was comparable. As regards to the oncological parameters of radicality, the specimen length was superior in TLC group, but the number of lymph nodes excised was equivalent. The length of the minilaparotomy was clearly shorter in TLC group (5.5 vs. 7.2 cm).

CONCLUSIONS

No evidence of relevant differences in terms of functional and safety outcomes between the two laparoscopic procedures. TLC determines less abdominal manipulation and shorter incision length, but clear advantages must be still demonstrated. Larger series are necessary to test the superiority of totally laparoscopic procedures for right colectomy.

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.

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.

Adequacy of lymphadenectomy in laparoscopic colorectal cancer surgery: a single-centre, retrospective study

PURPOSE

This study aimed at evaluating the lymph node (LN) harvest after both open and laparoscopic colorectal cancer surgery.

METHODS

In the period between 1996 and 2009, 404 patients with colorectal cancer underwent open resection, whereas 147 patients underwent laparoscopic surgery.

RESULTS

The overall number of harvested LNs was significantly higher in the laparoscopic group than in the open one (16.5 vs. 14.3, P<0.001). A higher number of LNs was found in moderately differentiated tumors of the laparoscopic group when compared with the open surgery group (16.7 vs. 14.2, P<0.01). The numbers of harvested LNs in the proximal tumors and in stage II and III tumors were higher in the laparoscopic group than in the open group (18.9 vs. 15.4, P<0.001; 17.9 vs. 14.2, P=0.002; 17.3 vs. 15.3, P=0.02, respectively).

CONCLUSIONS

Laparoscopic surgery for colorectal cancer can achieve LN retrieval similar to that achieved by the open approach.

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.

[Single port access surgery in colorectal disease: preliminary results]

INTRODUCTION

The aim of this study is to evaluate the single port access technique in colorectal disease, as regards its suitability to oncological criteria, reliability, safety and reproducibility of the technique. A descriptive and prospective case study is performed describing the preliminary results of our series.

MATERIAL AND METHODS

We present a series of 24 patients with colorectal disease who underwent single port access surgery using a Gel point® device between June and December 2010. The operations performed were, 9 right hemicolectomies, 9 sigmoid resections, 4 high anterior resections, 1 left hemicolectomy due to a tumour of the splenic flexure, and 1 sub-total colectomy.

RESULTS

The mean surgical time for the right colon was 82.8 minutes (range 40-170), 122.1 minutes (range 75-200) for the left colon and rectum, and 270 minutes for the sub-total colectomy. The median number of ganglia resected was 22 (range: 3-27) for the right colon and 21 (range: 11-28) left colon/rectum. The mean length of the surgical specimen was 20.37 cm (range: 16.2 - 27.5) for the right colon, and 24.92 cm (range: 14.5 - 31) for the left colon/rectum. The median overall hospital stay was 6 days (range: 5-13). Morbidity was 8.3% (2 patients); one with an occlusion due to adhesions, and another with a leak in the anastomosis. There were no deaths.

CONCLUSIONS

The single port access technique is safe and reproducible, maintaining oncological criteria, for surgeons accustomed to colorectal surgery by conventional laparoscopy. A larger number of cases would be required to standardise the technique.

Minimal invasive single-site surgery in colorectal procedures: Current state of the art

BACKGROUND

Minimally invasive single-site (MISS) surgery has recently been applied to colorectal surgery. We aimed to assess the current state of the art and the adequacy of preliminary oncological results.

METHODS

We performed a systematic review of the literature using Pubmed, Medline, SCOPUS and Web of Science databases. Keywords used were "Single Port" or "Single-Incision" or "LaparoEndoscopic Single Site" or "SILS™" and "Colon" or "Colorectal" and "Surgery".

RESULTS

Twenty-nine articles on colorectal MISS surgery have been published from July 2008 to July 2010, presenting data on 149 patients. One study reported analgesic requirement. The final incision length ranged from 2.5 to 8 cm. Only two studies reported fascial incision length. There were two port site hernias in a series of 13 patients (15.38%). Two "fully laparoscopic" MISS procedures with preparation and achievement of the anastomosis completely intracorporeally are reported. Future site of ileostomy was used as the sole access for the procedures in three studies. Lymph node harvesting, resection margins and length of specimen were sufficient in oncological cases.

CONCLUSIONS

MISS colorectal surgery is a challenging procedure that seems to be safe and feasible, but the existing clinical evidence is limited. In selected cases, and especially when an ileostomy is planned, colorectal surgery may be an ideal indication for MISS surgery leading to a no-scar surgery. Despite preliminary oncological results showing the feasibility of MISS surgery, we want to stress the need to standardize the technique and carefully evaluate its application in oncosurgery under ethical committee control.

Lymph node yield following colorectal cancer surgery

BACKGROUND

Lymph node yield (LNY) is a measure of quality of care and a strong prognostic factor for outcome from colorectal cancer (CRC). The main aims of this study were to determine LNY across multiple Australian centres and the clinico-pathologic factors that influence yield.

METHODS

Analysis of data from prospective CRC databases at 11 Australian centres between January 1988 and May 2008 was undertaken utilizing the linkage and analysis resources of BioGrid Australia. The LNY depending on different clinico-pathologic patient characteristics was evaluated.

RESULTS

In total, 10,082 cases (54.1% men, 45.9% women) were identified. Median LNY was 12 (range 0-174). LNY increased significantly (P < 0.001) over time, from a mean of 8.5 in 1988 to 13 in 2008. LNY also varied significantly between surgical centres. Female gender, younger age, right-sided disease, higher T and N stage, specific operation types and absence of preoperative radiotherapy were all significantly associated with higher LNY.

CONCLUSIONS

While varying across centres, the median LNYs in Australia are acceptable and have improved significantly over recent years. Multiple clinico-pathologic factors significantly influence the number of nodes retrieved.

Does a laparoscopic approach affect the number of lymph nodes harvested during curative surgery for colorectal cancer?

BACKGROUND

This study aimed to assess the number of lymph nodes (LNs) harvested after laparoscopic and open colorectal cancer resections.

METHODS

Between 1996 and 2007, 431 colorectal cancer patients underwent laparoscopic resection. During the periods of 1996-1997, 2002-2003, and 2006-2007, 243 patients undergoing laparoscopic colorectal cancer resection were matched 1-2 by age, operation, gender, operation date, body mass index (BMI), and tumor stage (TNM) to 486 patients undergoing open surgery. The numbers of examined and involved LNs were compared according to tumor location and year of surgery.

RESULTS

Colorectal cancer resections (243 laparoscopic and 486 open procedures) were performed for 729 patients (447 men) with a mean age of 66.2 +/- 12.3 years and a mean BMI of 28.5 +/- 7.3. The mean number of LNs per case was 24.8 +/- 20.6. The number of LNs retrieved did not differ between laparoscopic and open surgery (p = 0.4). A significant difference was observed between the number of involved LNs retrieved laparoscopically (2.2 +/- 3.8) and the number retrieved by open surgery (1.6 +/- 4; p = 0.03). There were significant differences between the numbers of LNs retrieved from the right colon (28.1 +/- 14.6), left colon (24.5 +/- 17.6), and rectum (19.1 +/- 15.1) (p < 0.001). There were significantly fewer examined LNs in laparoscopic than in open cases during 2002 and 2003 (p = 0.003).

CONCLUSION

Laparoscopic resection of colorectal cancer can achieve lymph node retrieval similar to that achieved by the open approach. In this era of new technology, laparoscopic lymph node harvest is becoming more optimized.

Factors that influence 12 or more harvested lymph nodes in early-stage colorectal cancer

BACKGROUND

The number of lymph nodes required for accurate staging is a critical component in early-stage (stage A and B) colorectal cancer (CRC). Current guidelines demand at least 12 lymph nodes to be retrieved. Results of previous studies were contradictory in factors, which influenced the number of harvested lymph nodes. This study was designed to determine the factors that influence the number of harvested lymph nodes (> or =12) in early-stage CRC in a single institution.

METHODS

Between 2003 and 2007, data on patients who underwent surgery for early-stage CRC were analyzed retrospectively. Data for a total of 470 patients were collected and all the tumor-bearing specimens were fixed with node identification performed. Several possible factors that influence 12 or more harvested lymph nodes were investigated and classified into four aspects: (1) operating surgeon, (2) examining pathologist, (3) patient (age, sex, and body mass index), and (4) disease (maximal length of tumor, length of specimen, tumor localization, tumor cell differentiation, Dukes stage, type of resection, and type of tumor).

RESULTS

A total of 289 patients (61.5%) with 12 or more harvested lymph nodes and 181 patients (38.5%) with < 12 lymph nodes were analyzed. The results demonstrate that within a single institution the maximal length of tumor, tumor localization, and depth of tumor invasion according to Dukes stage were independent influencing factors of 12 or more harvested lymph nodes. Maximal length of tumor was associated with more harvested lymph nodes (P < 0.001). Neither the operating surgeon nor the examining pathologist had significant influence on the number of harvested lymph nodes.

CONCLUSIONS

The number of harvested lymph nodes was highly variable in patients who underwent resection of early-stage CRC. Neither the operating surgeon nor the examining pathologist had significant influence on the number of harvested lymph nodes. Therefore, from the viewpoint of the surgeons, disease itself is the most important factor influencing the number of harvested lymph nodes.

Lymph node harvest after proctectomy for invasive rectal adenocarcinoma following neoadjuvant therapy: does the same standard apply?

PURPOSE

Recent reports indicate that neoadjuvant therapy significantly reduces the lymph node harvest of rectal cancer. The aim of this study was to interpret the lymph node harvest in this setting based on the primary tumor response.

METHODS

All patients undergoing proctectomy were included. Three variables were used as indicators of primary tumor response: ypT stage, tumor size, and tumor regression grade.

RESULTS

From 1998 to 2007, 237 patients were identified: 157 in the neoadjuvant therapy group and 80 in the nonneoadjuvant therapy group. Neoadjuvant therapy significantly reduced the number of lymph nodes harvested (P = 0.011). Compared with the nonneoadjuvant group, there were significantly fewer lymph nodes in the neoadjuvant early T stage group (P = 0.001), small tumor size group (P = 0.003), and low tumor regression grade group (P < 0.001). However, there was no significant difference between the nonneoadjuvant group and the neoadjuvant advanced T stage (P = 0.664), large tumor (P = 0.815), and high tumor regression grade groups (P = 0.566).

CONCLUSION

The current standard of lymph node harvest should be applied to patients with poorly responding primary tumors after neoadjuvant therapy. However, a new standard may be necessary to define the adequate number of lymph nodes for tumors that respond well to neoadjuvant therapy.