Lymph Node Ratio May Predict the Benefit of Postoperative Radiotherapy in Non–Small-Cell Lung Cancer

Postoperative radiotherapy improves survival in completely resected non-small cell lung cancer with pathologic N2 stage IIIA and positive lymph node count greater than one: a SEER-based retrospective cohort study

Objective

Non-small cell lung cancer (NSCLC) constitutes approximately 85% of lung cancer cases, with 20%-30% of patients diagnosed at stage III. While multimodal therapy is the standard for treating locally advanced NSCLC, the role of PORT remains controversial. This study seeks to evaluate the effect of postoperative radiotherapy (PORT) on overall survival (OS) and cancer-specific survival (CSS) in patients with resected pathologic N2 (pN2) stage IIIA NSCLC.

Methods

Data from the Surveillance, Epidemiology, and End Results Program (SEER) 17 registry (2010-2019) were analyzed. The cohort included 1,471 patients aged 65 years or older, diagnosed with stage IIIA pN2 NSCLC, who had undergone lobectomy or total pneumonectomy. Patients who had received neoadjuvant chemotherapy or radiotherapy were excluded. Univariate and multivariate analyses were conducted to assess the association of PORT with OS and CSS. Kaplan-Meier survival curves were employed to estimate survival outcomes, while the COX proportional hazards model was utilized for comparative analysis. PLN counts were stratified into two categories: ≤1 and >1.

Results

Among the 1,471 patients included in the study, 613 (41.67%) received PORT, while 858 (58.33%) did not. PORT was associated with a significantly higher 1- and 3-year OS (89.96% and 68.49%, respectively) compared to the non-PORT group (87.44% and 61.88%, respectively, P = 0.03). However, no significant difference in CSS was observed between the groups (P = 0.15). Among patients with PLN counts >1, PORT significantly improved OS (HR = 1.32, 95% CI = 1.04-1.68, P = 0.0016) and CSS (HR = 1.32, 95% CI = 0.99-1.70, P = 0.026), whereas no significant differences were seen in patients with PLN counts ≤1.

Conclusions

This study underscores the potential of PORT in enhancing OS in patients with resectable pN2 stage IIIA NSCLC, particularly in those with PLN counts exceeding one. These findings suggest that PORT may offer improved outcomes in patients with extensive lymph node involvement, emphasizing the need for further prospective studies to validate and expand upon these observations.

Is postoperative radiotherapy effective in patients with completely resected pathologic stage IIIA(N2) non-small cell lung cancer? High-risk populations should consider it

Background and purpose

We aimed to assess the benefits of postoperative radiotherapy (PORT) in completely resected patients with pathologic stage IIIA(N2) non-small cell lung cancer (NSCLC) with a high risk of locoregional recurrence (LRR).

Materials and methods

A prospective, randomized trial was conducted starting in July 2016 to explore the optimal timing of PORT in high-LRR-risk patients with completely resected IIIA(N2) NSCLC (NCT02974426). Patients were identified as high-LRR-risk patients via the prognostic index (PI) model and were randomly assigned to PORT-first or PORT-last treatment. To evaluate PORT for high-LRR-risk patients, all patients in this trial constituted the PORT cohort, whereas high-LRR-risk patients without PORT were selected from a retrospective cohort as the non-PORT cohort. Propensity score-matched (PSM) analyses were conducted to compare overall survival (OS), disease-free survival (DFS), locoregional recurrence-free survival (LRFS) and distant metastasis-free survival (DMFS).

Results

Between 2016 and 2022, 132 patients were included in the trial, with a median follow-up of 49.3 months. The 3-year OS rate was 83.2 %, and the 3-year DFS rate was 35.0 %. Among these patients, 122 patients (92 %) received planned PORT. For 132 intention-to-treat patients, PSM analysis with the non-PORT cohort (n = 307) resulted in 130 matched pairs. The results revealed that PORT improved LRFS (3-year LRFS, 77.6 % vs. 57.3 %; p = 0.00014), DFS (3-year DFS, 35.2 % vs. 28.6 %; p = 0.038), and OS (3-year OS, 83.0 % vs. 60.7 %; p = 0.00017), with no difference in DMFS (p = 0.17).

Conclusion

PORT could increase local control, DFS, and OS in high-LRR-risk patients with completely resected IIIA(N2) NSCLC. Future research should utilize multidimensional data to pinpoint more precise subgroups benefiting from PORT, with prospective trials validating these findings.

Prognostic biomarker tumor-infiltrating lymphocytes failed to serve as a predictive biomarker for postoperative radiotherapy in completely resected pN2 non-small cell lung cancer: a retrospective analysis

BACKGROUND

Evidence suggests that radiotherapy is a potent immunomodulator in non-small cell lung cancer (NSCLC). Conversely, it has rarely been demonstrated if immune infiltration can influence radiotherapy efficacy. Herein, we explored the effect of tumor-infiltrating lymphocytes (TILs) on the response to postoperative radiotherapy (PORT) in completely resected stage III-pN2 NSCLC.

METHODS

This retrospective study included 244 patients with pathologically confirmed stage III-N2 NSCLC who underwent complete resection at our institution between 2014 and 2020. TILs were assessed with permanent full-face hematoxylin and eosin (H&E) sections and the evaluation of TILs was based on a published guideline. Patients were stratified into the TILlow or TILhigh group with a cutoff value of 50%. Kaplan-Meier method and Log-rank test were utilized to assess disease-free survival (DFS) and overall survival (OS). Univariate and multivariate Cox regression analysis were conducted to determine prognostic indicators.

RESULTS

Among 244 patients, a total of 121 patients received PORT whereas 123 did not. TILs level in patients with PORT was significantly higher than that in patients without PORT (p < 0.001). High TILs level was significantly associated with an improved DFS and OS in all the entire chort (DFS, p < 0.001; OS, p = 0.001), PORT chort (DFS, p = 0.003; OS, p = 0.011) and non-PORT chort (DFS, p < 0.001; OS, p = 0.034). There were no significant survival differences between different treatment modalities in the low TILs infiltration (DFS, p = 0.244; OS, p = 0.404) and high TILs infiltration (DFS, p = 0.167; OS, p = 0.958) groups.

CONCLUSIONS

TILs evaluated with H&E sections could represent a prognostic biomarker in patients with completely resected pN2 NSCLC, and high TILs infiltration was associated with favorable survival outcomes.The predictive value of TILs for PORT still need to be further explored in the future.

Prognostic analysis of lung squamous cell carcinoma patients with second primary malignancies: a SEER database study

Background

As lung squamous cell carcinoma (LUSC) patients are at increased risk of developing a second primary cancer, this complicates the patient's condition and thus makes prognostic assessment more difficult, posing a significant prognostic challenge for clinicians. Our goal was to assess the prognosis of LUSC patients with a second primary tumor, and provide insights into appropriate therapy and monitoring strategies.

Methods

Data was obtained for LUSC patients from the Surveillance, Epidemiology, and End Results (SEER) database. The LUSC patients were divided into three groups (LS-SPM, OT-LUSC and LUSC-only). Univariate and stratified analyses were performed for the baseline and clinical characteristics of the participants. Multiple regression and Kaplan-Meier survival analyses were also performed, followed by a final life table analysis.

Results

In our sample of 101,626 patients, the HR for OS in the LS-SPM group was 0.40 in univariate analysis. Kaplan-Meier survival curves showed that LS-SPM patients had considerably longer lifespans compared to the other groups. The LS-SPM patients had median and mean survival times of 64 months and 89.11 months. Unadjusted and adjusted multiple regression analyses showed that LS-SPM patients had a superior survival compared to LUSC-only and OT-LUSC groups.

Conclusion

LS-SPM patients have a good prognosis with aggressive therapy and immune monitoring. The present study offers novel insights into the pathophysiological causes and treatments for LS-SPM.

Is there role of adjuvant radiotherapy after complete resection of locally advanced nonsmall cell lung cancer?

PURPOSE OF REVIEW

This review aims to provide a timely and relevant overview of the role of postoperative radiotherapy (PORT) in completely resected stage IIIA-N2 nonsmall cell lung cancer (NSCLC). Given the controversy surrounding the use of PORT and the emergence of advanced radiation techniques and therapies, this review provides valuable insight into current and potential treatment strategies.

RECENT FINDINGS

The Lung ART and PORT-C trials have provided valuable insights into the efficacy of PORT in stage IIIA-N2 NSCLC. While the results have been mixed, studies have shown that advanced radiation techniques, such as intensity-modulated radiotherapy (IMRT) and proton therapy, can reduce cardiopulmonary toxicities associated with PORT. Molecular targeted therapies and immunotherapies have also shown potential in improving NSCLC treatment outcomes.

SUMMARY

The role of radiotherapy becomes smaller and smaller in new era. However, it is too early to abolish radiotherapy for all the patients after complete resection of locally advanced NSCLC. Nowadays, it is recommended to adopt individualized treatment approaches guided by multidisciplinary team consultations. The integration of IMRT, proton therapy, and emerging therapies offers the potential to enhance treatment efficacy while minimizing toxicity. Further research is needed to optimize the use of PORT and explore the method to identify the patients who can really benefit from PORT.

Management of locally advanced non-small cell lung cancer: State of the art and future directions

Lung cancer is the second most common and the deadliest type of cancer worldwide. Clinically, non-small cell lung cancer (NSCLC) is the most common pathological type of lung cancer; approximately one-third of affected patients have locally advanced NSCLC (LA-NSCLC, stage III NSCLC) at diagnosis. Because of its heterogeneity, LA-NSCLC often requires multidisciplinary assessment. Moreover, the prognosis of affected patients is much below satisfaction, and the efficacy of traditional therapeutic strategies has reached a plateau. With the emergence of targeted therapies and immunotherapies, as well as the continuous development of novel radiotherapies, we have entered an era of novel treatment paradigm for LA-NSCLC. Here, we reviewed the landscape of relevant therapeutic modalities, including adjuvant, neoadjuvant, and perioperative targeted and immune strategies in patients with resectable LA-NSCLC with/without oncogenic alterations; as well as novel combinations of chemoradiation and immunotherapy/targeted therapy in unresectable LA-NSCLC. We addressed the unresolved challenges that remain in the field, and examined future directions to optimize clinical management and increase the cure rate of LA-NSCLC.

Nomogram to predict the risk of biochemical recurrence and structural recurrence in patients with stage cN1 papillary thyroid carcinoma

INTRODUCTION

Although papillary thyroid carcinoma (PTC) is thought to be the least aggressive thyroid cancer, it has a significant recurrence rate. Therefore, we aimed to develop a nomogram to estimate the probability of biochemical recurrence (BIR) and structural recurrence (STR) in patients with stage cN1 PTC.

METHODS

We studied the relationship between the characteristics of patients with stage N1a PTC and the risk of recurrence by analysing the data of 617 inpatients (training cohort) and 102 outpatients (validation cohort) in our hospital. We used the least absolute shrinkage and selection operator regression model to identify prognostic indicators to construct nomograms to predict the risk of BIR and STR.

RESULTS

There were 94 (15.24%) BIR cases in the training cohort and 36 (35.29%) in the validation cohort. There were 31 (5.02%) STR cases in the training cohort and 23 (22.55%) cases in the validation cohort. The variables included in the BIR nomogram were sex, age at diagnosis, tumour size, extrathyroidal infiltration, and lymph node ratio (LNR). While the variables included in the STR nomogram were tumour size, extrathyroidal infiltration, BRAF state, metastatic lymph nodes, and LNR. Both the prediction models demonstrated good discrimination ability. The results showed the calibration curve of the nomogram was near the optimum diagonal line, and the decision curve analysis showed a noticeably better benefit.

CONCLUSION

The LNR may be a valid prognostic indicator for patients with stage cN1 PTC. The nomograms could help clinicians identify high-risk patients and choose the best postsurgical therapy and monitoring.

Impact of pathological nodal staging and tumour differentiation on survival and postoperative radiotherapy in completely resected stage IIIA Non-small-cell lung cancer

BACKGROUND

Tumour differentiation is an important index for adjuvant therapy in many cancers; however, non-small cell lung cancer (NSCLC) is an exception. Furthermore, postoperative radiotherapy (PORT) is controversial in patients with NSCLC with N0-1 and N2 disease. We aimed to evaluate the impact of tumour-related factors on overall survival (OS), cancer-specific survival (CSS), and distant control (DC) in patients with completely resected stage IIIA NSCLC.

MATERIALS AND METHODS

Patients with stage IIIA non-metastatic NSCLC who underwent complete resection and adjuvant chemotherapy were identified from the Taiwan Cancer Registry (January 2007-December 2017). Logistic regression analysis was performed to determine the factors associated with PORT. Survival and relapse outcomes were compared using log-rank tests and Cox regression analysis. Sensitivity analysis was performed using propensity score-matched pairs.

RESULTS

In total, 1,897 patients were included and stratified according to PORT use (PORT vs. non-PORT). After adjusting for covariates, PORT was not found to be associated with improved survival outcomes. In patients with poorly differentiated tumours and N2 disease, absolute benefits for OS (adjusted hazard ratio [aHR] 0.76), CSS (aHR 0.80), and DC (aHR 0.74) were observed. Multivariable hazard models of propensity score-matched pN2 disease and poorly differentiated tumour subgroups also showed significant survival benefit with PORT treatment.

CONCLUSIONS

Patients with poorly differentiated tumours and receiving PORT for pN2 disease showed a lower risk of distant recurrence and more favourable survival outcomes in stage IIIA NSCLC with R0 resection.

Predictive Value of Clinicopathological Factors to Guide Post-Operative Radiotherapy in Completely Resected pN2-Stage III Non-Small Cell Lung Cancer

Introduction: With the evolution of radiotherapy techniques and a better understanding of clinicopathological factors, we aimed to evaluate the treatment effect of post-operative radiotherapy (PORT) and associated predictive factors in patients with completely resected pN2 stage III non-small cell lung cancer (R0 pN2-stage III NSCLC). Material and Method: The cancer registration database of a single medical center was searched for R0 pN2-stage III NSCLC. Clinicopathological factors and information about post-operative therapies, including PORT and adjuvant systemic treatment, were retrospectively collected and analyzed. The Kaplan-Meier method and a Cox regression model were applied for time-to-event analysis, with disease-free survival (DFS) being the primary outcome. Results: From 2010 to 2021, 82 R0 pN2-stage III NSCLC patients were evaluated, with 70.1% of tumors harboring epidermal growth factor receptor mutations (EGFR mut.). PORT was performed in 73.2% of cases, and the median dose was 54 Gy. After a median follow-up of 42 months, the 3-year DFS and overall survival (OS) rates were 40.6% and 77.3%, respectively. Distant metastasis (DM) was the main failure pattern. In the overall cohort, DFS was improved with PORT (3-year DFS: 44.9% vs. 29.8%; HR: 0.552, p = 0.045). Positive predictive factors for PORT benefit, including EGFR mut., negative extranodal extension, positive lymphovascular invasion, 1-3 positive lymph nodes, and a positive-to-dissected lymph node ratio ≤0.22, were recognized. OS improvement was also observed in subgroups with less lymph node burden. Conclusions: For R0 pN2-stage III NSCLC, PORT prolongs DFS and OS in selected patients. Further studies on predictive factors and the development of nomograms guiding the application of PORT are highly warranted, aiming to enhance the personalization of lung cancer treatment.

Lymph node ratio precisely predicts the benefit of postoperative radiotherapy in esophageal cancer: A retrospective cohort study

BACKGROUND

The matter of postoperative radiotherapy (PORT) in esophageal cancer (ESCA) was far from conclusive. Some evidence indicated that lymph node status could affect treatment. We evaluated lymph node ratio (LNR) as an indicator that could be applied to predict PORT benefit.

METHODS

Retrospective cohort study collected the data of N1, N2, N3 stage ESCA patients from the Surveillance, Epidemiology, and End Results database (SEER) to analyze the association between LNR and prognosis from 2004 to 2015. Patients were categorized into two subsets based on the LNR cut-off value of 0.23 using receiver operating characteristic curve (ROC). Kaplan-Meier analysis was utilized to estimate the proportion of overall survival (OS) and esophagus cancer-specific survival (CSS) in two LNR groups. Cox regression analysis and competitive risk model was adopted to investigate the impacts of LNR on prognosis.

RESULTS

Of 2,165 ESCA patients identified, 1,165 (53.8%) had LNR>0.23. The LNR was an independent prognostic factor and associated with better OS and CSS of LNR≤0.23 (P < 0.001). In competitive risk model, a worse CSS was analyzed of LNR>0.23 (HR = 1.71; 95% CI 1.53-1.91). Subgroup analyses indicated that PORT was associated with favorable OS and CSS. Furthermore, when stratified by Node stage, PORT was associated with a survival benefit only in N1 stage with higher LNR (LNR>0.23) after adjusting for other covariates.

CONCLUSIONS

LNR exceeding 0.23 was negatively associated with prognosis in ESCA. The survival benefit from PORT in ESCA seems to be limited to LNR of 23% or more only in N1 stage. This study highlights the biomarker meaning of LNR on identifying PORT beneficiary in N1 stage.

The impact of postoperative radiotherapy on the survival of patients with stage III non-small cell lung cancer: A CONSORT-compliant analysis using the SEER database

BACKGROUND

Postoperative radiotherapy (PORT) is commonly used to treat patients with resected stage III non-small cell lung cancer (NSCLC), but its effectiveness remains uncertain. This retrospective cohort study aimed to investigate the impact of PORT on overall survival (OS) and evaluate its heterogeneity among subgroups of patients.

METHODS

A total of 6305 patients with resected stage III NSCLC were included in this study from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching was conducted to balance baseline characteristics between the patients who received PORT and those who did not. OS was used as the primary outcome. Subgroup analysis was performed to identify which patient subgroups might benefit more from PORT.

RESULTS

Overall, no significant difference was observed in OS between the 2 groups with or without propensity score matching. However, subgroup analysis demonstrated that PORT improved OS in patients with certain characteristics, including stage IIIA/N2, stage IIIB, squamous cell carcinoma, tumor grade III-IV, or lymph node ratio (LNR) > 1/3. Multivariate analysis showed that several variables were associated with adverse prognostic factors for OS, such as marital status (others), race (white), male gender, squamous cell carcinoma, elderly age, advanced stage, poor histological differentiation grade, high LNR, and not receiving chemotherapy.

CONCLUSION

In patients with resected stage III NSCLC, PORT may not be beneficial for all patients. However, it may improve survival time in certain patient subgroups, such as those with stage IIIA/N2, stage IIIB, squamous cell carcinoma, tumor grade III to IV, or LNR > 1/3. These findings provide important information for clinical decision-making and future research regarding the use of PORT in patients with resected stage III NSCLC.

Lymph node ratio-based prognostic model for risk stratification and individualized adjuvant therapy for postoperative major salivary duct carcinoma

BACKGROUND

To investigate the value of lymph node ratio (LNR) for postoperative major salivary duct carcinoma (MSDC) and to establish a model for prognosis assessment and treatment optimization.

METHODS

Data of MSDC were retrieved in public database, and prognostic factors were identified by univariate and multivariate analyses. A nomogram and risk stratification system were constructed.

RESULTS

Four hundred and eleven eligible patients were included (training cohort vs. validation cohort: 287: 124). LNR ≥0.09 was associated with worse overall survival (OS). Age at diagnosis, sex, T stage, and LNR were identified as prognostic factors and integrated into nomogram. Low-risk patients were found to have better OS than high-risk patients. Furthermore, postoperative radiotherapy (PORT) significantly improved OS in the high-risk subgroup, but chemotherapy did not confer a long-term survival benefit.

CONCLUSIONS

A nomogram model integrating LNR could better assess postoperative prognosis and risk stratification in MSDC, and identify patients who might benefit from PORT to avoid overtreatment.

[Postoperative radiotherapy in non-small cell lung cancer stage IIIA - N2: Focus and perspectives]

Patients with resectable stage IIIA - N2 lung cancer represent a very heterogeneous population with variable risks of postoperative recurrence depending on the type of N2 involvement (unisite N2, multisite N2, bulky N2, extra-capsular rupture, incomplete resection…). This heterogeneity associated with the difficulty of carrying out prospective randomized studies with sufficient power in stages IIIA - 2, results in the absence of clear and consensual recommendations (except for stages IIIA - N2 resectable R0, since LungART and PORT-C studies). The objective of this article is to make an update on the place of postoperative radiotherapy in the management of stages IIIA - N2 following the publication of two recent randomized trials (PORT-C and LungART) but also compare them fort a better understanding of the current issues raised by these first published results. Indeed, these two trials do not find any benefit in terms of progression free survival and overall survival of postoperative radiotherapy but exploratory analyzes from these two studies seem to show a potential benefit of postoperative in some pN2 populations at high risk of locoregional recurrence (N2 multisite, N2 bulky…). In addition, the advent of immunotherapy (atezolizumab or pembrolizumab) and targeted therapies (osimertinib) in the adjuvant situation are redebating the place of a possible indication for postoperative radiotherapy in stage IIIA - 2.

Clinical Stage III NSCLC Patients Treated with Neoadjuvant Therapy and Surgery: The Prognostic Role of Nodal Characteristics

BACKGROUND: The aim of this study is to analyze the prognostic factors in patients that underwent induction therapy and surgery for clinical stage III NSCLC. METHODS: Clinical and pathological characteristics of stage III NSCLC patients for N2 involvement that underwent neoadjuvant treatment (NAD) and surgery from 1/01/1998 to 31/12/2017 were collected and retrospectively analyzed. Tumor characteristics, yClinical, yPathological stage and lymph node characteristics were correlated to Overall Survival (OS). RESULTS: The analysis was conducted on 180 patients. Five-year OS (5YOS) was 50.9%. Univariable analysis results revealed old age (p = 0.003), clinical N2 post-NAD (p = 0.01), pneumonectomy (0.005), persistent pathological N2 (p = 0.039, HR 1.9, 95% CI 1.09−2.68) and adjuvant therapy absence (p = 0.049) as significant negative prognostic factors. Multivariable analysis confirmed pN0N1 (p = 0.02, HR 0.29, 95% CI 0.13−0.62) as a favorable independent prognostic factor and adjuvant therapy absence (p = 0.012, HR 2.61, 95% CI 1.23−5.50) as a negative prognostic factor. Patients with persistent N2 presented a 5YOS of 35.3% vs. 55.8% in pN0N1 patients. Regarding lymph node parameters, the lymph node ratio (NR) significantly correlated with OS: 5YOS of 67.6% in patients with NR < 50% vs. 29.5% in NR > 50% (p = 0.029). CONCLUSION: Clinical response aided the stratification of prognosis in patients that underwent multimodal treatment for stage III NSCLC. Adjuvant therapy seemed to be an important option in these patients, while node ratio was a strong prognosticator in patients with persistent nodal involvement.

An Interpretable Two-Phase Modeling Approach for Lung Cancer Survivability Prediction

Although lung cancer survival status and survival length predictions have primarily been studied individually, a scheme that leverages both fields in an interpretable way for physicians remains elusive. We propose a two-phase data analytic framework that is capable of classifying survival status for 0.5-, 1-, 1.5-, 2-, 2.5-, and 3-year time-points (phase I) and predicting the number of survival months within 3 years (phase II) using recent Surveillance, Epidemiology, and End Results data from 2010 to 2017. In this study, we employ three analytical models (general linear model, extreme gradient boosting, and artificial neural networks), five data balancing techniques (synthetic minority oversampling technique (SMOTE), relocating safe level SMOTE, borderline SMOTE, adaptive synthetic sampling, and majority weighted minority oversampling technique), two feature selection methods (least absolute shrinkage and selection operator (LASSO) and random forest), and the one-hot encoding approach. By implementing a comprehensive data preparation phase, we demonstrate that a computationally efficient and interpretable method such as GLM performs comparably to more complex models. Moreover, we quantify the effects of individual features in phase I and II by exploiting GLM coefficients. To the best of our knowledge, this study is the first to (a) implement a comprehensive data processing approach to develop performant, computationally efficient, and interpretable methods in comparison to black-box models, (b) visualize top factors impacting survival odds by utilizing the change in odds ratio, and (c) comprehensively explore short-term lung cancer survival using a two-phase approach.

A decision support framework for postoperative radiotherapy in patients with pathological N2 non-small cell lung cancer

INTRODUCTION

Postoperative radiotherapy (PORT) plays a highly controversial role in pathological N2 (pN2) non-small cell lung cancer (NSCLC) disease. Recent studies reveal that not all patients can benefit from PORT. Further research is needed to identify predictors of PORT.

METHODS

A total of 1044 pathologic stage T1-3N2M0 NSCLC patients were analyzed. Risk factors of distant metastasis were identified by the log-rank tests and the multivariable Cox models. We integrated risk factors of distant metastasis and our previously published loco-regional recurrence (LRR) related prognostic index into a decision support framework (DSF) to predict the outcomes of PORT. An independent cohort was used to validate the DSF.

RESULTS

We defined patients with more than two of three identified LRR-related features (heavy cigarette smoking history, clinical N2 status, and more than four positive lymph nodes) as a high LRR risk group. We found the high-intermediate-risk histological type (with micropapillary and/or solid components) was associated with a higher risk of distant metastasis (HR=1.207, 95% CI 1.062 to 1.371, P=0.0129), but not LRR. We built the DSF by combining these two types of features. Patients were stratified into four groups by using the DSF. PORT significantly improved OS only in the subgroup without high-risk histological features (without micropapillary or solid components) and with a high risk for LRR (three-year OS: 66.7% in the PORT group vs. 50.2% in the non-PORT group; P=0.023).

CONCLUSIONS

A particular pN2 subgroup with a high risk of LRR and without micropapillary or solid components could benefit from PORT.

Machine learning to refine prognostic and predictive nodal burden thresholds for post-operative radiotherapy in completely resected stage III-N2 non-small cell lung cancer

BACKGROUND

The role of post-operative radiotherapy (PORT) for completely resected N2 non-small-cell lung cancer (NSCLC) is controversial in light of recent randomized data. We sought to utilize machine learning to identify a subset of patients who may still benefit from PORT based on extent of nodal involvement.

MATERIALS/METHODS

Patients with completely resected N2 NSCLC were identified in the National Cancer Database. We trained a machine-learning based model of overall survival (OS). SHapley Additive exPlanation (SHAP) values were used to identify prognostic and predictive thresholds of number of positive lymph nodes (LNs) involved and lymph node ratio (LNR). Cox proportional hazards regression was used for confirmatory analysis.

RESULTS

A total of 16,789 patients with completely resected N2 NSCLC were identified. Using the SHAP values, we identified thresholds of 3+ positive LNs and a LNR of 0.34+. On multivariate analysis, PORT was not significantly associated with OS (p=0.111). However, on subset analysis of patients with 3+ positive LNs, PORT improved OS (HR: 0.91; 95%CI: 0.86-0.97; p=0.002). On a separate subset analysis in patients with a LNR of 0.34+, PORT improved OS (HR: 0.90; 95%CI: 0.85-0.96; p=0.001). Patients with 3+ positive lymph nodes had a 5-year OS of 38% with PORT compared to 31% without PORT. Patient with positive lymph node ratio 0.34+ had a 5-year OS of 38% with PORT compared to 29% without PORT.

CONCLUSIONS

Patients with a high lymph node burden or lymph node ratio may present a subpopulation of patients who could benefit from PORT. To our knowledge, this is the first study to use machine learning algorithms to address this question with a large national dataset. These findings address an important question in the field of thoracic oncology and warrant further investigation in prospective studies.

Lymph node ratio predicts efficacy of postoperative radiation therapy in nonmetastatic Merkel cell carcinoma: A population-based analysis

BACKGROUND

After radical resection of a nonmetastatic Merkel cell carcinoma (M0 MCC), postoperative radiation therapy (RT) is recommended as it improves survival. However, the role of RT in specific subgroups of M0 MCC is unclear. We sought to identify whether there is a differential survival benefit from RT in specific M0 MCC patient subgroups.

METHODS

M0 MCC patients from the Surveillance, Epidemiology, and End Results (SEER) database registry were collected. The best prognostic age, tumor size, and lymph node ratio (LNR, ratio between positive lymph nodes and resected lymph nodes) cutoffs were calculated. The primary endpoint was overall survival (OS).

RESULTS

A total of 5644 M0 MCC patients (median age 77 years, 62% male) were included: 4022 (71%) node-negative (N0) and 1551 (28%) node-positive (N+). Overall, 2682 patients (48%) received RT. Age > 76.5 years, tumor size >13.5 mm, and LNR >0.215 were associated with worse OS. RT was associated with longer OS in the M0 MCC, N0, and N+ group and independently associated with a 25%, 27%, and 26% reduction in the risk for death, respectively. RT benefit on survival was increased in tumor size >13.5 mm in the N0 group and LNR >0.215 in the N+ group. No OS benefit from RT was observed in T4 tumors (N0 and N+ groups).

CONCLUSIONS

RT was associated with improved survival in M0 MCC, irrespective of the nodal status. LNR >0.215 is a useful prognostic factor for clinical decision-making and for stratification and interpretation of clinical trials.

Role of Adjuvant Radiotherapy in Non-Small Cell Lung Cancer-A Review

Simple Summary

The role of postoperative radiotherapy (PORT) in completely resected non-small cell lung cancer (NSCLC) with ipsilateral mediastinal lymph node involvement (pN2) is controversial. The aim of our review was to study the literature relating to PORT for completely resected NSCLC patients with pN2 involvement. The Lung ART and PORT-C trials indicate better locoregional control with PORT, but this has not yet translated into survival benefits. Given the conflicting results, guidelines do not recommend the use of PORT routinely. Future research should focus on identifying subgroups of patients who might benefit from PORT.

Abstract

Background: For patients with completely resected non-small cell lung cancer (NSCLC) with ipsilateral mediastinal lymph node involvement (pN2), the administration of adjuvant chemotherapy is the standard of care. The role of postoperative radiation therapy (PORT) is controversial. Methods: We describe the current literature focusing on the role of PORT in completely resected NSCLC patients with pN2 involvement and reflect on its role in current guidelines. Results: Based on the results of the recent Lung ART and PORT-C trials, the authors conclude that PORT cannot be generally recommended for all resected pN2 NSCLC patients. A substantial decrease in the locoregional relapse rate without translating into a survival benefit suggests that some patients with risk factors might benefit from PORT. This must be balanced against the risk of cardiopulmonary toxicity with potentially associated mortality. Lung ART has already changed the decision making for the use of PORT in daily practice for many European lung cancer experts, with lower rates of recommendations for PORT overall. Conclusions: PORT is still used, albeit decreasingly, for completely resected NSCLC with pN2 involvement. High-level evidence for its routine use is lacking. Further analyses are required to identify patients who would potentially benefit from PORT.

Indications and Parameters Around Postoperative Radiation Therapy for Lung Cancer

Patients with locally advanced resected non-small-cell lung cancer present a high risk of relapse. Although adjuvant platinum-based chemotherapy has become the standard of care, the role of postoperative radiation therapy (PORT) has been controversial for years. In patients with incomplete resection, PORT should be proposed, on the basis of a strong consensus, despite the absence of randomized evidence. In patients with completely resected (R0) non-small-cell lung cancer, a meta-analysis showed poorer outcomes after PORT in the absence of mediastinal involvement (pN0 and pN1). In patients with pN2, the role of PORT was less clear and required further research. The meta-analysis included trials using older radiation techniques and poorer quality of surgery according to today's standards, and selection of patients was not positron emission tomography-based. Newer retrospective and nonrandomized studies and subgroup analyses of randomized trials evaluating adjuvant chemotherapy suggested a survival benefit of PORT in patients with pN2 R0. Two recent randomized trials (Lung ART and PORT-C) evaluating conformal PORT versus no PORT retrieved no disease-free survival advantage for stage IIIA-N2 patients, even if mediastinal relapse was significantly decreased with PORT. PORT had no effect on survival, possibly given the high rate of distant relapse and risk of additional cardiopulmonary toxicity. Ongoing and future analyses are planned in Lung ART to identify patients for whom PORT could be recommended. Incorporation of newer systemic treatments (immune checkpoint inhibitors or targeted therapy in oncogene-addicted patients) is underway in the neoadjuvant and/or adjuvant setting. Better identification of patients at a high risk of disease recurrence, with analysis of circulating tumor DNA, on the basis of the detection of postsurgical minimal (or molecular) residual disease is warranted in future studies.

Role of Postoperative Radiotherapy in the Management for Resected NSCLC - Decision Criteria in Clinical Routine Pre- and Post-LungART

BACKGROUND

The role of postoperative radiation therapy (PORT) in stage III N2 NSCLC is controversial. We analyzed decision-making for PORT among European radiation oncology experts in lung cancer.

METHODS

Twenty-two experts were asked before and after presentation of the results of the LungART trial to describe their decision criteria for PORT in the management of pN+ NSCLC patients. Treatment strategies were subsequently converted into decision trees and analyzed.

RESULTS

Following decision criteria were identified: extracapsular nodal extension, incomplete lymph node resection, multistation lymph nodes, high nodal tumor load, poor response to induction chemotherapy, ineligibility to receive adjuvant chemotherapy, performance status, resection margin, lung function and cardiopulmonary comorbidities. The LungART results had impact on decision-making and reduced the number of recommendations for PORT. The only clear indication for PORT was a R1/2 resection. Six experts out of ten who initially recommended PORT for all R0 resected pN2 patients no longer used PORT routinely for these patients, while four still recommended PORT for all patients with pN2. Fourteen experts used PORT only for patients with risk factors, compared to eleven before the presentation of the LungART trial. Four experts stated that PORT was never recommended in R0 resected pN2 patients regardless of risk factors.

CONCLUSION

After presentation of the LungART trial results at ESMO 2020, 82% of our experts still used PORT for stage III pN2 NSCLC patients with risk factors. The recommendation for PORT decreased, especially for patients without risk factors. Cardiopulmonary comorbidities became more relevant in the decision-making for PORT.

The prognostic value of lymph node ratio in patients with surgically resected stage I-III small-cell lung cancer: a propensity score matching analysis of the SEER database

OBJECTIVES

Due to the lack of prospective studies, the role of the lymph node ratio (LNR) in small-cell lung cancer (SCLC) remains unknown. This study aimed to assess the prognostic effect of LNR in surgically resected stage I-III SCLC patients.

METHODS

Clinical data of stage I-III (excluding N3 and NX) SCLC patients diagnosed between 1998 and 2016 were extracted from the Surveillance, Epidemiology and End Results database. Patients were divided into low-risk and high-risk subsets based on the LNR cut-off value of 0.15 using X-tile software. Propensity score matching analysis was employed to reduce bias in baseline characteristics. Kaplan-Meier analysis was performed to determine the overall survival (OS) and lung cancer-specific survival (LCSS). Cox regression analysis was performed to evaluate the effects of multiple variables.

RESULTS

A total of 978 patients were identified, of whom 669 (68.40%) had LNR ≤0.15. Patients with LNR ≤0.15 showed better OS (P < 0.001) and LCSS (P < 0.001) both before and after propensity score matching. Multivariable analyses of the matched population confirmed LNR as an independent prognostic factor. Patients with LNR >0.15 showed poorer OS [hazard ratio (HR) 1.55, 95% confidence interval (CI) 1.09-2.19; P = 0.015] and LCSS (HR 1.65, 95% CI 1.13-2.43; P = 0.010). Subgroup analyses revealed that LNR ≤0.15 was associated with favourable OS (P = 0.009 and 0.197, respectively) and LCSS (P = 0.010 and 0.169, respectively) in N1 and N2 patients.

CONCLUSIONS

LNR was determined as an independent predictor for surgically resected stage I-III SCLC, indicating that higher LNR is associated with reduced survival. The predictive value of LNR should to be further validated in prospective studies.

Long-Term Survival Effect of the Interval between Postoperative Chemotherapy and Radiotherapy in Patients with Completely Resected Pathological N2 Non-Small-Cell Lung Cancer

Simple Summary

In patients with completely resected stage III pN2 non-small cell lung cancer (NSCLC), adjuvant chemotherapy of 4–6 cycles was recommended prior to post-operative radiotherapy (PORT). However, some were given concurrently or early-sequentially with PORT. The objectives of this study were to verify the benefit of adjuvant sequential chemotherapy and radiotherapy (SCRT) relative to that of concurrent chemoradiotherapy (CCRT) in an Asian population and to identify the optimal timing of initiation of PORT as part of adjuvant SCRT. A longer interval (>104 days and <180 days) between the initiation of adjuvant chemotherapy and PORT was associated with improved OS compared with CCRT. No locoregional recurrence-free survival (LRFS) difference related to the interval between the initiation of adjuvant chemotherapy and PORT was observed. In older patients (aged >60 years), the benefit of delayed PORT initiation was more significant. We suggest that PORT should be postponed in the completed-resected pN2 elderly patients.

Abstract

(1) Purpose: To investigate the effects of the time interval between initiation of adjuvant chemotherapy and radiotherapy on survival outcomes in patients with completely resected stage IIIA pN2 non-small-cell lung cancer (NSCLC); (2) Methods: Data on 2515 patients with completely resected stage IIIA pN2 NSCLC in 2007–2017 were extracted from the Taiwan Cancer Registry Database. The survival outcomes in patients who underwent concurrent chemoradiotherapy (CCRT) and sequential chemotherapy and radiotherapy (SCRT) with either a short (SCRT1) or long (SCRT2) interval between treatments were estimated using Kaplan–Meier, Cox regression, and propensity score matching (PSM); (3) Results: Multivariate analyses of OS showed that SCRT2 (hazard ratio [HR] 0.64, p = 0.017) was associated with improved overall survival (OS). After PSM, the median OS periods were 64 and 75 months in the SCRT1 and SCRT2 groups, respectively, which differed significantly from that of 58 months in the CCRT group (p = 0.003). In elderly patients, SCRT2 significantly improved survival relative to CCRT before PSM (p = 0.024) and after PSM (p = 0.002); (4) Conclusions: A longer interval between initiation of adjuvant chemotherapy and postoperative radiotherapy (PORT; SCRT2) improved OS relative to CCRT; the benefits were greater in elderly patients (age >60 years).

Prognostic index for estimating the survival benefit of postoperative radiotherapy in pathologic N2 non-small cell lung cancer: A real-world validation study

OBJECTIVES

This study aimed to evaluate the effect of postoperative radiotherapy (PORT) in patients with resected pathologic N2 (pN2) non-small cell lung cancer (NSCLC) with different locoregional recurrence (LRR) risks.

MATERIALS AND METHODS

The primary cohort and validation cohort were retrieved from two independent medical centres. Data for all consecutive patients with completely resected pathologic stage T1-3N2M0 NSCLC were analysed. Patients without PORT in the primary cohort were identified as a training set. Significant prognostic factors for LRR were identified by the Fine-Gray model to develop a prognostic index (PI) in the training set.

RESULTS

The primary cohort consisted of 357 patients who met the eligibility criteria (training set, 287 patients without PORT). The external validation cohort consisted of 1044 patients who met the eligibility criteria (validation set, 711 patients without PORT). Heavy cigarette smoking history, clinical N2 status (cN2), and the number of positive lymph nodes >4 were identified as independent risk factors. The PI was computed as follows: PI＝0.8*smoking history＋0.5*cN2＋0.7*the number of involved lymph nodes (reference level was assigned the value 1 and risk level the value 2). In the low-risk group (PI score< = 3), PORT showed a trend towards decreased LRR rates but not significantly improved overall survival (OS). In the high-risk group (PI score>3), PORT significantly reduced the risk of LRR and improved OS.

CONCLUSIONS

We constructed and validated a PI to predict individually the effect of PORT in patients with completely resected pN2 NSCLC. Patients with a higher PI score can benefit from PORT in terms of OS.

Patient prognostic scores and association with survival improvement offered by postoperative radiotherapy for resected IIIA/N2 non-small cell lung cancer: A population-based study

BACKGROUND

Currently, there is no consensus on the role of postoperative adjuvant radiotherapy (PORT) for resected stage IIIA/N2 non-small cell lung cancer (NSCLC). Our study sought to determine which patients may be able to benefit from PORT, based on a patient prognostic score.

METHODS

A retrospective cohort study was conducted to identify patients diagnosed with IIIA/N2 NSCLC between 1988 and 2016 in the SEER database. Eligible patients were divided into the following two groups: PORT group and non-PORT group. We classified patient prognostic scores as an ordinal factor and stratified patients based on prognostic scores. A Cox proportional hazards model with propensity score weighting was performed to evaluate cancer-specific mortality (CSM) between the two groups.

RESULTS

We identified 7060 eligible patients with IIIA/N2 NSCLC, 2833 (40.1%) in the PORT group and 4227 (59.9%) in the non-PORT group. Overall, the 10-year CSM rate in the weighted cohorts was 70.4% in the PORT group, 72.0% in the non-PORT group, and patients who received PORT had a lower CSM rate (p = 0.001). Compared with the non-PORT group, significant survival improvements in the PORT group were observed in patients with higher age, grade, T stage and lymph node ratio (LNR), and without chemotherapy. The improved survival of patients receiving PORT was significantly correlated with patient prognostic scores (p < 0.001).

CONCLUSIONS

In our population-based study, the prognostic score was associated with the survival improvement offered by PORT in IIIA/N2 NSCLC, suggesting that prognostic scores and clinicopathological characteristics may be helpful in proper candidate selection for PORT.

Local failure patterns after radical resection and adjuvant chemotherapy in patients with pN2 nonsmall-cell lung cancer: A retrospective analysis

Background

The patterns of local failure in stage pN2 nonsmall-cell lung cancer (NSCLC) patients undergoing radical resection and adjuvant chemotherapy are controversial.

Methods

The sites of local failure were compared in subgroups of patients with relevant clinicopathologic features (e.g., location and size of primary lesions).

Results

Totally 75 patients with local failure after radical resection and adjuvant chemotherapy for pN2 NSCLC were included in the analysis. Thirty-seven (49.3%) patients had distant metastasis. The median duration from surgical resection to local failure was 11 months (range: 3-45 months). Sites with ≥10% failure rate in all subgroups based on the location of the primary lesions included 4R, 7, the ipsilateral hilum, and the stump. Additional sites with ≥10% failure rate included 2R, 2L, 4L, and 5 for lesions in the left upper lobe; 4L and 5 for lesions in the left lower lobe; and 2R and 3P for lesions in the right upper-middle lobe. Squamous cell carcinoma affected the stump failure rate compared to adenocarcinoma (56.3% vs. 18.0%, P = 0.003). Tumor diameter ≥5 cm affected the stump failure rate compared to tumor diameter < 5 cm (44.0% vs. 18.0%, P = 0.016). Skip N2 metastasis affected the ipsilateral hilum failure rate compared to nonskip N2 metastasis (7.5% vs. 31.4%, P = 0.008).

Conclusions

For pN2 NSCLC patients undergoing radical resection and adjuvant chemotherapy, different lung lobes had different high-risk failure sites. Left lung cancer is prone to bilateral mediastinal lymph nodes recurrence, while right lung cancer mainly recurs with ipsilateral mediastinal lymph nodes. Moreover, the local failure patterns are influenced by pathological type, tumor size, and skip N2 metastasis.

Alternative methods of lymph node staging in lung cancer: a narrative review

The nodal status indicator in non-small cell lung cancer is one of the most crucial prognostic factors available. However, there are still many arguments among scientists regarding whether the currently used nodal status descriptor should be changed in the forthcoming editions of the Tumor Node Metastasis classification or whether it is precise enough and should be maintained as is. We reviewed studies concerning nodal factor classifications to evaluate their accuracy in non-small cell lung cancer patients and to address the previously mentioned challenge. We reviewed the PubMed database regarding the following classifications: ongoing 8^th edition of the Tumor Node Metastasis classification, number of positive lymph nodes, number of negative lymph nodes, number of dissected lymph nodes, lymph node ratio, nodal chains, log odds of positive lymph nodes, zone-based classification and one that is based on the number of lymph node stations involved. Moreover, we analysed data regarding various combinations of these classifications. Our analysis showed that the present nodal staging may not accurately categorize every lung cancer patient. The number of positive lymph nodes and lymph node ratio or the log odds of positive lymph nodes (as the mathematical modification of lymph node ratio) are more legitimate, as they possess very robust data and should be considered initially as additional factors that can be incorporated in ongoing nodal staging systems. Forthcoming non-small cell lung cancer staging systems could benefit from the addition of quantitative-based parameters. Additionally, the minimal extent of lymphadenectomy should be established as staging benefits from it. International, prospective validation studies need to be performed to optimize the cut-off values and prognostic groups and to confirm the superiority of the newly suggested descriptors in non-small cell lung cancer nodal staging.

Lymph-node ratio predicts survival among the different stages of non-small-cell lung cancer: a multicentre analysis†

OBJECTIVES

The prognostic role of the number of resected and metastatic lymph nodes in non-small-cell lung cancer (NSCLC) is still being debated. The aim of this study was to evaluate the impact of lymphadenectomy in addition to the already validated variables in NSCLC survival.

METHODS

From January 2002 to December 2012, data on 4858 patients with NSCLC undergoing anatomical lung resection and hilomediastinal lymphadenectomy in 6 institutions were analysed retrospectively. Established prognostic factors in addition to the number of resected lymph nodes and the ratio between the number of metastatic lymph nodes and the number of resected lymph nodes (NR) were correlated to overall survival (OS) and disease-free survival (DFS) using the multivariable Cox regression model. Harrell's C-statistic with the 95% confidence interval (CI) was determined. Analysis by means of maximally selected log-rank statistics was performed to find optimal cut-off points in order to split patients into groups with different outcome probabilities.

RESULTS

The median numbers of resected lymph nodes and of metastatic lymph nodes were 17 (range 6-85) and 2 (1-36), respectively. Hilar (N1) and mediastinal (N2) metastases were identified in 21.3% and 20.0% of cases, respectively. Overall, the 5-year OS and DFS rates were 54.6% and 44.8%, respectively. At multivariable analysis, age, gender, pathological stage, R0 resection, type of surgery and NR correlated with longer OS rates; the same variables plus tumour grading were further related to DFS. C-statistics were 66.0 (95% CI 62.7-69.4) for DFS and 60.5 (95% CI 58.3-62.6) for OS. An NR <40% significantly correlated with a higher 5-year survival rate in the total sample (OS 57.6% vs 23.8%, P < 0.001; DFS 48.2% vs 11.4, P < 0.001) and in patients with N1 (OS 47.9% vs 36.1%, P = 0.03; DFS 39% vs 24.2%, P = 0.02) and N2 (OS 36.9% vs 21.8%, P < 0.001 DFS 23.9% vs 9.1%, P < 0.001).

CONCLUSIONS

Our study confirms that the number of resected lymph nodes is a strong prognostic indicator in NSCLC. In particular, an NR cut-off value of 40% may predict both OS and DFS.

Radiotherapy for non-small cell lung cancer in the immunotherapy era: the opportunity and challenge-a narrative review

Immunotherapy has radically changed the clinical management of patients with cancer in recent years. Immune checkpoint inhibitors (ICIs) reversing the immunosuppressive effects of the tumor microenvironment are one type of immunotherapy, several of which are approved by the US Food and Drug Administration (FDA) as first-line treatments for patients with non-small cell lung cancer (NSCLC). However, response rates to ICIs are around 19-47% among patients with advanced NSCLC. As a result, the development of combined ICI and radiotherapy has begun with the aim of strengthening patients' antitumor immunity. Radiotherapy with substantial technological improvements not only achieves local tumor control through the induction of deoxyribonucleic acid (DNA) damage in irradiated regions, but also has the potential to mediate immunostimulatory effects that could result in tumor regression beyond irradiated regions. At present, numerous preclinical and clinical research are investigating the efficiency and safety of combining ICI with radiotherapy. The PACIFIC trial showed that combining chemoradiotherapy with ICI could improve clinical outcomes. In this review, we summarize the rationale for combining radiotherapy with immunotherapy. We also discuss the opportunities and challenges of combination therapy, including the timing of radiotherapy, optimal dose and fractionations, radiotherapy target and target volume, acquired resistance, patient selection, and radioimmunotherapy toxicity.

The Positive Lymph Node Ratio Predicts Survival in T1-4N1-3M0 Non-Small Cell Lung Cancer: A Nomogram Using the SEER Database

Background: An increasing number of studies have shown that the positive lymph node ratio (pLNR) can be used to evaluate the prognosis of non-small cell lung cancer (NSCLC) patients. To determine the predictive value of the pLNR, we collected data from the Surveillance, Epidemiology, and End Results (SEER) database and performed a retrospective analysis. Methods: We collected survival and clinical information on patients with T_1-4N_1-3M₀ NSCLC diagnosed between 2010 and 2016 from the SEER database and screened them according to inclusion and exclusion criteria. X-tile software was used to obtain the best cut-off value for the pLNR. Then, we randomly divided patients into a training set and a validation set at a ratio of 7:3. Pearson's correlation coefficient, tolerance and the variance inflation factor (VIF) were used to detect collinearity between variables. Univariate and multivariate Cox regression analyses were used to identify significant prognostic factors, and nomograms was constructed to visualize the results. The concordance index (C-index), calibration curves, and decision curve analysis (DCA) were used to assess the predictive ability of the nomogram. We divided the patient scores into four groups according to the interquartile interval and constructed a survival curve using Kaplan-Meier analysis. Results: A total of 6,245 patients were initially enrolled. The best cut-off value for the pLNR was determined to be 0.55. The nomogram contained 13 prognostic factors, including the pLNR. The pLNR was identified as an independent prognostic factor for both overall survival (OS) and cancer-specific survival (CSS). The C-index was 0.703 (95% CI, 0.695-0.711) in the training set and 0.711 (95% CI, 0.699-0.723) in the validation set. The calibration curves and DCA also indicated the good predictability of the nomogram. Risk stratification revealed a statistically significant difference among the four groups of patients divided according to quartiles of risk score. Conclusion: The nomogram containing the pLNR can accurately predict survival in patients with T_1-4N_1-3M₀ NSCLC.

Prognostic value of lymph node ratio in non-small-cell lung cancer: a meta-analysis

BACKGROUND

This meta-analysis aimed to investigate the prognostic value of lymph node ratio in non-small-cell lung cancer.

METHODS

We searched systematically for eligible studies in PubMed, Web of Science, Medline (via Ovid) and Cochrane library through 6 November 2018. The primary outcome was overall survival. Disease-free survival and cancer-specific survival were considered as secondary outcomes. Hazard ratio with corresponding 95% confidence interval were pooled. Quality assessment of included studies was conducted. Subgroup analyses were performed based on N descriptors, types of tumor resection, types of lymphadenectomy and study areas. Sensitivity analysis and evaluation of publication bias were also performed.

RESULTS

Altogether, 20 cohorts enrolling 76 929 patients were included. Mean Newcastle-Ottawa Scale was 7.65 ± 0.59, indicating the studies' quality was high. The overall result showed non-small-cell lung cancer patients with lower lymph node ratio was associated with better overall survival (HR: 1.946; 95% CI: 1.746-2.169; P < 0.001), disease-free survival (HR: 2.058; 95% CI: 1.717-2.467; P < 0.001) and cancer-specific survival (HR: 2.149; 95% CI: 1.864-2.477; P < 0.001). Subgroup analysis prompted types of lymphadenectomy and the station of positive lymph node have an important effect on the prognosis. No significant discovery was found in sensitivity analysis.

CONCLUSION

Patients with lower lymph node ratio was associated with better survival, indicating that lymph node ratio may be a promising prognostic predictor in non-small-cell lung cancer. The type of lymphadenectomy, an adequate examined number and the removed stations should be considered for more accurate prognosis assessment.

Mediastinal Up-Staging During Surgery in Non-Small-Cell Lung Cancer: Which Mediastinal Lymph Node Metastasis Patterns Better Predict The Outcome? A Multicenter Analysis

BACKGROUND

Unexpected N2 involvement occurs in approximately 10% to 20% of patients with non-small-cell lung cancer (NSCLC) and patients' prognostic factors remain unclear. The aim of this study was to evaluate prognostic factors in these patients.

METHODS

From January 2002 to December 2012, we retrospectively analyzed data of 550 patients with NSCLC with preoperative negative, but pathologic positive N2 involvement, who underwent anatomical lung resection and hilo-mediastinal lymphadenectomy, obtained from 6 institutions. An established prognostic factor panel and N2-type involvement were correlated to overall (OS), cancer-specific (CSS), and disease-free survival (DFS) using multivariate Cox Regression model. The following lymph node patterns were analyzed: number of resected nodes (#RNs), metastatic nodes (#MNs), ratio between #MNs and #RNs (NR), N2 subgroups proposed for the eighth TNM edition, and lobe-specific versus nonspecific metastasis.

RESULTS

Regarding our cohort, 419 patients were staged IIIA (T1-2N2), 131 IIIB (T3-4 N2), 113 pT1, 306 pT2, 94 pT3, and 37 pT4; 5-year OS, DFS, and CSS were 34.1%, 20.1%, and 64.6%, respectively. Independent prognostic factor for OS, in the multivariable analysis, were as follows: NR <17% (P = .009), proposed N2 classification subgroups (P = .014), age <66 (P < .001), and pT (P = .005); for DFS: NR <17% (P = .003), adjuvant treatment (P = .026), and pT (P = .026); and for CSS: NR <17% (P = .008), grading (P = .001), and adjuvant treatment (P < .001).

CONCLUSION

Our study confirms that adjuvant therapy is fundamental and NR, in patients with unexpected N2 involvement, has a strong prognostic factor. In particular, a NR cutoff value of 17% could predict OS, DFS, and CSS in patients with NSCLC.

Postoperative intensity-modulated radiation therapy reduces local recurrence and improves overall survival in III-N2 non-small-cell lung cancer: A single-center, retrospective study

Purpose

To determine the postoperative effects of radiotherapy (PORT) on the local recurrence‐free survival (LRFS) and overall survival (OS) of stage III‐N2 non‐small‐cell lung cancer (NSCLC).

Materials and Methods

183 patients with resected stage III‐pN2 NSCLC from Hunan Cancer Hospital between 2013 and 2016 were divided into two groups for postoperative chemotherapy (POCT) (n = 105) or combination chemotherapy and radiotherapy (POCRT) (n = 78). The LRFS and OS were compared and the factors affecting local recurrence were illustrated in these two groups. The sites of failure based on the lobe of the primary tumor in two groups were described.

Results

PORT leads to a strikingly lower risk for local recurrence and brought superior OS benefit. For different pN2 Subclassification, Patients with multiple‐station pN2 ± pN1 disease had the worst LRFS (11 months) and single‐station pN2 + multiple station pN1 disease had a relatively short LRFS (24 months) in group POCT. Short LRFS is correlated with multiple‐station pN2, older age (Y > 55), patients with a high positive LN ratio > 1/3 and a poor tumor histological differentiation degree. In group POCT, the most frequent failure site occurs at the ipsilateral hilum (21.0%), the bronchial stump (20.0%), followed by LNs4R (19.0%), LNs4L (18.1%), LNs7 (15.2%), most of left‐sided tumors more frequently involved the contralateral mediastinum, whereas the ipsilateral recurrences dominated for right‐sided tumors, especially for LNs4R. In group POCRT, the highest failure site was the bronchial stump (11.5%), followed by LNs4L (8.97%), LNs1 (7.69%), the ipsilateral hilum (6.41%) and LNs4R (6.41%).

Conclusion

PORT remarkably reduced local recurrence and improved OS in stage III‐pN2 NSCLC, especially in the multiple‐station pN2 group.

Deep Learning Improved Clinical Target Volume Contouring Quality and Efficiency for Postoperative Radiation Therapy in Non-small Cell Lung Cancer

Purpose: To investigate whether a deep learning-assisted contour (DLAC) could provide greater accuracy, inter-observer consistency, and efficiency compared with a manual contour (MC) of the clinical target volume (CTV) for non-small cell lung cancer (NSCLC) receiving postoperative radiotherapy (PORT).

Materials and Methods: A deep dilated residual network was used to achieve the effective automatic contour of the CTV. Eleven junior physicians contoured CTVs on 19 patients by using both MC and DLAC methods independently. Compared with the ground truth, the accuracy of the contour was evaluated by using the Dice coefficient and mean distance to agreement (MDTA). The coefficient of variation (CV) and standard distance deviation (SDD) were rendered to measure the inter-observer variability or consistency. The time consumed for each of the two contouring methods was also compared.

Results: A total of 418 CTV sets were generated. DLAC improved contour accuracy when compared with MC and was associated with a larger Dice coefficient (mean ± SD: 0.75 ± 0.06 vs. 0.72 ± 0.07, p < 0.001) and smaller MDTA (mean ± SD: 2.97 ± 0.91 mm vs. 3.07 ± 0.98 mm, p < 0.001). The DLAC was also associated with decreased inter-observer variability, with a smaller CV (mean ± SD: 0.129 ± 0.040 vs. 0.183 ± 0.043, p < 0.001) and SDD (mean ± SD: 0.47 ± 0.22 mm vs. 0.72 ± 0.41 mm, p < 0.001). In addition, a value of 35% of time saving was provided by the DLAC (median: 14.81 min vs. 9.59 min, p < 0.001).

Conclusions: Compared with MC, the DLAC is a promising strategy to obtain superior accuracy, consistency, and efficiency for the PORT-CTV in NSCLC.

Postoperative Radiotherapy for Resected Stage IIIA-N2 Non-small-cell Lung Cancer: A Population-Based Time-Trend Study

INTRODUCTION

The value of postoperative radiotherapy (PORT) for resected stage IIIA-N2 non-small-cell lung cancer (NSCLC) is controversial with few studies focusing on whether PORT always plays a part in clinical practice and generates benefits to patients across different time periods. We investigated this issue using the Surveillance, Epidemiology, and End Results Database (SEER) and assessed the temporal trends spanning 27 years.

METHODS

Within SEER, we selected stage IIIA-N2 NSCLC patients who underwent a lobectomy or pneumonectomy and coded as receiving PORT or never receiving radiotherapy over three time periods: 1988 to 1996, 1997 to 2005, 2006 to 2014. For each period, survival analyses were performed and propensity score matching (PSM) was used in the potentially beneficial subgroup.

RESULTS

45.4% of 5568 eligible patients received PORT. The yearly PORT use rates varied largely from 27.8% to 74.4%. Overall survival (OS) was distinctly improved over the period. The application of PORT had a significant impact on survival only in period 1 and 3. In subgroup analysis, the OS benefit of PORT was significant in each period in patients with 50% or more lymph node ratio (LNR) both before (hazard ratios, and P values of 0.647, P = .002; 0.804, P = .008; 0.721, P < .001 for period 1, 2, 3, respectively) and after PSM (0.642, P = .006; 0.785, P = .004; 0.748, P = .003 for period 1, 2, 3, respectively).

CONCLUSIONS

The benefits of PORT are lasting and stable throughout the years in patients with LNR of 50% or more. This might provide a clue on proper patient selection for PORT application.

The Prognostic Value Of Lymph Node Ratio In Patients With N2 Stage Lung Squamous Cell Carcinoma: A Nomogram And Heat Map Approach

Background

Lymph node ratio (LNR), defined as the ratio of the number of positive lymph nodes to the total of all resected nodes, has been reported to be a predictor of survival of patients with several types of cancer. However, the prognostic value of LNR and other factors in patients with resected N2 stage lung squamous cell carcinoma has never been considered.

Methods

Data from 1778 patients with resected N2 stage lung squamous cell carcinoma were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. The optimal cutoff value of LNR was identified by X-tile. A multivariable Cox model and corresponding nomogram were constructed to predict overall survival (OS) and cancer-specific survival (CSS). Both the cutoff value of LNR and the model were further validated in 146 similar patients treated in Zhongshan Hospital. Heat maps were created to visualize the distribution of LNR and the number of positive lymph nodes with the predicted survival probabilities.

Results

The optimal cutoff value for LNR was identified as 0.42. Multivariable analysis showed that age, sex, tumor laterality, type of surgery, T stage, chemotherapy and LNR were independently correlated with OS. Harrell’s C-index of the nomogram (0.64) was significantly higher than the index of the T stage-based model (0.54). Calibration curves showed good agreement between predicted and observed survival probabilities. The robustness of the model was also demonstrated by external validation.

Conclusion

LNR less than 0.42 was associated with improved OS and CSS for patients with resected N2 stage lung squamous cell carcinoma.

Integrated evaluation of clinical, pathological and radiological prognostic factors in squamous cell carcinoma of the lung

Objective

Little is known about prognostic factors for lung squamous cell carcinoma (SCC). We aimed to explore radiologic and clinical factors affecting prognosis and to compare the prognosis of both central and peripheral lung SCCs.

Materials and methods

Radiologic, clinical, and pathologic profiles of surgically confirmed SCCs from 382 patients were retrospectively reviewed. Tumor location, enhancement, necrosis, the presence of obstructive pneumonitis/atelectasis and underlying lung disease were evaluated on chest CT examination. Age, pulmonary function, tumor marker, and cancer stage were also assessed. Univariate and multivariate Cox regression analyses were performed to identify any correlation to overall survival (OS) and disease-free survival (DFS). Hazard rate estimation and competing risk analysis were done to evaluate recurrence pattern.

Results

The median follow-up period was 56.2 months. Tumors were located centrally in 230 patients (60.2%) and peripherally in 152 patients (39.8%). Age (p = 0.002, hazard ratio [HR] 1.03, 95% confidence interval [CI] = [1.01, 1.06]) and interstitial lung abnormalities (ILAs) (p<0.001, HR 5.41, 95% CI = [3.08, 9.52]) were associated with poor OS on multivariate analysis. ILAs also had a strong association to DFS (p<0.001, HR 4.25, 95% CI = [3.08, 9.52]). Central cancers had two peaks of local recurrence development at 15 and 60 months after surgery, and peripheral tumors showed rising curves for metastasis development at 60 months.

Conclusions

CT-determined ILAs are a strong biomarker predicting poor outcome. Prognosis may not vary according to tumor location, but the two groups exhibited different recurrence patterns.

A prognostic score system with lymph node ratio in stage IIIA-N2 NSCLC patients after surgery and adjuvant chemotherapy

PURPOSE

The survival of patients with IIIA-N2 non-small cell lung cancer after surgery followed by adjuvant chemotherapy is heterogeneous. The aim of this study is to form a prognostic system and a heat map method to visualize the overall survival rates in those patients.

METHODS

Univariate and multivariate Cox hazards regression models and the associated Wald Chi square coefficient were used to form the prognostic score system. Recursive partitioning analysis was used to determine the cutoff values of lymph node ratio and prognostic score in SEER cohort and validated in FDUSCC cohort. Meanwhile, a heat map method was used to visualize the overall survival probabilities of 3, 5 and 10 years for individual patient of both cohorts.

RESULTS

Lymph node ratio (with cutoff of 0.36) significantly correlates with overall survival of these patients. In addition, in patients with the same level of N2 disease, lymph node ratio still significantly affects survival. Also, after the multivariate analysis in SEER cohort, six factors were independent prognostic factors including age, sex, type of surgery, size, lymph node ratio and differentiation. A prognostic sore system with these factors (with cutoff of 12) was validated as a predictor for overall survival in FDUSCC cohort.

CONCLUSIONS

This prognostic score system including lymph node ratio can predict the survival rates of IIIA-N2 patient after surgery and post-operative chemotherapy. Lymph node ratio could be a useful supplementation in TNM stage classification for IIIA-N2 patients. The heat map method can visualize the predicted overall survival of an individual patient.

Evaluation of Lymph Node Ratio Association With Long-term Patient Survival After Surgery for Node-Positive Merkel Cell Carcinoma

Importance

Merkel cell carcinoma (MCC) carries the highest mortality rate among cutaneous cancers and is rapidly rising in incidence. Identification of prognostic indicators may help guide patient counseling and treatment planning. Lymph node ratio (LNR), the ratio of positive lymph nodes to the total number of examined lymph nodes, is an established prognostic indicator in other cancers.

Objectives

The primary objective was to evaluate the association between LNR and patient survival after surgery for node-positive MCC. The secondary objective was to evaluate whether the survival rates associated with adjuvant therapies vary by patient LNR status.

Design, Setting, and Participants

Retrospective cohort study of patients with node-positive MCC treated with surgery and lymphadenectomy. We queried the National Cancer Database (NCDB) and the Surveillance, Epidemiology, and End Results (SEER) registry for patient records. Data originated from 2004 through 2017 for the NCDB and from 1973 through 2016 for the SEER registry. The SEER registry comprises a population-based US cohort while cases from the NCDB include all reportable cases from Commission on Cancer-accredited facilities and represents approximately 70% of all newly diagnosed cancers in the United States. All data analysis took place between August 1, 2018, and February 11, 2019.

Exposures

The ratio of positive lymph nodes to the total number of examined lymph nodes, LNR, was stratified into quartiles.

Main Outcomes and Measures

Overall survival (NCDB) and disease-specific survival (SEER).

Results

We identified 736 eligible cases in the NCDB and 538 eligible cases in the SEER registry. Among these 1274 patients, the mean (SD) age was 71.1 (11.5) years, and 401 (31.5%) were women. After controlling for clinical and tumor factors including AJCC N staging, patient LNR of 0.07 to 0.31 (hazard ratio [HR], 1.37; 95% CI, 1.03-1.81) and greater than 0.31 (HR, 2.84; 95% CI, 2.10-3.86) was associated with significantly worse survival than an LNR less than 0.07. Univariate supplementary analysis performed in the SEER data set revealed a similar association of LNR with disease-specific survival. For patients with an LNR greater than 0.31, treatment with surgery and adjuvant chemoradiation therapy was associated with improved survival compared with surgery and adjuvant radiation therapy alone (HR, 0.61; 95% CI, 0.38-0.97), while this was not found for patients with an LNR of 0.31 or lower (HR, 0.93; 95% CI, 0.65-1.33).

Conclusions and Relevance

For lymph node-positive MCC, LNR offers a potentially prognostic metric alongside traditional TNM staging that may be useful for both patient counseling and treatment planning after surgery.

Postoperative radiotherapy is effective in improving survival of patients with stage pIII-N2 non-small-cell lung Cancer after pneumonectomy

Background

There were few reports of postoperative radiotherapy (PORT) in stage pIII-N2 Non-small-cell Lung Cancer (NSCLC) patients receiving pneumonectomy followed by adjuvant chemotherapy. This study aims to evaluate safety and efficacy of PORT among these patients.

Methods

Between Jan. 2004 and Dec. 2015, stage pIII-N2 NSCLC patients receiving pneumonectomy and adjuvant chemotherapy with or without PORT in our institution were retrospectively reviewed.

Results

Totally 119 patients were included, 32 patients receiving adjuvant chemotherapy and PORT (PORT group) and 87 receiving adjuvant chemotherapy alone (Control group). There were more patients with non-R0 resection in PORT group than Control group (25% vs. 8%, p = 0.031). In PORT group, ≥Grade 2 radiation-induced pneumonitis was 2/32. No severe radiation-related heart injury was observed. There was no PORT-related death. Of all patients, median follow-up time was 25 months. Median overall survival time (mOS) and median disease-free survival time (mDFS) were 46 months and 15 months, respectively. The PORT group had significantly better OS (not reached vs. 34 months, p = 0.003), DFS (19 months vs. 13 months, p = 0.024), local recurrence free survival (LRFS, p = 0.012), and distant metastasis free survival (DMFS, p = 0.047) than the Control group. As for failure pattern, PORT significantly reduced local regional failure rate (39.1% vs. 15.6%, p = 0.016). In subgroup analysis, patients with R0 resection (n = 104), OS and LRFS in PORT group were significantly longer, and PORT tended to increase DFS and DMFS.

Conclusion

For patients with stage pIII-N2 NSCLC after pneumonectomy and adjuvant chemotherapy, PORT can improve OS, DFS, LRFS and DMFS with tolerable toxicity.

Proposal of a new nodal classification for operable non-small cell lung cancer based on the number of negative lymph nodes and the anatomical location of metastatic lymph nodes

Lymph node metastasis is one of the most important prognostic indicators in patients with radically resected non-small cell lung cancer (NSCLC). This retrospective study aimed to compare the predictive value of metastatic lymph nodes (MNs), lymph node ratio (LNR), resected lymph nodes (RNs), and negative lymph nodes (NNs) with the currently used pathologic nodal (pN) staging category.We conducted a retrospective analysis of 1019 consecutive NSCLC patients treated with complete resection in a single institution. Prognostic values of various lymph node factors were evaluated by analysis of univariate and multivariate Cox proportional hazards model, and the results were compared with those using the location-based pN stage classification.The median follow-up duration was 47 months. During this period, 353 cases of cancer recurrence and 337 deaths were reported. Multivariate cox analysis indicated that both pN and NN categories were independent predictors of patient survival. The patients were divided into six groups on the basis of pN and NN categories. The survival rates of the groups were as follows: pN0, NN≥8, 81.4%; pN0, NN<8, 73.8%; pN1, NN≥8, 61.4%; pN1, NN<8, 54.2%; pN2, NN≥8, 48.4%; and pN2>1, NN<8, 35.0%. Comparison of the predictive values of the lymph node factors showed that the new N category was a more valuable prognostic factor in operable NSCLC.The combination of anatomically based pN stage classification and the number of MNs is an accurate prognostic determinant in patients with operable NSCLC which can be equal to 8th N category.

Survival Patterns for Patients with Resected N2 Non-Small Cell Lung Cancer and Postoperative Radiotherapy: A Prognostic Scoring Model and Heat Map Approach

INTRODUCTION

The positive-to-resected lymph node ratio (LNR) predicts survival in many cancers, but little information is available on its value for patients with N2 NSCLC who receive postoperative radiotherapy (PORT) after resection. We tested the applicability of prognostic scoring models and heat mapping to predict overall survival (OS) and cancer-specific survival (CSS) in patients with resected N2 NSCLC and PORT.

METHODS

Our test cohort comprised patients identified from the Surveillance, Epidemiology, and End Results database with N2 NSCLC who received resection and PORT in 2000-2014. Prognostic scoring models were developed to predict OS and CSS using Cox regression; heat maps were constructed with corresponding survival probabilities. Recursive partitioning analysis was applied to the Surveillance, Epidemiology, and End Results data to identify the optimal LNR cutoff point. Models and cutoff points were further tested in 183 similar patients treated at The University of Texas M. D. Anderson Cancer Center in 2000-2015.

RESULTS

Multivariate analyses revealed that low LNR independently predicted better OS and CSS in patients with resected N2 NSCLC who received PORT.

CONCLUSIONS

LNR can be used to predict survival of patients with resected N2 NSCLC followed by PORT. This approach, which to our knowledge is the first application of heat mapping of positive and negative lymph nodes, was effective in estimating 3-, 5-, and 10-year OS probabilities.

Prognostic value of lymph node ratio after induction therapy in stage IIIA/N2 non-small cell lung cancer: a monocentric clinical study

Background

The optimal treatment modalities for patients with stage IIIA N2 non-small cell lung cancer (NSCLC) are still a matter of debate. To provide best outcome and to avoid unnecessary treatment patient selection for surgical therapy is crucial. In addition to mediastinal downstaging the lymph node ratio (LNR) has been suggested as a prognosticator in this patient group.

Methods

We retrospectively reviewed clinical and histopathologic data of 78 patients with stage IIIA N2 NSCLC, who underwent induction therapy with two cycles of platinum-based chemotherapy for intended surgery at our clinic between 2009 and 2016. To evaluate the prognostic value of the LNR the cut off was set at 0.33 as reported in prior literature.

Results

The median follow-up time was 30.1 months. In multivariate analysis mediastinal down staging was associated with a longer overall survival (OS): 52.2 (range, 5.9-89.7) months for ypN0 versus 24.6 (4.4-84.2) months for ypN1/2 (HR, 2.76; 95% CI, 1.07-7.1, P=0.0348). LNR ≤0.33 was linked to a better OS of 39.3 (range, 5.9-89.7) months compared to 14.7 (range, 4.4-66.2) months for a LNR >0.33 in univariate analysis (P=0.037). In multivariate analysis a statistical trend could be observed (HR, 2.82; 95% CI, 0.98-8.14, P=0.1). In patients with persistent lymph node involvement the LNR could also identify a subgroup of patients with a favorable prognosis (30.1 vs. 14.7 months, P=0.145).

Conclusions

Mediastinal downstaging remains the best prognosticator in stage IIIA N2 NSCLC after induction therapy. However, using the LNR in patients with persistent mediastinal lymph node metastasis a subgroup with a favorable prognosis could be identified. The LNR could aid in finding the best treatment modalities for these patients.

The role of postoperative radiotherapy (PORT) in combined small cell lung cancer (C-SCLC)

Purpose

To explore the value of radiotherapy in C-SCLC patients, especially in those receiving a radical resection.

Results

The differences of survivals between the postoperative radiotherapy (PORT) and non-PORT groups were not statistically significant. But analyzing the benefits in subgroups, PORT significantly improved OS (p = 0.015), DFS (p = 0.026), LRFS (p = 0.008) and DMFS (p = 0.030) in stage III patients. For the patients with N2 stage, all survivals of the PORT group were also statistically significantly higher than non-PORT group (p = 0.018, 0.032, 0.008, 0.042). Patients with more than 10% of metastatic lymph nodes could get a significant benefit survivals by receiving PORT (p = 0.033, 0.030, 0.025, 0.031). Having a systematic dissection of more than 17 lymph nodes was a subset which could get better OS and LRFS by receiving PORT (p = 0.045, 0.048).

Methods

Between Jan. 2004 to Dec. 2012, fifty-five patients diagnosed as C-SCLC after complete surgical resection in our center were retrospectively analyzed. The overall survival (OS), disease free survival (DFS), loco-regional recurrence free survival (LRFS), and distant metastasis free survival (DMFS) were calculated by Kaplan-Meier method.

Conclusions

PORT can significantly improve the survival of C-SCLC patients with resected pathological pN2 stage. For the patients with a large percent of metastatic lymph nodes, PORT can also improve survivals.