Management of stage IIIA (N2) non-small-cell lung cancer: a transatlantic perspective†

An Updated Review of Management of Resectable Stage III NSCLC in the Era of Neoadjuvant Immunotherapy

Immune-checkpoint inhibitors (ICIs) have an established role in the treatment of locally advanced and metastatic non-small cell lung cancer (NSCLC). ICIs have now entered the paradigm of early-stage NSCLC. The recent evidence shows that the addition of ICI to neoadjuvant chemotherapy improves the pathological complete response (pCR) rate and survival rate in early-stage resectable NSCLC and is now a standard of care option in this setting. In this regard, stage III NSCLC merits special consideration, as it is heterogenous and requires a multidisciplinary approach to management. As the neoadjuvant approach is being adopted widely, new challenges have emerged and the boundaries for resectability are being re-examined. Consequently, it is ever more important to carefully individualize the treatment strategy for each patient with resectable stage III NSCLC. In this review, we discuss the recent literature in this field with particular focus on evolving definitions of resectability, T4 disease, N2 disease (single and multi-station), and nodal downstaging. We also highlight the controversy around adjuvant treatment in this setting and discuss the selection of patients for adjuvant treatment, options of salvage, and next line treatment in cases of progression on/after neoadjuvant treatment or after R2 resection. We will conclude with a brief discussion of predictive biomarkers, predictive models, ongoing studies, and directions for future research in this space.

Prognostic factors for recurrence-free survival in resected pathologic N2-stage III non-small cell lung cancer treated with upfront surgery

BACKGROUND

The standard treatment for pathological N2 (pN2) non-small-cell lung cancer (NSCLC) patients is definitive chemoradiation. Surgery might be beneficial for resectable pN2 disease, so we investigated the recurrence-free interval of upfront surgery for selected patients with resectable pN2 disease.

METHODS

The clinicopathologic characteristics of patients with pN2 NSCLC who underwent upfront anatomical resection at Taipei Veterans General Hospital from 2011 January to 2019 December were retrospectively reviewed. A Cox regression model was used to identify prognostic factors of recurrence-free survival (RFS).

RESULTS

In total, 84 patients after curative lung anatomic resection were analyzed, with a 44-month median survival. The 1-, 3-, and 5-year RFS rates were 63.1%, 31.3%, and 19.9%, respectively, with a median RFS of 18.9 months. Multivariable cox regression analysis identified that the significant predictor for RFS was a tumor size of more than 3 cm (hazard ratio [HR] = 1.74, 95% CI, 1.07-2.83, p = 0.027). Visceral pleural invasion, LN harvest number, tumor stage, and N2 status including single zone (N2a) or multiple zones (N2b) were not prognostic factors in this study.

CONCLUSION

Upfront surgery for resectable N2 disease achieved favorable outcomes in selected patients, especially better recurrence control with limited tumor size. Therapeutic advances might encourage surgeons to aggressive intervention.

Clinical utility of [18F]FDG PET/CT in the assessment of mediastinal lymph node disease after neoadjuvant chemoimmunotherapy for non-small cell lung cancer

OBJECTIVES

The performance of positron emission tomography/computed tomography (PET/CT) for the prediction of ypN2 disease in non-small cell lung cancer (NSCLC) after neoadjuvant chemoimmunotherapy has not been reported. This multicenter study investigated the utility of PET/CT to assess ypN2 disease in these patients.

METHODS

A total of 181 consecutive patients (chemoimmunotherapy = 86, chemotherapy = 95) at four institutions were enrolled in this study. Every patient received a PET/CT scan prior to surgery and complete resection with systematic nodal dissection. The diagnostic performance was evaluated through area under the curve (AUC). Kaplan-Meier method and Cox analysis were performed to identify the risk factors affecting recurrences.

RESULTS

The sensitivity, specificity, and accuracy of PET/CT for ypN2 diseases were 0.667, 0.835, and 0.779, respectively. Therefore, the AUC was 0.751. Compared with the false positive cases, the mean value of max standardized uptake value (SUVmax) (6.024 vs. 2.672, p < 0.001) of N2 nodes was significantly higher in true positive patients. Moreover, the SUVmax of true positive (7.671 vs. 5.976, p = 0.365) and false (2.433 vs. 2.339, p = 0.990) positive cases were similar between chemoimmunotherapy and chemotherapy, respectively. Survival analysis proved that pathologic N (ypN) 2 patients could be stratified by PET/CT-N2(+ vs. -) for both chemoimmunotherapy (p = 0.023) and chemotherapy (p = 0.010).

CONCLUSIONS

PET/CT is an accurate and non-invasive test for mediastinal restaging of NSCLC patients who receive neoadjuvant chemoimmunotherapy. The ypN2 patients with PET/CT-N2( +) are identified as an independent prognostic factor compared with PET/CT-N2(-).

CLINICAL RELEVANCE STATEMENT

Imaging with 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) plays an integral role during disease diagnosis, staging, and therapeutic response assessments in patients with NSCLC. PET/CT could be an effective non-invasive tool for predicting ypN2 diseases after neoadjuvant chemoimmunotherapy.

KEY POINTS

• PET/CT could serve as an effective non-invasive tool for predicting ypN2 diseases. • The ypN2 patients with PET/CT-N2( +) were a strong and independent prognostic factor. • The application of PET/CT for restaging should be encouraged in clinical practice.

Analysis of prognostic factors in pT1-2 N1 lung cancer patients in the light surgical results

Nodal metastasis status is an important parameter affecting the prognosis in lung cancer. Although surgical treatment is possible in most cases of N1 positive non-small cell lung cancer, this group of patients is clinically, radiologically and histologically heterogeneous. The aim of our study is to investigate the prognostic factors affecting survival in patients with pT1-2 N1 who underwent lung resection. From January 2010 to December 2019, patients who underwent lobectomy, bilobectomy or pneumonectomy for pT1-T2 N1 NSCLC in our center were included in the study. The preoperative, intraoperative and postoperative data of the patients were recorded by accessing the patient files and hospital records. The mean follow-up time was 39.8 months. The mean overall survival was 73.8 ± 3.6, and the mean disease-free survival was 67.5 ± 3.8. In multivariate analysis, age, N1 nodal metastasis pattern (occult vs obvious) and histology were found as independent variables affecting survival. In our study, age, histology, and clinical N1 status were found to be independent variables effective on overall survival.

Long-term clinical outcomes and prognostic factors of upfront surgery as a first-line therapy in biopsy-proven clinical N2 non-small cell lung cancer

Background

Multimodality therapy offers the best opportunity to improve pathological N2 non-small cell lung cancer (NSCLC) prognosis. This paper aimed to evaluate the long-term clinical outcomes and the prognostic factors of upfront surgery as first-line therapy in biopsy-proven clinical N2.

Methods

Retrospective review of biopsy-proven cN2 NSCLC patients operated between 2007 and 2017. Upfront surgery was considered if the primary tumour was deemed completely resectable, with mediastinal nodal involvement confined to a single station and no preoperative evidence of extranodal tumour invasion.

Results

Two hundred eighty-five patients who underwent radical resections were included. One hundred fifty-nine patients (55.8%) received induction chemotherapy. At follow-up completion, 127 (44.6%) patients had died. For the induction chemotherapy group, the median overall survival (OS) was 49 months [95% confidence interval (CI): 38–70 months], and the 5-year OS was 44.4%. The median and 5-year OS for the up front surgery group was 66 months (95% CI: 40–119 months) and 66.3%, respectively. There were no statistically significant differences between treatment approaches (p = 0.48). One hundred thirty-four patients (47.0%) developed recurrence. The recurrence-free survival (RFS) at 5 years was 17% (95% CI: 11–25%) for induction chemotherapy and 22% (95% CI: 9–32%) for upfront surgery; there were no statistically significant differences between groups (p = 0.93). No significant differences were observed based on the clinical N status (OS, p = 0.36; RFS, p = 0.65).

Conclusions

Upfront surgery as first-line therapy for biopsy-proven cN2 NSCLC showed favourable clinical outcomes, similar to those obtained after induction chemotherapy followed by surgery. Therefore, it should be considered one of the multimodality treatment options in resectable N2 NSCLC.

A risk model to predict the delivery of adjuvant chemotherapy following lung resection in patients with pathologically positive lymph nodes

To investigate factors associated with the ability to receive adjuvant chemotherapy in patients with pathological N1 and N2 stage after anatomic lung resections for non-small cell lung cancer (NSCLC). Multicenter retrospective analysis on 707 consecutive patients found pathologic N1 (pN1) or N2 (pN2) disease following anatomic lung resections for NSCLC (2014-2019). Multiple imputation logistic regression was used to identify factors associated with adjuvant chemotherapy and to develop a model to predict the probability of starting this treatment. The model was externally validated in a population of 253 patients. In the derivation set, 442 patients were pN1 and 265 pN2. 58% received at least one cycle of adjuvant chemotherapy. The variables significantly associated with the probability of starting chemotherapy after multivariable regression analysis were: younger age (p<0.0001), Body Mass Index (BMI) (p=0.031), Forced Expiratory Volume in 1 second (FEV1) (p=0.037), better performance status (PS) (p<0.0001), absence of chronic kidney disease (CKD) (p=0.016), resection lesser than pneumonectomy (p=0.010). The logit of the prediction model was: 6.58 -0.112 x age +0.039 x BMI +0.009 x FEV1 -0.650 x PS -1.388 x CKD -0.550 x pneumonectomy. The predicted rate of adjuvant chemotherapy in the validation set was 59.2 and similar to the observed one (59%, p=0.87) confirming the model performance in external setting. This study identified several factors associated with the probability of initiating adjuvant chemotherapy after lung resection in node-positive patients. This information can be used during preoperative multidisciplinary meetings and patients counseling to support decision-making process regarding the timing of systemic treatment.

Lymph Node Parameters Predict Adjuvant Chemoradiotherapy Efficacy and Disease-Free Survival in Pathologic N2 Non-Small Cell Lung Cancer

Pathologic N2 non-small cell lung cancer (NSCLC) is prominently intrinsically heterogeneous. We aimed to identify homogeneous prognostic subgroups and evaluate the role of different adjuvant treatments. We retrospectively collected patients with resected pathologic T1-3N2M0 NSCLC from the Shanghai Chest Hospital as the primary cohort and randomly allocated them (3:1) to the training set and the validation set 1. We had patients from the Fudan University Shanghai Cancer Center as an external validation cohort (validation set 2) with the same inclusion and exclusion criteria. Variables significantly related to disease-free survival (DFS) were used to build an adaptive Elastic-Net Cox regression model. Nomogram was used to visualize the model. The discriminative and calibration abilities of the model were assessed by time-dependent area under the receiver operating characteristic curves (AUCs) and calibration curves. The primary cohort consisted of 1,312 patients. Tumor size, histology, grade, skip N2, involved N2 stations, lymph node ratio (LNR), and adjuvant treatment pattern were identified as significant variables associated with DFS and integrated into the adaptive Elastic-Net Cox regression model. A nomogram was developed to predict DFS. The model showed good discrimination (the median AUC in the validation set 1: 0.66, range 0.62 to 0.71; validation set 2: 0.66, range 0.61 to 0.73). We developed and validated a nomogram that contains multiple variables describing lymph node status (skip N2, involved N2 stations, and LNR) to predict the DFS of patients with resected pathologic N2 NSCLC. Through this model, we could identify a subtype of NSCLC with a more malignant clinical biological behavior and found that this subtype remained at high risk of disease recurrence after adjuvant chemoradiotherapy.

Performance insights of endobronchial ultrasonography (EBUS) and mediastinoscopy for mediastinal lymph node staging in lung cancer

INTRODUCTION

Endobronchial Ultrasonography (EBUS) and mediastinoscopy are used for mediastinal lymph node staging in patients with suspected non-small cell lung carcinoma (NSCLC). In our hospital, confirmatory mediastinoscopy has been largely abandoned, which may reduce the number of surgical interventions and health care costs. This study provides insight into EBUS and mediastinoscopy performance in patients with proven NSCLC from January 2007 until January 2019.

METHODS

This is a single-centre, retrospective study, evaluating unforeseen N2 rates, negative predictive value and survival, providing insight into the diagnostic yield of EBUS and mediastinoscopy. Surgical lung resection with lymph node dissection was used as reference.

RESULTS

A total of 418 patients with proven NSCLC after lung resection (mean age: 66 years; 61 % male) and 118 patients who underwent mediastinoscopy, have been included in the study. The overall prevalence of N2 metastases after lung resection was 10.5 %. The percentage of unforeseen N2 cases after negative EBUS was 14.5 %, and 14.3 % after negative mediastinoscopy. Over the past nine years, none of the confirmatory mediastinoscopies were tumor positive after negative EBUS results. The median survival in patients with surgically confirmed N2 metastases was 33 months, compared to 23 months in patients with EBUS/mediastinoscopy-proven N2 metastases.

CONCLUSION

Despite optimisation of mediastinal staging procedures, it remains difficult to identify all patients with N2 metastases in the workup of NSCLC. In our institute, confirmatory mediastinoscopy has no added value after tumor-negative EBUS procedures, and has been abandoned as standard procedure.

New P16 Expression Criteria Predict Lymph Node Metastasis in Patients With Non-small Cell Lung Cancer

BACKGROUND

There have been many attempts to predict the prognosis of lung cancer based on the expression patterns of P16 protein, but with limited success. The Eighth American Joint Committee on Cancer (AJCC) for head and neck cancer recently developed new criteria for evaluating P16 expression. Here, we applied these new criteria to evaluate the prognosis of non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

A total of 148 patients who had undergone surgery for NSCLC were enrolled in the study. P16 protein expression patterns from NSCLC tissue microarray samples were examined by immunohistochemical analysis. The Eighth AJCC head and neck cancer staging criteria were used to evaluate positive P16 expression (moderate/strong nuclear expression intensity and distribution >75% cells) in NSCLC. The relationship between P16 expression and clinicopathological factors were evaluated and survival analysis was included.

RESULTS

Negative P16 expression was significantly associated with NSCLC with lymph node metastasis (p=0.025). In addition, patients with NSCLC with negative P16 expression demonstrated poor disease-free and disease-specific survival in multivariate analysis. The Kaplan-Meier survival curve confirmed that negative P16 expression was significantly correlated with a poor disease-free survival (p=0.017) and disease-specific survival (p=0.016).

CONCLUSION

P16 expression defined with the new AJCC criteria is useful for detecting lymph node metastasis in NSCLC.

Apolipoprotein E is a predictive marker for assessing non-small cell lung cancer patients with lymph node metastasis

BACKGROUND

Apolipoprotein E (APOE) modulates lipid homeostasis in the systemic circulation and induces inflammatory immune responses in the tumor microenvironment. We evaluated APOE expression in order to assess tumor progression in non-small cell lung cancer (NSCLC).

METHODS

Immunohistochemical staining for APOE was performed on tissue microarray blocks from 148 patients who had undergone surgery for NSCLC. The staining intensity and the proportion of APOE-positive tumor cells (based on distinct membranous and cytoplasmic staining) were scored. The relationships between APOE expression and clinical (age, sex, and smoking history) and pathological (TNM stage and histological type) factors were evaluated.

RESULTS

Positive APOE staining was observed in 93 (64.6%) patients. APOE expression patterns differed among NSCLC histological types (p-value = 0.016). Negative APOE expression was significantly associated with lymph node metastasis in NSCLC (p-value = 0.040). Both cases of N2 (stage IIIA) disease showed negative APOE expression.

CONCLUSIONS

APOE is a useful marker for assessing NSCLC patients with lymph node metastasis.