Modern outcome and risk analysis of surgically resected occult N2 non-small cell lung cancer

Clinical Effect of Endosonography on Overall Survival in Patients with Radiological N1 Non-Small Cell Lung Cancer

PURPOSE

It is unclear whether performing endosonography first in non-small cell lung cancer (NSCLC) patients with radiological N1 (rN1) has any advantages over surgery without nodal staging. We aimed to compare surgery without endosonography to performing endosonography first in rN1 on the overall survival (OS) of patients with NSCLC.

MATERIALS AND METHODS

This is a retrospective analysis of patients with rN1 NSCLC between 2013 and 2019. Patients were divided into 'no endosonography' and 'endosonography first' groups. We investigated the effect of nodal staging through endosonography on OS using propensity score matching (PSM) and multivariable Cox proportional hazard regression analysis.

RESULTS

In the no endosonography group, pathologic N2 occurred in 23.0% of patients. In the endosonography first group, endosonographic N2 and N3 occurred in 8.6% and 1.6% of patients, respectively. Additionally, 51 patients were pathologic N2 among 249 patients who underwent surgery and mediastinal lymph node dissection (MLND) in endosonography first group. After PSM, the 5-year OSs were 68.1% and 70.6% in the no endosonography and endosonography first groups, respectively. However, the 5-year OS was 80.2% in the subgroup who underwent surgery and MLND of the endosonography first group. Moreover, in patients receiving surgical resection with MLND, the endosonography first group tended to have a better OS than the no endosonography group in adjusted analysis using various models.

CONCLUSION

In rN1 NSCLC, preoperative endosonography shows better OS than surgery without endosonography. For patients with rN1 NSCLC who are candidates for surgery, preoperative endosonography may help improve survival through patient selection.

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.

True Prevalence of Unforeseen N2 Disease in NSCLC: A Systematic Review + Meta-Analysis

Patients with unforeseen N2 (uN2) disease are traditionally considered to have an unfavorable prognosis. As preoperative and intraoperative mediastinal staging improved over time, the prevalence of uN2 changed. In this review, the current evidence on uN2 disease and its prevalence will be evaluated. A systematic literature search was performed to identify all studies or completed, published trials that included uN2 disease until 6 April 2023, without language restrictions. The Newcastle-Ottawa Scale (NOS) was used to score the included papers. A total of 512 articles were initially identified, of which a total of 22 studies met the predefined inclusion criteria. Despite adequate mediastinal staging, the pooled prevalence of true unforeseen pN2 (9387 patients) was 7.97% (95% CI 6.67-9.27%), with a pooled OS after five years (892 patients) of 44% (95% CI 31-58%). Substantial heterogeneity regarding the characteristics of uN2 disease limited our meta-analysis considerably. However, it seems patients with uN2 disease represent a subcategory with a similar prognosis to stage IIb if complete surgical resection can be achieved, and the contribution of adjuvant therapy is to be further explored.

The effect of lymph node ratio on survival in non-small-cell lung cancer

BACKGROUND

The aim of this study was to evaluate the effect of prognostic factors and lymph node ratio (LNR) on survival in patients with resected non-small-cell lung cancer (NSCLC).

METHODS

Data from 421 patients with NSCLC who underwent complete resection between 2009 and 2015 were evaluated retrospectively. LNR was defined as the ratio of positive lymph nodes to the total number of lymph nodes removed. Associations between overall survival (OS) and LNR, node (N) status, and histopathologic status were evaluated.

RESULTS

The 5-year survival rate was 42.5% among all patients and 26.6% for patients aged 65 years or older. In the multivariate analysis, age ≥65 years, advanced-stage disease, non-squamous cell carcinomas, pN status, and having multiple-station pN2 and multiple-station pN1 disease were found to be poor prognostic factors (p < 0.05). There was no statistical difference in survival between patients with LNR (hazard ratio: 1.04, p = 0.45).

CONCLUSION

The results of our study indicate that pN stage, histopathologic type, pT stage, and geriatric age were the most important poor prognostic factors associated with survival after NSCLC resection. Although LNR is a factor associated with survival in gastrointestinal cancers, it did not impact survival in our study.

Survival impact of unexpected N2 in stage IIIB/N2 non-small cell lung cancer patients

BACKGROUND

We investigated the effect of unexpected N2 on survival in stage IIIB/N2 cases.

METHODS

We retrospectively analyzed 1803 non-small cell lung cancer patients between 2010 and 2016. There were 89 patients (4.9%) with unexpected N2 (pathological (p) IIIB/N2 group), whereas 49 patients (2.7%) with cN2 (clinical (c) IIIB/N2 group). Although pIIIB/N2 group underwent surgery followed by adjuvant therapy, the cIIIB/N2 group of patients had multimodality treatment including induction chemotherapy ± radiotherapy followed by surgery.

RESULTS

The five-year overall survival (OS) for all patients was 36.0% [median survival time (MST) 27.9 months], and disease-free survival (DFS) was 28.9% (MST, 18.2 months). The OS was 39.6% (MST: 34.4 months) and the median DFS time was 31.1% (Median: 23.1 months) in the pIIIB/N2 group, whereas it was 29.2% (MST: 23.0 months) for OS and 22% (median: 12.4 months) for DFS in the cIIIB/N2 group. There were no significant OS and DFS differences between the pIIIB/N2 group and the cIIIB/N2 group (p = 0.124 and p = 0.168, respectively).

CONCLUSIONS

In stage IIIB/N2 cases, the fact that N2 could not be detected preoperatively with minimally invasive or invasive methods and was detected in the pathological examination after surgery does not provide a survival advantage.

Long-Term Survival According to N Stage Diagnosed by Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration in Non-Small Cell Lung Cancer

BACKGROUND

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the main procedure for mediastinal staging. However, long-term survival analyses according to cN stage diagnosed by EBUS-TBNA (abbreviated to eN stage) have not been reported. The value of EBUS-TBNA has not been assessed through an analysis of survival in false-negative EBUS-TBNA cases.

RESEARCH QUESTIONS

What is the prognostic impact of eN stage in non-small cell lung cancer (NSCLC)? What is the survival rate in false-negative EBUS-TBNA cases?

STUDY DESIGN AND METHODS

We retrospectively (January 2006-December 2011) reviewed the medical records of NSCLC patients who underwent EBUS-TBNA (± transesophageal approach) for initial staging (n=1,089). Mediastinoscopy was not performed for EBUS-TBNA negative cases. We performed 5-year survival analyses according to eN stage and treatment modality. Survival in false-negative EBUS cases was compared with that in pN0-1 patients, including 941 non-EBUS cases, during the same period.

RESULTS

Among 1,089 EBUS patients (eN0-1=681, eN2=314, eN3=94), we observed significant differences in survival between the eN stages [eN0-1 vs eN2; p <0.0001, eN2 vs eN3; p=0.0118, estimated 5-year overall survival (5YOS) rate: eN0-1=57.4%, eN2=23.2%, eN3=12.8%]. Surgery cases had better survival than non-surgery cases among eN0-1 and eN2 patients (eN0-1/surgery vs. eN0-1/no surgery; p<0.0001, eN2/surgery vs. eN2/no surgery; p<0.0001). Among eN0-1 patients, there were 55 false-negative cases (eN0-1/pN2-3, pN2=54, pN3=1). The 5YOS rates of pN0, pN1, and eN0-1/pN2-3 patients were 76.4%, 56.0% and 56.4%, respectively. eN0-1/pN2-3 patients had worse survival than pN0 patients (p=0.0061), whereas there was no significant difference compared with pN1 patients (p=0.9191).

INTERPRETATIONS

Long-term survival significantly differed according to eN stage in NSCLC, highlighting the importance of EBUS-TBNA in NSCLC staging. False-negative EBUS-TBNA cases had favorable survival which was similar to that of pN1 patients, which may provide a rationale for performing surgery after negative EBUS-TBNA results.

FDG-PET/CT for pretherapeutic lymph node staging in non-small cell lung cancer: A tailored approach to the ESTS/ESMO guideline workflow

OBJECTIVES

In patients with NSCLC, current ESTS and ESMO guidelines recommend invasive lymph node (LN) staging with EBUS-TBNA even if FDG-PET/CT is negative for mediastinal LNs if at least one of three risk factors is present (cN1, non-peripheral primary or primary >3 cm). Modified workflows to avoid unnecessary invasive procedures were evaluated.

MATERIALS AND METHODS

Monocentric retrospective analysis of pretherapeutic FDG-PET/CT in 247 patients with NSCLC (62 % male; age, 68 [43-88] years) using an analog or digital PET/CT scanner. PET windowing was standardized. LNs were positive if 'LN uptake > mediastinal blood pool' or short axis >10 mm. Surgery or EBUS-TBNA served as reference for diagnostic accuracy per LN station. In all patients with negative mediastinal LNs by PET/CT, LN histology from surgery was available.

RESULTS

Among 700 L N stations analyzed, 180 were malignant. Sensitivity and specificity of PET/CT per LN station were 93 % and 71 %. Following current guidelines, 76 patients with mediastinal negative PET/CT required confirmatory invasive staging. Only 5/76 patients had unexpected pN2 (all had adenocarcinoma). In a modified approach, confirmatory invasive staging was confined to patients with mediastinal negative PET/CT who showed all three risk factors. Using this modification, EBUS-TBNA could have been omitted in 62 (82 %) of the 76 patients who required EBUS-TBNA based on current recommendation. Among these 62 patients, only one patient had unsuspected pN2 (single-level) while the remaining 61 of 62 omitted EBUS-TBNA were deemed unnecessary because mediastinal LNs were confirmed to be negative. No multi-level pN2 would have been missed.

CONCLUSION

In the current analysis, 82 % of EBUS-TBNA procedures in patients with mediastinal negative PET/CT could have been omitted by modifying the current guideline workflow as proposed (i.e., restricting EBUS-TBNA in patients with cN0/1 to those with all three risk factors). This was consistent with different PET/CT scanners. Prospective confirmation is required.

Oncological outcomes of unsuspected pN2 in patients with non-small-cell lung cancer: a systematic review and meta-analysis

OBJECTIVES

Optimal treatment of stage IIIA (N2) non-small-cell lung cancer (NSCLC) is controversial. Guidelines advise induction therapy before surgical resection. A proportion of patients with cN0 NSCLC are postoperatively upstaged due to unsuspected N2 disease. Survival of unsuspected N2 NSCLC treated with surgery varies and technical feasibility of video-assisted thoracic surgery (VATS) is unknown. The purpose of this study was to assess prevalence and survival of unsuspected N2 NSCLC treated with thoracotomy or VATS.

METHODS

A systematic review and meta-analysis was performed of all available literatures through Pubmed, Cochrane, EMBASE, Web of Science, Trials registries and System for Information on Grey Literature (SIGLE) from 2000 to 2019. Outcomes of interest were prevalence, overall survival (OS) and disease-free survival of unsuspected N2 NSCLC. Secondary outcomes were number of harvested lymph nodes, postoperative complications and survival of unsuspected N2 NSCLC treated with VATS.

RESULTS

Seventeen studies with patients with clinical stage N0-1 and unsuspected pN2 NSCLC were included. Prevalence of unsuspected pN2 was 8.6%. Three- and 5-year OS was 58% [95% confidence interval (CI) 37-78%) (N = 4337] and 35% (95% CI 28-43%) (N = 4337). Three- and 5-y ear disease-free survival was 48% (95% CI 30-66%) (N = 109) and 35% (95% CI 24-46%) (N = 517). VATS resulted in a low complication rate with similar 5-year OS as thoracotomy.

CONCLUSIONS

In patients with cN0-1 NSCLC, a minority has unsuspected pN2 NSCLC. Even for these patients, 5-year OS and disease-free survival are reasonable. VATS with adequate lymph node dissection is the treatment of choice when in experienced hands. Adjuvant therapy should be provided in absence of relevant comorbidity.

Prognostic factors for survival in patients with completely resected pN2 non-small-cell lung cancer

BACKGROUND

This study examined the incidence of pathologic N2 (pN2) non-small-cell lung cancer (NSCLC) and prognostic factors affecting survival of these patients.

METHODS

A total of 119 patients who underwent surgery for NSCLC (lobectomy and pneumonectomy) between January 2008 and December 2016 were evaluated retrospectively. The patients with pN2 included in this study were assessed in two groups; single pN2 and multiple pN2.

RESULTS

The most common type of resection was lobectomy (56.3%). Ninety-four patients (79%) received adjuvant therapy. Eighty-six patients (72.3%) had single-station pN2 and 33 (27.7%) had multiple pN2. The 5-year survival rates were 29.3% overall, 38.6% in single-station pN2, and 11% in multiple-station pN2 (hazard ratio [HR]: 0.581, p = .037). There was no statistically significant difference in 5-year survival rates between patients with pN1N2 and those with pN0N2 involvement (39.1% vs. 37.1%) (p = .625). Not receiving adjuvant therapy was associated with poor survival prognosis (HR: 8.2 p < .001). The 5-year survival rate was 36.2% among patients with pN2 involvement with 2 or more positive lymph nodes and 19.5% among those with fewer than 2 positive lymph nodes (HR: 0.83, p = .463).

CONCLUSIONS

The most significant prognostic factors associated with survival were pN2 status. Non-skip metastases (pN1N2) and positive lymph node count were not associated with prognosis.

Elevated preoperative CEA is associated with subclinical nodal involvement and worse survival in stage I non-small cell lung cancer: a systematic review and meta-analysis

BACKGROUND

The standard for clinical staging of lung cancer is the use of CT and PET scans, however, these may underestimate the burden of the disease. The use of serum tumor markers might aid in the detection of subclinical advanced disease. The aim of this study is to review the predictive value of tumor markers in patients with clinical stage I NSCLC.

METHODS

A comprehensive search was performed using the Medline, EMBASE, Scopus data bases. Abstracts included based on the following inclusion criteria: 1) adult ≥18 years old, 2) clinical stage I NSCLC, 3) Tumor markers (CEA, SCC, CYFRA 21-1), 4) further imaging or procedure, 5) > 5 patients, 6) articles in English language. The primary outcome of interest was utility of tumour markers for predicting nodal involvement and oncologic outcomes in patients with clinical stage I NSCLC. Secondary outcomes included sub-type of lung cancer, procedure performed, and follow-up duration.

RESULTS

Two hundred seventy articles were screened, 86 studies received full-text assessment for eligibility. Of those, 12 studies were included. Total of 4666 patients were involved. All studies had used CEA, while less than 50% used CYFRA 21-1 or SCC. The most common tumor sub-type was adenocarcinoma, and the most frequently performed procedure was lobectomy. Meta-analysis revealed that higher CEA level is associated with higher rates of lymph node involvement and higher mortality.

CONCLUSION

There is significant correlation between the CEA level and both nodal involvement and survival. Higher serum CEA is associated with advanced stage, and poor prognosis. Measuring preoperative CEA in patient with early stage NSCLC might help to identify patients with more advanced disease which is not detected by CT scans, and potentially identify candidates for invasive mediastinal lymph node staging, helping to select the most effective therapy for patients with potentially subclinical nodal disease. Further prospective studies are needed to standardize the use of CEA as an adjunct for NSCLC staging.

Trends and Outcomes in Minimally Invasive Surgery for Locally Advanced Non-Small-Cell Lung Cancer With N2 Disease

Few studies examine outcomes by surgical approach in non-small-cell lung cancer (NSCLC) with N2 disease. We examined time trends in surgical approach and outcomes among patients undergoing minimally invasive (MIS, robotic and video-assisted thoracoscopic surgery [VATS]) vs open lobectomy in this patient population. We performed a retrospective analysis of patients from the National Cancer Database diagnosed with clinical Stage IIIA-N2 NSCLC from 2010 to 2016. We examined the yearly proportion of MIS vs open resections. Multivariable regression was used to assess the association of surgical approach with length of stay, unplanned readmissions, 30-day and 90-day mortality. Multivariable Cox proportional hazards modeling was used to assess the association of surgical approach with 5-year overall mortality. We identified 5741 patients who underwent lobectomy for Stage IIIA-N2 NSCLC (459 robotic, 1403 VATS, 3879 open). From 2010 to 2016, the proportion of minimally invasive procedures increased from 20% to 45%. MIS patients, on average, stayed 1 day less in the hospital (95% confidence interval [CI] 0.7, 1.5) and had lower odds of 90-day (odds ratio [OR] 0.74; 95% CI 0.54, 0.99) and 5-year mortality (OR 0.82; 95% CI 0.75, 0.91), compared to open resections. There was no difference in odds of readmission by surgical approach (OR 0.97; 95% CI 0.71, 1.33). Among MIS procedures, robotic resections had lower odds of 90-day mortality (OR 0.42; 95% CI 0.18, 0.97) than VATS. Among patients undergoing lobectomy for locally advanced N2 NSCLC robotic and VATS techniques appear safe and effective compared to open surgery and may offer short- and long-term advantages.

How Effective Is Neoadjuvant Therapy Followed by Surgery for Pathologic Single-Station N2 Non-Small Cell Lung Cancer?

The optimal treatment strategy for pathologic single-station N2 (pN2a1) non-small cell lung cancer (NSCLC)-surgery first followed by adjuvant treatment (SF) or neoadjuvant therapy followed by surgery (NS)-remains unclear. We compared disease-free survival (DFS) and overall survival (OS) after NS versus SF for pN2a1 NSCLC. We retrospectively identified patients with pN2a1 NSCLC resected between 2000 and 2018. Patients in the SF group had cN0 disease and were treated with surgery before adjuvant chemotherapy; patients in the NS group had known preoperative nodal disease, cN2 disease, and were treated with neoadjuvant therapy before surgery. The matching-weights procedure was applied to generate a cohort with similar characteristics between groups. DFS and OS were calculated using the Kaplan-Meier approach and compared between groups using weighted log-rank test and Cox proportional hazards models. We identified 227 patients with pN2a1 disease: 121 treated with SF and 106 with NS. After the matching-weights procedure, 5- and 10-year DFS were 45% and 27% for SF versus 26% and 21% for NS (log-rank P = 0.056; hazard ratio [HR], 1.61; 95% confidence interval [CI], 0.98-2.65); 5- and 10-year OS were 49% and 30% for SF versus 43% and 20% for NS (log-rank P = 0.428; HR, 1.24; 95% CI, 0.67-2.28). SF and NS for pN2a1 NSCLC resulted in similar survival. A study comparing SF for known preresectional pN2a1 with occult pN2a1 disease could be a next step. Further investigation of SF for known N2a1 versus occult pN2a1 disease could power a clinical trial focused on N2a NSCLC.

Resectable IIIA-N2 Non-Small-Cell Lung Cancer (NSCLC): In Search for the Proper Treatment

Locally advanced non-small cell lung cancer accounts for one third of non-small cell lung cancer (NSCLC) at the time of initial diagnosis and presents with a wide range of clinical and pathological heterogeneity. To date, the combined multimodality approach involving both local and systemic control is the gold standard for these patients, since occult distant micrometastatic disease should always be suspected. With the rapid increase in treatment options, the need for an interdisciplinary discussion involving oncologists, surgeons, radiation oncologists and radiologists has become essential. Surgery should be recommended to patients with non-bulky, discrete, or single-level N2 involvement and be included in the multimodality treatment. Resectable stage IIIA patients have been the subject of a number of clinical trials and retrospective analysis, discussing the efficiency and survival benefits on patients treated with the available therapeutic approaches. However, most of them have some limitations due to their retrospective nature, lack of exact pretreatment staging, and the involvement of heterogeneous populations leading to the awareness that each patient should undergo a tailored therapy in light of the nature of his tumor, its extension and his performance status.

Prognostic Value of Tumor Size in Resected Stage IIIA-N2 Non-Small-Cell Lung Cancer

The eighth edition of the American Joint Committee on Cancer (AJCC) staging system for lung cancer was introduced in 2017 and included major revisions, especially of stage III. For the subgroup stage IIIA-N2 non-small-cell lung cancer (NSCLC), surgical resection remains controversial due to heterogeneous disease entity. The aim of this study was to evaluate the clinicopathologic features and prognostic factors of patients with completely resected stage IIIA-N2 NSCLC. We retrospectively evaluated 77 consecutive patients with pathologic stage IIIA-N2 NSCLC (AJCC eighth edition) who underwent surgical resection with curative intent in China Medical University Hospital between 2006 and 2014. Survival analysis was conducted, using the Kaplan–Meier method. Prognostic factors predicting overall survival (OS) and disease-free survival (DFS) were analyzed, using log-rank tests and multivariate Cox proportional hazards models. Of the 77 patients with pathologic stage IIIA-N2 NSCLC examined, 35 (45.5%) were diagnosed before surgery and 42 (54.5%) were diagnosed unexpectedly during surgery. The mean age of patients was 59 years, and the mean length of follow-up was 38.1 months. The overall one-, three-, and five-year OS rates were 91.9%, 61.3%, and 33.5%, respectively. Multivariate analysis showed that tumor size <3 cm (hazards ratio (HR): 0.373, p = 0.003) and video-assisted thoracoscopic surgery (VATS) approach (HR: 0.383, p = 0.014) were significant predictors for improved OS. For patients with surgically treated, pathologic stage IIIA-N2 NSCLC, tumor size <3 cm and the VATS approach seemed to be associated with better prognosis.

Utility of FDG PET/CT for Preoperative Staging of Non-Small Cell Lung Cancers Manifesting as Subsolid Nodules With a Solid Portion of 3 cm or Smaller

OBJECTIVE. The objective of our study was to investigate the utility of FDG PET/CT for the preoperative staging of subsolid non-small cell lung cancers (NSCLCs) with a solid portion size of 3 cm or smaller. MATERIALS AND METHODS. We retrospectively enrolled 855 patients with pathologically proven NSCLCs manifesting as subsolid nodules with a solid portion of 3 cm or smaller on CT. We then compared the diagnostic performances of FDG PET/CT and chest CT for detecting lymph node (LN), intrathoracic, or distant metastases in patients who underwent preoperative chest CT and FDG PET/CT. After propensity score matching, we compared the diagnostic performance of FDG PET/CT in the group who underwent both chest CT and FDG PET/CT with that of chest CT in patients who did not undergo FDG PET/CT. RESULTS. There were LN metastases in 25 of 765 patients (3.3%) who underwent surgical LN dissection or biopsy and intrathoracic or distant metastasis in two of 855 patients (0.2%). For LN staging, FDG PET/CT showed a sensitivity of 44.0%, specificity of 81.5%, positive predictive value of 9.6%, negative predictive value of 97.0%, and accuracy of 79.9%, which were lower than those of chest CT for accuracy (p < 0.0001). FDG PET/CT could not accurately detect any intrathoracic or distant metastasis. After propensity score matching, the diagnostic accuracy for LN staging of FDG PET/CT in the group who underwent both CT and FDG PET/CT was lower than that of chest CT in the group who did not undergo FDG PET/CT (p = 0.002), and the diagnostic accuracy for intrathoracic and distant metastases was not different (p > 0.999). CONCLUSION. FDG PET/CT has limited utility in preoperatively detecting LN or distant metastasis in patients with subsolid NSCLCs with a solid portion size of 3 cm or smaller.

[Correlation between Lymph Node Ratio and Clinicopathological Features and Prognosis of IIIa-N2 Non-small Cell Lung Cancer]

BACKGROUND

IIIa-N2 non-small cell lung cancer was significant different in survival, although N stage of lung cancer based on anatomic location of metastasis lymph node. Lymph node ratio considered of prognostic factor might be the evaluation index for IIIa-N2 non-small cell lung cancer prognosis. Therefore, the aim of the study was to evaluate the correlation between lymph node ratio and clinicopathological features and prognosis of IIIa-N2 non-small cell lung cancer prognosis.

METHODS

A total of 288 cases of pathological IIIa-N2 non-small cell lung cancer were enrolled who received radical resection at the Department of Thoracic Surgery II, Peking University Cancer Hospital from January 2006 to December 2016. The univariate analysis between clinicopathological variables and lymph node ratio used Pearson's chi-squared test. Cox regression was conducted to identify the independent prognosis factors for IIIa-N2 non-small cell lung cancer.

RESULTS

There were 139 cases in the lower lymph node ratio group, another 149 cases in the higher lymph node ratio group. Adenocarcinoma (χ²=5.924, P=0.015), highest mediastinal lymph node metastasis (χ²=46.136, P<0.001), multiple-number N2 metastasis (χ²=59.347, P<0.001), multiple-station N2 metastasis (χ²=77.387, P<0.001) and skip N2 lymph node metastasis (χ²=61.524, P<0.001) significantly impacted lymph node ratio. The total number of lymph node dissection was not correlated with the lymph node ratio (χ²=0.537, P=0.464). Cox regression analysis confirmed that adenocarcinoma (P=0.008), multiple-number N2 metastasis (P=0.025) and lymph node ratio (P=0.001) were the independent prognosis factors of disease free survival. The 5-year disease free survival was 18.1% in the higher lymph node ratio group, and 44.1% in the lower. Lymph node ratio was the independent prognosis factor of overall survival (P<0.001). The 5-year overall survival was 36.7% in the higher lymph node ratio group, and 64.1% in the lower.

CONCLUSIONS

Lymph node ratio was correlative with the pathology, highest mediastinal lymph node metastasis, multiple-number N2 metastasis, multiple-station N2 metastasis and skip N2 lymph node metastasis. Lymph node ratio was the independent prognosis factor for IIIa-N2 non-small cell lung cancer.

Risk analyses of N2 lymph-node metastases in patients with T1 non-small cell lung cancer: a multi-center real-world observational study in China

PURPOSE

N2 lymph-node metastases occur in approximately 6-17% of the patients with T1-2 non-small cell lung cancer (NSCLC). However, the clinical characteristics of N2 patients are not fully understood.

METHODS

This retrospective, multi-center analysis included T1 NSCLC patients receiving surgical resection during a period from Jan 2nd, 2014 to Dec 27th, 2017. The diagnosis was pathologically verified in all cases. Univariate and multivariate logistic regression analyses were conducted to analyze the factors that are associated with pN2 lymph-node metastases.

RESULTS

A total of 10,885 patients (48.4% men; 84.7% adenocarcinoma) were included in the analysis. The mean age was 59.0 ± 9.9 years. The mean tumor size was 1.8 ± 0.8 cm. Of the patients, 3260 (29.9%) were smokers or ex-smokers. Lymph-node metastases were verified in 1808 (16.6%) patients, and 1167 (10.7%) patients had N2 lymph-node metastases. The multivariate analyses indicated that larger tumor size, lower differentiation, CEA level ≥ 5 ng/mL, vascular invasion (+), and pleural involvement (+) were associated with higher percentages of N2 lymph-node metastases (p < 0.001 for all).

CONCLUSIONS

This study demonstrated the significant association between N2 lymph-node metastases and tumor size and differentiation, CEA levels, and status of vascular invasion and pleural involvement.

Induction Therapies Plus Surgery Versus Exclusive Radiochemotherapy in Stage IIIA/N2 Non-Small Cell Lung Cancer (NSCLC)

In spite of the growing body of data from prospective randomized clinical trials (PRCTs) and meta-analyses, the optimal treatment approach in patients with stage IIIA non-small cell lung cancer remains unknown. This review focuses on the available data directly confronting induction chemotherapy or induction radiochemotherapy (RT-CHT) when followed by surgery with exclusive RT-CHT. Seven PRCTs and 4 meta-analyses investigated this issue. In addition, numerous retrospective studies attempted to identify potential predictors and/or prognosticators that may have influenced the decision to offer surgery in a particular patient subgroup. Several retrospective studies also evaluated exclusive RT-CHT in this setting. There is not a single piece of the highest level of evidence (PRCT or MA) showing any advantage of induction therapies followed by surgery over exclusive RT-CHT with the former treatment option leading to significantly more morbidity and mortality. Although several studies attempted to identify patient subgroups favoring induction therapies followed by surgery, they have invariably been retrospective in nature, and their results have never been reproduced even in other retrospective setting. Furthermore, no PRCT investigated potential pretreatment patient and/or tumor-related predictors of surgical multimodality success. Exclusive RT-CHT achieves similar results to induction therapies followed by surgery but with less morbidity and mortality. This is accompanied with the finding that no pretreatment predictor exists to enable identification of even a subgroup of stage IIIA/pN2 patients benefiting from any surgical approach.

Multimodality therapy in subclassified stage IIIA-N2 non-small cell lung cancer patients according to the Robinson classification: heterogeneity and management

Background

Non-small cell lung cancer (NSCLC) with mediastinal lymph node involvement (N2) is a heterogeneous entity. The objective of this analysis is to investigate the results of treatment strategies for N2-positive patients.

Methods

Retrospective study (2009-2014) of 104 consecutive patients with stage IIIA-N2 NSCLC classified according to the Robinson classification (IIIA1-IIIA4) and treated within a multimodality treatment regime.

Results

The Robinson subgroups were: IIIA1 (n=27), IIIA3 (n=60) and IIIA4 (n=17). We had no stage IIIA2 samples because we did not perform an intraoperative frozen section of lymph nodes. Surgical resection with systematic lymph node dissection was performed in all patients with stage IIIA1 (n=27). After chemotherapy or chemo-/radiotherapy, 53.3% of patients in stage IIIA3 (n=32) and 11.7% of patients in stage IIIA4 (n=2) underwent surgery with curative intention. R0 was achieved in 92.6% in stage IIIA1, 93.8% in stage IIIA3 and 100% in stage IIIA4. The 30-day mortality was 3.2%. The overall median survival was 31.7 months (5-year survival was 30.5%). There were no significant differences (P=0.583) in survival regarding the Robinson subgroups. Patients who underwent tumour resection had significantly better median survival (39.8 vs. 19.6 months; P=0.014) compared to patients treated conservatively. Deviation from the interdisciplinary recommended therapy (12%) led to a reduced median survival (11.4 vs. 31.8 months; P=0.137).

Conclusions

N2-patients should be subclassified according to the Robinson classification and discussed in the tumour board. Surgical resection should be recommended in specific cases of N2-disease (non-bulky, sensitivity to systemic treatment).

Durvalumab: a potential maintenance therapy in surgery-ineligible non-small-cell lung cancer

Lung cancer is the most common cancer worldwide and the most common cause of cancer-related death. Non-small-cell lung cancer comprises ~87% of newly diagnosed cases of lung cancer, and nearly one-third of these patients have stage III disease. Despite improvements in the treatment of stage IV lung cancer, particularly with the introduction and dissemination of checkpoint inhibitors, very little progress has been made in the treatment of stage III lung cancer. In this article, we discuss the general staging criteria and treatment options for stage III lung cancer. We review how concurrent radiation and chemotherapy can have immunomodulatory effects, supporting the rationale for incorporating immunotherapy into existing treatment paradigms. Finally, we discuss the results of the PACIFIC trial and implications for the treatment of stage III lung cancer. In the PACIFIC trial, adding durvalumab as a maintenance therapy following the completion of chemoradiotherapy improved progression-free survival in patients with locally advanced unresectable stage III lung cancer. On the strength of these results, durvalumab has been approved by the US Food and Drug Administration for use in this setting, representing the first advance in the treatment of stage III lung cancer in nearly a decade.

Multimodality Treatment of Advanced Non-small Cell Lung Cancer: Where are we with the Evidence?

PURPOSE OF REVIEW

The majority of patients with non-small cell lung cancer (NSCLC) present with advanced disease and overall survival rates are poor. This article outlines the current and outstanding evidence for the use of multimodality treatment in this group of patients, including in combination with an increasing number of treatment options, such as immunotherapy and genotype-targeted small molecule inhibitors.

RECENT FINDINGS

Optimal therapy for surgically resectable stage III disease remains debatable and currently the choice of treatment reflects each individual patient's disease characteristics and the expertise and opinion of the thoracic multi-disciplinary team. Evidence for a distinct oligometastatic state in which improved outcomes can be achieved remains minimal and there is as yet no consensus definition for oligometastatic lung cancer. Whilst there is supporting evidence for the aggressive management of isolated metastases, the use of consolidative therapy for multiple metastases remains unproven.

SUMMARY

Evolution of new RT technologies, improved surgical technique and a plethora of interventional-radiology-guided ablative therapies are widening the choice of available treatment modalities to patients with NSCLC. In the setting of resectable locally advanced disease and the oligometastatic state, there is a growing need for randomised comparison of the available treatment modalities to guide both treatment and patient selection.

Is the prognosis of occult N2 disease similar to that of positive positron emission tomography-computed tomography (PET/CT) scan single-station N2 disease in patients with non-small cell lung cancer treated by surgical resection?

OBJECTIVE

A retrospective study, using a prospective database, was conducted on patients treated with surgery in order to analyze the prognosis between two groups: NSCLC (non-small cell lung cancer) patients with occult N2 disease and patients with single station N2 disease observed on pre-operative integrated PET/CT scan.

METHODS

A total of 772 patients underwent surgical treatment for lung cancer from January 2007 to December 2014. All of them had an integrated PET/CT scan in the pre-operative work-up and a pulmonary resection plus mediastinal lymphadenectomy were performed in all cases. In the selected cases, no one received induction treatment. All patients from both groups had N2 disease after examination of the histopathology specimen. Clinical and pathological characteristics, disease free survival, and overall survival, were analyzed in both groups.

RESULTS

A total of 34 cases presented occult N2 disease, whereas 11 cases showed single station N2 disease on pre-operative PET/CT scan. Mean disease free survival and mean overall survival for occult N2 disease compared to single-station N2 disease on PET/CT scan was 36.0 months (95% CI: 24.9-47.1) and 38.9 months (95% CI: 20.6-57.1), p=.586; and 52.3 months (95% CI: 38.9-65.7) and 38.2 months (95% CI: 21.9-54.5), p=.349, respectively.

CONCLUSION

The prognosis of patients with single-station N2 disease on PET/CT scan treated by surgical resection and mediastinal lymphadenectomy as first line treatment was similar to those with occult N2 disease. More studies are needed to support our findings.

Effect of visceral pleural invasion on the prognosis of patients with lymph node negative non-small cell lung cancer

Background

Visceral pleural invasion (VPI) is an adverse prognostic factor in non‐small cell lung cancer (NSCLC); however, its effect in relation to tumor size remains under debate. To better understand the prognostic impact and potential consequences for staging, we examined correlations between VPI and clinicopathologic characteristics in patients with NSCLC, particularly those with lymph node negative NSCLC.

Methods

We retrospectively analyzed 813 cases of radically resected NSCLC treated in our institution between December 2005 and December 2011. Patients were divided into two groups according to VPI status to compare their clinicopathologic characteristics. Survival analysis was performed in 521 cases with pN0 NSCLC.

Results

VPI was diagnosed in 379 (46.6%) cases. It was more common in women, patients with non‐squamous cell carcinoma, elevated preoperative serum carcinoembryonic antigen levels, moderately or poorly differentiated tumors, and larger‐sized tumors. The incidence of mediastinal lymph node metastasis, particularly multi‐station metastasis, was higher in patients with VPI. Patients with pN0 NSCLC, 2–3 cm tumors, and VPI had a significantly poorer prognosis (VPI vs. non‐VPI: five‐year overall survival 78.3% vs. 84.5%, P = 0.039; five‐year disease‐free survival 69.2% vs. 80.0%, P = 0.046, respectively); however, no significant effect was observed for tumors ≤2, 3–5, and 5–7 cm. P‐N0 patients with VPI had a significantly higher incidence of postoperative local recurrence and distant metastasis than those without VPI (P = 0.01), especially ipsilateral pleural recurrence.

Conclusion

VPI was an adverse prognostic factor in radically resected pN0 NSCLC, especially for tumors 2–3 cm in size.

Evaluation of new classifications of N descriptor in non-small cell lung cancer (NSCLC) based on the number and the ratio of metastatic lymph nodes

Background

The aim of the study was to evaluate the prognostic power of new classifications of N descriptor created basing on the number (NLN) and the ratio of metastatic lymph nodes (RLN) in NSCLC compared to the current classification (CLN).

Methods

The data of 529 patients with NSCLC operated with the intention of radical resection, were analyzed. The new categories of N descriptor were created as follows: 1) NLN - median number of metastatic nodes was 3, thus in NLN0 the number of metastatic nodes =0, in NLN1 1-2, in NLN2 ≥ 3, 2) RLN - median ratio (number of metastatic lymph nodes to all nodes removed) was 12.4 %, thus in RLN0 the ratio was 0, in RLN1 < 13 %, in RLN2 > 13 %. The prognostic value of each classification was calculated on the basis of hazard ratios defined in multivariate Cox proportional hazard model.

Results

The new classifications of N descriptor turned out to be an independent strong prognostic factor (p <0.001) with a 5-year survival rate NLN0-62 %, NLN1-39 %, NLN2-26 % and RLN0-62 %, RLN1-37 % and RLN2-26 %. For 5-year survival rates in CLN0-62 %, CLN1-42 %, CLN2-24 % (p < 0.001), a higher prognostic value of new classifications was not demonstrated, the hazard ratio amounted to 2.22, 2.08, 2.49 for NLN2, RLN2 and CLN2 respectively.

Conclusion

Despite the significantly high prognostic power, the new classifications cannot be considered superior over CLN. There are some deficiencies in the current classification, therefore further studies on its improvement are needed.

Mediastinal lymphadenectomy fulfilling NCCN criteria may improve the outcome of clinical N0-1 and pathological N2 non-small cell lung cancer

BACKGROUND

This retrospective study investigated whether mediastinal lymphadenectomy compliant with the National Comprehensive Cancer Network (NCCN) criteria will improve the oncological outcomes of clinical early-stage lung cancer.

METHODS

From 2003-2010, 712 consecutive cases of clinical N0/1 were included for retrospective analysis, including 152 confirmed cases of pN2 and 560 of pN0-1 disease following surgery. Group A was defined as the cases fulfilling NCCN lymphadenectomy criteria (≥ three stations of N2 nodes dissection) and group B included all other cases. The groups were stratified according to pN status and the outcomes were assessed.

RESULTS

Five-year overall survival (OS) and 5-year disease-free survival (DFS) were significantly different between group A versus B [72%±2% vs. 63%±4% (OS), P=0.014; 58.0%±2% vs. 49%±4% (DFS), P=0.038] in the whole cohort. After stratification by pN status, this difference was remained in pN2 subgroup [50%±5% vs. 25%±9% (OS), P=0.006; 31.0%±4% vs. 13%±7% (DFS), P=0.014], but not in pN0-1 subgroups. Cox regression analysis showed that performing a lymphadenectomy fulfilling NCCN criteria was a significant prognostic factor for OS either in the whole cohort [P=0.003, hazard ratio (HR): 0.598, 95% confidence interval (CI): 0.425-0.841] or in patients of pN2 status (P=0.038, HR: 0.559, 95% CI: 0.323-0.968). Cases with ≥4 N2 stations dissected did not achieve better survival benefit compared to those harvesting 3 stations in cN0/1-pN2 group (P=0.152).

CONCLUSIONS

Mediastinal lymphadenectomy fulfilling NCCN criteria appears to improve the survival of unexpected N2 group (cN0/1-pN2) among early-stage lung cancer patients. More extended N2 node dissection may not further improve the outcome in this group.