Lymph node harvest in colon and rectal cancer: Current considerations

Lymph Node Yield and Colorectal Cancer Survival: A Bowel Cancer Outcomes Registry Cohort Study

BACKGROUND

The current standard for lymph node (LN) sampling in colorectal cancer (CRC) surgery is a minimum of 12 LNs. Emerging evidence suggests higher LN yields may improve disease-free survival (DFS); however, an "optimal" number of LNs has yet to be definitively established. The aim of this study was to correlate LN yield with survival outcomes in patients undergoing surgery for nonmetastatic CRC.

METHODS

The Bowel Cancer Outcomes Registry (BCOR) is a clinical quality registry in Australia and New Zealand. Post-operative patients aged ≥ 18 years with histologically confirmed CRC, nonmetastatic disease at diagnosis and with follow-up status documented were included. Post-operative outcomes and survival were assessed with logistic regression. The primary endpoint was CRC-specific mortality. Secondary endpoints were CRC recurrence and all-cause mortality.

RESULTS

Of 91 271 patient episodes, 10 616 individual eligible patients were identified (45.4% male, n = 4828). The median number of LNs resected was 18 [quartiles 0-12, 13-17, 18-23 and > 23]. A significant difference in CRC-specific mortality was seen between quartiles (p = 0.023), with the primary significant difference demonstrated between the lowest quartile (≤ 12 LNs) and other groups. On long-term follow-up, CRC recurrence and CRC-specific mortality were higher in the group with ≤ 12 LNs resected (16.0% vs. 14.0%, adjusted p = 0.049 and 4.5% vs. 3.3%, adjusted p = 0.037 respectively).

CONCLUSION

This study supports the current consensus that > 12 LNs are required for adequate staging and oncological clearance in CRC surgery, and demonstrates yields ≤ 12 LNs are associated with higher CRC recurrence and mortality.

Short- and long-term outcomes of laparoscopic versus open abdominoperineal resection for rectal cancer: A propensity score matching analysis based on 1852 cases

BACKGROUND

Randomized studies have demonstrated that laparoscopic abdominoperineal resection is not inferior to open abdominoperineal resection for rectal cancer.

AIMS

Evaluate the immediate and extended results of laparoscopic abdominoperineal resection versus open abdominoperineal resection for rectal cancer.

METHODS

From January 2006 to December 2017, a total of 1852 patients with rectal cancer who had undergone abdominoperineal resection were enrolled in this investigation. The groups were matched in a 1:1 ratio using propensity score matching. The primary endpoints were overall survival and disease-free survival. The secondary endpoints were pathology and short-term postoperative outcomes.

RESULTS

Compared to the open abdominoperineal resection group, the laparoscopic abdominoperineal resection group exhibited a higher rate of positive circumferential resection margins (P < 0.001) and fewer postoperative complications (P < 0.001). 5-year disease-free survival (P = 0.449) and overall survival rates (P = 0.664) were comparable. Age (P < 0.001), comorbidity (P = 0.040), (y)pT (P = 0.024), (y)pN (P < 0.001), lymphovascular invasion (P = 0.003) and positive circumferential resection margins (P = 0.014) were independent prognostic risks for overall survival.

CONCLUSION

The pathological outcomes of laparoscopic abdominoperineal resection are inferior compared to open abdominoperineal resection. However, they demonstrate comparable long-term oncological outcomes, and laparoscopic abdominoperineal resection offers certain short-term advantages over the open approach.

Does lymph node dissection improve the prognosis of patients with colorectal cancer?

The number of lymph nodes (LNs) dissected during surgery has become an interesting topic. Simple intuition always leads us to believe that dissecting more LNs will result in more accurate pathological staging and assurance of surgical quality. However, when the number of LNs dissected reaches a certain threshold, the patient's prognosis does not continue to improve as the number of dissected nodes increases. Instead, an increase in the number of dissected LNs may be accompanied by a higher incidence of complications. Currently, there are only less than 40% of colorectal cancer patients undergoing adequate LN evaluation. Therefore, obtaining a sufficient number of LNs in clinical practice is extremely challenging. How to further address the insufficiency of LN dissection due to various reasons, which results in concerns of surgeons about patient prognosis, is currently a critical focus.

Randomized clinical trial on accelerated preoperative hyperfractionated radiotherapy versus preoperative hyperfractionated radio-chemotherapy in locally advanced rectal cancer

OBJECTIVES

The aim of this study was to compare pathological response rates after preoperative hyperfractionated radiotherapy with co-administration of chemotherapy based on 5FU (HART-CT) versus preoperative hyperfractionated radiotherapy (HART) in patients with resectable rectal cancer.

METHODS

Patients with T2/N+ or T3/any N rectal cancer were randomized either to HART twice a day (28 fractions of 1.5 Gy) to total dose 42 Gy or to HART-CT. Tumour regression grade was postoperatively assessed according to the 4-point scale as recommended by the American Joint Committee on Cancer (AJCC). The secondary endpoints included overall survival (OS), disease-free survival (DFS), toxicity of preoperative treatment, locoregional, and distant failure rates. There were 187 patients eligible for analysis: 95 in HART and 92 in the HART-CT. Median follow-up was 5.6 years.

RESULTS

The analysis demonstrated a significantly higher chance of achieving pathologic complete response in HART-CT arm: complete response was achieved in 4/95, 4% (HART) and 11/92, 12% (HART-CT) (P = .045). The differences in OS and DFS, while tending to favour HART-CT, were not significant: OS (P = .13, hazard ratio [HR] = 0.82, 95% CI, 0.63-1.06) and DFS (P = .32; HR = 0.88, 95% CI, 0.69-1.13). The locoregional failure and distant metastases rates did not statistically differ between the trial arms. The rate of late complications was similar (P = .51), grade 3+ being 8% versus 11% in the HART/HART-CT group, respectively.

CONCLUSIONS

The hyperfractionated preoperative radiotherapy with concurrent 5-Fu-based chemotherapy (HART-CT) improved pathological response rate compared to HART. This translated into favourable OS and DFS in HART-CT, but the differences did not reach the threshold for significance.

ADVANCES IN KNOWLEDGE

A new hyperfractionated chemo-RT scheme is proposed. Histopathological major response (TRG 0-1) is associated with better clinical outcome.

Oncological and Clinical Impacts of Routine Splenic Flexure Mobilization in Anterior Resection

Background Splenic flexure mobilization (SFM) is widely regarded as one of the most challenging steps in laparoscopic and robotic colorectal surgery, sparking ongoing debate. Some surgeons routinely advocate for SFM, citing its role in achieving greater left colonic reach, which facilitates a safe, tension-free, and well-vascularized anastomosis while adhering to oncological principles. Conversely, others argue that SFM does not consistently ensure these benefits and may increase the risk of complications, including splenic, bowel, or vascular injuries, as well as unnecessarily prolonging the procedure. While traditional surgical textbooks consider SFM a mandatory step in open colorectal resections, limited evidence supports its necessity in minimally invasive approaches. Aim This study aims to evaluate whether routinely mobilizing the splenic flexure offers advantages from both oncological and clinical perspectives. Materials and methods This retrospective cohort study evaluated the oncological and clinical outcomes of SFM versus splenic flexure preservation (SFP) in anterior resections for malignant pathologies. The study was conducted at New Cross Hospital in Wolverhampton, United Kingdom, over a 24-month period, from March 2022 to March 2024. Anterior resections for benign pathologies were excluded. Data analysis was performed using IBM SPSS Statistics for Windows, Version 24.0 (Released 2016; IBM Corp., Armonk, NY, USA) and Microsoft Excel (Microsoft Corporation, Redmond, WA, USA). Results This study included 94 patients, with 65 undergoing SFM and 29 having it preserved (SFP). No significant differences in baseline demographics (age and gender) were observed between the groups. Oncological outcomes revealed a significantly longer median length of resected specimens in the SFM group, although lymph node counts and high vascular ties were comparable between the groups. There were no differences in R0 resection rates. Clinical outcomes showed similar hospital stays and operation durations in both groups. The SFM group had a slightly higher rate of stoma formation but a lower incidence of anastomotic leaks compared to the SFP group. No significant differences in splenic injuries or other complications were noted. Conclusions Our study suggests that routine SFM offers certain oncological and clinical benefits. The specimens obtained were more complete for pathological staging. The additional length gained from the maneuver not only results in longer specimens but also provides sufficient mobility of the remaining colon, enabling anastomosis with minimal tension, which helps prevent anastomotic leaks. Surgeons may consider adjusting their practices based on the findings of this study.

A Prognostic Model Based on the Log Odds Ratio of Positive Lymph Nodes Predicts Prognosis of Patients with Rectal Cancer

OBJECTIVE

This study aimed to compare the prognostic value of rectal cancer by comparing different lymph node staging systems, and a nomogram was constructed based on superior lymph node staging.

METHODS

Overall, 8700 patients with rectal cancer was obtained from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2015. The area under the curve (AUC), the C index, and the Akaike informativeness criteria (AIC) were used to examine the predict ability of various lymph node staging methods. Prognostic indicators were assessed using univariate and multivariate COX regression, and further correlation nomograms were created after the data were randomly split into training and validation cohorts. To evaluate the effectiveness of the model, the C index, calibration curves, decision curves (DCA), and receiver operating characteristic curve (ROC) were used. We ran Kaplan-Meier survival analyses to look for variations in risk classification.

RESULTS

While compared to the N-stage positive lymph node ratio (LNR), the log odds ratio of positive lymph nodes (LODDS) had the highest predictive effectiveness. Multifactorial COX regression analyses were used to create nomograms for overall survival (OS) and cancer-specific survival (CSS). The C indices of OS and CSS for this model were considerably higher than those for TNM staging in the training cohort. The created nomograms demonstrated good efficacy based on ROC, rectification, and decision curves. Kaplan-Meier survival analysis revealed notable variations in patient survival across various patient strata.

CONCLUSIONS

Compared to AJCC staging, the LODDS-based nomograms have a more accurate predictive effectiveness in predicting OS and CSS in patients with rectal cancer.

Lymph node dissection does not affect the survival of patients with tumor node metastasis stages I and II colorectal cancer

BACKGROUND

The effect of the number of lymph node dissections (LNDs) during radical resection for colorectal cancer (CRC) on overall survival (OS) remains controversial.

AIM

To investigate the association between the number of LNDs and OS in patients with tumor node metastasis (TNM) stage I-II CRC undergoing radical resection.

METHODS

Patients who underwent radical resection for CRC at a single-center hospital between January 2011 and December 2021 were retrospectively analyzed. Cox regression analyses were performed to identify the independent predictors of OS at different T stages.

RESULTS

A total of 2850 patients who underwent laparoscopic radical resection for CRC were enrolled. At stage T1, age [P < 0.01, hazard ratio (HR) = 1.075, 95% confidence interval (CI): 1.019-1.134] and tumour size (P = 0.021, HR = 3.635, 95%CI: 1.210-10.917) were independent risk factors for OS. At stage T2, age (P < 0.01, HR = 1.064, 95%CI: 1.032-1.098) and overall complications (P = 0.012, HR = 2.297, 95%CI: 1.200-4.397) were independent risk factors for OS. At stage T3, only age (P < 0.01, HR = 1.047, 95%CI: 1.027-1.066) was an independent risk factor for OS. At stage T4, age (P < 0.01, HR = 1.057, 95%CI: 1.039-1.075) and body mass index (P = 0. 034, HR = 0.941, 95%CI: 0.890-0.995) were independent risk factors for OS. However, there was no association between LNDs and OS in stages I and II.

CONCLUSION

The number of LDNs did not affect the survival of patients with TNM stages I and II CRC. Therefore, insufficient LNDs should not be a cause for alarm during the 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.

Management of Surgically Accessible Lymph Nodes Beyond Normal Resection Planes

This article discusses the management of isolated metastatic lymph nodes for colon and rectal cancer. There are traditionally significant differences in how certain regions of lymph nodes for colon and rectal cancer are managed in the East and West. This has led to the development of the lateral lymph node dissection for rectal cancer and extended lymphadenectomy techniques for colon cancer. This article will evaluate the literature on these techniques and what the surgical and oncological outcomes are at this time. In addition, colon and rectal cancers can occasionally have isolated distant lymph node metastases. These would traditionally be treated as systemic disease with chemotherapy. There is consideration though that these could be treated as similar to isolated liver or lung metastases which have been shown to be able to be treated surgically with good oncological results. The literature for these isolated distant lymph node metastases will be reviewed and treatment options available will be discussed.

Prognostic Value of Metastatic Lymph Node Ratio and Identification of Factors Influencing the Lymph Node Yield in Patients Undergoing Curative Colon Cancer Resection

Due to the impact of nodal metastasis on colon cancer prognosis, adequate regional lymph node resection and accurate pathological evaluation are required. The ratio of metastatic to examined nodes may bring an additional prognostic value to the actual staging system. This study analyzes the identification of factors influencing a high lymph node yield and its impact on survival. The lymph node ratio was determined in patients with fewer than 12 or at least 12 evaluated nodes. The study included patients after radical colon cancer resection in UICC stages II and III. For the lymph node ratio (LNR) analysis, node-positive patients were divided into four categories: i.e., LNR 1 (<0.05), LNR 2 (≥0.05; <0.2), LNR 3 (≥0.2; <0.4), and LNR 4 (≥0.4), and classified into two groups: i.e., those with <12 and ≥12 evaluated nodes. The study was conducted on 7012 patients who met the set criteria and were included in the data analysis. The mean number of examined lymph nodes was 22.08 (SD 10.64, median 20). Among the study subjects, 94.5% had 12 or more nodes evaluated. These patients were more likely to be younger, women, with a lower ASA classification, pT3 and pN2 categories. Also, they had no risk factors and frequently had a right-sided tumor. In the multivariate analysis, a younger age, ASA classification of II and III, high pT and pN categories, absence of risk factors, and right-sided location remained independent predictors for a lymph node yield ≥12. The univariate survival analysis of the entire cohort demonstrated a better five-year overall survival (OS) in patients with at least 12 lymph nodes examined (68% vs. 63%, p = 0.027). The LNR groups showed a significant association with OS, reaching from 75.5% for LNR 1 to 33.1% for LNR 4 (p < 0.001) in the ≥12 cohort, and from 74.8% for LNR2 to 49.3% for LNR4 (p = 0.007) in the <12 cohort. This influence remained significant and independent in multivariate analyses. The hazard ratios ranged from 1.016 to 2.698 for patients with less than 12 nodes, and from 1.248 to 3.615 for those with at least 12 nodes. The LNR allowed for a more precise estimation of the OS compared with the pN classification system. The metastatic lymph node ratio is an independent predictor for survival and should be included in current staging and therapeutic decision-making processes.

Does robotic TME bring difference in lymph node yield and quality of TME?

BACKGROUNDS

Oncological outcomes of the robotic low anterior rectal resection with total mesorectal excision (TME) are still under discussion. Few studies have proven that robotic TME (rTME) is a safe and equivalent method for treatment of rectal carcinoma. But there is almost no comparison between the rTME and conventional TME in terms of the number of lymph nodes obtained and the quality of the TME.

METHODS

A single institution retrospective study was designed in a cohort of 261 patients. Cohort was divided into two groups depending on the type of surgery (rTME versus TME) and within these two groups, patients were divided according to whether they underwent neoadjuvant chemoradiation (nCHRT) or did not. The primary objective of the study was to compare obtained number of the lymph nodes in specimen. Secondary objectives were comparison of the quality of the TME and the number of positive circumferential resection margins.

RESULTS

Results of the study have shown no significant difference in number of the lymph nodes obtained by the rTME and TME. There was no difference in the quality of the TME, neither in the group with the previous nCHRT nor in the group without a nCHRT.

CONCLUSION

With results from the study we consider the rTME to be non-inferior to the conventional TME. Therefore, at least identical oncological results can be expected in patients treated by the rTME.

The topographical distribution of lymph node metastases in colon cancer resections

In accordance with international guidelines all lymph nodes in colon cancer specimens must be examined to obtain accurate staging. This study aimed to determine the topographical location of lymph node metastases and evaluate if a more limited sampling approach could be an alternative. Partial colectomies received at the Department of Pathology, Zealand University Hospital during a six-month period were included. At the macroscopic examination, each specimen was divided into three different segments: a segment containing the index tumor and the tumor-feeding artery, an oral and an anal segment. The number of lymph nodes and lymph node metastases were registered separately for each segment. Resections from 93 patients were included. Of 2466 lymph nodes, 1839 (74.6 %) were located in the tumor segment, 308 (12.5 %) in the oral, and 319 (12.9 %) in the anal segment, respectively. In 133 (5,4 %) lymph nodes a metastasis was present. Of these 129 (97.0 %) were located in the tumor segment, one (0.8 %) in the oral segment, and three (2.3 %) in the anal segment. No patients had metastasis in the oral or anal segments without metastases also being present in the tumor segment leading to consideration of the need for lymph node harvest of the complete specimen upon initial examination. As such, the segment containing the index tumor and tumor-feeding artery could be regarded as a sentinel segment indicating a potential need for lymph node dissection in the oral and anal segments.

Impact of neoadjuvant chemotherapy for locally advanced colon cancer on postoperative complications

PURPOSE

Although not considered standard therapy, neoadjuvant chemotherapy (NAC) is an encouraging alternative for selected patients with locally advanced colon cancer (LAC). The aim of this study was to compare 30-day postoperative outcomes between patients undergoing upfront surgery and those undergoing NAC for LAC.

METHODS

Using the ACS-NSQIP data from 2016 to 2020, 11,498 patients with LAC were divided into those who underwent upfront colectomy (96.2%) and those who received NAC (3.8%). The primary outcome was a composite outcome encompassing 30-day major postoperative complications. Propensity score matched (PSM) analysis and multivariable logistic regression were performed.

RESULTS

After PSM analysis, there was no statistically significant difference in the development of a major complication. NAC was not significantly associated with the primary outcome. Risk factors for postoperative complications were T4 stage, older age, male sex, black race, smoking, dependent status, severe COPD, hypoalbuminemia, and preoperative transfusion. Laparoscopic and robotic surgery was protective.

CONCLUSION

NAC did not increase the odds of developing a major complication.

Predictors and survival outcomes of having less than 12 harvested lymph nodes in proctectomy for rectal cancer

BACKGROUND

Current recommendations suggest that a minimum of 12 lymph nodes (LNs) should be harvested during curative rectal cancer resection. We aimed to assess predictors and survival outcomes of harvesting < 12 lymph nodes in rectal cancer surgery.

METHODS

A retrospective case-control analysis of factors associated with harvesting < 12 LNs in rectal cancer surgery was conducted. Data were derived from the National Cancer Database 2010-2019. Univariate and multivariate binary logistic regression analyses were performed to determine predictors of harvesting < 12 LNs. Association between harvesting < 12 LNs and 5-year overall survival (OS) was assessed using Cox regression and Kaplan Meier statistics.

RESULTS

67,529 patients (60.8% male; mean age: 61.2 ± 12.5 years) were included. Median number of harvested LNs was 15 (IQR: 11-20); 27.1% of patients had < 12 harvested LNs. Independent predictors of harvesting < 12 LNs were older age (OR: 1.016;p < 0.001), neoadjuvant systemic treatment (OR: 1.522;p < 0.001), neoadjuvant radiation treatment (OR: 1.367;p < 0.001), longer duration of radiation therapy (OR: 1.003;p < 0.001) and abdominoperineal resection (OR: 1.071;p = 0.017). Higher clinical TNM stage and tumor grade, pull-through coloanal anastomosis, and minimally invasive surgery were independently associated with ≥ 12 harvested LNs. < 12 harvested LNs was independently associated with lower 5-year OS (HR: 1.24;p < 0.001) and shorter mean OS (96.7 vs 102.8 months;p < 0.001) than ≥ 12 harvested LNs.

CONCLUSIONS

Older age, open resection, and neoadjuvant therapy were independent predictors of < 12 harvested LNs. Conversely, higher clinical TNM stage and tumor grade, coloanal anastomosis, and minimally invasive surgery were predictive of ≥ 12 harvested LNs. < 12 LNs harvested was associated with lower OS.

Lymph node yield in colorectal cancer specimens and its impact on pathological staging: Does number matter?

Introduction

Regional lymph node involvement is an important predictor of outcome in colorectal cancer (CRC). The lymph node yield in resected specimens varies from case to case.

Aim

To assess whether clinicopathologic factors have an impact on the number of lymph nodes harvested from surgical resection specimens of CRCs To assess whether the total number of lymph nodes retrieved has a bearing on the positivity of lymph nodes and hence the N category.

Materials and Methods

All resection specimens of treatment naïve CRC received in the department of pathology during a 2 year period (2017-2019) were reviewed. The lymph node yield was correlated with age, sex, type of surgical procedure, length of resected segment, tumor location, histological type and grade, T and N categories. The statistical tests used were Spearman rank, Mann-Whitney U, Kruskal-Wallis, and Chi-square tests.

Results

A total of 51 resections were studied. The mean age was 59.64 years with 72.55% being male. About 76.47% were hemicolectomies and 23.52% were rectosigmoid surgeries. The lymph node yield ranged from 0 to 38, the mean being 12.67. None of the parameters studied had a significant correlation with the lymph node yield except histological grade, specimens with higher-grade tumors yielding more number of nodes (P = 0.0242). There was no significant correlation between node positivity and the average number of lymph nodes (P = 0.0883). There was no significant correlation between total yield in cases with ≥12 lymph nodes and N category (P = 0.180). Furthermore, there was no significant correlation between total yield in node-positive cases with ≥12 lymph nodes and N category (P = 0.216). There was no significant difference in the sizes of the lymph nodes in node-positive and negative cases (P = 0.3930 and 0.2355, respectively).

Conclusion

Among the parameters affecting lymph node yield, the current study found a significant correlation between histological grade and lymph node yield. There was no significant difference in the size of lymph nodes between node-positive and negative cases. The total lymph node yield did not have a bearing on node positivity and this shows that a lower lymph node yield may be accepted as adequate after thorough examination of the specimen.

A systematic review and meta-analysis of the use of methylene blue to improve the lymph node harvest in rectal cancer surgery

BACKGROUND

Methylene blue staining of the resected specimen has been described as an alternative to the conventional palpation and visual inspection method to improve lymph node harvest. This meta-analysis evaluates the usefulness of this technique in surgery for rectal cancer, particularly after neoadjuvant therapy.

METHODS

Randomized controlled trials (RCTs) comparing lymph node harvest in methylene blue-stained rectal specimens to those of unstained specimens were identified from the Medline, Embase, and Cochrane databases. Non-randomized studies and those with only colonic resections were excluded. The quality of RCTs was assessed using Cochrane's risk of bias tool. A weighted mean difference (WMD) was calculated for overall harvest, harvest after neoadjuvant therapy, and metastatic nodal yield. In contrast, the risk difference (RD) was calculated to compare yields of less than 12 lymph nodes between the stained and unstained specimens.

RESULTS

Study selection comprised seven RCTs with 343 patients in the unstained group and 337 in the stained group. Overall lymph node harvest and harvest after neoadjuvant therapy were significantly higher in stained specimens with a WMD of 13.4 and 10.6 and a 95% confidence interval (CI) of 9.5-17.2 and 4.8-16.3, respectively. Harvest of metastatic lymph nodes was significantly higher in the stained group (WMD 1.0, 95% CI 0.6-1.4). The yield of less than 12 lymph nodes was significantly higher in the unstained group with RD of 0.292 and 95% CI of 0.182-0.403.

CONCLUSION

Despite a small number of patients, this meta-analysis confirms improved lymph node harvest in surgical specimens stained with methylene blue compared with unstained specimens.

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

Background

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

Methods

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

Results

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

Conclusion

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

Laparoscopic right colectomies with intracorporeal compared to extracorporeal anastomotic techniques are associated with reduced post-operative incisional hernias

Background

Owing to important differences in surgical technique, laparoscopic right colectomy with intracorporeal (ICA) compared to extracorporeal (ECA) anastomotic technique may result in improved patient outcomes. We aimed to compare both techniques according to incisional hernias and other pertinent perioperative characteristics, post-operative complications, and oncologic quality markers.

Methods

All adult patients undergoing laparoscopic right colectomies between 2015 and 2020 at a single institution were included. ICA and ECA techniques were compared based on selected outcomes using univariable and multivariable statistical analyses, as appropriate. Subgroup analyses were restricted to patients with neoplastic indications for surgery and non-urgent operations.

Results

A total of 517 patients met inclusion criteria, of which 139 (26.9%) underwent ICA and 378 (73.1%) underwent ECA. ICA and ECA patients had similar baseline characteristics. At two years of follow-up, a lower proportion of ICA patients developed a hernia at the extraction incision (1.5% vs. 7.1%, p = 0.02) and ICA was associated with an 80% reduction in extraction incision hernias (aHR 0.20, p = 0.03). These results were stable through subgroup and sensitivity analyses. Median operative time was longer in the ICA group (186 min vs. 135 min, p < 0.001), but the gap in operative time narrowed during the study period. Median length of stay was one calendar day shorter in the ICA group (3 days vs. 4 days, p = 0.007) and ICA was associated with a 13% decrease in the length of stay (aRR 0.87, p = 0.02). The incidence of superficial wound infections, anastomotic leaks and re-interventions was lower in ICA patients, but this difference was not statistically significant. 90-day unscheduled visits, readmissions, and mortalities were similar across both groups, as were oncologic outcomes.

Conclusion

Laparoscopic right colectomies with intracorporeal anastomoses are associated with a reduction in incisional hernias and shorter hospital lengths of stay without compromising on patient safety or oncologic principles.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-022-09585-0.

Lymph node regression grading of locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

Neoadjuvant chemoradiotherapy (nCRT) and total rectal mesenteric excision are the main standards of treatment for locally advanced rectal cancer (LARC). Lymph node regression grade (LRG) is an indicator of prognosis and response to preoperative nCRT based on postsurgical metastatic lymph node pathology. Common histopathological findings in metastatic lymph nodes after nCRT include necrosis, hemorrhage, nodular fibrosis, foamy histiocytes, cystic cell reactions, areas of hyalinosis, residual cancer cells, and pools of mucin. A number of LRG systems designed to classify the amount of lymph node regression after nCRT is mainly concerned with the relationship between residual cancer cells and regressive fibrosis and with estimating the number of lymph nodes existing with residual cancer cells. LRG offers significant prognostic information, and in most cases, LRG after nCRT correlates with patient outcomes. In this review, we describe the systematic classification of LRG after nCRT, patient prognosis, the correlation with tumor regression grade, and the typical histopathological findings of lymph nodes. This work may serve as a reference to help predict the clinical complete response and determine lymph node regression in patients based on preservation strategies, allowing for the formulation of more accurate treatment strategies for LARC patients, which has important clinical significance and scientific value.

Is a cutoff value of 12 still useful in stage II right-sided colon cancer without risk factors?

Purpose

Various clinical practice guidelines recommend at least 12 regional lymph nodes should be removed for resected colon cancer. According to a recent study, the lymph node yield (LNY) in colon cancer surgery in the last 20 years has tended to increase from 14.91 to 21.30. However, it is unclear whether these guidelines adequately reflect recent findings on the number of harvested lymph nodes in colon cancer surgery. The aim of this study is to assess the impact of an LNY of more than 25 on survival in right-sided colon cancer.

Methods

We included 285 patients who underwent a right hemicolectomy during the period from January 2010 through December 2015. Patients were divided into two groups (<25 nodes and ≥25 nodes). Primary endpoints included 5-year and 10-year survival including disease-free and overall.

Results

We found that survival outcomes of patients with a harvest of ≥25 nodes were not significantly different compared with a <25 group. Large tumor size (5 cm) is significantly associated with poor 5-year and 10-year overall survival.

Conclusion

Survival outcomes of patients with a harvest of ≥25 nodes were not significantly different compared with the <25 group in stage II colon cancer with no risk.

Validated Risk-Score Model Predicting Lymph Node Metastases in Patients with Non-Functional Gastroenteropancreatic Neuroendocrine Tumors

BACKGROUND

The incidence of, and factors associated with, lymph node metastasis (LN+) in non-functional gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) are not well characterized.

METHODS

Patients were identified from the 2010-2015 National Cancer Database who underwent surgical resection with lymphadenectomy for clinical stage I-III non-functional GEP NETs. Among a randomly selected training subset of 75% of the study population, variables associated with LN+ were identified using multivariable logistic regression analysis, and these variables were used to create a risk-score model for LN+, which was internally validated among the remaining 25% of the cohort.

RESULTS

Of 12,228 patients evaluated, 6,902 (56.4%) had LN+. Among the training set, variables associated with LN+ included age (70 years of age or older: odds ratio [OR] 1.12, 95% CI 1.00-1.24; ref: less than 70 years), tumor location (stomach: OR 3.72, 95% CI 2.94-4.71; small intestine: OR 19.60, 95% CI 17.31-22.19; ref: pancreas), tumor grade (moderately differentiated: OR 1.47, 95% CI 1.30-1.67; poorly differentiated/anaplastic: OR 1.53, 95% CI 1.21-1.95; ref: well-differentiated), tumor size (2-4 cm: OR 2.40, 95% CI 2.13-2.70; >4 cm: OR 5.25, 95% CI 4.47-6.17; ref: <2 cm), and lymphovascular invasion (OR 5.62, 95% CI 5.08-6.21; ref: no lymphovascular invasion). After internal validation, a risk-score model for LN+ using these variables was developed composed of low- (N = 2,779), intermediate- (N = 2,598), high- (N = 3,433), and very-high-risk (N = 3,418) groups; within each group the rate of LN+ was 8.7%, 48.6%, 64.9%, and 92.8%, respectively.

CONCLUSIONS

This developed risk-score model, including both patient and tumor variables, can be used to calculate the risk for LN metastases in patients with GEP NETs.

Long-term Outcomes of Minimally Invasive Versus Open Abdominoperineal Resection for Rectal Cancer: A Single Specialized Center Experience

BACKGROUND

Randomized studies have validated laparoscopic proctectomy for the treatment of rectal cancer as noninferior to an open proctectomy, but most of those studies have included sphincter-preserving resections along with abdominoperineal resection.

OBJECTIVE

This study aimed to compare perioperative and long-term oncological outcomes between minimally invasive and open abdominoperineal resection.

DESIGN

This study is a retrospective analysis of a prospectively maintained database.

SETTINGS

The study was conducted in a single specialized colorectal surgery department.

PATIENTS

All patients who underwent abdominoperineal resection for primary rectal cancer between 2000 and 2016 were included.

MAIN OUTCOME MEASURES

The primary outcomes measured were the perioperative and long-term oncological outcomes.

RESULTS

We included 452 patients, 372 in the open group and 80 in the minimally invasive group, with a median follow-up time of 74 months. There were significant differences between the groups in terms of neoadjuvant radiation treatment (67.5% of the open versus 81.3% of the minimally invasive group, p = 0.01), operative time (mean of 200 minutes versus 287 minutes, p < 0.0001), and mean length of stay (9.5 days versus 6.6 days, p < 0.0001). Overall complication rates were similar between the groups (34.5% versus 27.5%, p = 0.177). There were no significant differences in the mean number of lymph nodes harvested (21.7 versus 22.2 nodes, p = 0.7), circumferential radial margins (1.48 cm versus 1.37 cm, p = 0.4), or in the rate of involved radial margins (10.8% versus 6.3%, p = 0.37). Five-year overall survival was 70% in the open group versus 80% in the minimally invasive group (p = 0.344), whereas the 5-year disease-free survival rate in the open group was 63.2% versus 77.6% in the minimally invasive group (p = 0.09).

LIMITATIONS

This study was limited because it describes a single referral institution experience.

CONCLUSIONS

Although both approaches have similar perioperative outcomes, the minimally invasive approach benefits the patients with a shorter length of stay and a lower risk for surgical wound infections. Both approaches yield similar oncological technical quality in terms of the lymph nodes harvested and margins status, and they have comparable long-term oncological outcomes. See Video Abstract at http://links.lww.com/DCR/B754.RESULTADOS A LARGO PLAZO DE LA RESECCIÓN ABDOMINOPERINEAL MÍNIMAMENTE INVASIVA VERSUS ABIERTA PARA EL CÁNCER DE RECTO: EXPERIENCIA DE UN SOLO CENTRO ESPECIALIZADOANTECEDENTES:Estudios aleatorizados han validado la proctectomía laparoscópica para el tratamiento del cáncer de recto igual a la proctectomía abierta, pero la mayoría de esos estudios han incluido resecciones con preservación del esfínter junto con resección abdominoperineal.OBJETIVO:Comparar los resultados oncológicos perioperatorios y a largo plazo entre la resección abdominoperineal abierta y mínimamente invasiva.DISEÑO:Análisis retrospectivo de una base de datos mantenida de forma prospectiva.ENTORNO CLINICO:Servicio único especializado en cirugía colorrectal.PACIENTES:Todos los pacientes que se sometieron a resección abdominoperineal por cáncer de recto primario entre 2000 y 2016.PRINCIPALES MEDIDAS DE VALORACION:Resultados oncológicos perioperatorios y a largo plazo.RESULTADOS:Se incluyeron 452 pacientes, 372 en el grupo abierto y 80 en el grupo mínimamente invasivo, con una mediana de seguimiento de 74 meses. Hubo diferencias significativas entre los grupos en términos de tratamiento con radiación neoadyuvante (67,5% del grupo abierto versus 81,3% del grupo mínimamente invasivo, p = 0,01), tiempo operatorio (media de 200 minutos versus 287 minutos, p < 0,0001) y la duración media de la estancia (9,5 días frente a 6,6 días, p < 0,0001). Las tasas generales de complicaciones fueron similares entre los grupos (34,5% versus 27,5%, p = 0,177). No hubo diferencias significativas en el número medio de ganglios linfáticos extraídos (21,7 versus 22,2 ganglios, p = 0,7), márgenes radiales circunferenciales (1,48 cm y 1,37 cm, p = 0,4), ni en la tasa de márgenes radiales afectados (10,8 cm). % versus 6,3%, p = 0,37). La supervivencia general a 5 años fue del 70% en el grupo abierto frente al 80% en el grupo mínimamente invasivo (p = 0,344), mientras que la tasa de supervivencia libre de enfermedad a 5 años en el grupo abierto fue del 63,2% frente al 77,6% en el grupo mínimamente invasivo (p = 0,09).LIMITACIONES:Experiencia en una institución de referencia única.CONCLUSIONES:Si bien ambos tienen resultados perioperatorios similares, el enfoque mínimamente invasivo, beneficia a los pacientes con estadía más corta y menor riesgo de infecciones de la herida quirúrgica. Ambos enfoques, producen una calidad técnica oncológica similar en términos de ganglios linfáticos extraídos y estado de los márgenes, y tienen resultados oncológicos comparables a largo plazo. Consulte Video Resumen en http://links.lww.com/DCR/B754. (Traducción - Dr. Fidel Ruiz Healy).

Clinicopathological Factors Affecting Lymph Node Yield and Positivity in Left-Sided Colon and Rectal Cancers

Background

Colorectal cancer (CRC) is a significant cause of cancer‐related deaths worldwide and is the third most common cause of cancer deaths in the UK. The status of lymph node metastasis is a key factor for predicting the prognosis of a patient's CRC.

Aims

This study aimed to analyze the demographics of left-sided colonic and rectal cancers at a single institution. We looked closely at the correlation between patient age and various histological factors. We tried to find any significant difference in lymph node yield (LNY) between laparoscopic surgery (LS) and open surgery (OS). We aimed to identify any statistical correlation between LNY and lymph node positivity (LNP) with other patient, surgical and histopathological features.

Methodology

This is a retrospective, non-interventional review of consecutive patients who underwent left-sided colonic and rectal cancer resections over a three-year period between 01 April 2018 and 31 March 2021. Descriptive and inferential statistical analyses were used. Chi-squared / Fisher exact test was used on a categorical scale between two or more groups and non-parametric setting for qualitative data analysis.

Results

A total of 102 patients were included in the study. No statistical correlation was found between the age of the patient with the LNY, LNP, location of the tumor, type, and urgency of the operation. LNY ranged between one and 43 nodes (median (interquartile range (IQR)) 17, 8). There was no statistically significant difference in LNY between laparoscopic surgery (LS) and open surgery (OS) (p=0.1449). Significant statistical correlation was identified between LNP and completeness of resection (CoR) (p=0.039), vascular invasion (VI) (p<0.001), perineural invasion (PI) (p<0.001), and circumferential resectional margin involvement (CRMI) (p=0.039).

Discussion

LNY and LNP are important prognostic indices in colorectal cancer. Patient age, tumor location, the urgency of surgery, and consultant experience did not significantly impact the LNY. Our study showed a positive correlation between LNP and CRMI, VI and PI comparable to literature. Contrary to other studies, we found no statistical significance between LS vs. OS and LNY. Whether 12 nodes per patient is an appropriate level remains controversial.

Prognostic implications of ENE and LODDS in relation to lymph node-positive colorectal cancer location

•

This is the first study on LODDS and ENE together. The current study showed that LODDS and ENE are liable prognostic parameters of CRC or CC.

•

ENE is an independent influencing factor on the prognosis of both CRC and CC, and the prognostic impact of ENE was observed in both CRC and CC.

•

The frequency of ENE increases from the proximal (right) to the distal (left) colon as well as the rectum.

Background

Extranodal extension (ENE) and log odds of positive lymph nodes (LODDS) are associated with the aggressiveness of both colon and rectal cancers. The current study evaluated the clinicopathological significance and the prognostic impact of ENE and LODDS in the colon and rectal patients independently.

Methods

The clinical and histological records of 389 colorectal cancer (CRC) patients who underwent curative surgery were reviewed.

Results

For the ENE system, 244 patients were in the ENE1 group and 145 in the ENE2 system. Compared with the ENE1 system, the patients included in the ENE2 system were prone to nerve invasion (P < 0.001) and vessel invasion (P < 0.001) with higher TNM (P = 0.009), higher T category (P = 0.003), higher N category (P < 0.001), advanced differentiation (P = 0.013), more number of positive lymph nodes (NPLN) (P < 0.001), more lymph node ratio (LNR) (P < 0.001), and a higher value of LODDS (P < 0.001). ENE was more frequent in patients with left and rectal than right cancer. For the LODDS system, 280 patients were in the LODDS1 group, and 109 in the LODDS2 group. Compared to the LODDS1 group, the patients included in the LODDS2 group were more prone to nerve invasion (P = 0.0351) and vessel invasion (P < 0.001) with a higher rate of N2 stage, less NDLN (P < 0.001), more NPLN (P < 0.001), more LNR (P < 0.001), and a higher value of ENE (P < 0.001). Based on the results in the univariable analysis, the N, NPLN, LNR, LODDS, and ENE were separately incorporated into five different Cox regression models combined with the same confounders. The multivariable Cox regression analysis demonstrated that all the five staging systems were independent prognostic factors for overall survival.

Conclusion

The current study confirmed that the LODDS stage is an independent influence on the prognosis of both CRC and CC patients. ENE is an independent influencing factor on the prognosis of both CRC and CC patients, and the prognostic impact of extracapsular lymph node was observed in both CRC and CC. The frequency of ENE increases from the proximal (right) to the distal (left) colon as well as the rectum. Therefore, combining ENE and LODDS into the current TNM system to compensate for the inadequacy of pN staging needs further investigation.

Outcomes of level of ligation of inferior mesenteric artery in colorectal cancer: a systematic review and meta-analysis

The level of ligation of the inferior mesenteric artery (IMA) is a critical factor that can influence outcomes. The aim of this meta-analysis was to compare outcomes following high or low ligation of IMA. A systematic search was performed for relevant articles published between 2000 and 2020. Meta-analysis was performed using fixed-effects or random-effects models; 31 studies were included. Results show significantly lower rates of anastomotic leak, postoperative morbidity and urinary dysfunction with low ligation compared with high ligation. Though recurrence rates were similar, 5-year overall survival was longer in the low ligation group. Low ligation of IMA decreases anastomotic leak rates and overall morbidity. Addition of IMA nodal clearance to low ligation appears to improve overall survival in colorectal cancer.

Real-world comparison of curative open, laparoscopic and robotic resections for sigmoid and rectal cancer-single center experience

There has been an increase in the utilization of robotic surgery in addition to traditional open or laparoscopic approaches. Aim of this study is to compare the short-term outcomes for open, laparoscopic, and robotic surgery for rectal and sigmoid cancer. One hundred and forty-seven patients (open n = 48, laparoscopic n = 49, robotic n = 50) undergoing curative resections by two surgeons between 2013 and 2020 were included. Data analyzed included patient demographics, tumor characteristics, length of stay, post-operative outcomes, and pathologic surrogates of oncologic results, including total mesorectal excision (TME) quality, circumferential resection margin (CRM) involvement and lymph node (LN) yield. Median age of population was 68 years (IQR 59-73), majority (68%) were males. Median distance from anal verge in the robotic surgery group was 8 cm, compared to 15 and 14.5 cm in the open and laparoscopic groups, respectively, p = 0.029, (laparoscopic vs robotic, p = 0.005 and open vs robotic, p = 0.027). Proportion of patients who received neoadjuvant radiotherapy in robotic surgery group was higher, p = 0.04. In sub-group of tumors between 3 and 7 cm from anal verge more patients in the robotic surgery group had sphincter preservation, p = 0.006. Length of stay, maximum C-reactive protein, and white blood cell rise favored minimally invasive approaches compared to open surgery. There were no differences in post-operative complications, lymph node yield or CRM positivity rate between the three groups. Robotic surgery approach is safe and allows sphincter preservation without compromising TME quality in rectal cancer surgery.

Effect of rurality and socioeconomic deprivation on presentation stage and long-term outcomes in patients undergoing surgery for colorectal cancer

BACKGROUND

Geographical remoteness and socioeconomic status (SES) are important factors affecting presentation stage and survival for colorectal cancer. A series of patients from a single institution in northern New South Wales was studied to determine if rural isolation or SES affected presentation and survival in patients undergoing resection.

METHODS

Consecutive colorectal cancer resections performed at Lismore Base Hospital from 2011 to 2019 were identified. Patient residential addresses were categorized by the Modified Monash Model (MMM), an Australian Government definition of rural isolation, and Socioeconomic Index for Areas (SEIFA) quintiles, an Australian Bureau of Statistics index of socioeconomic deprivation. Univariate and Cox regression survival analysis was performed on data from histopathology and clinical notes matched with survival data.

RESULTS

A total of 405 patients were included in MMM categories 3 (n = 207, 51.1%), 4 (n = 69, 17%) and 5 (n = 129, 31.9) corresponding to large, medium and small rural towns. MMM 3 was associated with emergency cases (25.6% versus 18.7%, P < 0.001), nodal disease (44.4% versus 38.4%, P = 0.018) and T3/4 tumours (82.1% versus 73.7%, P < 0.001) compared with isolated patients without difference in 5-year survival (P = 0.370). Disadvantaged SEIFA quintiles 1/2 demonstrated increased poor differentiation (23.0% versus 15.4%, P < 0.001) and vascular invasion (15.8% versus 9.1%, P < 0.001) with reduced 5-year survival (57.0% versus 70.4%, P = 0.039). Independent predictors of survival included age, emergency cases, group stage, lymphatic invasion and low lymph node yield.

CONCLUSION

A 'rural reversal' may be present for patients in northern New South Wales; however, SES and established clinicopathological factors are the strongest predictors of survival in our population.

Small Molecules for Multi-Wavelength Near-Infrared Fluorescent Mapping of Regional and Sentinel Lymph Nodes in Colorectal Cancer Staging

Assessing lymph node (LN) status during tumor resection is fundamental for the staging of colorectal cancer. Current guidelines require a minimum of 12 LNs to be harvested during resection and ultra-staging regional lymph nodes by sentinel lymph node (SLN) assessment is being extensively investigated. The current study presents novel near-infrared (NIR) fluorescent dyes for simultaneous pan lymph node (PanLN; regional) and SLN mapping. PanLN-Forte was intravenously injected in mice and assessed for accumulation in regional LNs. SLN800 was injected intradermally in mice, after which the collection and retention of fluorescence in SLNs were measured using indocyanine green (ICG) and its precursor, SLN700, as references. LNs in the cervical, inguinal, jejunal, iliac, and thoracic basins could clearly be distinguished after a low dose intravenous injection of PanLN-Forte. Background fluorescence was significantly lower compared to the parent compound ZW800-3A (p < 0.001). SLN700 and SLN800 specifically targeted SLNs with fluorescence being retained over 40-fold longer than the current clinically used agent ICG. Using SLN700 and SLN800, absolute fluorescence in SLN was at least 10 times higher than ICG in second-tier nodes, even at 1 hour post-injection. Histologically, the fluorescent signal localized in the LN medulla (PanLN-Forte) or sinus entry (SLN700/SLN800). PanLN-Forte and SLN800 appear to be optimal for real-time NIR fluorescence imaging of regional and SLNs, respectively.

Using the Fat-Clearing Technique to Improve Lymph Node Retrieval in Colorectal Cancer

College of American Pathologists recommended that at least 12 lymph nodes should be harvested for adequate staging of colorectal carcinoma. Lymph node harvesting is routinely performed by a manual technique of inspection and palpation, which is laborious and time-consuming. The study assessed the influence of the improved fat-clearing technique on the number of lymph nodes retrieved from colorectal cancer specimens and the clinical efficacy. Seventy colorectal cancer resection specimens were examined and assessed by 4 pathology residents. Thirty-five specimens were handled with the conventional manual technique by inspection and palpation, and the other 35 specimens with the improved fat-clearing technique to retrieve lymph nodes. As a result, compared with the conventional manual technique, the numbers of lymph nodes retrieved with the improved fat-clearing technique were significantly increased from 14.7 ± 6.2 lymph nodes to 20.8 ± 9.0 lymph nodes per specimen (P < .05). Besides, the percentage of cases with at least 12 lymph nodes retrieved increased from 80% to 91%. The result of this study pointed out that using the improved fat-clearing technique to process colorectal specimens could increase the lymph node yield effectively, and was effective, practical, and suitable for routine gross examination.

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.

The quality of lymph node harvests in extralevator abdominoperineal excisions

Background

Lymph node (LN) harvest in colorectal cancer resections is a well-recognised prognostic factor for disease staging and determining survival, particularly for node-negative (N0) diseases. Extralevator abdominoperineal excisions (ELAPE) aim to prevent “waisting” that occurs during conventional abdominoperineal resections (APR) for low rectal cancers, and reducing circumferential resection margin (CRM) infiltration rate. Our study investigates whether ELAPE may also improve the quality of LN harvests, addressing gaps in the literature.

Methods

This retrospective observational study reviewed 2 sets of 30 consecutive APRs before and after the adoption of ELAPE in our unit. The primary outcomes are the total LN counts and rates of meeting the standard of 12-minimum, particularly for those with node-negative disease. The secondary outcomes are the CRM involvement rates. Baseline characteristics including age, sex, laparoscopic or open surgery and the use of neoadjuvant chemoradiotherapy were accounted for in our analyses.

Results

Median LN counts were slightly higher in the ELAPE group (16.5 vs. 15). Specimens failing the minimum 12-LN requirements were almost significantly fewer in the ELAPE group (OR 0.456, P = 0.085). Among node-negative rectal cancers, significantly fewer resections failed the 12-LN standard in the ELAPE group than APR group (OR 0.211, P = 0.044). ELAPE led to a near-significant decrease in CRM involvement (OR 0.365, P = 0.088). These improvements were persistently observed after taking into account baselines and potential confounders in regression analyses.

Conclusion

ELAPE provides higher quality of LN harvests that meet the 12-minimal requirements than conventional APR, particularly in node-negative rectal cancers. The superiority is independent of potential confounding factors, and may implicate better clinical outcomes.

Staging of Locally Advanced Rectal Cancer Beyond TME

The management of rectal cancer is complex and continually evolving. With advancements in technology and the use of multidisciplinary teams to guide the treatment decision making, staging, oncologic, and functional outcomes are improving, and the management is moving toward personalized treatment strategies to optimize each individual patient's outcomes. Key in this evolution is imaging. Magnetic resonance imaging (MRI) has emerged as the dominant method of pelvic imaging in rectal cancer, and use of MRI for staging is best practice in multiple international guidelines. MRI allows a noninvasive assessment of the tumor site, relationship to surrounding structures, and provides highly accurate rectal cancer staging, which is necessary for determining the appropriate treatment strategy. However, the applications of MRI extend far beyond pretreatment staging. MRI can be used to predict outcomes in locally advanced rectal cancer and guide the surgical or nonsurgical plan, serving as a predictive and prognostic biomarker. With continued MRI hardware improvement and new sequence development, MRI may offer new perspectives in the assessment of treatment response and new innovations that could provide better insight into the staging, restaging, and outcomes with rectal cancer.

Log odds of positive lymph nodes is prognostically equivalent to lymph node ratio in non-metastatic colon cancer

BACKGROUND

Globally, colorectal cancer (CRC) is the third and second leading cancer in men and women respectively with 600,000 deaths per year. Traditionally, clinicians have relied solely on nodal disease involvement, and measurements such as lymph node ratio (LNR; the ratio of metastatic/positive lymph nodes to total number of lymph nodes examined), when determining patient prognosis in CRC. The log odds of positive lymph nodes (LODDS) is a logistic transformation formula that uses pathologic lymph node data to stratify survival differences among patients within a single stage of disease. This formula allows clinicians to identify whether patients with clinically aggressive tumours fall into higher-risk groups regardless of nodal positivity and can potentially guide adjuvant treatment modalities. The aim of this study was to investigate whether LODDS in colon cancer provides better prognostication compared to LNR.

METHODS

A retrospective study of patients on the prospectively maintained Cabrini Monash University Department of Surgery colorectal neoplasia database, incorporating data from hospitals in Melbourne Australia, identified patients entered between January 2010 and March 2016. Association of LODDS and LNR with clinical variables were analysed. Disease-free (DFS) and overall (OS) survival were investigated with Cox regression and Kaplan-Meier survival analyses.

RESULTS

There were 862 treatment episodes identified in the database (402 male, 47%). The median patient age was 73 (range 22-100 years). There were 799 colonic cancers and 63 rectosigmoid cancers. The lymph node yield (LNY) was suboptimal (< 12) in 168 patients (19.5%) (p = 0.05). The 5-year OS for the different LNR groups were 86, 91 and 61% (p < 0.001) for LNR₀ (655 episodes), LNR₁ (128 episodes) and LNR₂ (78 episodes), respectively. For LODDS, they were 85, 91 and 61% (p < 0.001) in LODDS₀ (569 episodes), LODDS₁ (217 episodes) and LODDS₂ (75 episodes) groups (p < 0.001). Overall survival rates were comparable between the LNR and LODDS group and for LNY < 12 and stage III patients when each were sub-grouped by LODDS and LNR.

CONCLUSION

This study has shown for that the prognostic impact of LODDS is comparable to LNR for colon cancer patients. Accordingly, LNR is recommended for prognostication given its ease of calculation.

Three-dimensional Versus Two-dimensional Laparoscopic Surgery for Colorectal Cancer: Systematic Review and Meta-analysis

BACKGROUND/AIM

Three-dimensional (3D) laparoscopy is being steadily adopted instead of two-dimensional (2D) for various procedures. Our aim was to compare the outcomes between 2D and 3D laparoscopic procedures for colorectal cancer in order to ascertain the safety, efficacy and potential advantages of 3D imaging systems.

MATERIALS AND METHODS

A systematic database search was conducted in March 2019. Comparative studies reporting clinical outcomes between patients undergoing elective colorectal procedures using either 2D or 3D laparoscopic equipment were eligible.

RESULTS

Six studies were selected, including 614 patients in total. Minor reduction in operative time, similar blood loss and increased number of harvested lymph nodes was noted for the 3D group. There was no difference for conversion to open surgery, time to flatus, postoperative hospital stay or postoperative complications.

CONCLUSION

3D Laparoscopic surgery for colorectal cancer may result in reduction of operative time and higher lymph node yields, leading to improved survival.

A reappraisal of lymph node dissection in colorectal cancer during primary surgical resection

Purpose

Controversy exists regarding the extent to which lymph node dissection (LND) should be performed for operable colorectal cancers (CRCs) during primary surgical resection. We reappraised the role of LND in CRCs.

Methods

Seventy-three CRC patients (mean age, 65.3 years; 43 males) undergoing primary surgical resection at Taipei Hospital, Ministry of Health and Welfare, Taiwan, within a 3-year period were retrospectively analyzed. Their pathological T/N/M statuses and cancer stages were defined according to the American Joint Committee on Cancer (AJCC) 8th edition staging system. The numbers of total dissected lymph nodes (TDLNs), positive dissected lymph nodes (PDLNs), and negative dissected lymph nodes (NDLNs) for each CRC patient were recorded in detail (TDLNs = PDLNs + NDLNs). Possible prognostic variables were evaluated.

Results

An advanced N status (N1/N2 vs. N0; HR, 5.749/17.677 vs. 1.000; p = 0.056/0.009) and M1 status (M1 vs. M0; HR, 7.517 vs. 1.000; p = 0.010) were independent variables for a poor prognosis. For all 73 CRC patients (p = 0.030), as well as T2 CRC patients (p = 0.061), those with > 15 TDLNs tended to have more PDLNs than those with ≤ 15 TDLNs. For 42 N(+) CRC patients (p = 0.007), as well as N2 CRC patients (p = 0.011), those with > 21 TDLNs tended to have more PDLNs than those with ≤ 21 TDLNs.

Conclusion

For CRC patients undergoing primary surgical resection, the number of TDLNs influences the accuracy of nodal staging. A minimum of 15 TDLNs is necessary for positive lymph nodes to be identified in CRC patients, and 21 TDLNs is sufficient for the severity of the N(+) status to be distinguished in N(+) CRC patients.

Immunogenicity of Protein Therapeutics: A Lymph Node Perspective

The continuous development of molecular biology and protein engineering technologies enables the expansion of the breadth and complexity of protein therapeutics for in vivo administration. However, the immunogenicity and associated in vivo development of antibodies against therapeutics are a major restriction factor for their usage. The B cell follicular and particularly germinal center areas in secondary lymphoid organs are the anatomical sites where the development of antibody responses against pathogens and immunogens takes place. A growing body of data has revealed the importance of the orchestrated function of highly differentiated adaptive immunity cells, including follicular helper CD4 T cells and germinal center B cells, for the optimal generation of these antibody responses. Understanding the cellular and molecular mechanisms mediating the antibody responses against therapeutics could lead to novel strategies to reduce their immunogenicity and increase their efficacy.

Prognostic importance of lymph node yield after curative resection of gastroenteropancreatic neuroendocrine tumours

BACKGROUND

The prognostic significance of lymph nodes (LNs) metastases and the optimum number of LN yield in gastroenteropancreatic neuroendocrine tumours (GEP NETs) undergoing curative resection is still debatable. Many studies have demonstrated that cure rate for patients with GEP NETs can be improved by the resection of the primary tumour and regional lymphadenectomy

AIM

To evaluate the effect of lymph node (LN) status and yield on relapse-free survival (RFS) and overall survival (OS) in patients with resected GEP NETs.

METHODS

Data on patients who underwent curative resection for GEP NETs between January 2002 and March 2017 were analysed retrospectively. Grade 3 tumours (Ki67 > 20%) were excluded. Univariate Cox proportional hazard models were computed for RFS and OS and assessed alongside cut-point analysis to distinguish a suitable binary categorisation of total LNs retrieved associated with RFS.

RESULTS

A total of 217 patients were included in the study. The median age was 59 years (21-97 years) and 51% (n = 111) were male. Primary tumour sites were small bowel (42%), pancreas (25%), appendix (18%), rectum (7%), colon (3%), gastric (2%), others (2%). Median follow up times for all patients were 41 mo (95%CI: 36-51) and 71 mo (95%CI: 63–76) for RFS and OS respectively; 50 relapses and 35 deaths were reported. LNs were retrieved in 151 patients. Eight or more LNs were harvested in 106 patients and LN positivity reported in 114 patients. Three or more positive LNs were detected in 62 cases. The result of univariate analysis suggested perineural invasion (P = 0.0023), LN positivity (P = 0.033), LN retrieval of ≥ 8 (P = 0.047) and localisation (P = 0.0049) have a statistically significant association with shorter RFS, but there was no effect of LN ratio on RFS: P = 0.1 or OS: P = 0.75. Tumour necrosis (P = 0.021) and perineural invasion (P = 0.016) were the only two variables significantly associated with worse OS. In the final multivariable analysis, localisation (pancreas HR = 27.33, P = 0.006, small bowel HR = 32.44, P = 0.005), and retrieval of ≥ 8 LNs (HR = 2.7, P = 0.036) were independent prognostic factors for worse RFS.

CONCLUSION

An outcome-oriented approach to cut-point analysis can suggest a minimum number of adequate LNs to be harvested in patients with GEP NETs undergoing curative surgery. Removal of ≥ 8 LNs is associated with increased risk of relapse, which could be due to high rates of LN positivity at the time of surgery. Given that localisation had a significant association with RFS, a prospective multicentre study is warranted with a clear direction on recommended surgical practice and follow-up guidance for GEP NETs.

The re-evaluation of optimal lymph node yield in stage II right-sided colon cancer: is a minimum of 12 lymph nodes adequate?

PURPOSE

Adequate lymphadenectomy is critical for accurate nodal staging and planning adjuvant therapy in colon cancer. However, the optimal lymph node (LN) yield for stage II right-sided colon cancer (RSCC) is still unclear. This population-based study aimed to determine the optimal LN yield associated with survival and LN positivity in patients with stage II RSCC.

METHODS

All patients with stage II-III RSCC were identified from the Surveillance, Epidemiology, and End Results database over a 10-year interval (2006-2015). The optimal threshold for LN yield was explored using an outcome-oriented approach based on survival and LN positivity.

RESULTS

The median number of LNs examined for all 17,385 patients with stage II RSCC was 17 (IQR 12-23). Nineteen LNs were determined as the optimal cut-off point to maximize survival benefit from lymphadenectomy. Increased LN yield was associated with a gradual increase in the risk of node positivity, with no change after 19 nodes. Compared with patients with 19 or more LNs examined, the group with fewer LNs had a significantly poor cancer-specific survival (< 12 nodes: hazard ratio (HR) 2.26, P < 0.001; 12-18 nodes: HR 1.58, P < 0.001) and overall survival (< 12 nodes: HR 1.80, P < 0.001; 12-18 nodes: HR 1.31, P < 0.001). Similar survival results were found in the validation cohort. Patients with older age, small tumor size, and appendix and transverse colon cancer were more likely to receive inadequate LN harvest.

CONCLUSION

A minimum of 19 LNs is needed to be examined for optimal survival and adequate node staging in lymph node-negative RSCC.

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.

Tumor sidedness influences prognostic impact of lymph node metastasis in colon cancer patients undergoing curative surgery

This study aimed to evaluate prognostic impacts of the number of lymph nodes (LNs) examined and LN ratio on cancer-specific mortality after surgery in patients with right-sided colon cancer (RCC) or left-sided colon cancer (LCC) using the Surveillance, Epidemiology, and End Results database. Number of LNs examined and LN ratio were treated as categorical and/or continuous. Competing risks proportional hazards regressions adjusted by propensity score were performed. All included patients had stage I, II, or III disease, and 45.1% of them had RCC. RCC and LCC patients with high level of LNs examined had better prognosis after segmental resection or hemicolectomy. RCC and LCC patients with higher LN ratio had worse prognosis regardless of surgery. Survival benefit of having high level of LNs examined was observed in RCC patients with stage I, II, or III disease, but only in LCC patients with stage II disease. Both higher LN ratio and high level of LN were negative prognostic factors for cancer-specific mortality in stage III patients regardless of tumor sidedness. In conclusion, RCC patients in various conditions had worse or comparable prognosis compared to their LCC counterparts, which reflected the severity of LN metastasis.

A Systematic Review and Meta-Analysis of Single-Incision Versus Multiport Laparoscopic Complete Mesocolic Excision Colectomy for Colon Cancer

Background. Our aim was to compare the emerging technique of single-incision laparoscopic surgery complete mesocolic excision (SILS CME) colectomy with the standard multiport laparoscopic CME (MPL CME) colectomy. Methods. MEDLINE (PubMed), Scopus, EMBASE, Ovid, and the Cochrane library were searched. Studies comparing the SILS CME with MPL CME in adults with colon adenocarcinoma were included. The Jadad and Newcastle Ottawa Scales were used to critically appraise the studies. The presence of statistical heterogeneity or publication bias was examined. Results. Seven studies (3 randomized) with a total number of 1344 patients were included (546 SILS CME and 798 MPL CME). No difference was found in anastomotic leakage (odds ratio [OR] = 0.79 [0.31 to 2.03]; P = .63), number of lymph nodes (weighted mean difference [WMD] = 0.85 [-0.97 to 2.66]; P = .36), hospital stay (WMD = 0.01 [-0.19 to 0.20]; P = .96), overall survival (hazard ratio [HR] = 1.19 [0.29 to 4.80]; P = .81), and disease-free survival (HR = 1.30 [0.30 to 5.61]; P = .72). Skin incision was shorter in SILS CME group (WMD = -3.02 [-3.25 to -2.80]; P < .00001) but with no difference in pain reported in postoperative day 1 (standardized mean difference [SMD] = -0.21 [-0.50 to 0.09]; P = .17) or day 2 (SMD = 0.16 [-0.52 to 0.84]; P = .64). Conclusions. SILS CME, although technically more demanding, has equivalent short- and long-term outcomes when compared with MPL CME. Potential benefits in cosmesis or postoperative pain need to be further explored by high-quality randomized controlled trials.

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.

Laparoscopic versus open transverse-incision right hemicolectomy: a retrospective comparison study

BACKGROUND

The optimal surgical approach to right colon cancer is still under debate. The aim of the present study was to compare the short- and long-term outcomes of laparoscopic and transverse-incision open approaches to right hemicolectomy for colon cancer.

METHODS

Data on 99 adult patients with right-side colon cancer undergoing either laparoscopic or open transverse-incision right hemicolectomy at two different university hospitals, between January 2013 and December 2016, were retrospectively reviewed. Data concerning patients' characteristics, operative details and post-operative recovery were retrieved from prospective databases and analysed.

RESULTS

Forty-nine subjects were operated on laparoscopically, while 50 through an open transverse incision. Operating time was significantly longer in the laparoscopic group compared with the open group (182 versus 105 min; P < 0.01). Patients treated laparoscopically had a shorter time to first bowel movement, while time to resume a normal diet and post-operative length of hospital stay were comparable in between groups. The median number of lymph nodes harvested was higher in the laparoscopic group (25.6 versus 18.6; P < 0.01), but no significant difference in overall survival between groups was detected. At long-term follow-up, the incidence of incisional hernia was higher in the laparoscopic group as compared to the open group (24.5% versus 0%; P = 0.0002).

CONCLUSION

Our results show that laparoscopic right hemicolectomy when compared to the transverse-incision open procedure may guarantee the same oncological radicality, but short-term functional benefits are still unclear. Randomized control studies are warranted to better clarify the comparison of these two approaches for right-sided colon cancers.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

PURPOSE

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

METHOD

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

RESULTS

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

CONCLUSION

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

Defining the Role of Lymphadenectomy for Pancreatic Neuroendocrine Tumors: An Eight-Institution Study of 695 Patients from the US Neuroendocrine Tumor Study Group

BACKGROUND

Preoperative factors that reliably predict lymph node (LN) metastases in pancreatic neuroendocrine tumors (PanNETs) are unclear. The number of LNs needed to accurately stage PanNETs has not been defined.

METHODS

Patients who underwent curative-intent resection of non-functional PanNETs at eight institutions from 2000 to 2016 were analyzed. Preoperative factors associated with LN metastases were identified. A procedure-specific target for LN retrieval to accurately stage patients was determined.

RESULTS

Of 695 patients who underwent resection, 33% of tumors were proximal (head/uncinate) and 67% were distal (neck/body/tail). Twenty-six percent of patients (n = 158) had LN-positive disease, which was associated with a worse 5-year recurrence-free survival (RFS; 60% vs. 86%; p < 0.001). The increasing number of positive LNs was not associated with worse RFS. Preoperative factors associated with positive LNs included tumor size ≥ 2 cm (odds ratio [OR] 6.6; p < 0.001), proximal location (OR 2.5; p < 0.001), moderate versus well-differentiation (OR 2.1; p = 0.006), and Ki-67 ≥ 3% (OR 3.1; p < 0.001). LN metastases were also present in tumors without these risk factors: < 2 cm (9%), distal location (19%), well-differentiated (23%), and Ki-67 < 3% (16%). Median LN retrieval was 13 for pancreatoduodenectomy (PD), but only 9 for distal pancreatectomy (DP). Given that PD routinely includes a complete regional lymphadenectomy, a minimum number of LNs to accurately stage patients was not identified. However, for DP, removal of less than seven LNs failed to discriminate 5-year RFS between LN-positive and LN-negative patients (less than seven LNs: 72% vs. 83%, p = 0.198; seven or more LNs: 67% vs. 86%; p = 0.002).

CONCLUSIONS

Tumor size ≥ 2 cm, proximal location, moderate differentiation, and Ki-67 ≥ 3% are preoperative factors that predict LN positivity in resected non-functional PanNETs. Given the 9-23% incidence of LN metastases in patients without such risk factors, routine regional lymphadenectomy should be considered. PD inherently includes sufficient LN retrieval, while DP should aim to remove seven or more LNs for accurate staging.

Predictive Value of [18F]FDG PET/CT for Lymph Node Metastasis in Rectal Cancer

[18F]Fluorodeoxyglucose ([18F]FDG) Positron emission tomography/computed tomography (PET/CT) is commonly used for rectal cancer staging, but improved diagnostic methods for nodal metastases are needed. We aimed to evaluate whether the combination model of the metabolic tumor volume of primary tumor (T_MTV) and maximum standardized uptake value of lymph node (N_SUVmax) on pretreatment [18F]FDG PET/CT could improve nodal metastases prediction in rectal cancer. We enrolled a total of 166 rectal cancer patients who underwent pretreatment [18F]FDG PET/CT and surgical resection without neoadjuvant treatment between January 2009 and August 2016. Visual and semiquantitative PET/CT parameters were obtained. Associations between clinicopathological, PET/CT-derived variables and nodal metastases were evaluated by logistic regression analysis. Nodal metastases were confirmed histologically in 68 of the 166 patients (41%). Uni- and multivariate analyses demonstrated T_MTV and N_SUVmax were independent predictive factors for nodal metastases. The c-statistics of the combination model was 0.806 (Standard Error, 0.034; 95% Confidence Interval, 0.737-0.863), which showed significant improvement compared to T_MTV (0.698, P = 0.0002) or N_SUVmax (0.720, P = 0.0008) alone. T_MTV and N_SUVmax are independently correlated with nodal metastases. Furthermore, the combination model showed improved performance for risk prediction; thus, [18F]FDG PET/CT might have a role in rectal cancer staging and treatment planning.

A Review of Current Challenges in Colorectal Cancer Reporting

Context.—

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

Objective.—

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

Data Sources.—

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

Conclusions.—

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