lymph node ratio as a prognostic factor in patients with stage III rectal cancer treated with total mesorectal excision followed by chemoradiotherapy

Standardizing data collection in adjuvant colon cancer trials: A consensus project from the IDEA and ACCENT international consortia and national experts

BACKGROUND

Despite contributions provided by the recent clinical trials, several issues and challenges still remain unsolved in adjuvant colon cancer (CC). Hence, further studies should be planned to better refine risk assessment as well as to establish the optimal treatment strategy in the adjuvant setting. However, it is necessary to request adequate, contemporary and relevant variables and report them homogeneously in order to bring maximal information when analyzing their prognostic value.

MATERIAL AND METHODS

The project was devised to gain a consensus from experts engaged in the planning, accrual and analyses of stage II and III CC clinical trials, to identify mandatory and recommended baseline variables in order to i) harmonize future data collection worldwide in clinical trials dedicated to adjuvant treatment of CC; ii) propose guidance for Case Report Forms to be used for clinical trials in this setting. A total of 72 questions related to variables that should be reported and how to report them in adjuvant clinical trials were approved and then voted to reach a final consensus from panelists.

RESULTS

Data items on patient-related factors, histopathological features, molecular profile, circulating biomarkers and blood analyses were analyzed and discussed by the whole expert panel. For each item, we report data supporting the acquired consensus and the relevant issues that were discussed. Nineteen items were deemed to be mandatory for resected stage III patients and 24 for resected stage II disease. In addition, 9 and 4 items were judged as recommended for stage III and II, respectively.

CONCLUSION

In our opinion, these 28 variables should be used and uniformly reported in more comprehensive CRFs as research groups design future clinical trials in the field of adjuvant colon cancer.

Lymph Node Ratio as a Predictor of Survival for Colon Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Lymph node ratio is the number of lymph nodes with evidence of metastases on pathological review compared to the total number of lymph nodes harvested during oncologic resection. Lymph node ratio is a proven predictor of long-term survival. These data have not been meta-analyzed to determine the prognosis associated with different lymph node ratio cut-offs in colon cancer.

METHODS

Medline, Embase, and CENTRAL were systematically searched. Articles were included if they compared 5-year overall survival (OS) or disease-free survival (DFS) between different lymph node ratios for patients undergoing oncologic resection for stages I-III colon cancer. Pairwise meta-analyses using inverse variance random effects were performed.

RESULTS

From 2587 citations, nine studies with 97,631 patients (female: 51.9%, median age: 61.65 years) were included. A lymph node ratio above .1 resulted in a 49% decrease in the odds of 5-year OS (2 studies; OR: 0.51, 95% CI: 0.49-.53, P < .00001). A lymph node ratio above .25 resulted in a 56% decrease in the odds of 5-year OS (3 studies; OR: 0.44, 95% CI: 0.43-.45, P < .00001). A lymph node ratio above .5 resulted in a 65% decrease in the odds of 5-year OS (3 studies; OR: 0.35, 95% CI: 0.33-.37, P < .00001).

CONCLUSIONS

Lymph node ratios from .1 to .5 are effective predictors of 5-year OS for colon cancer. There appears to be an inverse dose-response relationship between lymph node ratio and 5-year OS. Further study is required to determine whether there is an optimal lymph node ratio cut-off for prognostication and whether it can inform which patients may benefit from more aggressive adjuvant therapy and follow-up protocols.

INFLUENCE OF NEOADJUVANT THERAPY ON THE RATIO OF LYMPH NODES

BACKGROUND

To evaluate the relationship between the ratio of affected lymph nodes (LNR) and clinical and anatomopathological variables in patients with rectal adenocarcinoma submitted or not to neoadjuvant chemoradiotherapy.

METHODS

The LNR was determined by dividing the number of compromised LNR by the total number of LNR dissected in the surgical specimen. Patients were divided into two groups: with QRT and without QRT. In each group, the relationship between LNR and the following variables was evaluated: degree of cell differentiation, depth of invasion in the rectal wall, angiolymphatic /perineural invasion, degree of tumor regression and occurrence of metastases. The LNR was evaluated in patients with more than 1, LNR (LNR >12) or less (LNR<12) in the surgical specimen with overall survival (OS) and disease-free survival (DFS). The results were expressed as the mean with the respective standard deviation. Qualitative variables were analyzed using Fisher's exact test, while quantitative variables were analyzed using the Kruskal -Wallis and Mann-Whitney tests. The significance level was 5%.

RESULTS

We evaluated 282 patients with QRT and 114 without QRT, between 1995-2011. In the QRT Group, LNR showed a significant association with mucinous tumors (P=0.007) and degree of tumor regression (P=0.003). In both groups, LNR was associated with poorly differentiated tumors (P=0.001, P=0.02), presence of angiolymphatic invasion (P<0.0001 and P=0.01), perineural (P=0.0007, P=0.02), degree of rectal wall invasion (T3>T2; P<0.0001, P=0.02); Compromised LNR (P<0.0001, P<0.01), metastases (P<0.0001, P<0.01). In patients with QRT, LNR<12 was associated with DFS (5.889; 95%CI1.935-19.687; P=0.018) and LNR>12 with DFS and OS (17.984; 95%CI5.931-54.351; P<0.001 and 10.286; 95%CI 2.654-39.854; P=0.007, respectively).

CONCLUSION

LNR was associated with histological aspects of poor prognosis, regardless of the use of QRT. In the occurrence of less than 12 evaluated LNR, the LNR was associated only with the DFS.

BACKGROUND

• Assessment of the lymph nodes during pathological analysis of the surgical specimen is crucial to determine treatment and prognosis.

BACKGROUND

• Neoadjuvance therapy reduces the number of lymph nodes, being lower than recommended, therefore the lymph node ratio can be an alternative analysis for a better prognosis.

A retrospective study analyzing if lymph node ratio carbon nanoparticles predict stage III rectal cancer recurrence

Background

Lymph node ratio has garnered increasing attention as a prognostic marker for rectal cancer; however, few studies have investigated the relationship between lymph node ratio and rectal cancer recurrence. Additionally, Carbon Nanoparticle tracking is a safe and effective strategy for locating tumors and tracking lymph nodes. However, no studies have reported the relationship between Carbon Nanoparticles and rectal cancer recurrence.

Methods

Patients with stage III rectal cancer who underwent radical resection between January 2016 and 2020 were analyzed. The primary outcome was tumor recurrence. 269 patients with stage III rectal cancer were included in this study. The effects of lymph node ratio, Carbon Nanoparticles, and other clinicopathological factors on rectal cancer recurrence were assessed using univariate, multivariate analyses and the t-test.

Results

Univariate analysis determined tumor recurrence using cytokeratin 19 fragment, CA-199, CEA, N-stage, positive lymph nodes, total lymph nodes, and lymph node ratio(positive/total); with the lymph node ratio being the most relevant. Receiver operating characteristic (ROC) analysis determined lymph node ratio =0.38 as the optimal cutoff value. The analysis of lymph node ratio ≥0.38 and <0.38 showed statistical differences in three indicators: tumor recurrence, CEA, and use of Carbon Nanoparticles.

Conclusion

Lymph node ratio is a strong predictor of stage III rectal cancer recurrence and may be considered for inclusion in future tumor-node-metastasis staging and stage III rectal cancer stratification. In addition, we found that Carbon Nanoparticles use significantly increased total lymph nodes and decreased lymph node ratio.

Post-Chemoradiation Metastatic, Persistent and Resistant Nodes in Locally Advanced Rectal Cancer: Metrics and Their Impact on Long-Term Outcome

BACKGROUND

The purpose of this study was to evaluate the long-term oncological progression pattern of locally advanced rectal cancer patients with post-neoadjuvant nodal metastatic disease (ypN+) and correlate potential prognostic features associated with proven radiochemoresistant nodal biology.

METHODS

Individual patient data (100 variables) from a 20-year consecutive single-institution multidisciplinary experience (1995-2015), delivering multimodal therapy to rectal cancer patient candidates for radical treatment, including a neoadjuvant component and surgical resection with or without intraoperative radiotherapy followed by optional adjuvant chemotherapy. The ypN+ disease data was registered in the context of initial staging categories post-neoadjuvant T status (ypT).

RESULTS

Data on 487 patients showed histologically confirmed diagnoses of metastatic nodal disease in 108 specimens (ypN+, 22.1). There was a significant age difference (p = 0.009) between the ypN groups: age ≥ 65 was 57.6% in pN0 and 43.5% in ypN+ and patients aged < 65 constituted 42.4% of pN0 and 56.5% of ypN+. According to the clinical stage there were statistically significant differences (p = 0.001) in the categories' distribution: ypN+ patients 10.8% were stage II and 89.2% were stage III. Univariant analysis on outcome variables showed statistically significant differences in overall survival at 7 years (63.8% vs. 55.7%, p = 0.016) disease-free survival (DFS) (78% vs. 53.8%, p = 0.000) and local recurrence-free survival (LRFS) (93.6% vs. 84%, p = 0.002).

CONCLUSIONS

The presence of nodal metastases (ypN+) after neoadjuvant therapy containing long-course pelvic irradiation severely impacts the long-term outcome for patients with locally advanced rectal cancer and correlates with multiple clinical and therapeutic variable metrics. Implementation of local and systemic therapies should be adapted and intensified in relation to the finding of ypN+ category in surgical specimens.

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.

Systemic inflammation score as a preoperative prognostic factor for patients with pT2-T4 resectable gastric cancer: a retrospective study

BACKGROUND

Systemic inflammation has been reported to be associated with cancer progression and metastasis. Systemic inflammation score (SIS), calculated from preoperative serum albumin level and lymphocyte-to-monocyte ratio, has been shown to be a novel prognostic factor for several types of tumors. This study aimed to evaluate the prognostic value of the SIS in patients with pT2-4 resectable gastric cancer (GC).

METHODS

Total 97 patients with pT2-4 GC who underwent curative surgery from 322 cases between 2009 and 2015 in Fukushima Medical University Hospital were included. We performed univariate and multivariate analyses to evaluate the usefulness of preoperative SIS and other prognostic factors for relapse-free survival (RFS) and overall survival (OS).

RESULTS

The higher SIS score was associated with undifferentiated cancer and recurrence. Univariate analysis of RFS identified deeper tumor invasion and higher SIS were significant risk factors and multivariate analysis revealed that both of them were independent prognostic factors for RFS. As for OS, age, tumor invasion, SIS and LNR were significantly correlated with RFS. In multivariate analysis, tumor invasion, SIS and LNR were independent prognostic factors for OS.

CONCLUSIONS

SIS was an independent prognostic factor for RFS and OS in pT2-4 resectable gastric cancer patients who underwent curative gastrectomy.

The prognostic value of the number of positive lymph nodes and the lymph node ratio in early-stage cervical cancer

INTRODUCTION

To establish the impact of the number of lymph node metastases (nLNM) and the lymph node ratio (LNR) on survival in patients with early-stage cervical cancer after surgery.

MATERIAL AND METHODS

In this nationwide historical cohort study, all women diagnosed between 1995 and 2020 with International Federation of Gynecology and Obstetrics (FIGO) 2009 stage IA2-IIA1 cervical cancer and nodal metastases after radical hysterectomy and pelvic lymphadenectomy from the Netherlands Cancer Registry were selected. Optimal cut-offs for prognostic stratification by nLNM and LNR were calculated to categorize patients into low-risk or high-risk groups. Kaplan-Meier overall survival analysis and flexible parametric relative survival analysis were used to determine the impact of nLNM and LNR on survival. Missing data were imputed.

RESULTS

The optimal cut-off point was ≥4 for nLNM and ≥0.177 for LNR. Of the 593 women included, 500 and 501 (both 84%) were categorized into the low-risk and 93 and 92 (both 16%) into the high-risk groups for nLNM and LNR, respectively. Both high-risk groups had a worse 5-year overall survival (p < 0.001) compared with the low-risk groups. Being classified into the high-risk groups is an independent risk factor for relative survival, with excess hazard ratios of 2.4 (95% confidence interval 1.6-3.5) for nLNM and 2.5 (95% confidence interval 1.7-3.8) for LNR.

CONCLUSIONS

Presenting a patient's nodal status postoperatively by the number of positive nodes, or by the nodal ratio, can support further risk stratification regarding survival in the case of node-positive early-stage cervical cancer.

Application of Carbon Nanoparticles in Tracing Lymph Nodes and Locating Tumors in Colorectal Cancer: A Concise Review

Background

Accurate lymph node (LN) staging has considerably prognostic and therapeutic value in patients with colorectal cancer (CRC). The purpose of this study is to evaluate the feasibility of applying carbon nanoparticles (CNPs) to track LN metastases in CRC.

Methods

Two researchers independently screened publications in PubMed, EMBASE, Cochrane and Ovid MEDLINE databases. The keywords were (carbon nanoparticles OR activated carbon nanoparticles) AND (colon cancer OR rectal cancer OR colorectal cancer). Titles and abstracts of the articles were meticulously read to rule out potential publications. Next, full texts of the ultimately obtained eligible publications were retrieved and analyzed in detail.

Results

The search produced 268 publications, and 140 abstracts were identified after a bibliographic review. Finally, 20 studies relevant to our subject were obtained; however, only 14 papers met our inclusion criteria and were included for final review. All studies included have compared the control group with carbon nanoparticles group (control group, defined as nontattooed group; and carbon nanoparticles group, defined as administering carbon nanoparticles during surgery) for their efficacy in intraoperative detecting and positioning. After analysis, appreciably less amount of bleeding (3/5 trials), shorter operation time (2/4 trials), and shorter time to detect lesions and dissect LNs (2/2 trials) were revealed in CNPs group compared to control group. Thirteen studies have recorded the numbers of the harvested LNs in both groups; meanwhile, CNPs group shows superiority to control group in LN retrieval as well (11/13 trials), which also could effectively aid in locating and harvesting more LNs with diameter below 5 mm.

Conclusion

The tracing technique for CNPs is a safe and useful strategy both in localizing tumor and tracing LNs in CRC surgery. But there is still a need for more randomized controlled trials to further establish its contribution to patient survival.

Prognostic Factors Affecting Short- and Long-Term Recurrence-Free Survival of Patients with Rectal Cancer using Cure Models: A Cohort Study

Background:

Understanding the prognostic factors affecting the recurrence-free survival (RFS) of patients with rectal cancer (RC) is the mainstay of care. The present study aimed to identify factors affecting both short- and long-term RFS of patients with RC using semiparametric mixture cure models.

Methods:

The data were obtained from the database of the Colorectal Research Center of Shiraz University of Medical Sciences, Shiraz, Iran, which was collected during 2007-2017. To determine the factors affecting recurrence, cure models were applied to short-term and long-term RFS of patients with RC separately. The cure rate was calculated using the smcure package in R 3.5.1 (2018-07-02) software. P<0.05 was considered statistically significant.

Results:

Out of the 376 eligible patients with RC, 75.8% of men and 74.5% of women were long-term survivors. The mean age of the patients was 57.0±13.8 years. Lymph node ratio (LNR)≤0.2 increased the probability of short-term RFS. The prominent factors affecting long-term RFS were body mass index (BMI)<25 kg/m² (OR=1.98, P=0.047), tumor-node-metastasis (TNM) stage (OR=6.48, P<0.001), abdominal pain (OR=2.15, P=0.007), and computed tomography (CT) scan detected pelvic lymph nodes (OR=3.40, P=0.01). Over a 9-year follow-up period, the empirical and estimated values of cure rates were 75.3% and 83.9%, respectively.

Conclusion:

The results showed that factors affecting short-term RFS might be different from long-term RFS. A lower BMI was related to a poorer prognosis in patients with RC. Early diagnosis leads to a lower TNM stage and could increase the probability of long-term RFS.

Lymph Node Ratio as a Prognostic Marker in Rectal Cancer Survival: A Systematic Review and Meta-Analysis

Introduction 

The lymph node ratio (LNR) is defined as the ratio of the number of positive lymph nodes to the total number of nodes retrieved. LNR has recently emerged as a prognostic factor in rectal cancer. The objective of our study was to pool eligible studies to elucidate the prognostic role of LNR on overall survival (OS) and disease-free survival (DFS) in rectal cancer patients using a meta-analysis.

Methods

A systematic database search was performed in MEDLINE and Embase for relevant studies that reported LNR in rectal cancer. Two authors independently screened the relevant articles for selection and data extraction. As a result, a list of such studies and references, published in English up to December 2019, was obtained, and a total of 4,486 node-positive patients in 18 studies were included in this meta-analysis. RevMan software 5.3 (Cochrane Collaboration, the Nordic Cochrane Centre, Copenhagen) was used for conducting all statistical analyses.

Results

A higher LNR was significantly correlated with worse OS [hazard ratio (HR): 2.60; 95% confidence interval (CI): 2.21-3.06; p≤.00001] and DFS (HR: 2.43; 95% CI: 2.11-2.80; p≤.00001) in node-positive rectal cancer patients. Besides, LNR is an independent predictive and prognostic marker of OS and DFS (HR: 2.52; 95% CI: 2.17-2.94; p≤.00001 with I²=0%; p=.32 and HR: 2.63; 95% CI: 2.17-3.18; p≤.00001 with I²=0%; p=.63 respectively, irrespective of lymph nodal harvest).

Conclusions

Our present study demonstrates that LNR is an independent predictor of survival in rectal cancer. LNR should be considered as a parameter in future oncological staging systems. Further well-designed randomized control trials to prospectively assess LNR as an independent predictor of rectal cancer survival are necessary before its application in daily practice.

Contrast-enhanced CT imaging for the assessment of lymph node status in patients with colorectal cancer

The aim of the present study was to identify a novel strategy that predicts the metastatic status of lymph nodes (LNs) in patients diagnosed with colorectal cancer, using detailed characteristics of contrast-enhanced CT scan images. A total of 284 preoperative CT scans derived from patients diagnosed with colorectal cancer at Second Affiliated Hospital, Zhejiang University School of Medicine between January 2013 and July 2018 were retrospectively reviewed. A total of 794 LNs were assessed for size, margins, morphology and subtle internal enhancements in the equilibrium phase. Imaging features were analyzed by two abdominal radiologists (Department of Radiology, Second Affiliated Hospital, Zhejiang University School of Medicine and Departments of Radiology; Shaoxing Second Hospital Departments of Radiology, Shaoxing Second Hospital) in a blind manner. If the conclusions were not concordant, the final score was determined by a senior radiologist who specialized in abdominal radiology for ≥30 years. According to the histopathology results, 27.3% (217/794) of LNs were metastatic (LN+). In addition, LNs >10 mm in size demonstrated sensitivity, specificity, positive predictive values (PPVs) and negative predictive values (NPVs) of 47.0, 80.9, 48.1 and 80.2%, respectively [odds ratio (OR), 3.77; 95% confidence interval (CI), 2.69–5.28]. LNs in the shape of a kidney bean (middle fat depression like kidney) and/or those with an oblong shape were more likely to be metastasis negative LNs (LN-), while lobulated and irregular LNs were more likely to be LN+. In magnified images, internal enhancement characteristics of LN- were defined as homogeneous, spotted, striped and core enhancing. By contrast, rim and heterogeneity enhancement features for LN+ demonstrated sensitivity, specificity, PPVs and NPVs of 46.5, 89.9, 63.5 and 81.7%, respectively (OR, 7.79; 95% CI, 5.33–11.40). The results demonstrated that the internal enhancement features of LNs may be used as a predictor of metastasis. The detailed benign characteristics, such as homogeneity, spotted, striped and core enhancement of LNs may facilitate the identification of LN- in patients with colorectal cancer.

Prognosis of colorectal cancer patients is associated with the novel log odds of positive lymph nodes scheme: derivation and external validation

Background and aim: To construct proper and externally validate cut-off points for log odds of positive lymph nodes scheme (LODDS) staging scheme in colorectal cancer (CRC). Patients and methods: The X-tile approach was used to find the cut-off points for the novel LODDS staging scheme in 240,898 patients from the Surveillance, Epidemiology and End Results (SEER) database and externally validated in 1,878 from the international multicenter cohort. Kaplan-Meier plot and multivariate Cox proportional hazard models were performed to investigate the role of the novel LODDS classification. Results: The prognostic cut-off values were determined as -2.18, and -0.23 (P< 0.001). Patients had 5-year cancer-specific survival rates of 83.8%, 57.4% and 24.4% with increasing LODDS (P< 0.001) in the SEER database. Five-year overall survival rates were 77.2%, 55.0% and 26.7% with increasing LODDS (P< 0.001) in the external international multicenter cohort. Multivariate survival analysis identified both the LODDS classification, the patient's age, the T category, the M status, and the tumor grade as independent prognostic factors in both two independent databases. The analyses of the subgroup of patients stratified by tumor location (colon or rectum), number of retrieved lymph node (< 12 or ≥ 12), TNM stage III, lymph node-negative also confirmed the LODDS as independent prognostic factors (P< 0.001) in both two independent databases. Conclusions: The novel LODDS classification was an independent prognostic factor for patients with CRCs and should be calculated for additional risk group stratification with pN scheme.

Clinical Implications of Lymph Node Metastasis in Colorectal Cancer: Current Status and Future Perspectives

Lymph node metastasis is regarded as an indubitable prognostic factor for predicting disease recurrence and survival in patients with colorectal cancer. Lymph node status based on examination of a resected specimen is a key element of the current staging system and is also a crucial factor to determine use of adjuvant chemotherapy after surgical resection. However, the current tumor-node-metastasis (TNM) staging system only incorporates the number of metastatic lymph nodes in the N category. Numerous attempts have been made to supplement this simplified N staging including lymph node ratio, distribution of metastatic lymph nodes, tumor deposits, or extracapsular invasion. In addition, several attempts have been made to identify more specific prognostic factors in resected colorectal specimens than lymph node status. In this review, we will discuss controversies in lymph node staging and factors that may influence survival beyond lymph node status.

Effect of Responsiveness of Lymph Nodes to Preoperative Chemoradiotherapy in Patients With Rectal Cancer on Prognosis After Radical Resection

BACKGROUND

The influence of lymph node (LN) response to preoperative chemoradiotherapy (PCRT) has not been well evaluated for prognosis and additional use of adjuvant treatment after PCRT in rectal cancer patients. The aim of this study was to evaluate the prognostic effect of LN regression grade (LRG) in rectal cancer after PCRT and radical resection.

PATIENTS AND METHODS

From 2008 to 2011, 389 patients with rectal cancer treated with PCRT followed by radical resection were identified. The pathologic LRG (pLRG) score was determined on the basis of the proportion of tumor cells and fibrosis. The sum of the pLRG of each evaluated LN was used as the final LRG score, LRG-sum. Cox regression analysis was used to evaluate the association of LRG-sum and recurrence-free survival (RFS).

RESULTS

The distribution of LRG-sum was significantly associated with tumor regression grade of the primary tumor (P < .001). LRG-sum showed different values even in patients with the same number of metastatic LNs. LRG-sum was confirmed as the most relevant associated factor among LN-related variables with RFS along with ypT stage in multivariate analysis. Patients were categorized according to the cutoff points of LRG-sum distribution: LRG1 (LRG-sum 0 to ≤3), LRG2 (LRG-sum 3 to ≤21), and LRG3 (LRG-sum >21). RFS showed a significant difference according to LRG group (P < .001) and showed more effective difference in RFS in the same ypN stage subgroup on the basis of the number of metastatic LNs.

CONCLUSION

LRG was a prognostic factor of oncologic outcomes of rectal cancer. LN response to PCRT might help in prognostication and determination of treatments after PCRT.

Prognostic significance of lymph node ratio in node-positive cervical cancer patients

To determine whether the pelvic lymph node ratio (LNR) has significant prognostic value for survival and disease recurrence in node-positive, early stage cervical cancer patients.The medical records of 872 consecutive women who received postoperative adjuvant chemoradiotherapy were reviewed. Of these, 397 women with pathologically proven lymph nodal metastasis were included in this analysis and categorized into 3 groups according to their LNR: low (<0.1, n = 251), intermediate (0.1-0.4, n = 121), and high (>0.4, n = 25). The association between LNR and oncological outcome was evaluated using the Kaplan-Meier method and multivariate analysis.A total of 13,491 LNs were retrieved from 397 women, with a median harvest of 32 nodes per patient. There was a strong positive correlation between the number of metastatic LNs and LNR (r = 0.83, P < .01). With a median follow-up duration of 48 months, the 5-year overall survival (OS) and disease-free survival (DFS) rates were 73% and 67%, respectively. The OS and DFS curves among the pelvic LNR groups significantly differed: the 5-year OS rates of the low, intermediate, and high pelvic LNR groups were 83%, 66%, and 17% (P < .01), and the 5-year DFS rates were 77%, 56%, and 20% (P < .01), respectively.LNR is an important prognostic factor for survival outcomes in patients with uterine cervical cancer who underwent radical hysterectomy followed by adjuvant chemoradiotherapy.

Prognostic role of the lymph node ratio in node positive colorectal cancer: a meta-analysis

The lymph node ratio (LNR) (i.e. the number of metastatic lymph nodes divided by the number of totally resected lymph nodes) has recently emerged as an important prognostic factor in colorectal cancer (CRC). However, the tumor node metastasis (TNM) staging system for colorectal cancer does not consider it as a prognostic parameter. Therefore, we conducted a meta-analysis to evaluate the prognostic role of the LNR in node positive CRC. A systematic search was performed in PubMed, Embase and the Cochrane Library for relevant studies up to November 2015. As a result, a total of 75,838 node positive patients in 33 studies were included in this meta-analysis. Higher LNR was significantly associated with shorter overall survival (OS) (HR = 1.91; 95% CI 1.71–2.14; P = 0.0000) and disease free survival (DFS) (HR = 2.75; 95% CI: 2.14–3.53; P = 0.0000). Subgroup analysis showed similar results. Based on these results, LNR was an independent predictor of survival in colorectal cancer patients and should be considered as a parameter in future oncologic staging systems.

Negative to positive lymph node ratio is a superior predictor than traditional lymph node status in stage III colorectal cancer

Negative lymph node counts has recently attracted attention as a prognostic indicator in colorectal cancer (CRC). But little is known about prognostic significance of negative to positive lymph node ratio (NPR) in CRC. Our aim was to determine impact of NPR on oncological outcomes in patients with stage III CRC. This retrospective study included 2,256 patients with stage III CRC under curative resection at Fudan university Shanghai cancer center. Kaplan-Meier methods and multivariable Cox regression models were built for the analysis of survival outcomes and risk factors. Accuracy of the NPR was assessed with the Harrell's concordance-index(C-index).X-tile program identified 2.38 or 0.55/2.38 as the optimal cutoff value for NPR to divide the cohort into high/low risk or high/middle/low risk subsets in terms of CRC cause specific survival (CCSS). In a multivariate analysis, NPR was significant independent prognostic factors for CCSS (P<0.05), notably, N classification was not an independently prognostic factor (P>0.05). Further analysis found NPR could give detailed prognostic classification for both N1 and N2 stage (P<0.05). Interestingly, patients in N2+ NPR >2.38 stage have similar survival outcome with N1+ NPR >2.38 stage (χ2=0.030, P=0.863), and better than those at N1+ NPR ≤2.38 and N2+ NPR ≤2.38 stage (P<0.001). The TN_NPRM stage was more accurate for predicting CCSS (C-index = 0.659) than current TNM stage system(C-index = 0.628) (P<0.001). Collectively, NPR was an independent prognostic factor for stage III CRC patients, it could provide more accurate prognostic information than the current node stage system.

Population-based screening improves histopathological prognostic factors in colorectal cancer

INTRODUCTION

Diagnosis of colorectal cancer (CRC) based on clinical symptoms is usually established in its advanced stages. One strategy for reducing mortality is the early detection and removal of preneoplastic and initial neoplastic lesions, even before the first symptoms appear, by means of population-based screening campaigns. The aim of the present study is to determine whether CRC diagnosed via a screening campaign has more favourable histopathological prognostic factors than when diagnosed in the symptomatic phase.

MATERIAL AND METHODS

The prospective study of all the patients undergoing programmed CRC surgery at the JM Morales Meseguer Hospital (Spain) is between 2004 and 2010. The patients were divided into two groups: one diagnosed from clinical symptoms and one through a screening campaign. The following factors were compared: tumour size; degree of tumour invasion of the wall; lymph node, perineural and lymphovascular involvement; tumour stage; and grade of differentiation.

RESULTS

Compared to the symptomatic group, the screen-detected patients had smaller-sized tumours (lesions of less than 5 cm in 84 vs 69.55%, p < 0.001), a lower degree of colorectal wall invasion (T0-1 in 36 vs 9.02%, p < 0.001), less lymph node involvement (N0 in 72 vs 58.76%, p > 0.05), less vascular invasion (7.20 vs 15.22%, p = 0.79) and less perineural invasion (6.4 vs 20.70%, p < 0.001). The TNM staging in the screening group was lower than in the symptomatic group (stage 0-1 in 50.40 vs 18.58%, p < 0.001).

CONCLUSIONS

CRC diagnosed through a population-based screening programme presents more favourable histopathological characteristics than that diagnosed from the appearance of symptoms.

10-Year Oncologic Outcomes After Laparoscopic or Open Total Mesorectal Excision for Rectal Cancer

BACKGROUND

Only few studies have compared laparoscopic total mesorectal excision (LTME) and open total mesorectal excision (OTME) for rectal cancer with follow-up longer than 5 years. The aim of this study was to compare 10-year oncologic outcomes after LTME and OTME for nonmetastatic rectal cancer.

METHODS

We conducted a retrospective analysis of a prospective database of rectal cancer patients undergoing LTME or OTME. Statistical analyses were performed on an ''intention-to-treat'' basis and by actual treatment. Overall survival (OS) and disease-free survival (DFS) were compared by using the Kaplan-Meier method. A multivariable analysis was performed to identify predictors of poor survival.

RESULTS

Between April 1994 and August 2005, a total of 153 LTME patients and 154 OTME patients were included. Similarly, 10-year OS and DFS after LTME and OTME were observed: 76.8 versus 70.6 % (P = 0.138) and 69.1 versus 67.6 % (P = 0.508), respectively. Conversion to OTME did not adversely affect OS and DFS. Stage-by-stage comparison showed no significant differences between LTME and OTME. No significant differences were observed in local recurrence rates after LTME and OTME (6.5 vs. 7.8 %, P = 0.837). Median time until local recurrence was 24.5 (range, 12-56) months after LTME and 22 (6-64) months after OTME (P = 0.777). Poor tumor differentiation, lymphovascular invasion, and a lymph node ratio of 0.25 or more were the independent predictors of poorer OS and DFS.

CONCLUSION

This retrospective study with long follow-up did not show significant differences between the two groups in OS and DFS.

Extranodal extension status is a powerful prognostic factor in stage III colorectal cancer

Purpose

The present study aimed to evaluate the clinicopathologic characteristics of patients with extranodal extension (ENE) and the prognostic implications of ENE in stage III colorectal cancer (CRC).

Results

ENE was more frequent in younger patients and those with rectal cancer, higher T stage, higher N stage, lymphovascular invasion (LVI), and perineural invasion (PNI). Five-year disease-free survival (DFS) and overall survival (OS) were lower in patients with ENE-positive than in those with ENE-negative tumors (DFS, 66.4% vs. 80.1%; and OS, 74.8% vs. 85.6%, respectively; P < 0.001 both). In multivariate analysis, pathologic stage, the presence of ENE, LVI, PNI, and no adjuvant chemotherapy were significant independent prognostic factors for DFS and OS. There were no statistically significant differences in DFS and OS between ENE-positive stage IIIB tumors and ENE-negative stage IIIC tumors.

Materials and Methods

The records of 1,948 stage III CRC patients who underwent curative surgery between January 2003 and December 2010 were retrospectively reviewed.

Conclusions

The presence of ENE is independently and significantly associated with lower DFS and OS rates after curative resection for stage III CRC. ENE status should be considered in both the pathologic report and CRC staging system.

Lymph node ratio and surgical quality are strong prognostic factors of rectal cancer: results from a single referral centre

AIM

Nodal stage is a strong prognostic factor of oncological outcome of rectal cancer. To compensate for the variation in total number of harvested nodes, calculation of the lymph node ratio (LNR) has been advocated. The aim of the study was to compare the impact, on the long-term oncological outcome, of the LNR with other predictive factors, including the quality of total mesorectal excision (TME) and the state of the circumferential resection margin.

METHOD

Consecutive patients having elective surgery for nonmetastatic rectal cancer were extracted from a prospectively maintained database. Retrospective uni- and multivariate analyses were performed based on patient-, surgical- and tumour-related factors. The prognostic value of the LNR on overall survival (OS) and on overall recurrence-free survival (ORFS) was assessed and a cut-off value was determined.

RESULTS

From 1998 to 2013, out of 456 patients, 357 with nonmetastatic disease were operated on for rectal cancer. Neoadjuvant radiochemotherapy was administered to 66.7% of the patients. The mean number of lymph nodes retrieved was 12.8 ± 8.78 per surgical specimen. A lower lymph node yield was obtained in patients who received neoadjuvant chemoradiotherapy (11.8 vs 14.2; P = 0.014). The 5-year ORFS was 71.8% and the 5-year OS was 80.1%. Multivariate analysis confirmed LNR, the quality of TME and age to be independent prognostic factors of OS. LNR, age and perineural infiltration were independently associated with ORFS. Low- and high-risk patients could be discriminated using an LNR cut-off value of 0.2.

CONCLUSION

LNR is an independent prognostic factor of OS and ORFS. In line with the principles of optimal surgical management, the quality of TME and lymph node yield are essential technical requirements.

Prognostic Value of Lymph Node Ratio in Locally Advanced Rectal Cancer Patients After Preoperative Chemoradiotherapy Followed by Total Mesorectal Excision

Although the absolute number of positive lymph nodes (LNs) has been established as 1 of the most important prognostic factors in rectal cancers, many researchers have proposed that the lymph node ratio (LNR) may have better predicted outcomes. We conducted a retrospective study to compare the predictive ability of LNR and ypN category in rectal cancer. A total of 264 locally advanced rectal cancer (LARC) patients who underwent preoperative chemoradiotherapy (CRT) followed by total mesorectal excision (TME) between 2005 and 2012 were reviewed. All patients were categorized into 3 groups or patients with metastatic LNs were categorized into 2 groups according to the LNR. The prognostic effect on overall survival (OS) and disease-free survival (DFS) was evaluated. With a median follow-up of 45 months, the OS and DFS were 68.4% and 59.3% for the entire cohort, respectively. The respective 5-year OS and DFS rates for the 3 groups (LNR = 0, 0 < LNR ≤ 0.20, and 0.20 < LNR ≤ 1.0) were as follows: 83.2%, 72.6%, and 49.4% (P < 0.001) and 79.5%, 57.3%, and 33.5% (P < 0.001), respectively. Multivariate analysis revealed that LNR and differentiation, but not the number of positive LNs, had independent prognostic value for OS (hazard ratio [HR] = 2.328, 95% confidence interval [CI]: 1.850-4.526, P < 0.001) and DFS (HR = 3.004, 95% CI: 1.616-5.980, P < 0.001). As for patients with positive LNs, the respective 5-year OS and DFS rates for the 2 groups (0 < LNR ≤ 0.20, and 0.20 < LNR ≤ 1.0) were 72.6% and 49.4% (P < 0.001) and 57.3% and 33.5% (P < 0.001), respectively. Multivariate analysis revealed that only LNR was an independent factor for OS (HR = 3.214, 95% CI: 1.726-5.986, P < 0.001) and DFS (HR = 4.230, 95% CI: 1.825-6.458, P < 0.001). Subgroups analysis demonstrated that the ypN category had no impact on survival whereas increased LNR was a significantly prognostic indicator for worse survival in the LNs < 12 subgroup. LNR is an independent prognostic factor in LARC patients treated with preoperative CRT followed by TME. It may be a better independent staging method than the number of metastatic LNs when <12 LNs are harvested after preoperative CRT.

Prognostic value of lymph node ratio in survival of patients with locally advanced rectal cancer

BACKGROUND

The lymph node ratio (LNR) has been shown to be an important prognostic factor in patients with gastric, breast, pancreatic and colorectal cancer. We investigated the prognostic impact of the LNR in addition to TNM classification in patients with locally advanced rectal cancer.

METHODS

We retrospectively analyzed patients who underwent curative resection for locally advanced rectal cancer between July 2005 and December 2010. We determined the LNR cutoff value using a receiver operating characteristic curve. The Kaplan-Meier method was used to estimate survival curves, while Cox regression analyses were used to evaluate the relationship between LNR and survival.

RESULTS

We included 180 patients aged 28-83 years with median follow-up of 41.8 months. The median number of lymph nodes examined and lymph nodes involved were 11.5 and 4, respectively, and the median LNR was 0.366. An LNR of 0.19 (19%) was the cutoff point to separate patients with regard to median overall survival. Median overall survival was 64.2 months for patients with an LNR of 0, 59.1 for an LNR of 0.19 or less and 37.6 for an LNR greater than 0.19 (p = 0.004). The median disease-free survival was 32.9 months for patients with an LNR of 0, 30.4 for an LNR of 0.19 or less and 17.8 for an LNR greater than 0.19 (p = 0.002).

CONCLUSION

Our results suggest that LNR should be considered an additional prognostic factor in patients with locally advanced rectal cancer.

Impact of Lymph Node Ratio on Oncologic Outcomes in ypStage III Rectal Cancer Patients Treated with Neoadjuvant Chemoradiotherapy followed by Total Mesorectal Excision, and Postoperative Adjuvant Chemotherapy

PURPOSE

To evaluate the prognostic impact of the lymph node ratio (LNR) in ypStage III rectal cancer patients who were treated with neoadjuvant chemoradiotherapy (NCRT).

MATERIALS AND METHODS

We retrospectively reviewed the data of 638 consecutive patients who underwent NCRT followed by total mesorectal excision, and postoperative adjuvant chemotherapy for rectal cancer from 2004 to 2011. Of these, 125 patients were positive for lymph node (LN) metastasis and were analyzed in this study.

RESULTS

The median numbers of examined and metastatic LNs were 17 and 2, respectively, and the median LNR was 0.143 (range, 0.02-1). Median follow-up time was 55 months. In multivariate analyses, LNR was an independent prognostic factor for overall survival (OS) (hazard ratio [HR] 2.17, p = 0.041), disease-free survival (DFS) (HR 2.28, p = 0.005), and distant metastasis-free survival (DMFS) (HR 2.30, p = 0.010). When ypN1 patients were divided into low (low LNR ypN1 group) and high LNR (high LNR ypN1 group) according to a cut-off value of 0.152, the high LNR ypN1 group had poorer OS (p = 0.043) and DFS (p = 0.056) compared with the low LNR ypN1 group. And there were no differences between the high LNR ypN1 group and the ypN2 group in terms of the OS (p = 0.703) and DFS (p = 0.831).

CONCLUSIONS

For ypN-positive rectal cancer patients, the LNR was a more effective prognostic marker than the ypN stage, circumferential resection margin, or tumor regression grade after NCRT, and could be used to discern the high-risk group among ypN1 patients.

Lymph node ratio predicts tumor recurrence in stage III colon cancer

OBJECTIVE

To evaluate the lymph node ratio as a predictor for tumor recurrence in stage III colon cancer patients.

METHODS

Patients with stage III colon cancer who underwent curative resection between January 2005 and December 2010 were retrospectively reviewed. The main outcomes were tumor recurrence and death. The impact of lymph node ratio and other clinicopathological factors on disease-free survival were evaluated by uni- and multivariate analysis. Receiver operator characteristic (ROC) analysis was conducted in order to identify the best cutoff value for lymph node ratio to predict tumor recurrence. Disease-free survival was estimated by the Kaplan-Meier method.

RESULTS

Seventy patients were included in the study (50% male). The mean age was 64 years. Univariate analysis identified four factors for tumor recurrence: carcinoembryonic antigen, N stage, number of positive lymph nodes and lymph node ratio. Lymph node ratio was the one with the greatest magnitude of association. Receiver operator characteristic analyzes identified 0.15 as the best cutoff value. Patients with a lymph node ratio < 0.15 had a disease-free survival of 90% in 3 years (versus 64%, p = 0.011).

CONCLUSION

Lymph node ratio is a strong predictor for tumor recurrence in stage III colon cancer.

Ratio of metastatic lymph nodes is more important for rectal cancer patients treated with preoperative chemoradiotherapy

AIM: To evaluate the predictive value of the lymph node (LN) ratio (LNR, number of metastatic LNs/ examined LNs) for recurrence in patients with rectal cancer and to compare its applicability according to preoperative chemoradiotherapy (PCRT).

METHODS: From 2000 to 2009, 967 patients with metastatic LNs after curative resection for locally advanced rectal cancer were identified. Patients were categorized according to PCRT (PCRT vs No PCRT). The cut-off LNR was determined based on the pN1 vs pN2 when the recommended number of LNs was harvested. The 5-year recurrence-free survival (RFS) rates using the Kaplan-Meier method were compared according to p/yp N stage and the LNR in each group.

RESULTS: Among patients with the same p/ypN stage, the 5-year RFS rate differed according to the LNR. In addition, the 5-year RFS rate was significantly different between pN and LNR groups in patients with No PCRT. In PCRT group, however, only LNR was associated with prognosis. On multivariate analysis, both pN and LNR were significant independent prognostic factors for 5-year RFS in the No PCRT group. In the PCRT group, only LNR category was found to be associated with RFS (HR = 2.36, 95%CI: 1.31-3.84, and P = 0.001).

CONCLUSION: The LNR is an important prognostic predictor of RFS in rectal cancer patients especially treated with PCRT. Current pN categories could not discriminate between prognostic groups of RFS after PCRT.

The prognostic value of lymph node ratio and updated TNM classification in rectal cancer patients with adequate versus inadequate lymph node dissection

BACKGROUND

The aim of this study was to clarify whether the lymph node ratio (LNR) is superior to the updated TNM classification regarding the prognosis of stage III rectal cancer patients who have not undergone neoadjuvant therapy. The TNM system is based on the absolute number of lymph nodes involved, and the LNR takes into account involved and examined nodes.

METHODS

In 237 patients with stage III rectal cancer, we evaluated prognostic factors for 5-year overall survival (OS), disease-free survival (DFS), and risk of distant metastases (DM) using the Kaplan-Meier method, with patients divided based on adequate versus inadequate lymph node dissection (≥12 vs. <12 lymph nodes examined). The updated TNM divides patients into four groups (1, 2-3, 4-6, and ≥7 involved nodes), while LNR divides patients into quartiles. Multivariate Cox regression analyses were performed.

RESULTS

Among patients with adequate lymph node dissection, the distributions within the two systems were in agreement in 141/178 (79.2 %, kappa 0.721), and the predictive values for OS, DFS, and DM were similar. In patients with inadequate lymph node dissection, the classifications of both systems were concordant in only 13/59 (22 %, kappa 0.021). The pN system significantly under-staged patients, while the LNR classification was a better predictor of OS, DFS, and DM.

CONCLUSIONS

In patients with adequate lymph node dissection, LNR staging does not add substantial information to the predictions of updated TNM lymph node staging. However, in patients with inadequate lymph node harvesting, the LNR compensates for the under-staging of the TNM classification and provides a better estimation of prognosis than the updated TNM system.

Prognostic value of lymph node ratios in node positive rectal cancer treated with preoperative chemoradiation

BACKGROUND

To investigate the impact of the lymph node ratio (LNR) on the prognosis of patients with locally advanced rectal cancer undergoing pre-operative chemoradiation.

METHODS

Clinicopathologic and follow up data of 128 patients with stage III rectal cancer who underwent curative resection from 1996 to 2007 were reviewed. The patients were divided into two groups according to the lymph node ratio: LNR ≤ 0.2 (n=28), and >0.2 (n=100). Kaplan-Meier and the Cox proportional hazard regression models were used to evaluate the prognostic effects according to LNR.

RESULTS

Median numbers of lymph nodes examined and lymph nodes involved by tumour were 10.3 (range 2-28) and 5.8 (range 1-25), respectively, and the median LNR was 0.5 (range, 0-1.6). The 5-year survival rate significantly differed by LNR (≤ 0.2, 69%; >0.2, 19%; Log-rank p value < 0.001). LNR was also a significant prognostic factor of survival adjusted for age, sex, post-operative chemotherapy, total number of examined lymph nodes, metastasis and local recurrence (≤ 0.2, HR=1; >0.2, HR=4.8, 95%CI=2.1-11.1) and a significant predictor of local recurrence and distant metastasis during follow-up independently of total number of examined lymph node.

CONCLUSIONS

Total number of examined lymph nodes and LNR were significant prognostic factors for survival in patients with stage III rectal cancer undergoing pre-operative chemoradiotherapy.

Proposal of a new classification for stage III colorectal cancer based on the number and ratio of metastatic lymph nodes

BACKGROUND

The objective of this retrospective study was to determine whether the current staging system for stage III colorectal cancer (CRC) is appropriate and to assess the value of the metastatic lymph node ratio (LNR) in predicting the prognosis of patients with stage III CRC.

METHODS

From 2000 to 2006 inclusively, 245 patients with stage III CRC underwent curative resection. The follow-up was closed in March 2012. Kaplan-Meier survival curves and log-rank tests were used for the survival analysis.

RESULTS

Survival time of patients with T3N1M0 was significantly better than that for patients in other subgroups of stage IIIB and similar to that of patients with stage IIIA disease. The greatest survival difference was found with 0.30 as the LNR cutoff point for patients with current stage III CRC. Survival time of patients with LNR ≤ 0.30 was significantly better than that of those with LNR > 0.30. rN1 included stage III patients with LNR ≤ 0.30, and rN2 included patients with LNR > 0.30. Survival time of patients with T4aN1(rN2)M0 staging was significantly worse than that for patients with T4aN1(rN1)M0 staging and similar to that of patients with stage IIIC CRC.

CONCLUSIONS

We propose an algorithm to incorporate LNR into the current American Joint Committee on Cancer staging system. In it the patients with T3N1M0 are excluded from the current stage IIIB and included in the stage IIIA group. Also, patients with T4aN1(rN2)M0 are excluded from the current stage IIIB group and included in the stage IIIC group.

Proposal of a new classification for stage III colorectal cancer based on the number and ratio of metastatic lymph nodes

BACKGROUND

The objective of this retrospective study was to determine whether the current staging system for stage III colorectal cancer (CRC) is appropriate and to assess the value of the metastatic lymph node ratio (LNR) in predicting the prognosis of patients with stage III CRC.

METHODS

From 2000 to 2006 inclusively, 245 patients with stage III CRC underwent curative resection. The follow-up was closed in March 2012. Kaplan-Meier survival curves and log-rank tests were used for the survival analysis.

RESULTS

Survival time of patients with T3N1M0 was significantly better than that for patients in other subgroups of stage IIIB and similar to that of patients with stage IIIA disease. The greatest survival difference was found with 0.30 as the LNR cutoff point for patients with current stage III CRC. Survival time of patients with LNR ≤ 0.30 was significantly better than that of those with LNR > 0.30. rN1 included stage III patients with LNR ≤ 0.30, and rN2 included patients with LNR > 0.30. Survival time of patients with T4aN1(rN2)M0 staging was significantly worse than that for patients with T4aN1(rN1)M0 staging and similar to that of patients with stage IIIC CRC.

CONCLUSIONS

We propose an algorithm to incorporate LNR into the current American Joint Committee on Cancer staging system. In it the patients with T3N1M0 are excluded from the current stage IIIB and included in the stage IIIA group. Also, patients with T4aN1(rN2)M0 are excluded from the current stage IIIB group and included in the stage IIIC group.

An appraisal of lymph node ratio in colon and rectal cancer: not one size fits all

BACKGROUND

Lymph node ratio (LNR) is increasingly accepted as a useful prognostic indicator in colorectal cancer. However, variations in methodology, statistical stringency and cohort composition has led to inconsistency in respect of the optimally prognostic LNR.

OBJECTIVE

The aim was to apply a robust regression-based analysis to generate and appraise LNRs optimally prognostic for colon and rectal cancer, both separately and in combination.

METHODS

LNR was established for all patients undergoing either a colonic (n = 379) or rectal (n = 160) cancer resection with curative intent. The optimal LNR associated with disease-free and overall survival were established using a classification and regression tree technique. This process was repeated separately for patients who underwent either colonic or rectal resection and for the combined cohort. Survival associated with differing LNR was estimated using the Kaplan-Meier method and compared using a log-rank test. Relationships between LNR, disease-free survival (DFS) and overall survival (OS) were further characterised using Cox regression analysis. All statistical analyses were conducted in the R programming environment, with statistical significance was taken at a level of p < 0.05.

RESULTS

Optimal LNRs differed between each cohort, when either overall or disease-free survival was considered. LNRs generated from combined cohorts also differed from those generated by individual cohorts. In relation to DFS, LNR values were obtained and included 0.18 for the colon cancer cohort and 0.19 for the rectal and combined colorectal cancer cohorts. In relation to OS, multiple LNR values were obtained for colon and combined cohorts; however, an optimal LNR was not evident in the rectal cancer cohort. Survival patterns according to LNR closely resembled those associated with standard nodal staging.

CONCLUSION

Application of a data-driven approach based on recursive partitioning generates differing lymph node ratios for colon, rectal and combined colorectal cohorts. In each cohort, LNR was similarly prognostic to standard nodal staging in respect to overall and disease-free survival. Overall survival was associated with a multiplicity of LNR values, whilst disease-free survival was associated with a single LNR only. The paper demonstrates the merits of utilising a data-driven approach to determining lymph node ratios from specific patient cohorts. Utilising such an approach enabled the generation of those LNRs that were most associated with particular survival trends in relation to overall and disease-free survival. These differed markedly for colon cancer, rectal cancer and combined cohorts. In general, the survival patterns associated with LNRs generated were similar to those observed with standard nodal staging.

Prognostic impact of the metastatic lymph node ratio on survival in rectal cancer

Purpose

Lymph-node metastasis is the most important predictor of survival in stage III rectal cancer. The number of metastatic lymph nodes may vary depending on the level of specimen dissection and the total number of lymph nodes harvested. The aim of this study was to evaluate whether the lymph node ratio (LNR) is a prognostic parameter for patients with rectal cancer.

Methods

A retrospective review of a database of rectal cancer patients was performed to determine the effect of the LNR on the disease-free survival (DFS) and the overall survival. Of the total 228 patients with rectal cancer, 55 patients with stage III cancer were eligible for analysis. Survival curves were estimated using the Kaplan-Meier method. Cox regression analyses, after adjustments for potential confounders, were used to evaluate the relationship between the LNR and survival.

Results

According to the cutoff point 0.15 (15%), the 2-year DFS was 95.2% among patients with a LNR < 0.15 compared with 67.6% for those with LNR ≥ 0.15 (P = 0.02). In stratified and multivariate analyses adjusted for age, gender, histology and tumor status, a higher LNR was independently associated with worse DFS.

Conclusion

This study showed the prognostic significance of ratio-based staging for rectal cancer and may help in developing better staging systems. LNR 0.15 (15%) was shown to be a cutoff point for determining survival and prognosis in rectal cancer cases.

Lymph node ratio is a stronger prognostic factor than microsatellite instability in colorectal cancer patients: results from a 7 years follow-up study

BACKGROUND

The presence of high microsatellite instability (MSI-H) in colorectal cancers has been generally associated with better survival, opposite an increased ratio between metastatic lymph-nodes and nodes sampled in the specimen (LNR) has been associated with a worse outcome. The study aims to detect the incidence and prognostic significance of MSI and LNR in a consecutive series of 119 colorectal cancers.

METHODS

119 consecutive colorectal cancer patients undergone resection at our Department were enrolled from 2000 to 2004. The MSI status has been evaluated by amplification of target sequences. The LNR has been calculated and patients stratified into 4 groups on the basis of the ratio values. Clinical/pathological data were collected and analyzed; the overall, disease free and disease specific survivals were analyzed by the Kaplan-Meier and Cox regression analyses (mean follow-up: 81 months).

RESULTS

MSI-H was detected in 11.7% of the cases and patients were compared with the microsatellite stable (MSS) group. We observed a higher prevalence of right colon localizations (p 0.01) and locally advanced tumors (p 0.0012) in the MSI-H subgroup. Kaplan-Meier analysis documented no significant difference comparing MSS patients vs MSI-H, although the latter showed a better survival trend (p ns); worse survivals were observed according with the LNR stratification (p < 0.0001). Multivariate analysis documented a statistical value associated with the LNR sub-groups in relationship with survival.

CONCLUSION

According to our results the MSI-H status was associated with particular features (right locations/locally advanced tumors). The results of a long-term follow-up indicate a trend for better survival in MSI-H vs MSS patients. Notably, an increased LNR is associated with worse survivals, both at the univariate and multivariate analysis, displaying this ratio as the strongest prognostic factor of cancer-related survival.

Adequate lymph node recovery improves survival in colorectal cancer patients

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Prognostic significance of lymph node yield after long-course preoperative radiotherapy in patients with rectal cancer: a systematic review

AIM

A literature review was performed to elucidate whether long-course preoperative radiotherapy for patients with rectal cancer affects lymph node yield, and whether this influences prognosis.

METHOD

Cochrane Database, PubMed/MEDLINE, Scopus, Web of Knowledge, Embase and CINAHL databases and reference lists from published journal articles published between 1 January 1990 and 30 June 2011 were searched. Studies examining lymph node yield and prognosis were selected for review.

RESULTS

One thousand and twenty-nine articles were found, of which 11 met the inclusion criteria. None was a randomized controlled trial and all were cohort studies. Four studies showed that long-course preoperative radiotherapy reduced lymph node yield; however only one demonstrated a statistically significant survival benefit in patients with higher lymph node yields. Five-year survival was 48% in patients with fewer than and 69% in those with more than 11 lymph nodes identified in the operative specimen (P = 0.04).

CONCLUSION

Whilst long-course preoperative radiotherapy appears to reduce lymph node yield in patients with rectal cancer, no causal relationship between lymph node yield and survival can be established in this group of patients.

Evaluation of lymph nodes in patients with colon cancer undergoing colon resection: a population-based study

BACKGROUND

Though lymph node status may predict long-term outcome of patients with non-metastatic colon cancer, discordant findings exist among various expressions of lymph node status. The present study was designed to assess the prognostic value among these lymph node evaluations.

METHODS

The analysis was based on surgical patients with newly diagnosed colon adenocarcinoma registered in the Taiwan Cancer Database from 2003 to 2005. Exclusion criteria included those patients who had stage IV disease, those whose survival period was <1 month, or those whose lymph node information was unavailable. Studied variables included total number of lymph nodes (LNT), number of positive lymph nodes (LNP), number of negative lymph nodes (LNN), ratio of positive lymph nodes (LNR), and log odds of positive lymph nodes (LODDS).

RESULTS

Of 16,790 newly diagnosed colon cancer patients, there were 9,644 (65.4 ± 13.5 years; male 54.9 %) patients with non-metastatic disease who met the criteria. Correlation analyses for patients with stage III disease showed that LNR and LODDS were highly correlated, as were LNT and LNN. By the Cox proportional hazard model, LNT was prognostic of long-term survival in patients with stage II disease, while LNR and LNP were the most powerful prognosticators for patients with stage III disease (p < 0.001). Both the receiver operating characteristics curve analysis and area under the curve indicated that LNR had the best discriminating capability to predict 5-year survival (0.704, 0.700, and 0.709 for overall, disease-free, and disease-specific survival, respectively), followed by LODDS.

CONCLUSIONS

For patients undergoing resection for colon cancer, LNR, LODDS, and LNP are better prognostic factors for those with stage III disease than LNT is for patients with stage III disease.

A novel approach to segment and classify regional lymph nodes on computed tomography images

Morphology of lymph nodal metastasis is critical for diagnosis and prognosis of cancer patients. However, accurate prediction of lymph node type based on morphological information is rarely available due to lack of pathological validation. To obtain correct morphological information, lymph nodes must be segmented from computed tomography (CT) image accurately. In this paper we described a novel approach to segment and predict the status of lymph nodes from CT images and confirmed the diagnostic performance by clinical pathological results. We firstly removed noise and preserved edge details using a revised nonlinear diffusion equation, and secondly we used a repulsive-force-based snake method to segment the lymph nodes. Morphological measurements for the characterization of the node status were obtained from the segmented node image. These measurements were further selected to derive a highly representative set of node status, called feature vector. Finally, classical classification scheme based on support vector machine model was employed to simulate the prediction of nodal status. Experiments on real clinical rectal cancer data showed that the prediction performance with the proposed framework is highly consistent with pathological results. Therefore, this novel algorithm is promising for status prediction of lymph nodes.

Prognostic significance of lymph node ratio in patients undergoing abdominoperineal resection of rectum

BACKGROUND

Lymph node ratio (LNR) has been shown to be an independent prognostic factor in stage III colorectal cancer. Abdominoperineal resection (APR) of rectum is historically associated with poorer oncological outcomes compared to other colorectal resections, and significance of LNR in this group of patients has not been studied.

OBJECTIVE

Our aim was to determine impact of LNR on oncological outcomes in a series of patients with rectal cancers undergoing APR.

PATIENTS AND METHODS

A series of patients who had undergone APR and had lymph node metastasis were identified from a prospectively maintained clinical, histopathological and radiological database. LNR was calculated, and Cox regression was used to determine the impact of factors affecting local recurrence, distal metastases and overall survival.

RESULTS

Fifty-eight (42 males) patients were identified to have rectal cancer with lymph node involvement. LNR was an independent predictor of distal metastasis and overall survival at cutoff levels of 0.17, 0.41 and 0.69.

CONCLUSION

Lymph node ratio is an independent predictor of survival outcomes in patients with stage III tumours undergoing APR. LNR may help improve stratification of this group of patients.

Prognostic significance of the lymph node ratio regarding recurrence and survival in rectal cancer patients treated with postoperative chemoradiotherapy

Background/Aims

To evaluate the prognostic impact of the lymph node ratio (LNR: the ratio of positive lymph nodes to the total number of lymph nodes examined) on disease recurrence and survival among rectal cancer patients who received curative surgery and postoperative chemoradiotherapy (CRT).

Methods

Between 1995 and 2008, 124 patients with pathologic T3-4 or node-positive rectal cancer underwent curative surgery and postoperative CRT. Postoperative radiotherapy was delivered at a median dose of 50.4 Gy (range, 45 to 59.4 Gy) for 6 weeks. Chemotherapy consisted of a bolus injection of 5-fluorouracil and leucovorin in the first and last week of radiotherapy (91.9%) or daily capecitabine during radiotherapy (8.1%). Further adjuvant chemotherapy was administered after chemoradiation.

Results

The median follow-up was 5.1 years. In the multivariate analysis, pathologic N (pN) stage and lymphovascular invasion were significantly associated with disease-free survival and disease-specific survival (p<0.05). However, when the LNR with a cutoff value of 0.2 was included as a covariate in the model, the LNR was highly significant (p<0.001), and the pN stage lost its significance (p>0.05).

Conclusions

The LNR predicts recurrence and survival more accurately than pN stage. The pN stage and the LNR should be considered together when estimating the risk of disease recurrence among rectal cancer patients.

Lymph node ratio is an independent prognostic factor in patients with rectal cancer treated with preoperative chemoradiotherapy and curative resection

PURPOSE

To evaluate the prognostic effect of lymph node ratio (LNR) in patients with locally advanced rectal cancer who were treated with curative resection after preoperative chemoradiotherapy (CRT).

METHODS

Between October 2001 and December 2007, 519 patients who had undergone curative resection of primary rectal cancer after preoperative CRT were enrolled. Of these, 154 patients were positive for lymph node (LN) metastasis and were divided into three groups according to the LNR (≤ 0.15 [n=80], 0.16-0.3 [n=44], >0.3 [n=30]) to evaluate the prognostic effect on overall survival (OS) and disease-free survival (DFS).

RESULTS

LNR (≤ 0.15, 0.16-0.3, and >0.3) was significantly associated with 5-year OS (90.3%, 75.1%, and 45.1%; p<0.001) and DFS (66.7%, 55.8%, and 21.9%; p<0.001) rates. In a multivariate analysis, LNR (≤ 0.15, 0.16-0.3, and >0.3) was a significant independent prognostic factor for OS (hazard ratios [HRs], 1, 3.609, and 8.197; p<0.001) and DFS (HRs, 1, 1.699, and 3.960; p<0.001). LNR had a prognostic impact on OS and DFS in patients with <12 harvested LNs, as well as in those with ≥ 12 harvested LNs (p<0.05).

CONCLUSION

LNR was a significant independent prognostic predictor for OS and DFS in patients with locally advanced rectal cancer who were treated with curative resection after preoperative CRT.

Dukes C colorectal cancer: is the metastatic lymph node ratio important?

PURPOSE

Although the regional lymph node status is essential for staging of colorectal cancer, the importance of the total number of collected nodes remains controversial. Our aim was to examine the impact of the metastatic lymph node ratio (LNR) on the survival of patients with Dukes C colorectal cancer.

METHODS

All patients with Dukes C histology were selected from a prospectively collected database of all colorectal cancers resected between 1997 and 2007 at our institution. Demographic, histopathological and adjuvant treatment data were collected. The total number of positive lymph nodes was divided by the total number of lymph nodes examined to calculate the LNR. Patients were categorised into LNR groups 1 to 5 according to cut-off points: ≤0.1, 0.21, 0.36, 0.6 and ≥0.61. Survival from the date of operation was calculated using Kaplan-Meier estimates. Multivariate analysis was performed to identify those factors influencing survival.

RESULTS

Of 1,098 patients who underwent colorectal cancer resections, 41% were staged as Dukes C. Sixty-four percent of patients received chemotherapy. The median number of lymph nodes harvested and positive for tumour were 11 (range 1-52) and 4 (range 1-28), respectively. In patients who received chemotherapy, 5-year survival was 69.3% for LNR 1 and 23.6% for LNR 5. When no chemotherapy was given, the 5-year survival was 43.1% for LNR 1 and 8.7% for LNR 5.

CONCLUSIONS

Current evaluation of positive lymph nodes may not accurately stage Dukes C colorectal cancer. The assessment of the LNR is a useful prognostic method in this heterogenous group of patients.

Estimating underreported N2 disease in rectal cancer patients with low lymph node counts

BACKGROUND

The variability in the number of lymph nodes examined needs to be taken into account for adequate staging. The definition of nodal staging was refined by quantifying the likelihood of N2 disease when the patient had fewer than four positive LN.

METHODS

In a retrospective study a total of 548 patients with node positive rectal cancer and curative surgery between 1990 and 2006 were identified. The misclassification of pN staging was estimated with a Bayesian computation. The prognostic value of the calculated probability, lymph node ratio (LNR), and nodal stage was assessed with Cox proportional hazard regression.

RESULTS

A probability of understaging of 40% or more indicated worse prognosis of cancer-specific survival (CSS) with hazard ratio 2.6 (95%CI: 1.8-3.9, P < 0.001). The concordance index of a multivariate model with probability of N2 disease as a prognostic factor for survival was 0.68 for all patients and 0.75 for patients with less than 10 lymph nodes examined.

CONCLUSION

Utilizing estimated probabilities of N2 disease improves our ability to predict survival, in particular in patients with low LN count. These probabilities allow for a simple rule in patient counseling and clinical decision making.

Impact of lymph node retrieval on surgical outcomes in colorectal cancers

BACKGROUND

Adequacy of lymph node sampling is fundamental to the accuracy of nodal status (N-status) assessment in colorectal cancers (CRCs). This study aimed to determine the minimum sampling number to achieve reliable prognosis and to look for any association between the positive lymph node ratio (LNR) and overall survival (OS). Pathological reports of 533 stages I-III CRC patients who underwent curative resection during the period from January 1998 to December 2007 were retrospectively reviewed with regard to the number of lymph nodes obtained for pathological diagnosis (nLN) and number of positive nodes.

RESULTS

The median nLN was 10 nodes and the mean number of positive nodes was 1.7 nodes. On the N-status attribution plot, the cut-off point where the converging curves turned parallel was at 12 nodes. This cut-off was supported by the significant difference in OS between cases with nLN ≥ 12 (5-year OS 73.0%) and those with nLN < 12 (5-year OS 62.7%), (P-value < 0.01). Multivariate analysis showed that both nLN-12 and LNR were independent factors predicting survival probability.

CONCLUSION

Our data emphasize the importance of lymph node harvesting during the surgical resection of CRCs. In addition, LNR is a strong independent factor associated with CRC survival.

Dukes C colorectal cancer: is the metastatic lymph node ratio important?

PURPOSE

Although the regional lymph node status is essential for staging of colorectal cancer, the importance of the total number of collected nodes remains controversial. Our aim was to examine the impact of the metastatic lymph node ratio (LNR) on the survival of patients with Dukes C colorectal cancer.

METHODS

All patients with Dukes C histology were selected from a prospectively collected database of all colorectal cancers resected between 1997 and 2007 at our institution. Demographic, histopathological and adjuvant treatment data were collected. The total number of positive lymph nodes was divided by the total number of lymph nodes examined to calculate the LNR. Patients were categorised into LNR groups 1 to 5 according to cut-off points: ≤0.1, 0.21, 0.36, 0.6 and ≥0.61. Survival from the date of operation was calculated using Kaplan-Meier estimates. Multivariate analysis was performed to identify those factors influencing survival.

RESULTS

Of 1,098 patients who underwent colorectal cancer resections, 41% were staged as Dukes C. Sixty-four percent of patients received chemotherapy. The median number of lymph nodes harvested and positive for tumour were 11 (range 1-52) and 4 (range 1-28), respectively. In patients who received chemotherapy, 5-year survival was 69.3% for LNR 1 and 23.6% for LNR 5. When no chemotherapy was given, the 5-year survival was 43.1% for LNR 1 and 8.7% for LNR 5.

CONCLUSIONS

Current evaluation of positive lymph nodes may not accurately stage Dukes C colorectal cancer. The assessment of the LNR is a useful prognostic method in this heterogenous group of patients.