Effect of examining lymph nodes count on mortality risk in resected T1 non-small-cell lung cancer

OBJECTIVES

This study aims to estimate the effect of the examined lymph node count (ELNC) on the cancer-related mortality risk and non-cancer-related mortality risk in patients with resected T1 non-small-cell lung cancer (NSCLC).

METHODS

Patients diagnosed as primary T1 NSCLC between 2000 and 2017 were extracted from the Surveillance, Epidemiology and End Results database. Patients were divided into 2 groups according to the ELNC cutoff value, which was calculated based on overall survival outcomes. Propensity score matching was used to equalize the differences in baseline characteristics between groups.

RESULTS

A total of 38 242 resected T1 NSCLC patients were extracted from the database with the ELNC cutoff value of 8. After propensity score matching, 27 676 patients were included in this study. Examining ≥8 ELNC was associated with a more accurate assessment of lymph node (LN) metastasis and significantly improving the prognosis. These trends remained consistent in subgroup analysis by histology type. In competing risk mode, examining ≥8 LNs could significantly reduce the risk of death from lung cancer, risk of death from chronic obstructive pulmonary disease, and risk of death from cardiac diseases. In the subgroup analysis, these trends were consistent.

CONCLUSIONS

Given the mortality risk associated with lung cancer, chronic obstructive pulmonary disease, and cardiac diseases, at least 8 LNs should be examined in surgery for T1 NSCLC.

Prognostic value of nodal staging classification and number of examined lymph nodes among patients with ampullary cancer

BACKGROUND

Metastatic disease in the regional lymph nodes (LNs) is a strong indicator of worse outcomes among patients after curative-intent resection of ampullary cancer (AC). This study aimed to ascertain the threshold number of examined LNs (ELNs) for AC to compare the prognosis accuracy of various nodal classification schemes relative to long-term prognosis.

METHODS

Patients who underwent pancreatoduodenectomy (PD) for AC (2004-2019) were identified using the National Cancer Database. Locally weighted regression scatter plot smoothing (LOWESS) curves were used to ascertain the optimal cut point for ELNs. The accuracy of the American Joint Committee on Cancer N classification, LN ratio, and log odds transformation (LODDS) ratio to stratify patients relative to survival was examined.

RESULTS

Among 8127 patients with AC, 67% were male with a median age of 67 years (IQR, 59-74). Tumors were most frequently classified as T3 (34.9%), followed by T2 (30.6%); T1 (12.9%) and T4 (17.6%) were less common. LN metastasis was identified in 4606 patients (56.7%). Among patients with nodal disease, 37.0% and 19.7% had N1 and N2 disease, respectively. The LOWESS curves identified an inflection cutoff point in the hazard of survival at 20 ELNs. The survival benefit of 20 ELNs was more pronounced among patients without LN metastasis vs patients with N1 disease (median overall survival [OS]: 54.1 months [IQR, 45.9-62.1] in ≥20 ELNs vs 39.0 months [IQR, 35.8-42.2] in <20 ELNs; P < .001) or N2 disease (median OS: 22.5 months [IQR, 18.9-26.2] in ≥20 ELNs vs 25.4 months [IQR, 23.3-27.6] in <20 ELNs; P < .001). When comparing the 4 different N classification schemes, the LODDS classification scheme yielded the highest predictive ability.

CONCLUSIONS

Evaluation of a minimum of 20 LNs was needed to stratify patients with AC relative to the prognosis and to minimize stage migration. The LODDS nodal classification scheme had the highest prognostic accuracy to differentiate survival among patients after PD for AC.

The minimal number of examined lymph nodes for accurate nodal staging and favorable prognosis in T1-2 supraglottic laryngeal squamous cell carcinoma

OBJECTIVE

The study aimed to investigate the minimal number of examined lymph nodes (ELNs) for accurate assessment of lymph node status and favorable prognosis in patients with stage T1-2 supraglottic laryngeal squamous cell carcinoma (LSCC) who received radical resection.

METHODS

Patients with stage T1-2 supraglottic LSCC from the Surveillance, Epidemiology, and End Results (SEER) database and the Chinese Academy of Medical Sciences, Cancer Hospital/National Cancer Center (NCC) were reviewed. The association of the ELN count with the identification of nodal metastasis and overall survival (OS) was analyzed using a multivariate regression model. Locally weighted scatterplot smoothing fitting curve and the 'changepoint' package were adopted to identify the optimal cut points using R.

RESULTS

A total of 429 patients from the SEER database and 53 patients from NCC were enrolled. The probability of identifying nodal metastasis was positively related to the ELN count. For patients diagnosed with pathological stage N0 (pN0) disease, the mortality risks rapidly decreased when the amount of ELNs exceeded ten, and those with ELNs >10 had better OS.

CONCLUSION

An adequate amount of ELNs benefits precise nodal staging in patients with stage T1-2 supraglottic LSCC. Ten lymph nodes are the minimum number of ELNs. For pN0 patients, an ELN count ≤10 is an unfavorable prognostic factor.

The optimal number of examined lymph nodes for accurate staging of intrahepatic cholangiocarcinoma: A multi-institutional analysis using the nodal staging score model

BACKGROUND

This study aims to develop a nodal staging score (NSS) to determine the optimal number of lymph nodes (LNs) examined in intrahepatic cholangiocarcinoma (iCCA) patients.

METHODS

Clinicopathologic data were collected from the SEER database (development cohort, n = 2782) and seven Chinese tertiary hospitals (validation cohort, n = 363). NSS was constructed based on a binomial distribution to indicate the probability of nodal disease absence. In addition, its prognostic value was examined by survival analysis and multivariable modeling on pN0 patients.

RESULTS

A model fit was performed in node-positive patients and a subgroup analysis was performed according to clinical characteristics. Statistically significant differences were only found in the subgroups when divided by the tumor size of 3 cm. As the number of examined lymph nodes (ELNs) increased, the likelihood of missing a metastatic LN decreased. NSS escalated as ELNs increased in groups with different tumor sizes, with plateaus at 7 and 11 LNs ensuring an NSS of 90.0% for ≤3 cm and >3 cm tumors, respectively. For pN0 patients, multivariate analysis revealed that NSS was an independent prognostic factor for overall survival (OS) and recurrence-free survival (RFS).

CONCLUSIONS

For accurate staging of iCCA, the optimal number of ELNs was related to tumor size. We recommend that at least 7 and 11 LNs should be examined for tumor size ≤3 cm and >3 cm, respectively. Therefore, the NSS model could be helpful to make clinical decisions for pN0 iCCA.

Prognostic significance of examined lymph node count in older patients with stage T1N0M0 pulmonary carcinoid tumours: a population-based propensity score-matched analysis

BACKGROUND

The optimal number of examined lymph nodes (ELNs) for older early-stage pulmonary carcinoid tumour (PC) patients is unknown.

AIMS

To explore the prognostic effect of the ELN count in older patients with stage T1N0M0 PC resection.

METHODS

Clinical data from the Surveillance, Epidemiology, and End Results database on stage T1N0M0 PC older patients (age ≥ 65 years) who underwent sublobar resection and lobectomy between 2000 and 2018 were retrospectively analysed for two ELNs-stratified (≥ 7 vs. < 7 ELNs) propensity score-matched (PSM) groups. Overall survival (OS) was calculated and compared with Kaplan-Meier analysis and log-rank test, respectively, and the independent prognostic factors were estimated using a Cox proportional hazard model.

RESULTS

Among 1077 participants (median dissected LN 4; mean ELNs 6.19 ± 7.04), 393 (36.49%) in the ≥ 7 ELNs group had better 5- and 10-year OS than the < 7 ELNs group (before PSM: 5-year OS = 93.01 vs. 85.22%, 10-year OS = 72.38 vs. 58.99%, p < 0.001; after PSM: 5-year OS = 93.12 vs. 85.97%, 10-year OS = 75.25 vs. 60.03%, p = 0.001). Subgroup analysis stratified by histologic type and surgical method showed a similar survival trend. Age-stratified analysis showed that, compared with the < 7 ELNs group, the ≥ 7 ELNs group had better 5- and 10-year OS but only better 5-year OS in participants > 75 years. Compared with the < 7 ELNs group, subgroup analysis by tumour size showed superior OS with 1.1-3.0 cm tumours in the ≥ 7 ELNs group, but no significant intergroup difference with tumours < 1.0 cm. Multivariate Cox analysis showed ≥ 7 ELNs was associated with improved OS.

CONCLUSION

Higher ELNs correlated with increased long-term survival in older early‑stage PC patients, and a minimum of 7 ELNs are recommended for prognostication in these patients (especially those aged 65-75 years, with tumour size 1.1-3.0 cm).

Number of Examined Lymph Nodes as a Risk Factor for Recurrence in pT1N+ or pT2-3N0 Gastric Cancer

BACKGROUND/AIM

Japanese Gastric Cancer Treatment Guidelines do not recommend adjuvant chemotherapy after radical gastrectomy for pathological stage (p) T1N+ or pT2~3N0 gastric cancer. However, some patients experience disease recurrence. This study aimed to identify the risk factors for recurrence in pT1N+ or pT2-3N0 gastric cancer.

PATIENTS AND METHODS

The study included 157 patients with diagnosed pT1N+ or pT2-3N0 gastric cancer who underwent radical gastrectomy at our institution between January 2001 and December 2020. Clinicopathological data and surgical data were obtained. Independent prognostic factors were analyzed using a Cox proportional hazards regression model.

RESULTS

Thirteen patients (8.3%) experienced disease recurrence. Multivariate analysis revealed that the number of examined lymph nodes was an independent prognostic factor for recurrence-free survival (hazard ratio=10.90; 95% confidence interval=1.39-85.86; p=0.023). The group with ≤35 examined lymph nodes had significantly worse recurrence-free survival compared with the group with ≥36 examined lymph nodes (80.7% versus 98.7%; p=0.0005).

CONCLUSION

The number of examined lymph nodes (≤35) was an independent risk factor for recurrence after radical gastrectomy with pT1N+ or pT2-3N0 gastric cancer.

The minimum number of examined lymph nodes for accurate nodal staging and optimal survival of stage T1-2 esophageal squamous cell carcinoma: A retrospective multicenter cohort with SEER database validation

BACKGROUND

The extent of lymphadenectomy during esophagectomy remains controversial for patients with T1-2 ESCC. The aim of this study was to identify the minimum number of examined lymph node (ELN) for accurate nodal staging and overall survival (OS) of patients with T1-2 esophageal squamous cell carcinoma (ESCC).

MATERIALS AND METHODS

Patients with T1-2 ESCC from three institutes between January 2011 and December 2020 were retrospectively reviewed. The associations of ELN count with nodal migration and OS were evaluated using multivariable models, and visualized by using locally weighted scatterplot smoothing (LOWESS). Chow test was used to determine the structural breakpoints of ELN count. External validation in the SEER database was performed.

RESULTS

In total, 1537 patients were included. Increased ELNs was associated with an increased likelihood of having positive nodal disease and incremental OS. The minimum numbers of ELNs for accurate nodal staging and optimal survival were 14 and 18 with validation in the SEER database (n = 519), respectively. The prognostic prediction ability of N stage was improved in the group with ≥14 ELNs compared with those with fewer ELNs (iAUC, 0.70 (95%CI 0.66-0.74) versus 0.61(95%CI 0.57-0.65)). The higher prognostic value was found for patients with ≥18 ELNs than those with <18 ELNs (iAUC, 0.78 (95%CI 0.74-0.82) versus 0.73 (95%CI 0.7-0.77)).

CONCLUSION

The minimum numbers of ELNs for accurate nodal staging and optimal survival of stage T1-2 ESCC patients were 14 and 18, respectively.

Stage migration resulting from inadequate number of examined lymph nodes impacts prognosis in stage II colon cancer after radical surgery

PURPOSE

We evaluated the impact of examined lymph node (ELN) number on the prognosis of stage II colon cancer after radical surgery and developed a novel prognostic scoring system by combining primary tumor extension (pT) and ELN number for reclassification of stage II colon cancer.

METHODS

Three cohorts of patients diagnosed with colon cancer between 2004 and 2010 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate analyses were performed to evaluate the relationship between factors and patients' survival including cause-specific survival (CSS) and overall survival (OS). Survival curves from subgroups were plotted by the Kaplan-Meier method and compared by the log-rank test.

RESULTS

Cohort 1 and cohort 2 consisted of 13,960 and 5312 stage II colon cancer patients, respectively. Cohort 3 consisted of 4713 stage III patients. Factors including ELN, age, and pT were found to be associated with patients' survival in cohorts 1 and 2. Patients who were older or with smaller tumors were more likely to experience inadequate ELN. Patients with a higher score, as calculated by the novel scoring system, showed worse survival. Compared with stage III colon cancer patients, stage II patients with high scores had a comparable or even worse survival than stage IIIA and IIIB patients.

CONCLUSION

Inadequate ELN leads to understaging in stage II colon cancer and predicts inferior prognosis. Our analyses show that the novel prognostic scoring system, consisting of combined pT and ELN, quantified stage migration effect and can be applied to the reclassification of stage II colon cancer.

Prognostic Significance of Lymph Node Count Removed at Sublobar Resection in Pathologic Stage IA Non-Small-cell Lung Cancer: A Population-Based Analysis

BACKGROUND

We sought to elucidate the associations between the examined lymph node (ELN) count and survival after sublobar resection (SLR) in pathologic stage IA non-small-cell lung cancer and assess the survival efficacy for patients undergoing SLR with an adequate ELN count compared with lobar resection (LR).

PATIENTS AND METHODS

The newly released U.S. Surveillance, Epidemiology, and End Results database was queried. The association between the ELN count in SLR and survival was analyzed using Cox regression and propensity score matching analyses. The optimal cutoff for the ELN count in SLR was determined using the Chow test and "segmented" function. Survival differences between SLR with an adequate ELN count and LR were compared using the log-rank test.

RESULTS

A total of 16,630 lobectomies, 3979 wedge resections, and 1119 segmentectomies were included in the present study. The median ELN count was 3 (interquartile range [IQR], 1-7), 1 (IQR, 0-4), and 7 (IQR, 4-12) for segmentectomy, wedge resection, and lobectomy, respectively (P < .001). The optimal cutoff for ELNs was 2.40 (IQR, 2.15-2.65) and 2.59 (IQR, 2.19-3.00) for patients undergoing wedge and segmental resection. SLR patients with ≥ 3 ELNs showed better overall survival and lung cancer-specific survival compared with those with < 3 ELNs. SLR patients with ≥ 3 ELNs had a noninferior prognosis compared with LR patients after matching of potential confounders.

CONCLUSIONS

In SLR, an adequate ELN count (≥ 3) could confer an improved prognosis compared with an inadequate ELN count (< 3). SLR patients with an adequate ELN count had noninferior survival outcomes compared with LR patients when the ELNs were well matched.

Implication of lymph node staging in migration and different treatment strategies for stage T2N0M0 and T1N1M0 resected gastric cancer: a SEER population analysis

PURPOSE

The purpose of this study was to explore the differences between stage T2N0M0 and stage T1N1M0 gastric cancer (GC) and to identify the necessity of adjuvant treatment (AT) for these stages.

METHODS

Between years 2004 and 2015, 1971 stage IB GC patients who underwent radical surgery were recruited using the Surveillance, Epidemiology and End Results database. We conducted univariate/multivariate analyses, the propensity score matching and evaluated gastric cancer-specific survival (GCSS) and overall survival (OS) with the log-rank test.

RESULTS

T1N1M0 had a significantly worse survival than T2N0M0 in both GCSS and OS before and after the propensity score matching. Examined lymph nodes (ELN) ≤ 15 and T1N1M0 were independent risk factors for worse GCSS and OS in stage IB GC. The absence of adjuvant chemotherapy (CT) was an independent risk factor for worse GCSS and OS in T1N1M0 but not in T2N0M0. AT demonstrated similar GCSS and OS with surgery alone (SA) for T2N0M0 but better survival for T1N1M0. Compared to CT and adjuvant chemoradiotherapy (CRT) group, SA demonstrated significantly worse GCSS and OS for T1N1M0. There was no significant difference between CT and CRT in both T2N0M0 and T1N1M0 stages. T2N0M0 had a better survival than T1N1M0 in ELN ≤ 15 subgroup. However, similar survival was demonstrated in ELN > 15 subgroup.

CONCLUSIONS

T2N0M0 GC has a better survival rate than T1N1M0 GC when ELN are ≤ 15. Moreover, T2N0M0 GC may not benefit from AT. T1N1M0 GC requires CT but not adjuvant radiotherapy.

Determining the optimal number of examined lymph nodes for accurate staging of pancreatic cancer: An analysis using the nodal staging score model

INTRODUCTION

The aim of this study was to determine the optimal number of examined lymph nodes (ELNs) for accurate staging of pancreatic cancer using the nodal staging score model.

MATERIALS AND METHODS

Clinicopathological data for patients with resected pancreatic cancer were collected from SEER database (development cohort [DC]) and Fudan University Shanghai Cancer Center database (validation cohort [VC]). Multivariable models were constructed to assess how the number of ELNs was associated with stage migration and overall survival (OS). Using the β-binomial distribution, we developed a nodal staging score model from the DC and tested it with the VC.

RESULTS

Both cohorts exhibited significant proportional increases from node-negative to node-positive disease (DC: odds ratio [OR], 1.047; P < 0.001; VC: OR, 1.035; P < 0.001) and improved OS (DC: hazard ratio [HR], 0.982; P < 0.001; VC: HR, 0.979; P < 0.001) as ELNs increased. Nodal staging scores escalated separately as ELNs increased for different tumor (T) stages, with plateaus at 16, 21, and 23 LNs (cut-offs) for T1, T2, and T3 tumors, respectively. Multivariable analysis indicated that examining more LNs than the corresponding cut-off value was a significant survival predictor (DC: HR, 0.813; P < 0.001; VC: HR, 0.696; P = 0.028).

CONCLUSION

The optimal number of ELNs for adequate staging of pancreatic cancer was related to T stage. We recommend examining at least 16, 21, and 23 LNs for T1, T2, and T3 tumors, respectively, as a nodal staging quality measure for both surgery and pathological analysis.

Prognostic value of number of examined lymph nodes in patients with node-negative gastric cancer

AIM: To elucidate the potential impact of examined lymph nodes (eLNs) on long-term survival of node-negative gastric cancer patients after curative surgery.

METHODS: A total of 497 node-negative gastric cancer patients who underwent curative gastrectomy between January 2000 and December 2008 in our center were enrolled in this study. Patients were divided into 4 groups according to eLNs through cut-point analysis. Clinicopathological features were compared between ≤ 15 eLNs group and > 15 eLNs group and potential prognostic factors were analyzed. The Log-rank test was used to assess statistical differences between the groups. Independent prognostic factors were identified using the Cox proportional hazards regression model. Stratified analysis was performed to investigate the impact of eLNs on patient survival in each stage. Overall survival was also compared among the four groups. Finally, we explored the recurrent sites associated with eLNs.

RESULTS: Patients with eLNs > 15 had a better survival compared with those with eLNs ≤ 15 for the entire cohort. By the multivariate survival analysis, we found that the depth of invasion and the number of eLNs were the independent predictors of overall survival (OS) of patients with node-negative gastric cancer. According to the cut-point analysis, T2-T4 patients with 11-15 eLNs had a significantly longer mean OS than those with 4-10 eLNs or 1-3 eLNs. Patients with ≤ 15 eLNs were more likely to experience locoregional and peritoneal recurrence than those with > 15eLNs.

CONCLUSION: Number of eLNs could predict the prognosis of node-negative gastric cancer, and dissection of > 15 eLNs is recommended during lymphadenectomy so as to improve the long-term survival.