Improving the Inaccuracies of Clinical Staging of Patients with NSCLC: A Prospective Trial

Inaccurate Clinical Stage is Common and Associated With Poor Survival in Patients With Lung Cancer

INTRODUCTION

Clinical staging in lung cancer has implications for treatment planning and prognosis. We sought to determine the rate of inaccurate clinical stage (relative to pathologic), identify risk factors for inaccuracy, and evaluate the association of inaccuracy on survival. We hypothesized that inaccurate staging was associated with poor survival.

METHODS

In this retrospective cohort study, adult patients who received surgical resection without neoadjuvant treatment for nonsmall cell lung cancer from 2004 to 2020 in the National Cancer Database were categorized by accuracy of clinical stage (relative to pathologic stage). Multivariate models were used to determine risk factors for inaccuracy. The association between inaccuracy and overall survival was also analyzed.

RESULTS

We identified 255,598 patients with lung cancer, including 84,543 patients (33.1%) who were inaccurately staged. Stage inaccuracy was associated with higher tumor, node, metastasis stage (T-category 3: odds ratio [OR] = 1.2, 95% confidence interval [CI] 1.15-1.28; N-category 2: OR = 2.6, 95% CI 2.47-2.79), greater quantity of lymph nodes evaluated, and more extensive resection (extended lobectomy/bilobectomy: OR = 1.3, 95% CI 1.20-1.37; pneumonectomy: OR = 1.6, 95% CI 1.54-1.74). Patients undergoing robotic surgery were less likely to be inaccurately staged (OR = 0.89, 95% CI 0.852-0.939). Inaccurate staging was associated with worse overall survival (5-y 67.5% accurate versus 55.4% inaccurate, P < 0.001). Inaccurate staging was also associated with worse survival in a multivariate Cox model (hazard ratio [HR] = 1.3, 95% CI 1.29-1.33). Both "understaging" (path > clinical) and "overstaging" (clinical > path) were associated with inferior survival.

CONCLUSIONS

Inaccurate clinical stage (relative to pathologic) occurs in one-third of patients receiving surgery for lung cancer. Inaccuracy is associated with poor survival. Quality improvement initiatives should focus on improving clinical staging accuracy.

Discordance between clinical and pathologic staging and the timeliness of care of non-small cell lung cancer patients diagnosed with operable tumors

AIM

This study was performed to evaluate concordance between clinical and pathologic staging of non-small cell lung cancer (NSCLC) in our hospital network.

METHODS

We retrospectively reviewed records of 417 patients with NSCLC who received curative surgery and whose pathology was evaluated in our hospital between 2016 and 2021. Cytology, tissue pathology, and associated clinical, surgical, and imaging information were retrieved from hospital digital records.

RESULTS

The cohort included 214 female and 203 male patients aged 20.6-85.8 years. Median times among staging computed tomography and surgery (105 days [interquartile range (IQR) 77.0-143.0]), positron emission tomography and surgery (78.5 days [IQR 56.0-109.0]), and endobronchial ultrasound-guided transbronchial needle aspiration and surgery (59 days [IQR 42-94]) indicated that Australian guidelines of <42 days between original referral and commencement of treatment were not being met in the majority of cases. Discordance between clinical TNM (cTNM) and pathologic TNM staging was 25.9%, including 18.4% cases that were clinically understaged and two patients with undetected stage IVA disease. cTNM understaging was significantly associated with time between the final staging investigation and surgery (p = .023), pleural (p < .05) and vessel (p < .05) invasion, and diagnosis of high-grade adenocarcinoma (p = .001).

CONCLUSION

Discordance between clinical and pathologic staging of NSCLC is associated with tumor histopathologic characteristics and treatment delays. Although tumor factors that lead to discordant staging cannot be controlled, reduced time to surgery may have resulted in better outcomes for some patients in this potentially curable lung cancer cohort.

Intraoperative ultrasound: "Alternative eye" in lymph nodal dissection in non-small cell lung cancer

INTRODUCTION

Staging of the mediastinum lymph nodes involvement in patients with non-small cell lung cancer (NSCLC) is an important prognostic factor determining the most appropriate multimodality treatment plan. The objective of this study is to assess ultrasound characteristics of mediastinal lymph nodes metastasis and effectiveness of intraoperative ultrasound-guided mediastinal nodal dissection in patients with resected NSCLC.

MATERIALS AND METHODS

All patients undergoing video-assisted thoracoscopic surgery lobectomy and pulmonary lymphadenectomy from November 2020 to March 2022 at the thoracic surgery department of the Vanvitelli University of Naples underwent intraoperative ultrasound-guided mediastinal lymph nodal dissection.

RESULTS

This study evaluates whether individual B-mode features and a compounding thereof can be used to accurately and reproducibly predict lymph node malignancy.

DISCUSSION

Intraoperative ultrasound, during systematic mediastinal lymph node dissection, is helpful in preventing lesion to mediastinal structures. Pathological nodal sonographic characteristics are round shape, short-axis diameter, echogenicity, margin, the absence or presence of coagulation necrosis sign, and the absence or presence of central hilar structure, increased color Doppler flow, the absence or presence of calcification, and nodal conglomeration. Operating time was not substantially prolonged. The procedure is simple, safe and highly accurate.

CONCLUSIONS

Ultrasonic techniques allow surgeons to detect the relationship between lymph nodes and surrounding large blood vessels during biopsy, improving the safety and simplicity of the operation, increasing the number of harvested lymph nodes, and reducing the risk of intraoperative injury; it is a fast, easily reproducible, and inexpensive method.

Occult lymph node metastasis in radiologic stage I non-small cell lung cancer: The role of endobronchial ultrasound

RATIONALE

The use of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is currently recommended for staging non-small cell lung cancer (NSCLC) in centrally located tumors, tumors >3 cm, or with radiologic evidence of lymph node (LN) metastasis. Current guidelines do not recommend staging EBUS-TBNA in patients with stage I NSCLC who do not have any of the aforementioned conditions.

OBJECTIVE

We hypothesize that using EBUS-TBNA is useful for detecting occult metastasis in radiologic stage I NSCLC.

METHODS

In this single-center, retrospective study, charts of patients ≥18 years old who underwent staging EBUS-TBNA from January 2005 to May 2019 were reviewed. Only patients with combined positron-emission tomography and computed tomography (PET/CT) scans consistent with radiologic stage I NSCLC were included. Identified variables included: age, gender, personal history of any cancer, smoking history, tumor location, tumor centrality, tumor size, tumor PET activity, histopathologic type of NSCLC, and LN biopsy results. Patients whose LN samples showed a diagnosis other than NSCLC were excluded. The association between LN positivity, and each of the variables was assessed using Pearson's correlation for categorical variables, and logistic regression analysis for continuous variables.

RESULTS

From the 2,892 initially screened patients, 188 were included. Of those, 13 (6.9%; 95% CI, 4%-11%) had a malignancy-positive LN biopsy. The number needed to test (NNT) in order to detect one case of any occult metastasis was 15. Among the included variables, a significant association was found between LN positivity and tumor centrality, with central tumors found in 61.5% of patients with positive LN (n = 8) (p < 0.01). This association stayed significant after adjusting for age, gender, smoking history, tumor size, tumor location, and PET activity (p = 0.015). Among patients with malignancy-positive LN biopsies, five (38.5%; 95% CI, 17.6%-64.6%) were upstaged to N1, and eight (61.5%; 95% CI, 35.4%-82.4%) were upstaged to N2, with NNT of 23 to detect one case of occult N2 metastasis. Subgroup analysis comparing LN-positive patients based on their N stage did not show statistically significant association with any of the variables.

CONCLUSION

Based on our results and along with the existing evidence, EBUS-TBNA should be recommended as part of the routine staging in all patients with radiologic stage I NSCLC.

Endobronchial Ultrasound Staging of Operable Non-small Cell Lung Cancer: Do Triple-Normal Lymph Nodes Require Routine Biopsy?

BACKGROUND

Staging guidelines for lung cancer recommend endobronchial ultrasound (EBUS) and systematic biopsy of at least three mediastinal lymph node (LN) stations for accurate staging. A four-point ultrasonographic score (Canada Lymph Node Score [CLNS]) was developed to determine the probability of malignancy in each LN. A LN with a CLNS of < 2 is considered low probability for malignancy. We hypothesized that, in patients with cN0 non-small cell lung cancer, LNs with CLNS of < 2 may not require routine biopsy because they represent true node-negative disease.

RESEARCH QUESTION

Do LNs considered triple normal on CT scanning, PET scanning, and CLNS evaluation require routine biopsy?

STUDY DESIGN AND METHODS

LNs were evaluated for ultrasonographic features at the time of EBUS and the CLNS was applied. Triple-normal LNs were defined as cN0 on CT scanning (short axis, < 1 cm), PET scanning (no hypermetabolic activity), and EBUS (CLNS, < 2). Specificity and negative predictive value (NPV) were calculated against the gold standard pathologic diagnosis from surgically excised specimens.

RESULTS

In total, 143 LNs from 57 cN0 patients were assessed. Triple-normal LNs showed a specificity and NPV of 60% (95% CI, 51.2%-68.3%) and 93.1% (95% CI, 85.6%-97.4%), respectively. After pathologic assessment, only 5.6% (n = 8/143) of triple-normal nodes were proven to be malignant.

INTERPRETATION

At the time of staging for lung cancer, combining CT scanning, PET scanning, and CLNS criteria can identify triple-normal LNs that have a high NPV for malignancy. This raises the question of whether triple-normal LNs require routine sampling during EBUS and transbronchial needle aspiration. A prospective trial is required to confirm these findings.

Preoperative identification of clinicopathological prognostic factors for relapse-free survival in clinical N1 non-small cell lung cancer: a retrospective single center-based study

Background

Given the difficulty in preoperatively diagnosing lymph node metastasis, patients with Stage I–III non-small cell lung cancer (NSCLC) are likely to be included in the clinical N1 (cN1) group. However, better treatment options might be selected through further stratification. This study aimed to identify preoperative clinicopathological prognostic and stratification factors for patients with cN1 NSCLC.

Methods

This retrospective study evaluated 60 patients who were diagnosed with NSCLC during 2004–2014. Clinical nodal status had been evaluated using routine chest computed tomography (CT) and/or positron emission tomography (PET). To avoid biasing the fluorodeoxyglucose uptake values based on inter-institution or inter-model differences, we used only two PET systems (one PET system and one PET/CT system). Relapse-free survival (RFS) and overall survival (OS) were the primary study outcomes. The maximum standardized uptake value (SUVmax) was calculated for each tumor and categorized as low or high based on the median value. Patient sex, age, histology, tumor size, and tumor markers were also assessed.

Results

Poor OS was associated with older age (P = 0.0159) and high SUVmax values (P = 0.0142). Poor RFS was associated with positive carcinoembryonic antigen (CEA) expression (P = 0.0035) and high SUVmax values (P = 0.015). Multivariate analyses confirmed that poor OS was independently predicted by older age (hazard ratio [HR] = 2.751, confidence interval [CI]: 1.300–5.822; P = 0.0081) and high SUVmax values (HR = 5.121, 95% CI: 1.759–14.910; P = 0.0027). Furthermore, poor RFS was independently predicted by positive CEA expression (HR = 2.376, 95% CI: 1.056–5.348; P = 0.0366) and high SUVmax values (HR = 2.789, 95% CI: 1.042–7.458; P = 0.0410). The primary tumor’s SUVmax value was also an independent prognostic factor for both OS and RFS.

Conclusions

For patients with cN1 NSCLC, preoperative prognosis and stratification might be performed based on CEA expression, age, and the primary tumor’s SUVmax value. To enhance the prognostic value of the primary tumor’s SUVmax value, minimizing bias between facilities and models could lead to a more accurate prognostication.

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.

Evidence for Expanding Invasive Mediastinal Staging for Peripheral T1 Lung Tumors

BACKGROUND

Guidelines recommend invasive mediastinal staging for patients with non-small cell lung cancer and a "central" tumor. However, there is no consensus definition for central location. As such, the decision to perform invasive staging largely remains on an empirical foundation.

RESEARCH QUESTION

Should patients with peripheral T1 lung tumors undergo invasive mediastinal staging?

STUDY DESIGN AND METHODS

All participants with a screen-detected cancer with a solid component between 8 and 30 mm were identified from the National Lung Screening Trial. After translation of CT data, cancer location was identified and the X, Y, Z coordinates were determined as well as distance from the main carina. A multivariable logistic regression model was constructed to evaluate for predictors associated with lymph node metastasis.

RESULTS

Three hundred thirty-two participants were identified, of which 69 had lymph node involvement (20.8%). Of those with lymph node metastasis, 39.1% were N2. There was no difference in rate of lymph node metastasis based on tumor size (OR, 1.03; P = .248). There was also no statistical difference in rate of lymph node metastasis based on location, either by distance from the carina (OR, 0.99; P = .156) or tumor coordinates (X: P = .180; Y: P = .311; Z: P = .292). When adjusted for age, sex, histology, and smoking history, there was no change in the magnitude of the risk, and tests of significance were not altered.

INTERPRETATION

Our data indicate a high rate of N2 metastasis among T1 tumors and no significant relationship between tumor diameter or location. This suggests that patients with small, peripheral lung cancers may benefit from invasive mediastinal staging.

Minimizing residual occult nodal metastasis in NSCLC: recent advances, current status and controversies

Introduction: Nodal involvement in lung cancer is a significant determinant of prognosis and treatment management. New evidence exists regarding the management of occult lymph node metastasis and residual disease in the fields of imaging, mediastinal staging, and operative management.Areas covered: This review summarizes the latest body of knowledge on the identification and management of occult lymph node metastasis in NSCLC. We focus on tumor-specific characteristics; imaging modalities; invasive mediastinal staging; and operative management including, technique, degree of resection, and lymph node examination.Expert opinion: Newly identified risk-factors associated with nodal metastasis including tumor histology, location, radiologic features, and metabolic activity are not included in professional societal guidelines due to the heterogeneity of their reporting and uncertainty on how to adopt them into practice. Imaging as a sole diagnostic method is limited. We recommend confirmation with invasive mediastinal staging. EBUS-FNA is the best initial method, but adoption has not been uniform. The diagnostic algorithm is less certain for re-staging of mediastinal nodes after neoadjuvant therapy. Mediastinal node sampling during lobectomy remains the gold-standard, but evidence supports the use of minimally invasive techniques. More study is warranted regarding sublobar resection. No consensus exists regarding lymph node examination, but new evidence supports reexamination of current quality metrics.

Accuracy of positron emission tomography and computed tomography (PET/CT) in detecting nodal metastasis according to histology of non-small cell lung cancer

Positron emission tomography and computed tomography (PET-CT) is the non-invasive gold standard method for determining the oncological stage of patient with diagnosis of lung cancer. A correct preoperative staging is significant because only patients who do not have a history of regional or distant disease are those who will benefit from a surgical treatment. However, due to the different values of the PET-CT in terms of sensitivity and specificity to evaluate the mediastinal lymph node involvement, it is often necessary to perform a surgical mediastinal sampling through a cervical video mediastinoscopy (VM). Patient's risk factors which could modify the results of the PET scan, performing differences between non-invasive staging and the lymph node sampling due to VM are not yet clearly established in the literature. This knowledge will allow to identify in whom a surgical staging by sampling the mediastinal lymph nodes is needed. We included 234 patients with diagnosis of lung cancer who underwent a mediastinal lymph node staging by PET-CT images and histopathological results of mediastinal sampling by VM, analyzing the sensitivity and specificity of this non-invasive imaging study. We also analyzed variables that could modify the results of PET-CT, such as tumor type, location of the tumor and patient's history. We showed that those PET-CT presented an overall sensitivity and specificity of 93.8 and 62.7%, respectively, with negative and positive predictive values of 95.05 and 57.1%, respectively. The false-positive rate was 25% (57 of 234 patients). Analyzing risk factors involved in this false-positive rate (n = 57), we found that the only statistically significant factor that could explain these results was the histology of squamous carcinoma (p < 0.03). In this group of patients, it is essential to perform a mediastinal lymph node biopsy to know the real state of lymph node involvement.

Propensity-score adjusted comparison of pathologic nodal upstaging by robotic, video-assisted thoracoscopic, and open lobectomy for non-small cell lung cancer

OBJECTIVE

To assess the effectiveness of intraoperative lymph node (LN) staging by comparing upstaging between robotic-assisted surgery, video-assisted thoracoscopic surgery (VATS), and open thoracotomy approach for lobectomy for non-small cell lung cancer.

METHODS

We retrospectively analyzed 1053 patients with clinical stage N0/N1 non-small cell lung cancer who underwent lobectomy at 2 centers between 2011 and 2018. Propensity score adjustment by inverse probability of treatment weighting was used to balance baseline characteristics. The primary end point was LN upstaging.

RESULTS

A total of 911 patients (254 robotic, 296 VATS, and 261 open) were included in the inverse probability of treatment weighting adjusted analysis. The overall rate of LN upstaging was highest with open lobectomy (21.8%), followed by robotic (16.2%), and VATS (12.3%) (P = .03). Mediastinal N2 upstaging was observed in similar frequencies (open 6.9% vs robotic 6.3% vs VATS 4.4%; P = .6). No differences were seen for total LN counts, but were observed in the number of stations sampled (mean, open 4.0 vs robotic 3.8 vs VATS 3.6; P = .001). On multivariate analysis, LN upstaging was lower for VATS compared with open (odds ratio, 0.50; 95% confidence interval, 0.29-0.85), but not different between robotic and open (odds ratio, 0.72; 95% confidence interval, 0.44-1.18). No significant differences were seen in mediastinal N2 upstaging between groups.

CONCLUSIONS

Pathologic LN upstaging following lobectomy for clinically N0/N1 NSCLC remains high. Compared with a traditional thoracotomy approach, robotic lobectomy was associated with similar and VATS with lower overall nodal upstaging. A thorough evaluation of hilar and mediastinal LNs remains critical to ensure accurate staging by detection of occult LN metastases.

Combined Endosonographic Mediastinal Lymph Node Staging in Positron Emission Tomography and Computed Tomography Node-Negative Non-Small-Cell Lung Cancer in High-Risk Patients

Positron emission tomography (PET) with computed tomography (CT) is routinely utilized to investigate lymph node (LN) metastases in non-small-cell lung cancer. However, it is less sensitive in normal-sized LNs. This study was performed in order to define the prevalence of mediastinal LN metastases discovered on combined endosonography by endobronchial ultrasound (EBUS) and endoscopic ultrasound (EUS) fine needle aspiration in patients with a radiologically normal mediastinum. This study consists of a retrospective, single-institution, tertiary care referral center review of a prospectively maintained database. Patients were identified from a cohort between January 2009 and December 2014. One hundred and sixty-one patients with biopsy-proven, non-small-cell lung cancer were identified in whom both the preendosonography CT and PET-CT were negative for mediastinal LN metastases. Combined endosonography (EBUS + EUS-FNA) was performed in all patients. Z test was used for statistical analysis. A P value of <0.05 was considered statistically significant. A total of 161 consecutive patients were included. Patients were staged if they had central tumor, tumor size >3 cm, N1 lymph node involvement on PET-CT/CT, or if there was low SUV (<2.5) in the primary tumor. A total of 416 lymph nodes were biopsied in the 161 patients using combined endosonography; 147 with EBUS and 269 with EUS. Mean and median number of lymph nodes biopsied per patient using combined EBUS/EUS was 2.5 and 3, respectively (mean and median EBUS: 0.91 and 2.5; mean and median EUS 1.6 and 3). Endosonographic staging upstaged 13% of patients with radiologically normal lymph nodes in the mediastinum, hilum, lobar, and sublobar regions (confidence interval 8.22-19.20). Twenty-one out of 161 patients (13%) with radiologically normal mediastinum were positive on combined EBUS/EUS staging. Out of 21 patients upstaged on endosonography, 15 (71%) had tumor size >3 cm. Six (28%) had occult N1 disease. Thirteen (61%) had occult N2 disease and 2 (9%) had adrenal involvement. None of the upstaged patients had N1 LN involvement on PET-CT or CT scan. Combined endosonographic lymph node staging should be considered in the pretreatment staging of high-risk patients with non-small-cell lung cancer in the presence of radiologically normal mediastinal lymph nodes due to the significant rate of radiologically occult lymph node metastases.

The Accuracy of Clinical Staging of Stage I-IIIa Non-Small Cell Lung Cancer: An Analysis Based on Individual Participant Data

BACKGROUND

Clinical staging of non-small cell lung cancer (NSCLC) helps determine the prognosis and treatment of patients; few data exist on the accuracy of clinical staging and the impact on treatment and survival of patients. We assessed whether participant or trial characteristics were associated with clinical staging accuracy as well as impact on survival.

METHODS

We used individual participant data from randomized controlled trials (RCTs), supplied for a meta-analysis of preoperative chemotherapy (± radiotherapy) vs surgery alone (± radiotherapy) in NSCLC. We assessed agreement between clinical TNM (cTNM) stage at randomization and pathologic TNM (pTNM) stage, for participants in the control group.

RESULTS

Results are based on 698 patients who received surgery alone (± radiotherapy) with data for cTNM and pTNM stage. Forty-six percent of cases were cTNM stage I, 23% were cTNM stage II, and 31% were cTNM stage IIIa. cTNM stage disagreed with pTNM stage in 48% of cases, with 34% clinically understaged and 14% clinically overstaged. Agreement was not associated with age (P = .12), sex (P = .62), histology (P = .82), staging method (P = .32), or year of randomization (P = .98). Poorer survival in understaged patients was explained by the underlying pTNM stage. Clinical staging failed to detect T4 disease in 10% of cases and misclassified nodal disease in 38%.

CONCLUSIONS

This study demonstrates suboptimal agreement between clinical and pathologic staging. Discrepancies between clinical and pathologic T and N staging could have led to different treatment decisions in 10% and 38% of cases, respectively. There is therefore a need for further research into improving staging accuracy for patients with stage I-IIIa NSCLC.

Predictors of lymph node metastasis and possible selective lymph node dissection in clinical stage IA non-small cell lung cancer

Background

The pathologic stages of lymph nodes usually differ from preoperatively predicted in lung cancers and it is difficult to predict the metastasis of lymph nodes for the patients diagnosed as clinical stage IA non-small cell lung cancers (NSCLC). This study aimed to investigate the patterns of lymph node metastasis and the risk factors predicting lymph node metastasis in the patients with clinical stage IA NSCLCs.

Methods

All patients diagnosed as clinical stage IA NSCLC from July 2013 to June 2017 in our center were retrospectively reviewed, and a total number of 1,543 patients who underwent anatomical lobectomy with systematic lymph node dissection were enrolled in this study. Multivariate logistic regression analysis was performed to identify the risk factors predicting lymph node metastasis, and Fisher's exact test was used to confirm the lymph node spread mode according to the locations of primary tumors.

Results

Totally, lymph node metastases presented in 131 patients (8.5%) in this series. Sixty-three patients presented N1 diseases, 17 patients showed only skipped N2 diseases, and 51 patients had simultaneous N1 and N2 positive lymph nodes. No lymph node metastasis was found in the patients with pure ground grass opacity (GGO). When patients were arbitrarily divided into six groups by the longest tumor diameter of ≤0.5, 0.6-1, 1.1-1.5, 1.6-2.0, 2.1-2.5, 2.6-3 cm, the lymph node metastasis rates of each group were 0% (0/20), 1.5% (4/264), 4.7% (20/429), 8.6% (29/336), 13.1% (38/290), 19.6% (40/204), respectively. When the patients with pure GGO were excluded, the lymph node metastasis rates in the patients with partial or total solid tumors were 0% (0/10), 2.4% (4/164), 6.6% (20/303), 11.7% (29/249), 16.0% (38/238) and 23.1% (40/173). The cut off value showed by receiver operating characteristic (ROC) curve for tumor size was 1.95 cm, and the area under the curve (AUC) was measured as 0.681 (P<0.001, 95% CI: 0.630-0.726). Multivariate logistic regression analysis indicated that male patients [odds ratio (OR) =3.34, P=0.012], smoking history (OR =14.12, P<0.001), solid components (OR =3.34, P=0.01), large tumor size (OR =1.9, P<0.001), poor differentiation (OR =2.25, P=0.013), lymphovascular invasion (OR =58.45, P<0.001), visceral pleural invasion (OR =48.37, P<0.001) were significantly associated with lymph node metastasis in clinical stage IA NSCLC. The rate of non-lobe specific lymph node metastasis was 15.8-40.0% when any of the lobe specific lymph nodes was positive, while it was only 0-2.2% when all lobe specific lymph nodes were negative.

Conclusions

Tumor size, solid components, poor differentiation, lymphovascular invasion, visceral pleural invasion and smoking history were significant factors predicting lymph node metastasis of clinical stage IA NSCLC. Patients with negative lobe-specific lymph node have very low risk of metastasis to the non-lobe specific lymph nodes. Lobe-specific lymph node dissection may become an alternative lymph node dissection mode for clinical stage IA NSCLC, especially for tumors ≤2 cm.

Diagnosing Lung Cancer: The Complexities of Obtaining a Tissue Diagnosis in the Era of Minimally Invasive and Personalised Medicine

The role of the respiratory physician in diagnosing lung cancer has increased in complexity over the last 20 years. Adenocarcinoma is now the prevailing histopathological sub-type of non-small cell lung cancer (NSCLC) resulting in more peripheral cancers. Conventional bronchoscopy is often not sufficient to obtain adequate tissue samples for diagnosis. Radiologically guided transthoracic biopsy is a sensitive alternative, but carries significant risks. These limitations have driven the development of complimentary bronchoscopic navigation techniques for peripheral tumour localisation and sampling. Furthermore, linear endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA) is increasingly being chosen as the initial diagnostic procedure for those with central lesions and/or radiological evidence of node-positive disease. This technique can diagnose and stage patients in a single, minimally invasive procedure with a diagnostic yield equivalent to that of surgical mediastinoscopy. The success of molecular targeted therapies and immune checkpoint inhibitors in NSCLC has led to the increasing challenge of obtaining adequate specimens for accurate tumour subtyping through minimally invasive procedures. This review discusses the changing epidemiology and treatment landscape of lung cancer and explores the utility of current diagnostic options in obtaining a tissue diagnosis in this new era of precision medicine.

Mediastinal staging by videomediastinoscopy in clinical N1 non-small cell lung cancer: a prospective multicentre study

A quarter of patients with clinical N1 (cN1) non-small cell lung cancer (NSCLC) based on positron emission tomography-computed tomography (PET-CT) imaging have occult mediastinal nodal involvement (N2 disease). In a prospective study, endosonography alone had an unsatisfactory sensitivity (38%) in detecting N2 disease. The current prospective multicentre trial investigated the sensitivity of preoperative mediastinal staging by video-assisted mediastinoscopy (VAM) or VAM-lymphadenectomy (VAMLA).Consecutive patients with operable and resectable (suspected) NSCLC and cN1 after PET-CT imaging underwent VAM(LA). The primary study outcome was sensitivity to detect N2 disease. Secondary endpoints were the prevalence of N2 disease, negative predictive value (NPV) and accuracy of VAM(LA).Out of 105 patients with cN1 on imaging, 26% eventually developed N2 disease. Invasive mediastinal staging with VAM(LA) had a sensitivity of 73% to detect N2 disease. The NPV was 92% and accuracy 93%. Median number of assessed lymph node stations during VAM(LA) was 4 (IQR 3-5), and in 96%, at least three stations were assessed.VAM(LA) has a satisfactory sensitivity of 73% to detect mediastinal nodal disease in cN1 lung cancer, and could be the technique of choice for pre-resection mediastinal lymph node assessment in this patient group with a one in four chance of occult-positive mediastinal nodes after negative PET-CT.

Randomized Phase II Trial Comparing Chemoradiotherapy with Chemotherapy for Completely Resected Unsuspected N2-Positive Non-Small Cell Lung Cancer

INTRODUCTION

We investigated whether concurrent chemoradiotherapy (CCRT) would increase survival in patients with completely resected unsuspected N2-positive NSCLC versus in patients who received adjuvant chemotherapy alone.

METHODS

Eligible patients were randomly assigned (1:1) to either the CCRT arm or the chemotherapy arm. In the CCRT arm, patients received concurrent thoracic radiotherapy (50 Gy in 25 fractions) with five cycles of weekly paclitaxel (50 mg/m²) and cisplatin (25 mg/m²), followed by two additional cycles of paclitaxel (175 mg/m²) plus cisplatin (80 mg/m²) at 3-week intervals. In the chemotherapy arm, patients received four cycles of adjuvant paclitaxel (175 mg/m²) and carboplatin (area under the curve = 5.5) every 3 weeks. The primary end point was disease-free survival.

RESULTS

We enrolled and analyzed 101 patients (51 received CCRT and 50 received chemotherapy). In all, 74 and 27 patients were preoperatively staged as N0 and N1 diseases, respectively. The baseline characteristics were well balanced between the two arms. The median disease-free survival of the CCRT arm was 24.7 months, which was not significantly different from that of the chemotherapy arm (21.9 months) (hazard ratio = 0.94, 95% confident interval: 0.58-1.52, p = 0.40). There was no difference in overall survival (74.3 months in CCRT arm and 83.5 months in the chemotherapy arm) (hazard ratio = 1.33, 95% confident interval: 0.71-2.49).

CONCLUSIONS

There was no survival benefit from adjuvant CCRT compared with from platinum-based chemotherapy alone for completely resected unsuspected N2-positive NSCLC. However, the role of sequential radiotherapy administered after adjuvant chemotherapy is being evaluated, and further study is needed to evaluate the optimal radiotherapy approach for completely resected N2-positive NSCLC.

The role of endobronchial ultrasound versus mediastinoscopy for non-small cell lung cancer

This review provides an update on the current role of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and mediastinoscopy (Med) in assessment of patients with non-small cell lung cancer (NSCLC). Invasive mediastinal lymph node (LN) staging is the major application for both of these techniques. Up until recently, Med was the gold standard for invasive mediastinal LN staging in NSCLC. However, EBUS-TBNA has shown to be equivalent, and in some studies better than Med for invasive staging of lung cancer. EBUS-TBNA offers access to N1 LNs and development of the thin convex probe EBUS (TCP-EBUS) will expand EBUS-TBNA access from the paratracheal region and central airways to more distal parabronchial regions allowing for more extensive N1 LN assessment and sampling more distal lung tumors. EBUS-TBNA is more cost-effective than Med and it is currently recommended as the test of first choice for invasive mediastinal LN staging in lung cancer. Confirmatory Med should be performed selectively in patients with high pretest probability of metastatic disease. Addition of esophageal ultrasound fine needle aspiration (EUS-FNA) may increase diagnostic yield of EBUS-TBNA mediastinal staging. Both Med and EBUS-TBNA can be used in primary lung cancer diagnosis, restaging of the mediastinum following neoadjuvant therapy and in diagnosis of lung cancer recurrence. In the future, a combination of EBUS-TBNA with or without EUS-FNA and Med is most likely going to provide the most optimal invasive assessment of the mediastinum in patients with lung cancer. The decision on test choice and sequence should be made on a case-by-case basis and factoring in local resources and expertise.

Mediastinal Staging: Endosonographic Ultrasound Lymph Node Biopsy or Mediastinoscopy

Combined endosonographic lymph node biopsy techniques are a minimally invasive alternative to surgical staging in non-small cell lung cancer and may be superior to standard mediastinoscopy and surgical mediastinal staging techniques. Endosonography allows for the biopsy of lymph nodes and metastases unattainable with standard mediastinoscopy. Standard cervical mediastinoscopy is an invasive procedure, which requires general anesthesia and is associated with higher risk, cost, and major complication rates compared with minimally invasive endosonographic biopsy techniques. Combined endosonographic procedures are the new gold standard in staging of non-small cell lung cancer when performed by an experienced operator.

Clinical Staging of Stage I Non-Small Cell Lung Cancer in the Netherlands-Need for Improvement in an Era With Expanding Nonsurgical Treatment Options: Data From the Dutch Lung Surgery Audit

BACKGROUND

The clinical stage of non-small cell lung cancer (NSCLC) determines the initial treatment, whereas the pathologic stage best determines prognosis and the need for adjuvant treatment. In an era in which stereotactic ablative radiotherapy (SABR) has become an alternative modality to surgical intervention, clinical staging is even more important, because pathologic staging is omitted in the case of SABR. The objective of this study was to determine the concordance between clinical and pathologic stage in routine clinical practice for patients with early-stage NSCLC.

METHODS

Prospective data were derived from the Dutch Lung Surgery Audit (DLSA) in 2013 and 2014. Patients with clinical stage I NSCLC who underwent surgical resection and had a positron emission tomography-computed tomography (PET-CT) scan in their clinical workup were selected. Clinical and pathologic TNM (cTNM and pTNM) stages were compared.

RESULTS

From a total of 1,790 patients with clinical stage I, 1,555 (87%) patients were included in this analysis. Concordance between cTNM and pTNM was 59.9%. Of the patients with clinical stage I, 22.6% were upstaged to pathologic stage II or higher. In total, 14.9% of all patients with clinical stage I had nodal metastases, and 5.5% of all patients had unforeseen N2 disease. In patients with clinical stage T2a tumors, 21.3% had nodal metastases, 14.5% being N1 and 6.7% being N2 disease.

CONCLUSIONS

Concordance between clinical and pathologic stage is 59.9%. In patients with clinical stage I NSCLC, 22.6% were upstaged to pathologic stage II or higher, which is an indication for adjuvant chemotherapy. Improvement in accuracy of staging is thus needed, particularly for these patients.

The role of cervical mediastinoscopy in Nigerian thoracic surgical practice

Introduction

Cervical mediastinoscopy is the gold standard for obtaining histological diagnosis of mediastinal pathology. It has been used for the staging of lung cancer as well as to determine the cause of Isolated Mediastinal Lymphadenopathy. There is very limited evidence in the literature of its use in Nigeria to assess mediastinal pathology. The aim of this study was to describe our institutional experience with cervical mediastinoscopy.

Methods

This study was a retrospective analysis of 40 patients that underwent cervical mediastinoscopy in our institution between March 2007 and February 2013.

Results

The indication for Cervical Mediastinoscopy was Isolated Mediastinal Lymphadenopathy in 24 patients (60%) and lung cancer staging in 16 patient (40%). The mean age of the patients was 52.7 + 15.1 years. There were 21 females (52.5%) and 19 males (47.5%). The most commonly biopsied lymph nodes were level 4 in 35 patients (87.5%) and level 7 in 21 patients (52.5%). Malignant diagnosis was made in 16 (66.7%) patients with Isolated Mediastinal Lymphadenopathy and in 13 (81.3%) patients staged for lung cancer. Hospital stay was less than 24 hours in all patients and there were no complications.

Conclusion

Cervical Mediastinoscopy is available in Nigeria and has been performed in our institution with high diagnostic yield and no complications. Its increased use, along with the development of other mediastinal biopsy techniques is advocated to increase tissue biopsy of mediastinal pathology, especially for lung cancer and isolated mediastinal lymphadenopathy.

Induction Chemotherapy is Not Superior to a Surgery-First Strategy for Clinical N1 Non-Small Cell Lung Cancer

BACKGROUND

Guidelines recommend primary surgical resection for non-small cell lung cancer (NSCLC) patients with clinical N1 disease and adjuvant chemotherapy if nodal disease is confirmed after resection. We tested the hypothesis that induction chemotherapy for clinical N1 (cN1) disease improves survival.

METHODS

Patients treated with lobectomy or pneumonectomy for cT1-3 N1 M0 NSCLC from 2006 to 2011 in the National Cancer Data Base were stratified by treatment strategy: surgery first vs induction chemotherapy. Propensity scores were developed and matched with a 2:1 nearest neighbor algorithm. Survival analyses using Kaplan-Meier methods were performed on the unadjusted and propensity-matched cohorts.

RESULTS

A total of 5,364 cN1 patients were identified for inclusion, of which 565 (10.5%) were treated with induction chemotherapy. Clinical nodal staging was accurate in 68.6% (n = 3,292) of patients treated with surgical resection first, whereas 16.3% (n = 780) were pN0 and 10.7% (n = 514) were pN2-3. Adjuvant chemotherapy was given to 60.9% of the surgery-first patients who were pN1-3 after resection. Before adjustment, patients treated with induction chemotherapy were younger, with lower comorbidity burden, were more likely to be treated at an academic center and to have private insurance (all p < 0.001), but were significantly more likely to have T3 tumors (28.7% vs 9.9%, p < 0.001) and to require pneumonectomy (23.5% vs 18.5%, p = 0.005). The unadjusted and propensity-matched analyses found no differences in short-term outcomes or survival between groups.

CONCLUSIONS

Induction chemotherapy for cN1 NSCLC is not associated with improved survival. This finding supports the currently recommended treatment paradigm of surgery first for cN1 NSCLC.

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.

Systematic Endobronchial Ultrasound-guided Mediastinal Staging Versus Positron Emission Tomography for Comprehensive Mediastinal Staging in NSCLC Before Radical Radiotherapy of Non-small Cell Lung Cancer: A Pilot Study

Despite known limitations of positron emission tomography (PET) for mediastinal staging of non-small cell lung cancer (NSCLC), radiation treatment fields are generally based on PET-identified disease extent. However, no studies have examined the accuracy of FDG-PET/CT on a per-node basis in patients being considered for curative-intent radiotherapy in NSCLC.In a prospective trial, patients with NSCLC being considered for definitive thoracic radiotherapy (± systemic chemotherapy) underwent minimally invasive systematic mediastinal evaluation with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) following noninvasive staging with integrated PET-CT.Thirty patients underwent EBUS-TBNA, with TBNA performed from a mean 2.5 lymph node (LN) stations per patient (median 3, range 1-5). Discordant findings between PET-CT and EBUS-TBNA were observed in 10 patients (33%, 95% CI 19%-51%). PET-occult LN metastases were demonstrated by EBUS in 4 patients, whereas a lesser extent of mediastinal involvement, compared with FDG-PET, was demonstrated by EBUS in 6 patients, including 2 patients downstaged from cN3 to pN2. LNs upstaged by EBUS were significantly smaller than nodes downstaged by EBUS, 7.5 mm (range 7-9) versus 12 mm (range 6-21), P = 0.005.A significant proportion of patients considered for definitive radiotherapy (+/-chemotherapy) undergoing systematic mediastinal evaluation with EBUS-TBNA in this study have an extent of mediastinal NSCLC involvement discordant with that indicated by PET-CT. Systematic EBUS-TBNA may aid in defining the extent of mediastinal involvement in NSCLC patients undergoing radiotherapy. Systematic EBUS-TBNA has the potential to contribute significantly to radiotherapy planning and delivery, by either identifying occult nodal metastases, or demonstrating FDG-avid LNs to be disease-free.

2nd ESMO Consensus Conference in Lung Cancer: locally advanced stage III non-small-cell lung cancer

To complement the existing treatment guidelines for all tumour types, ESMO organises consensus conferences to focus on specific issues in each type of tumour. The 2nd ESMO Consensus Conference on Lung Cancer was held on 11-12 May 2013 in Lugano. A total of 35 experts met to address several questions on non-small-cell lung cancer (NSCLC) in each of four areas: pathology and molecular biomarkers, first-line/second and further lines of treatment in advanced disease, early-stage disease and locally advanced disease. For each question, recommendations were made including reference to the grade of recommendation and level of evidence. This consensus paper focuses on locally advanced disease.

Endosonography for mediastinal nodal staging of clinical N1 non-small cell lung cancer: a prospective multicenter study

BACKGROUND

Patients with clinical N1 (cN1) lung cancer based on imaging are at risk for malignant mediastinal nodal involvement (N2 disease). Endosonography with a needle technique is suggested over surgical staging as a best first test for preoperative invasive mediastinal staging. The addition of a confirmatory mediastinoscopy seems questionable in patients with a normal mediastinum on imaging. This prospective multicenter trial investigated the sensitivity of preoperative linear endosonography and mediastinoscopy for mediastinal nodal staging of cN1 lung cancer.

METHODS

Consecutive patients with operable and resectable cN1 non-small cell lung cancer underwent a lobe-specific mediastinal nodal staging by endosonography. The primary study outcome was sensitivity to detect N2 disease. The secondary end points were the prevalence of N2 disease, the negative predictive value (NPV) of both endosonography and endosonography with confirmatory mediastinoscopy, and the number of patients needed to detect one additional N2 disease with mediastinoscopy.

RESULTS

Of the 100 patients with cN1 on imaging, 24 patients were diagnosed with N2 disease. Invasive mediastinal nodal staging with endosonography alone has a sensitivity of 38%, which can be increased to 73% by adding a mediastinoscopy. NPV was 81% and 91%, respectively. Ten mediastinoscopies are needed to detect one additional N2 disease missed by endosonography.

CONCLUSIONS

Endosonography alone has an unsatisfactory sensitivity to detect mediastinal nodal metastasis in cN1 lung cancer, and the addition of a confirmatory mediastinoscopy is of added value.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01456429; URL: www.clinicaltrials.gov.

Lung cancer staging: the value of PET depends on the clinical setting

BACKGROUND

Although positron emission tomography (PET) imaging is widely recommended in the evaluation of patients with lung cancer, randomized controlled trials (RCTs) assessing this have demonstrated inconsistent results. We asked whether differences in the clinical context and endpoints could explain these discrepancies.

METHODS

We used realist synthesis methods to analyze how contextual differences among RCTs affected the results. We focused on RCTs to minimize confounding yet permit evaluation of differences by comparing across studies.

RESULTS

This analysis suggests that the impact of PET depends on the clinical setting. PET is of greatest benefit in identifying M1 disease in patients with a high chance of such involvement and when little traditional imaging [e.g., abdominal/pelvis computed tomography (CT) and bone scan] is used. Identification of N2,3 involvement by PET prior to resection is seen primarily when there is at least a moderate probability of such and the rate of invasive staging is high. The rate of N2 disease not identified preoperatively appears to increase if PET is used to avoid invasive mediastinal staging in clinical settings in which the risk of N2,3 involvement is moderately high. There is both a potential benefit in avoiding stage-inappropriate resection as well as a risk of missed (stage-appropriate) resection if PET findings are not evaluated carefully.

CONCLUSIONS

A blanket recommendation for PET may be too simplistic without considering nuances of the clinical setting.

Using pet-ct to reduce futile thoracotomy rates in non-small-cell lung cancer: a population-based review

BACKGROUND

Combined positron-emission tomography and computed tomography (pet-ct) reduces futile thoracotomy (ft) rates in patients with non-small-cell lung cancer (nsclc). We sought to identify preoperative risk factors for ft in patients staged with pet-ct.

METHODS

We retrospectively reviewed all patients referred to the BC Cancer Agency during 2009-2010 who underwent pet-ct and thoracotomy for nsclc. Patients with clinical N2 disease were excluded. An ft was defined as any of a benign lesion; an exploratory thoracotomy; pathologic N2 or N3, stage iiib or iv, or inoperable T3 or T4 disease; and recurrence or death within 1 year of surgery.

RESULTS

Of the 108 patients who met the inclusion criteria, ft occurred in 27. The main reason for ft was recurrence within 1 year (14 patients) and pathologic N2 disease (10 patients). On multivariate analysis, an Eastern Cooperative Oncology Group performance status greater than 1, a pet-ct positive N1 status, a primary tumour larger than 3 cm, and a period of more than 16 weeks from pet-ct to surgery were associated with ft. N2 disease that had been negative on pet-ct occurred in 21% of patients with a pet-ct positive N1 status and in 20% of patients with tumours larger than 3 cm and non-biopsy mediastinal staging only. The combination of pet-ct positive N1 status and a primary larger than 3 cm had 85% specificity, and the presence of either risk factor had 100% sensitivity, for ft attributable to N2 disease.

CONCLUSIONS

To reduce ft attributable to N2 disease, tissue biopsy for mediastinal staging should be considered for patients with pet-ct positive N1 status and with tumours larger than 3 cm even with a pet-ct negative mediastinum.

Impact of point spread function modelling and time of flight on FDG uptake measurements in lung lesions using alternative filtering strategies

BACKGROUND

The use of maximum standardised uptake value (SUVmax) is commonplace in oncology positron emission tomography (PET). Point spread function (PSF) modelling and time-of-flight (TOF) reconstructions have a significant impact on SUVmax, presenting a challenge for centres with defined protocols for lesion classification based on SUVmax thresholds. This has perhaps led to the slow adoption of these reconstructions. This work evaluated the impact of PSF and/or TOF reconstructions on SUVmax, SUVpeak and total lesion glycolysis (TLG) under two different schemes of post-filtering.

METHODS

Post-filters to match voxel variance or SUVmax were determined using a NEMA NU-2 phantom. Images from 68 consecutive lung cancer patients were reconstructed with the standard iterative algorithm along with TOF; PSF modelling - Siemens HD·PET (HD); and combined PSF modelling and TOF - Siemens ultraHD·PET (UHD) with the two post-filter sets. SUVmax, SUVpeak, TLG and signal-to-noise ratio of tumour relative to liver (SNR(T-L)) were measured in 74 lesions for each reconstruction. Relative differences in uptake measures were calculated, and the clinical impact of any changes was assessed using published guidelines and local practice.

RESULTS

When matching voxel variance, SUVmax increased substantially (mean increase +32% and +49% for HD and UHD, respectively), potentially impacting outcome in the majority of patients. Increases in SUVpeak were less notable (mean increase +17% and +23% for HD and UHD, respectively). Increases with TOF alone were far less for both measures. Mean changes to TLG were <10% for all algorithms for either set of post-filters. SNR(T-L) were greater than ordered subset expectation maximisation (OSEM) in all reconstructions using both post-filtering sets.

CONCLUSIONS

Matching image voxel variance with PSF and/or TOF reconstructions, particularly with PSF modelling and in small lesions, resulted in considerable increases in SUVmax, inhibiting the use of defined protocols for lesion classification based on SUVmax. However, reduced partial volume effects may increase lesion detectability. Matching SUVmax in phantoms translated well to patient studies for PSF reconstruction but less well with TOF, where a small positive bias was observed in patient images. Matching SUVmax significantly reduced voxel variance and potential variability of uptake measures. Finally, TLG may be less sensitive to reconstruction methods compared with either SUVmax or SUVpeak.

PET-CT for assessing mediastinal lymph node involvement in patients with suspected resectable non-small cell lung cancer

BACKGROUND

A major determinant of treatment offered to patients with non-small cell lung cancer (NSCLC) is their intrathoracic (mediastinal) nodal status. If the disease has not spread to the ipsilateral mediastinal nodes, subcarinal (N2) nodes, or both, and the patient is otherwise considered fit for surgery, resection is often the treatment of choice. Planning the optimal treatment is therefore critically dependent on accurate staging of the disease. PET-CT (positron emission tomography-computed tomography) is a non-invasive staging method of the mediastinum, which is increasingly available and used by lung cancer multidisciplinary teams. Although the non-invasive nature of PET-CT constitutes one of its major advantages, PET-CT may be suboptimal in detecting malignancy in normal-sized lymph nodes and in ruling out malignancy in patients with coexisting inflammatory or infectious diseases.

OBJECTIVES

To determine the diagnostic accuracy of integrated PET-CT for mediastinal staging of patients with suspected or confirmed NSCLC that is potentially suitable for treatment with curative intent.

SEARCH METHODS

We searched the following databases up to 30 April 2013: The Cochrane Library, MEDLINE via OvidSP (from 1946), Embase via OvidSP (from 1974), PreMEDLINE via OvidSP, OpenGrey, ProQuest Dissertations & Theses, and the trials register www.clinicaltrials.gov. There were no language or publication status restrictions on the search. We also contacted researchers in the field, checked reference lists, and conducted citation searches (with an end-date of 9 July 2013) of relevant studies.

SELECTION CRITERIA

Prospective or retrospective cross-sectional studies that assessed the diagnostic accuracy of integrated PET-CT for diagnosing N2 disease in patients with suspected resectable NSCLC. The studies must have used pathology as the reference standard and reported participants as the unit of analysis.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data pertaining to the study characteristics and the number of true and false positives and true and false negatives for the index test, and they independently assessed the quality of the included studies using QUADAS-2. We calculated sensitivity and specificity with 95% confidence intervals (CI) for each study and performed two main analyses based on the criteria for test positivity employed: Activity > background or SUVmax ≥ 2.5 (SUVmax = maximum standardised uptake value), where we fitted a summary receiver operating characteristic (ROC) curve using a hierarchical summary ROC (HSROC) model for each subset of studies. We identified the average operating point on the SROC curve and computed the average sensitivities and specificities. We checked for heterogeneity and examined the robustness of the meta-analyses through sensitivity analyses.

MAIN RESULTS

We included 45 studies, and based on the criteria for PET-CT positivity, we categorised the included studies into three groups: Activity > background (18 studies, N = 2823, prevalence of N2 and N3 nodes = 679/2328), SUVmax ≥ 2.5 (12 studies, N = 1656, prevalence of N2 and N3 nodes = 465/1656), and Other/mixed (15 studies, N = 1616, prevalence of N2 to N3 nodes = 400/1616). None of the studies reported (any) adverse events. Under-reporting generally hampered the quality assessment of the studies, and in 30/45 studies, the applicability of the study populations was of high or unclear concern.The summary sensitivity and specificity estimates for the 'Activity > background PET-CT positivity criterion were 77.4% (95% CI 65.3 to 86.1) and 90.1% (95% CI 85.3 to 93.5), respectively, but the accuracy estimates of these studies in ROC space showed a wide prediction region. This indicated high between-study heterogeneity and a relatively large 95% confidence region around the summary value of sensitivity and specificity, denoting a lack of precision. Sensitivity analyses suggested that the overall estimate of sensitivity was especially susceptible to selection bias; reference standard bias; clear definition of test positivity; and to a lesser extent, index test bias and commercial funding bias, with lower combined estimates of sensitivity observed for all the low 'Risk of bias' studies compared with the full analysis.The summary sensitivity and specificity estimates for the SUVmax ≥ 2.5 PET-CT positivity criterion were 81.3% (95% CI 70.2 to 88.9) and 79.4% (95% CI 70 to 86.5), respectively.In this group, the accuracy estimates of these studies in ROC space also showed a very wide prediction region. This indicated very high between-study heterogeneity, and there was a relatively large 95% confidence region around the summary value of sensitivity and specificity, denoting a clear lack of precision. Sensitivity analyses suggested that both overall accuracy estimates were marginally sensitive to flow and timing bias and commercial funding bias, which both lead to slightly lower estimates of sensitivity and specificity.Heterogeneity analyses showed that the accuracy estimates were significantly influenced by country of study origin, percentage of participants with adenocarcinoma, (¹⁸F)-2-fluoro-deoxy-D-glucose (FDG) dose, type of PET-CT scanner, and study size, but not by study design, consecutive recruitment, attenuation correction, year of publication, or tuberculosis incidence rate per 100,000 population.

AUTHORS' CONCLUSIONS

This review has shown that accuracy of PET-CT is insufficient to allow management based on PET-CT alone. The findings therefore support National Institute for Health and Care (formally 'clinical') Excellence (NICE) guidance on this topic, where PET-CT is used to guide clinicians in the next step: either a biopsy or where negative and nodes are small, directly to surgery. The apparent difference between the two main makes of PET-CT scanner is important and may influence the treatment decision in some circumstances. The differences in PET-CT accuracy estimates between scanner makes, NSCLC subtypes, FDG dose, and country of study origin, along with the general variability of results, suggest that all large centres should actively monitor their accuracy. This is so that they can make reliable decisions based on their own results and identify the populations in which PET-CT is of most use or potentially little value.

Utility of mediastinoscopy in clinical stage I lung cancers at risk for occult mediastinal nodal metastases

OBJECTIVE

The prevalence of mediastinal lymph node metastases is unknown for patients with clinical N0 lung cancer who are thought to be at high risk for occult nodal metastases. Further, the utility of mediastinoscopy in these patients is unknown. We performed a prospective trial to evaluate the utility of routine cervical mediastinoscopy for patients who may be at high risk of occult nodal metastases.

METHODS

From January 1, 2008, July 31, 2013, 90 patients with lung cancer with clinical stage T2N0 or T1N0 with standardized uptake value greater than 10 by positron emission tomography/computed tomography underwent routine cervical mediastinoscopy before lung resection. Biopsy of a minimum of 3 nodal stations at mediastinoscopy and a minimum of 4 nodal stations with lung resection was advised. The prevalence of nodal metastases at mediastinoscopy and lung resection was recorded.

RESULTS

Some 64% of patients with lung cancer were male with a mean age of 67.3 years. A total of 81 patients had clinical T2N0 and 9 patients had T1N0 with standardized uptake value greater than 10. Mean tumor size was 4.3 ± 1.7 cm, and mean standardized uptake value was 13.5 ± 6.8. One patient (1.1%) had occult metastases detected at mediastinoscopy. A total of 86 patients underwent surgical resection; 4 patients (4.6%) were upstaged to pN2, and 18 patients (21%) were upstaged to pN1. Of 90 patients with clinically staged N0 lung cancer by positron emission tomography/computed tomography, 5.6% (5) were upstaged to pN2 and 20% (18) were upstaged to pN1 (total nodal upstaging = 25.6%).

CONCLUSIONS

Mediastinoscopy seems to have limited utility in these patients with T1 and T2 clinically staged N0 by positron emission tomography/computed tomography. Selective use of mediastinoscopy is recommended, along with thorough mediastinal lymph node evaluation in all patients at the time of lung cancer resection.

The efficacy of restaging endobronchial ultrasound in patients with non-small cell lung cancer after preoperative therapy

BACKGROUND

Patient selection for surgery after neoadjuvant therapy for locally advanced non-small cell lung cancer depends on accurate restaging of mediastinal (N2) lymph nodes. Our objective is to assess the accuracy of endobronchial ultrasound (EBUS) for restaging N2 lymph nodes after neoadjuvant therapy.

METHODS

This is a retrospective review of patients with non-small cell lung cancer who underwent staging with repeat computed tomography and positron emission tomography and had restaging EBUS for sampling of N2 lymph nodes. Endobronchial ultrasound was performed for suspicious nodes in stations 2R, 2L, 4R, 4L, and 7. Selected patients who were N2-negative underwent thoracotomy with complete thoracic lymphadenectomy.

RESULTS

There were 32 patients with N2 disease who underwent preoperative chemotherapy or radiotherapy, or both, and subsequently had restaging EBUS. There were 3 patients who had recalcitrant N2 nodal disease detected by EBUS. There were 5 patients with pulmonary function or comorbidities that were prohibitive for surgery. Of the remaining 24 patients with negative EBUS, 3 underwent mediastinoscopy and 2 had recalcitrant N2 disease. The remaining 22 patients underwent thoracotomy. Recalcitrant N2 disease was noted in 1 patient at thoracotomy in the EBUS-assessable nodal stations. Thus EBUS was falsely negative in 3 patients. The sensitivity and negative predictive value of restaging EBUS were 50% and 88%, respectively.

CONCLUSIONS

Restaging EBUS is relatively accurate at predicting the absence of metastatic disease in N2 mediastinal lymph node in patients who underwent neoadjuvant therapy for non-small cell lung cancer.

Accuracy of positron emission tomography in identifying hilar (N1) lymph node involvement in non-small cell lung cancer: Implications for stereotactic body radiation therapy

PURPOSE

To assess the efficacy of preoperative positron emission tomography (PET) to stage the ipsilateral hilum in resected non-small cell lung cancer (NSCLC).

METHODS AND MATERIALS

All patients who underwent surgery for NSCLC between 1995 and 2008 were evaluated. Patients who underwent preoperative PET imaging at our institution and had hilar nodal sampling were included. Those whose primary tumors extended to the hilum or who received preoperative chemotherapy or radiation therapy were excluded. All PET studies were interpreted by an attending nuclear medicine radiologist and were scored as positive or negative in the hilum or peribronchial area based on visual analysis alone. A 2-sided Fisher exact test compared patient subgroups.

RESULTS

During the time interval, 1558 patients underwent surgery for NSCLC, of whom 484 were eligible for this analysis. The ipsilateral hilum was positive on preoperative PET in 107 patients. The median number of N1 lymph nodes sampled was 4 (range, 1-31). Positive ipsilateral N1 lymph nodes were identified pathologically in 91 patients (19%). Among the 91 patients with involved N1 lymph nodes, 40 were PET positive resulting in a sensitivity of 44%. Among 393 patients without pathologic involvement of hilar lymph nodes, 326 were PET negative resulting in a specificity of 83%. The positive predictive and negative predictive values were 37% and 86%, respectively.

CONCLUSIONS

Positron emission tomography appears to have limitations in staging the ipsilateral hilar lymph nodes. Invasive sampling is appropriate if treatment would differ based on the nodal status.

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

BACKGROUND

This study was performed to assess the incidence, survival, and risk factors associated with unsuspected pathologic N2 disease in patients with resectable clinical N0-1 non-small cell lung cancer.

METHODS

Between January 2002 and December 2010, 1,821 patients with clinical N0-1 non-small cell lung cancer underwent pulmonary resection and mediastinal lymph node dissection. Clinical outcomes and risk factors for pathologic N2 disease were retrospectively analyzed for this cohort.

RESULTS

Unsuspected pathologic N2 disease was identified in 196 patients (10.8%). The most common type of resection was lobectomy (81.6%). Adjuvant therapy was administered in 177 patients (90.3%). The median follow-up time was 28 months (range, 1 to 101 months). N2 involvement was single-station in 121 (66.8%) and multiple-station in 65 (33.2%). The 5-year overall and disease-free survival rates were 56.1% and 35.0%, respectively. The 5-year survival rates of single-station and multiple-station N2 were 66.6% and 36.4%, respectively (p < 0.001). Adenocarcinoma, clinical N1, tumor size (>3 cm), and a right middle lobe tumor were identified as independent risk factors for unsuspected multiple-station N2 disease by multivariate analysis. Incidence of unsuspected multiple-station N2 disease in low-risk classes (aggregate score, 0 to ≤2) was only 5.5%.

CONCLUSIONS

The incidence of unsuspected N2 disease in our cohort was similar to that of previous reports. Survival outcomes were favorable for unsuspected single-station N2 disease but were poor for unsuspected multiple-station N2 disease. Clinical N0-1 non-small cell lung cancer patients with risk class of low score for unsuspected multiple-station N2 disease can be exempted from aggressive mediastinal staging.

Increasing the accuracy of 18F-FDG PET/CT interpretation of "mildly positive" mediastinal nodes in the staging of non-small cell lung cancer

INTRODUCTION

The aim of this study was to identify radiological factors that may reduce false-positive results and increase diagnostic accuracy when staging the mediastinum of patients with non-small cell lung carcinoma (NSCLC).

METHODS

This was a retrospective, interdisciplinary, per-node analysis study. We included patients with NSCLC and mediastinal nodes with an SUV max in the range of 2.5-4.0 on PET-CT. We hypothesized that the greatest number of false positive cases would occur in this cohort of patients.

RESULTS

A total of 92 mediastinal lymph nodes were analyzed in 44 patients. Mediastinal disease (N2/N3) was histologically confirmed in 15 of 44 patients and in 34 of 92 lymph nodes; positive predictive value of 37% and false positive rate of 63%. Lymph node SUV max, tumor size, ratio of node SUV max to tumor SUV max (SUVn/SUVp), and ratio of node SUV max to node size (SUV n/SADn) were significantly higher in true positive cases. Using a threshold of 0.3 for SUV node/tumor and 3 for SUV node/size yielded sensitivities of 91% and 71% and specificities of 71% and 69% respectively for the detection of mediastinal disease. Using both ratios in combination resulted in a sensitivity of 65% and a specificity of 88%. Concurrent benign lung disease was observed significantly more frequently in false-positive cases.

CONCLUSION

SUVn/SUVpt and SUVn/SADn may be complimentary to conventional visual interpretation and SUV max measurement in the assessment of mediastinal disease in patients with NSCLC.

Invasive and noninvasive advances in the staging of lung cancer

Accurate staging of lung cancer is crucial to ensure the validity of lung cancer clinical research efforts and constitutes the cornerstone of the management of affected patients. The last decade has witnessed unprecedented technological advances allowing for more accurate and less invasive staging. In general, these techniques should be viewed as complementary rather than competitive, and indications, contraindications, and limitations of all staging techniques should be fully understood by providers involved with lung cancer patients. Noninvasive imaging techniques include chest computed tomography (CT) and positron emission tomography (PET). Invasive techniques can be nonsurgical such as needle-based techniques (endobronchial or endoscopic ultrasound) or surgical (mediastinoscopy and variants). The necessary multidisciplinary approach to lung cancer patients dictates that all stakeholders be familiar with the benefits and limitations of these newer techniques.

Heterogeneity Analysis of (18)F-FDG Uptake in Differentiating Between Metastatic and Inflammatory Lymph Nodes in Adenocarcinoma of the Lung: Comparison with Other Parameters and its Application in a Clinical Setting

PURPOSE

Lymph node (LN) characterization is crucial in determining the stage and treatment decisions in patient with lung cancer. Although (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) has a higher diagnostic accuracy in LN characterization than anatomical imaging, differentiating between metastatic and inflammatory LNs is still challenging because both could show high (18)F-FDG uptake. The purpose of this study was to assess if the heterogeneity of the (18)F-FDG uptake could help in differentiating between inflammatory and metastatic LNs in lung cancer, and to compare with other parameters.

METHODS

A total of 44 patients with adenocarcinoma of the lung, who underwent preoperative (18)F-FDG PET/CT without having any previous treatments and were revealed to have (18)F-FDG-avid LNs, were enrolled. There were 52 pathology-proven metastatic lymph nodes in 26 subjects. The pathology-proven metastatic LNs were compared with 42 pathology-proven inflammatory/benign LNs in 18 subjects. The coefficient of variation (CV) was used to assess the heterogeneity of (18)F-FDG uptake by dividing the standard deviation of standardized uptake value (SUV) by mean SUV. The volume of interest was manually drawn based on the combined CT images of (18)F-FDG PET/CT (no threshold is used). Comparisons were made with the maximum standardized uptake values (SUVmax), visual assessment of (18)F-FDG uptake, longest diameter, and maximum Hounsfield units (HUmax).

RESULTS

Metastatic lymph nodes tended to have higher CVs than the inflammatory LNs. The mean CV of metastatic LNs (0.30 ± 0.08; range: 0.08-0.55) was higher than that of inflammatory LNs (0.17 + 0.06; range, 0.07-0.32; P < 0.0001). On receiver operating characteristic (ROC) curve analysis, the area under curve was 0.901, and using 0.20 as cut-off value, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 88.5 %, 76.2 %, 82.2 %, 84.3, and 83.0 % respectively. Accuracy of CV was slightly higher than SUVmax and diameter, but significantly higher than visual assessment and HUmax.

CONCLUSIONS

In patients with adenocarcinoma of the lung having no prior treatments, metastatic LNs showed more heterogeneous (18)F-FDG uptake than inflammatory LNs. Measuring the CV of the SUV derived from a manual volume of interest (VOI) can be helpful in determining metastatic LN of adenocarcinoma of the lung. Including diagnostic criteria of CV into the diagnostic approach can increase the accuracy of mediastinal node status.

Methods for staging non-small cell lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Correctly staging lung cancer is important because the treatment options and prognosis differ significantly by stage. Several noninvasive imaging studies and invasive tests are available. Understanding the accuracy, advantages, and disadvantages of the available methods for staging non-small cell lung cancer is critical to decision-making.

METHODS

Test accuracies for the available staging studies were updated from the second iteration of the American College of Chest Physicians Lung Cancer Guidelines. Systematic searches of the MEDLINE database were performed up to June 2012 with the inclusion of selected meta-analyses, practice guidelines, and reviews. Study designs and results are summarized in evidence tables.

RESULTS

The sensitivity and specificity of CT scanning for identifying mediastinal lymph node metastasis were approximately 55% and 81%, respectively, confirming that CT scanning has limited ability either to rule in or exclude mediastinal metastasis. For PET scanning, estimates of sensitivity and specificity for identifying mediastinal metastasis were approximately 77% and 86%, respectively. These findings demonstrate that PET scanning is more accurate than CT scanning, but tissue biopsy is still required to confirm PET scan findings. The needle techniques endobronchial ultrasound-needle aspiration, endoscopic ultrasound-needle aspiration, and combined endobronchial ultrasound/endoscopic ultrasound-needle aspiration have sensitivities of approximately 89%, 89%, and 91%, respectively. In direct comparison with surgical staging, needle techniques have emerged as the best first diagnostic tools to obtain tissue. Based on randomized controlled trials, PET or PET-CT scanning is recommended for staging and to detect unsuspected metastatic disease and avoid noncurative resections.

CONCLUSIONS

Since the last iteration of the staging guidelines, PET scanning has assumed a more prominent role both in its use prior to surgery and when evaluating for metastatic disease. Minimally invasive needle techniques to stage the mediastinum have become increasingly accepted and are the tests of first choice to confirm mediastinal disease in accessible lymph node stations. If negative, these needle techniques should be followed by surgical biopsy. All abnormal scans should be confirmed by tissue biopsy (by whatever method is available) to ensure accurate staging. Evidence suggests that more complete staging improves patient outcomes.