The Role of Log Odds of Positive Lymph Nodes in Predicting the Survival after Resection for Ampullary Adenocarcinoma

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.

N, LNR or LODDS: Which Is the Most Appropriate Lymph Node Classification Scheme for Patients with Radically Resected Pancreatic Cancer?

Simple Summary

To date, no data are available regarding the most appropriate alternative LN classification system with respect to prognostic power and discriminative ability in cases with resectable pancreatic ductal adenocarcinoma (PDAC). We compared different lymph node classification systems with regard to accurate evaluation of overall survival in 319 patients with resected PDAC. One LNR and one LODDS classification scheme were found to out-perform the N category in distinct patient subgroups. Only the LODDS classification exhibited statistically significant, gradually increasing HRs of their subcategories and, at the same time, significantly better discriminative potential in the subgroups of patients with PDAC of the head or corpus and in patients with tumor-free resection margins or M0 status, respectively.

Abstract

Background: Even though numerous novel lymph node (LN) classification schemes exist, an extensive comparison of their performance in patients with resected pancreatic ductal adenocarcinoma (PDAC) has not yet been performed. Method: We investigated the prognostic performance and discriminative ability of 25 different LN ratio (LNR) and 27 log odds of metastatic LN (LODDS) classifications by means of Cox regression and C-statistic in 319 patients with resected PDAC. Regression models were adjusted for age, sex, T category, grading, localization, presence of metastatic disease, positivity of resection margins, and neoadjuvant therapy. Results: Both LNR or LODDS as continuous variables were associated with advanced tumor stage, distant metastasis, positive resection margins, and PDAC of the head or corpus. Two distinct LN classifications, one LODDS and one LNR, were found to be superior to the N category in the complete patient collective. However, only the LODDS classification exhibited statistically significant, gradually increasing HRs of their subcategories and at the same time significantly higher discriminative potential in the subgroups of patients with PDAC of the head or corpus and in patients with tumor free resection margins or M0 status, respectively. On this basis, we built a clinically helpful nomogram to estimate the prognosis of patients after radically resected PDAC. Conclusion: One LNR and one LODDS classification scheme were found to out-perform the N category in terms of both prognostic performance and discriminative ability, in distinct patient subgroups, with reference to OS in patients with resected PDAC.

Development and Validation of a New Lymph Node Ratio-Based Staging System for Ampullary Carcinoma After Curative Pancreaticoduodenectomy

Background

Lymph node metastasis (LNM) is closely associated with the prognosis of ampullary carcinoma (AC). The purpose of this study is to explore the relationship between lymph node ratio (LNR) and the prognosis of patients with AC after curative pancreaticoduodenectomy and to establish a new LNR-based staging system.

Methods

AC patients in the Cancer Hospital, Chinese Academy of Medical Sciences, between 1998 and 2020 were retrospectively reviewed as the training cohort; and AC patients in the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2018 were obtained as the validation cohort. Within the training group, Kaplan–Meier survival analyses and Cox proportional hazards regression were conducted to assess the prognostic value of LNR and establish a new LNR-based staging system. Then, the new staging system was compared with the 8th American Joint Committee on Cancer (AJCC) TNM staging system in both the training and validation cohorts.

Results

A total of 264 patients in the training cohort and 199 patients in the validation cohort were enrolled. Significant overall survival (OS) difference was observed between LNR-low stage and LNR-high stage in both training (p = 0.001) and validation cohorts (p < 0.001). Then a new LNR-based staging system was developed. Under the new system, the number of patients in the training cohort and validation cohort of stage I, stage II, and stage III was 30 (11%) vs. 18 (9%), 190 (72%) vs. 96 (48%), and 44 (17%) vs. 85 (43%), respectively. The new staging system classified patients with respect to survival better than did the 8th AJCC TNM staging system.

Conclusions

The new LNR-based staging system had better discriminability for predicting survival in AC patients after curative pancreaticoduodenectomy. More data are needed for further validation.

Comparison of Different Lymph Node Staging Schemes for Predicting Survival Outcomes in Node-Positive Endometrioid Endometrial Cancer Patients

Objective: To compare the prognostic predictive performance of six lymph node (LN) staging schemes: American Joint Committee on Cancer (AJCC) N stage, number of retrieved lymph nodes (NRLN), number of positive lymph nodes (NPLN), number of negative lymph nodes (NNLN), lymph node ratio (LNR), and log odds of positive lymph nodes (LODDS) among node-positive endometrioid endometrial cancer (EEC) patients. Methods: A total of 3,533 patients diagnosed with node-positive EEC between 2010 and 2016 from the Surveillance, Epidemiology, and End Results (SEER) database were retrospectively analyzed. We applied X-tile software to identify the optimal cutoff value for different staging schemes. Univariate and multivariate Cox regression models were used to assess the relationships between different LN schemes and survival outcomes [disease-specific survival (DSS) and overall survival (OS)]. Moreover, Akaike information criterion (AIC) and Harrell concordance index (C-index) were used to evaluate the predictive performance of each scheme in both continuous and categorical patterns. Results: N stage (N1/N2) was not an independent prognostic factor for node-positive EEC patients based on multivariate analysis (DSS: p = 0.235; OS: p = 0.145). Multivariate model incorporating LNR demonstrated the most superior goodness of fit regardless of continuous or categorical pattern. Regarding discrimination power of the models, LNR outperformed other models in categorical pattern (OS: C-index = 0.735; DSS: C-index = 0.737); however, LODDS obtained the highest C-index in continuous pattern (OS: 0.736; DSS: 0.739). Conclusions: N stage (N1/N2) was unable to differentiate the prognosis for node-positive EEC patients in our study. However, LNR and LODDS schemes seemed to have a better predictive performance for these patients than other number-based LN schemes whether in DSS or OS, which revealed that LNR and LODDS should be more helpful in prognosis assessment for node-positive EEC patients than AJCC N stage.

Prognostic value of log odds of positive lymph nodes in node-positive lung squamous cell carcinoma patients after surgery: a SEER population-based study

Background

Log odds of positive lymph nodes (LODDS) is a novel and promising ratio-based lymph node (LN) staging system in many malignancies. This study aimed to evaluate the prognostic value of LODDS, and comprehensively compare the prognostic predictive performance of LODDS with the American Joint Committee on Cancer (AJCC) N classification, number of positive lymph node (NPLN), and lymph node ratio (LNR) among node-positive lung squamous cell carcinoma (SCC) patients after surgery.

Methods

We identified 2,561 patients with N1/N2 stage SCC diagnosed between 2004 and 2014 from the Surveillance, Epidemiology, and End Results (SEER) database. X-tile analysis was used to calculate the optimal cut-off value for each staging system. Univariable and Multivariable Cox regression analyses were used to assess the association of cancer-specific survival (CSS), and overall survival (OS) with N, NPLN, LNR, and LODDS, separately, and integrally. Moreover, linear trend χ² score, likelihood ratio (LR) test, Akaike information criterion (AIC), and Harrell concordance index (C-index) were adopted as criteria for assessing the predictive ability of each model.

Results

The optimal cut-off values for NPLN, LNR, and LODDS were 3, 0.28, and −0.37, respectively. N, NPLN, LNR, and LODDS were identified as independent prognostic predictors for CSS and OS in patients with SCC when each of them was incorporated into multivariable Cox model separately. Additionally, LODDS had the higher linear trend χ² score, higher LR χ² test score, lower AIC, and higher C-index compared to the other three systems. Moreover, a combination of N, NPLN, and LODDS was superior to any staging system alone for predicting prognosis.

Conclusions

LODDS showed better predictive performance than N, NPLN, and LNR among patients with node-positive SCC after surgery. A combination of LODDS and the current AJCC TNM classification has the potential for becoming a better staging method to more precisely predicting prognosis.