Variability in the lymph node retrieval after resection of colon cancer: Influence of operative period and process

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.

Association between the number of retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer: a systematic review and meta-analysis

OBJECTIVE

Clinical practice guidelines recommend retrieving at least 12 lymph nodes for correct staging in colorectal cancer. However, it is difficult to retrieve adequate lymph nodes because of various factors. We aimed to evaluate the association between the number of retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer.

DESIGN

Systematic review and meta-analysis of primary studies.

DATA SOURCES

PubMed, Embase, Cochrane and Web of Science were searched from January 2016 to June 2023.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies that evaluated the association between retrieved lymph nodes and demographic/tumour-related characteristics in colorectal cancer were included.

DATA EXTRACTION AND SYNTHESIS

OR with 95% conference intervals was extracted and pooled.

RESULTS

A total of 54 studies containing 2 05 821 patients were included in this meta-analysis. The results showed that fewer nodes were retrieved from elderly patients (OR=0.70, 95% CI (0.54 to 0.90), p=0.005), and from tumours located in the left colon than in the right colon (OR=0.43, 95% CI (0.33 to 0.56), p<0.001). More lymph nodes were obtained from females than males (OR=1.15, 95% CI (1.04 to 1.28), p=0.006), from the advanced T stage (T3+T4) than T1+T2 stage (OR=1.57, 95% CI (1.25 to 1.97), p<0.001) and from the N2 stage than N0 stage (OR=1.32, 95% CI (1.15 to 1.51), p<0.001). Body mass index, ethnicity, N1 stage, M stage, tumour differentiation and lymph-vascular invasion were not significantly associated with the lymph node yield.

CONCLUSIONS

The study results suggest that clinicians have an increased opportunity to retrieve sufficient lymph nodes for accurate pathological staging to guide treatment decisions in patients with colorectal cancer who are young, female, with tumours located in the right colon, advanced T stage and N2 stage.

N1c colon cancer and the use of adjuvant chemotherapy: a current audit of the National Cancer Database

AIM

Colorectal cancer staging has evolved to define N1c as the presence of tumour deposits without concurrent positive lymph nodes. Work to date reports poor prognosis in N1c colon cancer, with Stage III categorization and adjuvant chemotherapy (AC) recommended. No study has yet evaluated the prevalence, treatment compliance or treatment-related outcomes on a national scale. We aimed to evaluate the prevalence of N1c colon cancer, use, outcomes and factors associated with AC in the USA.

METHOD

The National Cancer Database was reviewed for N1cM0 colon adenocarcinomas that underwent resection from 2010 to 2016. Cases were stratified into 'AC' or 'no AC' cohorts. The Kaplan-Meier method was used to estimate overall survival (OS) and compare the AC and no AC cohorts using the log-rank test. Multivariable logistic regression identified factors associated with AC. The main outcome measures were the prevalence and factors associated with AC use and its impact in N1c disease.

RESULTS

Of the 5684 (1.59% of 357 752) colon adenocarcinomas that were N1c, 55% (n = 3071) received AC. AC significantly improved 1-, 3- and 5-year OS compared with no AC (96.2%, 80%, 67.4% and 72.9%, 48.5%, 33.8%, respectively; P < 0.001). Compared with the no AC group, AC patients were younger, had less comorbidity, were of the male gender and received minimally invasive surgery at an academic treatment centre (all P < 0.05). Socioeconomic and procedural factors significantly impacted the use of AC.

CONCLUSION

In the USA, AC is underutilized in N1c colon cancer despite significantly improved OS. Socioeconomic and procedural factors associated with AC were identified, highlighting disparities in AC use and opportunities to improve oncological outcomes and survival.

Laparoscopic colectomies associated with decreased retrieval of 12 or more lymph nodes compared to open in elective colon cancer surgery

Background

Colorectal cancer is the third most commonly diagnosed cancer worldwide. Lymph node (LN) retrieval is a key factor for pathologic staging and prognosis of colorectal cancer. Increase in number of LNs removal suggests improvement in tumour clearance and decrease in metastatic spread. Studies have suggested that excising 12 or more LNs during colectomy in patients with colon cancer is associated with improved survival. To date, there have been no studies to determine whether minimally invasive surgery affects the ability to retrieve 12+ LNs in elective colon cancer surgery. Therefore, we elected to determine whether a difference exists on the ability to retrieve 12+ nodes in elective colon cancer colectomies performed open versus laparoscopic.

Methods

The National Surgical Quality Improvement Program (NSQIP) Procedure Specific Colectomy database was analysed for the year 2014–2015. Inclusion criteria were colon cancer (ICD-9 Code 153.9), age greater than 18 years. Exclusion criteria were missing data. Data abstracted included patient demographics, type of operation performed and number of LNs retrieved. The patients were categorised based on their elective colon cancer colectomies such as laparoscopic or open. Binary logistic regression was used to identify confounding variables in the retrieval of 12+ LNs.

Results

After accounting for missing cases, a total of 18,792 patients with a diagnosis of colon cancer were analysed. Twelve or more LNs were retrieved in 88% (16,538) of patients, Among them, 2,516 patients underwent laparoscopic colectomy and 5,284 patients underwent open colectomy. The difference was not statistically significant for the average number of LNs retrieved among both the groups. Open operative approach compared to the laparoscopic approach was associated with 15% greater odds of retrieval of >12 LNs (OR 1.148; 95% CI (1.035–1.272); p = 0.008).

Conclusion

The majority of colectomies such as open or laparoscopic are able to retrieve 12 or more LNs. However, there are greater odds of retrieving more than 12 LNs with the open approach compared to the laparoscopic approach. By allowing for more LN retrieval, open colectomies suggest improvement in tumour clearance and decrease metastatic spread. Additional research is needed to further investigate the specific factors influencing the ability to retrieve an adequate number of LNs, such as viewing angles provided with an open approach versus laparoscopic approach.

Selective central vascular ligation (D3 lymphadenectomy) in patients undergoing minimally invasive complete mesocolic excision for colon cancer: optimizing the risk-benefit equation

AIM

Complete mesocolic excision (CME) with central vascular ligation (CVL) has been advocated for right colon adenocarcinoma (RC), but the radicality of vascular dissection remains controversial. Our aim is to report outcomes of selective CVL (D3 lymphadenectomy) during minimally invasive CME for RC.

METHOD

A prospective database identified patients who were treated for RC between 2009 and 2016. Minimally invasive CME was standard. The radicality of lymphadenectomy was defined as high ligation (HL) versus CVL based on operative reports and videos. Two blinded radiologists independently evaluated the pre- and postoperative CT scans for radiographically abnormal nodes.

RESULTS

Of 197 patients who underwent CME, HL was performed in 56 (28%) and CVL in 141 (72%). There were no baseline differences in age, sex, body mass index, American Society of Anesthesiologists score or pathological staging, and there were no major intra-operative complications in either group (including no major vascular injuries). The median total number of nodes retrieved was 27 and 31 (P = 0.011) in HL and CVL groups, resepctively, with pathologically positive nodes identified in 33.9% and 39.8% (P = 0.704), respectively. Preoperative imaging identified abnormal cN3 nodes in 1.5% of patients; all of whom underwent CVL. No abnormal cN2 or cN3 nodes remained on postoperative imaging. The 60-day mortality was 0.5%, and major morbidity was 4%. One patient (0.5%) had an anastomotic recurrence after a median follow-up of 22 months.

CONCLUSION

With imperfect preoperative clinical nodal staging, and in the absence of randomized data, the low morbidity and oncological outcomes observed support the approach of CME with HL as a minimum standard, with CVL (D3 lymphadenectomy) in selected cases.

Preoperative endoscopic tattooing technique improved lymph node retrieval in rectal cancer patients receiving neoadjuvant concurrent chemoradiotherapy

Aims

To describe the clinical utility of lymph node retrieval and prognostic value of tattooing in rectal cancer (RC) patients undergoing neoadjuvant concurrent chemoradiotherapy (CCRT).

Methods

A total 97 RC patients underwent preoperative CCRT, and 38 patients had preoperative endoscopic tattooing. Surgical intervention was performed after CCRT and the specimens were sampled as standard protocol in all patients. Other clinicopathological parameters correlated with lymph node retrieval status were also analysed.

Results

Fifteen patients (39.5%) of 38 RC patients in the tattooing group (TG) had adequate lymph node retrieval (>12) compared with 12 (20.3%) of 59 in the non-tattooing group. Higher lymph node retrieval rate was noted in the TG (p=0.04). In multivariable analysis, it showed tattooing was an independent predictive factor for higher lymph node retrieval in RC patients after CCRT (p=0.024) by logistic regression modelling. Besides histological grade, positive lymphovascular invasion, presence of lymph node metastasis, poor CCRT response and advanced pathological stage, inadequate lymph node retrieval was significantly associated with poor survival (all p<0.05) by Kaplan-Meier analysis. In multivariable analyses, the results revealed that lymph node retrieval (p=0.005), pathological stage (p=0.001) and tumour progression grade (p=0.02) were independent prognostic markers in RC patients receiving CCRT.

Conclusion

Preoperative endoscopic tattooing is a useful technique for RC patient receiving neoadjuvant CCRT. It can improve lymph node retrieval and provide an adequate diagnosis for proper treatment and prognosis.

Right Colon Resection for Colon Cancer: Does Surgical Approach Matter?

BACKGROUND

Surgical resection with curative intent remains the standard of care for colon cancer. This study aims to compare the 30-day outcomes and oncologic results following open, laparoscopic, and robot-assisted right colon resection for colon cancer using the Targeted Colectomy American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database.

MATERIALS AND METHODS

All patients undergoing elective, right colon resection with primary anastomosis were identified within the targeted colectomy ACS-NSQIP database. Only patients with stage I, II, or III colon cancer were included. The association of surgical approach with oncologic results and 30-day morbidity and mortality outcomes was investigated using a variety of statistical tests.

RESULTS

A total of 3518 patients met inclusion criteria; 1024 (29.1%) underwent open surgery (OS), 2405 (63.4%) underwent laparoscopic surgery, and 89 (2.5%) underwent robotic surgery. Patients undergoing OS were significantly more likely to have positive resection margins (P < .001). Patients undergoing OS were significantly more likely to experience prolonged intubation (P = .02), deep wound infections (P = .001), wound dehiscence (P = .005), deep venous thrombosis (P = .04), bleeding requiring a blood transfusion (P < .001), a prolonged postoperative ileus (P < .001), and longer length of hospital stay (P < .001), and were more likely to die (P = .02).

CONCLUSION

The laparoscopic approach to colon resection for colon cancer has lower 30-day morbidity compared to OS. The robotic approach is equivalent to the laparoscopic approach, and its utilization may increase in the future.

A Population-based Study on Lymph Node Retrieval in Patients with Esophageal Cancer: Results from the Dutch Upper Gastrointestinal Cancer Audit

BACKGROUND

For esophageal cancer, the number of retrieved lymph nodes (LNs) is often used as a quality indicator. The aim of this study is to analyze the number of retrieved LNs in The Netherlands, assess factors associated with LN yield, and explore the association with short-term outcomes. This is a population-based study on lymph node retrieval in patients with esophageal cancer, presenting results from the Dutch Upper Gastrointestinal Cancer Audit.

STUDY DESIGN

For this retrospective national cohort study, patients with esophageal carcinoma who underwent esophagectomy between 2011 and 2016 were included. The primary outcome was the number of retrieved LNs. Univariable and multivariable regression analyses were used to test for association with ≥ 15 LNs.

PATIENTS AND RESULTS

3970 patients were included. Between 2011 and 2016, the median number of LNs increased from 15 to 20. Factors independently associated with ≥ 15 LNs were: 0-10 kg preoperative weight loss (versus: unknown weight loss, odds ratio [95% confidence interval]: 0.71 [0.57-0.88]), Charlson score 0 (versus: Charlson score 2: 0.76 [0.63-0.92]), cN2 category (reference: cN0, 1.32 [1.05-1.65]), no neoadjuvant therapy and neoadjuvant chemotherapy (reference: neoadjuvant chemoradiotherapy, 1.73 [1.29-2.32] and 2.15 [1.54-3.01]), minimally invasive transthoracic (reference: open transthoracic, 1.46 [1.15-1.85]), open transthoracic (versus open and minimally invasive transhiatal, 0.29 [0.23-0.36] and 0.43 [0.32-0.59]), hospital volume of 26-50 or > 50 resections/year (reference: 0-25, 1.94 [1.55-2.42] and 3.01 [2.36-3.83]), and year of surgery [reference: 2011, odds ratios (ORs) 1.48, 1.53, 2.28, 2.44, 2.54]. There was no association of ≥ 15 LNs with short-term outcomes.

CONCLUSIONS

The number of LNs retrieved increased between 2011 and 2016. Weight loss, Charlson score, cN category, neoadjuvant therapy, surgical approach, year of resection, and hospital volume were all associated with increased LN yield. Retrieval of ≥ 15 LNs was not associated with increased postoperative morbidity/mortality.