The total number of lymph nodes in resected colon cancer specimens is affected by several factors but the lymph node ratio is independent of these

Retrospective Cohort Analysis of the Effect of Age on Lymph Node Harvest, Positivity, and Ratio in Colorectal Cancer

Introduction: Colon cancer among young patients has increased in incidence and mortality over the past decade. Our objective was to determine if age-related differences exist for total positive nodes (TPN), total lymph node harvest (TLH), and lymph node ratio (LNR). Material and Methods: A retrospective review of stage III surgically resected colorectal cancer patient data in the National Cancer Database (2004−2016) was performed, reviewing TPN, TLH, and LNR (TPN/TLH). Results: Unadjusted analyses suggested significantly higher levels of TLH and TPN (p < 0.0001) in younger patients, while LNR did not differ by age group. On adjusted analysis, TLH remained higher in younger patients (<35 years 1.56 (CI 95 1.54, 1.59)). The age-related effect was less pronounced for LNR (<35 years 1.16 (CI 95 1.13, 1.2)). Conclusion: Younger patients have increased TLH, even after adjusting for known confounders, while age does not have a strong independent impact on LNR.

Number of negative lymph nodes with a positive impact on survival of stage III colon cancer; a retrospective observation study for right side and left side colon

Background

The purpose was to examine the effect of negative lymph nodes (NLN) number on survival in stage III colon cancer. To reduce the interference of acute inflammation, we included patients with stage III colon cancer who had undergone elective surgery and excluded those who had tumor perforation, obstruction, ischemia, or massive tumor bleeding.

Methods

This retrospective cohort study included 2244 patients with stage III colon cancer between 1995 and 2016 at a single center. The effect of NLN on 5-year relapse-free survival (RFS), 5-year overall survival (OS), and comparison of multivariate factors was assessed according to tumor locations.

Results

The two optimal cutoff values of NLN for proximal and distal colon, namely 27 and 12, were determined by plotting the time-dependent receiver operating characteristic curve. Overall, 499 of 891 and 1020 of 1353 patients with right-side and left-side colon cancer, respectively, had high NLN. In right-side colon cancer, patients with high NLN (≥ 27) had superior OS (74.9% vs. 62.7%, P <  0.001) and RFS (75.0% vs. 61.9%, P <  0.001) than did those with low NLN. Moreover, in left-side colon cancer, patients with high NLN (≥12) experienced significantly superior OS (80.8% vs. 68.6%, P <  0.001) and RFS (77.3% vs. 66.2%, P <  0.001) than did those with low NLN. Among the different subgroups of stage III colon cancer, the high NLN group showed significantly superior RFS and OS in stage IIIB (RFS: 77.0% vs. 68.0%, P = 0.001; OS: 78.6% vs. 67.9%, P <  0.001) and IIIC (RFS: 58.2% vs. 44.1%, P = 0.001; OS: 65.7% vs. 51.1%, P <  0.001) colon cancer. However, in stage IIIA colon cancer, high NLN only showed survival benefit in OS (91.5% vs. 89.8%, P = 0.041). Multivariate analyses confirmed that high NLN, high carcinoembryonic antigen (≥ 5 ng/mL) level, and stage IIIC status are three independent prognostic factors in both the proximal and distal colon.

Conclusions

NLN is a crucial prognostic factor for stage III colon cancer in various tumor locations or in the subgroups of stage III disease. In advanced stage III colon cancer, the importance of NLN and its role in anti-cancer immune response could be highlighted.

Predictors of adequate lymph node harvest during colectomy for colon cancer

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Harvest of lymph nodes in colorectal cancer depends on demographic and clinical characteristics of the patients

PURPOSE

This study aims to study the impact of clinical factors on the lymph node sampling in a large cohort of patients with colorectal cancer.

METHODS

A colorectal cancer database of 2298 patients in Queensland, Australia, was established. Zero-inflated regression method was used to model positive lymph node counts given the number of lymph nodes examined, with patient's demographic and clinical factors as covariates in the model. Sensitivity and survival analyses were performed to illustrate the applicability of the recommendation of the minimum number of lymph nodes need to be pathologically examined.

RESULTS

Younger patients with a larger sized tumour located at the left colon or rectum require fewer lymph nodes to be pathologically examined. Overall, 45.9% of the patients require eight or nine lymph nodes and 31.5% needs ten or 11 lymph nodes to be harvested for pathological examination. A simple formula could be used to obtain the minimum number of lymph node sampling required in patients with colorectal cancer based on patients' age as well as site and dimension of the cancer.

CONCLUSIONS

The findings provide practical information about that the minimum number of lymph nodes that could be harvested at the time of collection of lymph nodes for pathological examination for patients with colorectal cancer. The minimum number of lymph nodes harvested depends on demographic (age) and clinical (location and dimension of cancer) characteristics of the patients with colorectal cancer.

CXCR4, CXCL12 and the relative CXCL12-CXCR4 expression as prognostic factors in colon cancer

The CXCL12-CXCR4 axis is proposed to mediate metastasis formation. In this study, we examined CXCL12, CXCR4 and the relative CXCL12-CXCR4 expression as prognostic factors in two cohorts of colon cancer patients. Immunohistochemistry (IHC) and in situ hybridization (ISH) were used to study CXCR4, CXCL12 and relative CXCL12-CXCR4 expression in tissue microarrays. Our study included totally 596 patients, 290 in cohort 1 and 306 in cohort 2. For tumour, node, metastasis (TNM) stage III, low nuclear expression of CXCR4 was a positive prognostic factor for 5-year disease-free survival (DFS) in cohort 1 (P = 0.007) and cohort 2 (P = 0.023). In multivariate analysis for stage III, nuclear expression of CXCR4 in cohort 1 was confirmed as a prognostic factor for DFS (hazard ratio (HR), 0.27; 95 % CI, 0.09 to 0.77). For TNM stage III, high cytoplasmic expression of CXCL12 was associated with better 5-year DFS in both cohorts (P = 0.006 and P = 0.006, respectively). We further validated the positive prognostic value of CXCL12 expression for 5-year DFS in stage III with ISH (P = 0.022). For TNM stage III, the relative CXCL12-CXCR4 expression (CXCL12 > CXCR4 vs CXCL12 = CXCR4 vs CXCL12 < CXCR4) was a prognostic factor for 5-year DFS in cohort 1 (92 % vs 46 % vs 31 %, respectively; P < 0.001) and cohort 2 (92 % vs 66 % vs 30 %, respectively; P = 0.006). In conclusion, CXCL12 and relative CXCL12-CXCR4 expression are independent prognostic factors for 5-year DFS in TNM stage III colon cancer.

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

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

Prognostic significance of lymph node metastases in small intestinal neuroendocrine tumors

BACKGROUND/AIMS

Current staging guidelines for small intestinal neuroendocrine tumors (SI-NETs) differentiate between the presence (N1) and absence (N0) of lymph node (LN) metastases. However, the prognostic significance of the extent of LN involvement remains unknown. In this study, we used data from a population-based cancer registry to examine whether involvement of a higher number of LNs is associated with worse survival.

METHODS

We used the Surveillance, Epidemiology, and End Results (SEER) database to identify patients with histologically confirmed, surgically resected SI-NETS diagnosed between 1988 and 2010. Patients were classified into three groups by the LN ratio (number of positive LNs/number of total LNs examined, LNR): ≤0.2, >0.2-0.5, and >0.5. We used the Kaplan-Meier method and Cox models to assess NET cancer-specific survival differences (up to 10 years from diagnosis) according to LNR status.

RESULTS

We identified 2,984 surgically resected patients with stage IIIb (N1, M0) SI-NETs with detailed LN data. More than half of the NETs were located in the ileum. A higher LNR was significantly associated with worse NET cancer-specific survival (p < 0.0001). Ten-year NET-specific survival was 85, 77, and 74% for patients in the ≤0.2, >0.2-0.5, and >0.5 LNR groups, respectively. In stratified analyses, higher LNR groups had worse survival only in early tumor (T1, T2) disease (p < 0.0001).

CONCLUSIONS

The extent of LN involvement provides independent prognostic information on patients with LN-positive SI-NETs. This information may be used to identify patients at high risk of recurrence and inform decisions about the use of adjuvant therapy.