Occult metastases in lymph nodes predict survival in resectable non-small-cell lung cancer: report of the ACOSOG Z0040 trial

Predicting Regional Recurrence and Prognosis in Stereotactic Body Radiation Therapy-Treated Clinical Stage I Non-small Cell Lung Cancer Using a Radiomics Model Constructed With Surgical Data

PURPOSE

Risk stratification of regional recurrence (RR) is clinically important in the design of adjuvant treatment and surveillance strategies in patients with clinical stage I non-small cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT). This study aimed to develop a radiomics model predicting occult lymph node metastasis (OLNM) using surgical data and apply it to the prediction of RR in SBRT-treated early-stage NSCLC patients.

METHODS AND MATERIALS

Patients with clinical stage I NSCLC who underwent curative surgery with systematic lymph node dissection from January 2013 to December 2018 (the training cohort) and from January 2019 to December 2020 (the validation cohort) were included. A preoperative computed tomography-based radiomics model, a clinical feature model, and a fusion model predicting OLNM were constructed. The performance of the 3 models was quantified and compared in the training and validation cohorts. Subsequently, the radiomics model was used to predict RR in a cohort of consecutive SBRT-treated early-stage NSCLC patients from 2 academic medical centers.

RESULTS

A total of 769 patients were included. Eight computed tomography features were identified in the radiomics model, achieving areas under the curves of 0.85 (95% CI, 0.81-0.89) and 0.83 (95% CI, 0.80-0.88) in the training and validation cohorts, respectively. Nevertheless, adding clinical features did not improve the performance of the radiomics model. With a median follow-up of 40.0 (95% CI, 35.2-44.8) months, 32 of the 213 patients in the SBRT cohort developed RR and those in the high-risk group based on the radiomics model had a higher cumulative incidence of RR (P < .001) and shorter regional recurrence-free survival (P = .02), progression-free survival (P = .004) and overall survival (P = .006) than those in the low-risk group.

CONCLUSIONS

The radiomics model based on pathologically confirmed data effectively identified patients with OLNM, which may be useful in the risk stratification among SBRT-treated patients with clinical stage I NSCLC.

Can cell-free DNA (cfDNA) in pleural lavage serve as a predictive and prognostic biomarker among surgically treated Stage I-III a nonsmall cell lung cancer (NSCLC)? A pilot study

BACKGROUND AND OBJECTIVES

The role of cell-free DNA (cfDNA) in operable nonsmall cell lung cancer (NSCLC) is unclear. This study was aimed to evaluate the feasibility for identification of cfDNA in pleural lavage fluid and its correlation with plasma in resectable NSCLCs.

METHODS

Consecutively resected NSCLCs were evaluated for cfDNA levels in preoperative plasma (PLS1), intraoperative pleural-lavage (PLV) and postoperative (at 1 month) plasma sample (PLS2). CfDNA was isolated and measured quantitatively by qPCR in a TaqMan probe-detection approach using the human β-actin gene as the amplifying target.

RESULTS

All (n = 34) except one were negative for malignant cells in PLV cytology. CfDNA could be isolated from all the three samples (PLS1, PLV, and PLS2) successfully in each patient. The median cfDNA levels in PLS1, PLV and PLS2 were 118 ng/mL (IQR 61-158), 167 ng/mL (IQR 59.9-179.9) and 103 ng/mL (IQR 66.5-125.4) respectively. The median follow-up was 34.1 months (IQR 25.2-41.6). A significant overall-survival (OS) and disease-free survival (DFS) were recorded for patients with cfDNA level cut-offs at 125, 170, and 100 ng/mL, respectively for PLS1, PLV, and PLS2. Patients with raised cfDNA in PLS1 (>125 ng/mL) and PLV (>170 ng/mL) had significantly poorer 2-year OS, p = 0.005 and p = 0.012, respectively. The hazards (OS) were also higher for those with raised cfDNA in PLV (HR = 5.779, 95% CI = 1.162-28.745, p = 0.032). PLV (>170 ng/mL) had increased pleural recurrences (p = 0.021) and correlated significantly with poorer DFS at 2-years (p = 0.001) with increased hazards (HR = 9.767, 95% CI = 2.098-45.451, p = 0.004). Multivariable analysis suggested higher cfDNA in PLV as a poor prognostic factor for both OS and DFS.

CONCLUSIONS

Among patients with operable NSCLC, it is feasible to identify cfDNA in pleural lavage and correlate PLV cfDNA with pleural recurrences and outcomes.

Clustered Circulating Tumor Cells as a Predictor of Adjuvant-chemotherapy Efficacy in Lung Cancer

BACKGROUND

Surrogate markers of minimal residual disease primarily include cell-free tumor DNA and circulating tumor cells. Cell-free tumor DNA might aid precise decision-making regarding who should receive adjuvant chemotherapy. However, there are no relevant reports on circulating tumor cells. Therefore, we aimed to verify whether perioperative clustered circulating tumour cells identification is a predictor of therapeutic efficacy in non-small cell lung cancer adjuvant chemotherapy.

METHODS

Circulating tumor cells were diagnosed under light microscopy using a size selection method in 128 patients with clinical stage I/II non-small cell lung cancer around surgery. The main endpoint was recurrence-free survival, and the effect of adjuvant chemotherapy was verified in both groups based on perioperative clustered circulating tumor cell identification.

RESULTS

In total, 49 and 79 patients were included in the clustered circulating tumor cell-positive and clustered circulating tumor cell-negative patient groups, respectively. In the clustered circulating tumor cell-positive patient group, adjuvant chemotherapy was performed in 18 patients (2-year recurrence-free survival rate, 71.8%). However, the 2-year recurrence-free survival rate was 36.3% in 31 patients who did not receive adjuvant chemotherapy (P < .01). In the clustered circulating tumor cell-negative patient group, adjuvant chemotherapy was provided in 11 patients (2-year recurrence-free survival rate, 90.9%). However, 68 patients did not receive adjuvant chemotherapy (2-year recurrence-free survival rate, 94.9%) (not significant).

CONCLUSIONS

In surgical cases of clinical stage I/II non-small cell lung cancer, patients with perioperative clustered circulating tumor cells had a poor prognosis, but adjuvant chemotherapy improved their prognosis.

Survival benefit of adjuvant chemotherapy after resection of Stage I lung adenocarcinoma containing micropapillary components

BACKGROUND

The usefulness of postoperative adjuvant chemotherapy (ACT) for patients with stage I lung adenocarcinoma with micropapillary (MIP) components remains unclear. We analyzed whether postoperative ACT could reduce recurrence in patients with stage I lung adenocarcinoma with MIP components, thereby improving their overall survival (OS) and disease-free survival (DFS).

METHODS

Data for patients with pathologically confirmed stage I lung adenocarcinoma with MIP components from January 2012 to December 2018 were retrospectively analyzed. OS and DFS were analyzed in groups and subgroups.

RESULTS

Overall, 259 patients were enrolled. Patients who received ACT in stage IA showed significantly better survival than did those with no-adjuvant chemotherapy (NACT); (5-year OS 89.4% vs. 73.6%, p < 0.001; 5-year DFS 87.2% vs. 66.0%, p = 0.008). A difference was also observed for in-stage IB patients (5-year OS 82.0% vs. 51.8%, p = 0.001; 5-year DFS 76.0% vs. 41.11 %, p = 0.004). In subgroup analysis based on the proportion of MIP components, patients with 1%-5% MIP components had a significantly better prognosis in the ACT group than in the NACT group (5-year OS 82.4% vs. 66.0%, p = 0.005; 5-year DFS 76.5% vs. 49.1%, p = 0.032). A similar difference was observed for patients with MIP ≥5% (5-year OS 80.7% vs. 47.8%, p = 0.009; 5-year DFS 73.11% vs. 43.5%, p = 0.007).

CONCLUSION

Among patients with stage I lung adenocarcinoma with MIP components, those who received ACT showed significant survival benefits compared to those without ACT. Patients with lung adenocarcinoma with MIP components could benefit from ACT when the MIP was ≥1%.

Impact of the Number of Harvested Lymph Nodes on Long-Term Survival in Node-Negative Non-Small-Cell Lung Cancer: Based on Clinical Stage But Not Pathological Stage

BACKGROUND

We aimed to investigate the impact of the number of harvested lymph nodes (LNs) on the overall survival (OS) and disease-free survival (DFS) of patients with clinical node-negative (cN0) non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

A total of 2247 patients with cN0 NSCLC between 2001 and 2014 were included. Scatter plots of hazard ratios from Cox proportional hazards models against the number of harvested LNs were created, and curves were fitted using a LOWESS smoother. Chow test was used to determine the cut-off points for the optimal number of harvested LNs. Long-term survival was compared between groups divided by the cut-off points.

RESULTS

The increasing numbers of harvested LNs and N2 level LNs were independent factors favoring OS and DFS. Seventeen LNs and 10 N2 level LNs were determined as the optimal cut-off points. The patients with ≥17 harvested LNs had a better OS (P = .001) and DFS (P = .002), while the patients with ≥10 harvested N2 level LNs also had a better OS (P < .001) and DFS (P = .001). The increasing numbers of harvested LNs and N2 level LNs were independent prognostic factors associated with prolonged OS and DFS only in patients with clinical T2 (cT2) NSCLC.

CONCLUSIONS

The increasing numbers of harvested LNs and N2 level LNs were associated with better OS and DFS in cN0 NSCLC patients that were suitable for lobectomies. At least 17 LNs and 10 N2 level LNs were required to be harvested, especially in cT2 patients.

Development of a minimally invasive endoscopic technique for excisional biopsy of the axillary lymph nodes in dogs

OBJECTIVE

To develop and describe a minimally invasive technique for excisional biopsy of the axillary lymph nodes in dogs.

STUDY DESIGN

Descriptive cadaver and clinical case series.

ANIMALS

Four canine cadavers and three clinical patients.

METHODS

A 3D computed tomographic reconstruction of the canine axilla was used to identify an optimal avenue of approach to the lymph nodes. This approach was refined using endoscopic techniques in four cadavers (six procedures) and potential surgical hazards, landmarks, and the surgical time required for excisional biopsy of the nodes was recorded. The procedure was then performed in three clinical cases.

RESULTS

Axillary lymph node removal was achieved using an endoscopic technique with surgical times of 58 and 35 minutes in two of three clinical cases. The third case required conversion to an open approach after endoscopic identification of the node. No major complications were encountered.

CONCLUSION

Excisional biopsy of the axillary lymph nodes can be performed successfully using a minimally invasive technique in the dog. Further investigation in clinical cases is needed to determine the risks and complications of this procedure.

CLINICAL SIGNIFICANCE

Minimally invasive excisional biopsy of the axillary lymph nodes in dogs can be performed and may have a role in assisting with staging and local disease control in oncologic cases.

Systematic review and meta-analysis of the prognostic impact of lymph node micrometastasis and isolated tumour cells in patients with stage I-IIIA non-small cell lung cancer

Lymph node micrometastases could be one of the reasons for the high recurrence rate after complete surgical resection in stage I-IIIA non-small cell lung cancer (NSCLC). The standard evaluation of a single haematoxylin and eosin (H&E) slide of a paraffin-embedded section of a lymph node is insufficient for the detection of micrometastases, and there is a need for additional histopathological evaluation. The association of lymph node micrometastases with survival remains as yet unresolved. The aim of this systematic review and meta-analysis is to investigate if lymph node micrometastases and isolated tumour cells in patients with stage I-IIIA NSCLC, detected with multiple sectioning and/or immunohistochemistry (IHC) and/or reverse transcriptase polymerase chain reaction (RT-PCR), are associated with overall survival (OS) and disease-free survival (DFS) after surgical resection. We performed a meta-analysis of time-to-event outcomes based on 15 articles using ancillary techniques to detect micrometastases. We extracted the OS and DFS every 3-6 months after surgery, for patients with and without occult lymph node micrometastasis, from the survival curves published in each article. These data were used to reconstruct OS and DFS for 'micrometastasis' and 'no micrometastasis' groups. Based on all included studies that used IHC, serial sectioning, or RT-PCR, we found a 5-year OS of 55% (micrometastasis) vs. 75% (no micrometastasis), and a 5-year DFS of 53% (micrometastasis) vs. 75% (no micrometastasis). Patients with stage I-IIIA NSCLC with lymph node micrometastases detected by ancillary histopathological and molecular techniques have a significantly poorer OS and DFS compared to patients without lymph node micrometastases.

Identification of Metastatic Lymph Nodes Using Indocyanine Green Fluorescence Imaging

Indocyanine green (ICG) has been used to detect several types of tumors; however, its ability to detect metastatic lymph nodes (LNs) remains unclear. Our goal was to determine the feasibility of ICG in detecting metastatic LNs. We established a mouse model and evaluated the potential of ICG. The feasibility of detecting metastatic LNs was also evaluated in patients with lung or esophageal cancer, detected with computed tomography (CT) or positron-emission tomography (PET)/CT, and scheduled to undergo surgical resection. Tumors and metastatic LNs were successfully detected in the mice. In the clinical study, the efficacy of ICG was evaluated in 15 tumors and fifty-four LNs with suspected metastasis or anatomically key regional LNs. All 15 tumors were successfully detected. Among the fifty-four LNs, eleven were pathologically confirmed to have metastasis; all eleven were detected in ICG fluorescence imaging, with five in CT and seven in PET/CT. Furthermore, thirty-four LNs with no signals were pathologically confirmed as nonmetastatic. Intravenous injection of ICG may be a useful tool to detect metastatic LNs and tumors. However, ICG is not a targeting agent, and its relatively low fluorescence makes it difficult to use to detect tumors in vivo. Therefore, further studies are needed to develop contrast agents and devices that produce increased fluorescence signals.

Sentinel Lymph Node in Non-Small Cell Lung Cancer: Assessment of Feasibility and Safety by Near-Infrared Fluorescence Imaging and Clinical Consequences

Occult micrometastases can be missed by routine pathological analysis. Mapping of the pulmonary lymphatic system by near-infrared (NIR) fluorescence imaging can identify the first lymph node relay. This sentinel lymph node (SLN) can be analyzed by immunohistochemistry (IHC), which may increase micrometastasis detection and improve staging. This study analyzed the feasibility and safety of identifying SLNs in thoracic surgery by NIR fluorescence imaging in non-small cell lung cancer (NSCLC). This was a prospective, observational, single-center study. Eighty adult patients with suspected localized stage NSCLC (IA1 to IIA) were included between December 2020 and May 2022. All patients received an intraoperative injection of indocyanine green (ICG) directly in the peri tumoural area or by electromagnetic navigational bronchoscopy (ENB). The SLN was then assessed using an infrared fluorescence camera. SLN was identified in 60 patients (75%). Among them, 36 SLNs associated with a primary lung tumor were analyzed by IHC. Four of them were invaded by micrometastases (11.1%). In the case of pN0 SLN, the rest of the lymphadenectomy was cancer free. The identification of SLNs in thoracic surgery by NIR fluorescence imaging seems to be a feasible technique for improving pathological staging.

Pathologic node-negative lung cancer: Adequacy of lymph node yield and a tool to assess the risk of occult nodal disease

INTRODUCTION

Accurate lymph node (LN) staging is crucial for prognostication in NSCLC. Diagnosis of pN0 disease is based on the absence of positive LNs, irrespective of the number of LNs excised, and is thus susceptible to sampling error. Tumors that are assumed to be pN0 may in fact be understaged. We developed a tool to quantify the risk of occult nodal disease (OND) among patients with pN0 NSCLC in terms of the number of LNs examined.

METHODS

Patients treated surgically for stage I-III primary NSCLC between 2004 and 2014 (n = 49,356) were extracted from the Surveillance, Epidemiology, and End Results database. The probability of missing a positive node in terms of the number of LNs examined was modeled using a beta-binomial model. A mathematical tool was then used to calculate the negative predictive value (NPV) corresponding to the number of LNs examined. Ranging from 0 to 100%, higher NPV reflects greater confidence in the pN0 diagnosis and a lower probability of OND.

RESULTS

The median number of LNs examined was 7 for N0, 10 for N1/N2, and 8 for N3 disease. The probability of missing a positive node decreased as LNs examined increased. Additionally, higher T stage required more LNs to confirm an N0 diagnosis. After accounting for false-negative diagnoses, the prevalence of node-positive disease was readjusted from 16% to 22% among patients with T1 disease. According to our tool, with 10 LNs examined, the NPV was 85% (15% probability of OND) for a patient with T3 disease, compared with 95% (5% probability of OND) for a patient with T1 disease.

CONCLUSIONS

Accurate pN0 diagnosis depends on the number of LNs examined. The proposed tool offers the ability to quantify, in a patient-specific manner, the confidence in a diagnosis of node-negative disease on the basis of the number of LNs examined.

A germline SNP in BRMS1 predisposes patients with lung adenocarcinoma to metastasis and can be ameliorated by targeting c-fos

About 50% of patients with early-stage, surgically resected lung cancer will develop distant metastasis. There remains an unmet need to identify patients likely to develop recurrence and to design innovative therapies to decrease this risk. Two primary isoforms of BRMS1, v1 and v2, are present in humans. Using next-generation sequencing of BRMS1 on matched human noncancerous lung tissue and non-small cell lung cancer (NSCLC) specimens, we identified single-nucleotide polymorphism (SNP) rs1052566 that results in an A273V mutation of BRMS1v2. This SNP is homozygous (BRMS1v2^A273V/A273V) in 8% of the population and correlates with aggressive biology in lung adenocarcinoma (LUAD). Mechanistically, we show that BRMS1v2 A273V abolishes the metastasis suppressor function of BRMS1v2 and promotes robust cell invasion and metastases by activation of c-fos-mediated gene-specific transcriptional regulation. BRMS1v2 A273V increases cell invasion in vitro and increases metastases in both tail-vein injection xenografts and LUAD patient-derived organoid (PDO) intracardiac injection metastasis in vivo models. Moreover, we show that BRMS1v2 A273V fails to interact with nuclear Src, thereby activating intratumoral c-fos in vitro. Higher c-fos results in up-regulation of CEACAM6, which drives metastases in vitro and in vivo. Using both xenograft and PDO metastasis models, we repurposed T5224 for treatment, a c-fos pharmacologic inhibitor investigated in clinical trials for arthritis, and observed suppression of metastases in BRMS1v2^A273V/A273V LUAD in mice. Collectively, we elucidate the mechanism of BRMS1v2^A273V/A273V-induced metastases and offer a putative therapeutic strategy for patients with LUAD who have this germline alteration.

18F-FDG PET/CT radiomics nomogram for predicting occult lymph node metastasis of non-small cell lung cancer

Purpose

To investigate the ability of a PET/CT-based radiomics nomogram to predict occult lymph node metastasis in patients with clinical stage N0 non-small cell lung cancer (NSCLC).

Materials and methods

This retrospective study included 228 patients with surgically confirmed NSCLC (training set, 159 patients; testing set, 69 patients). ITKsnap3.8.0 was used for image(CT and PET images) segmentation, AK version 3.2.0 was used for radiomics feature extraction, and Python3.7.0 was used for radiomics feature screening. A radiomics model for predicting occult lymph node metastasis was established using a logistic regression algorithm. A nomogram was constructed by combining radiomics scores with selected clinical predictors. Receiver operating characteristic (ROC) curves were used to verify the performance of the radiomics model and nomogram in the training and testing sets.

Results

The radiomics nomogram comprising six selected features achieved good prediction efficiency, including radiomics characteristics and tumor location information (central or peripheral), which demonstrated good calibration and discrimination ability in the training (area under the ROC curve [AUC] = 0.884, 95% confidence interval [CI]: 0.826-0.941) and testing (AUC = 0.881, 95% CI: 0.8031-0.959) sets. Clinical decision curves demonstrated that the nomogram was clinically useful.

Conclusion

The PET/CT-based radiomics nomogram is a noninvasive tool for predicting occult lymph node metastasis in NSCLC.

Comparison of recurrence risk between patients with clinically node-positive and -negative stage I non-small cell lung cancer following surgery: A propensity score matching analysis

Background

Identifying patients with stage I non‐small cell lung cancer (NSCLC) at increased risk of tumor recurrence following surgery remains a major challenge. The current study aimed to compare disease‐free survival (DFS) rates after surgery between patients with clinically node‐positive (cN+) and ‐negative (cN0) stage I NSCLC.

Methods

Patients with pathological stage I resected NSCLC were identified from the lung cancer database of Changhua Christian Hospital in Taiwan. Patients with clinical N status 1 or 2 and pathological N status 0 were identified as the cN+/pN0 cohort, whereas others were identified as the cN0/pN0 cohort. Propensity score matching (PSM) was used to balance the baseline characteristics between both cohorts. Kaplan–Meier method and Cox proportional hazards model were used to evaluate DFS.

Results

From January 2010 to July 2019, 754 eligible patients were enrolled into the study, among whom 41 (5.4%) were cN+/pN0. The median follow‐up time was 43.4 months. Before PSM, the 5‐year DFS rate was 79.0% and 90.3% in cN+/pN0 and cN0/pN0 cohorts (log‐rank test, p = 0.009), respectively. After a 1:4 PSM, multivariate analysis showed that the cN+/pN0 cohort still had a poorer DFS compared to the cN0/pN0 cohort in (hazard ratio, 3.17; p = 0.040).

Conclusion

Among patients with stage I resected NSCLC, cN+ patients had a worse DFS compared to cN0 patients. Surgeons should therefore consider more aggressive adjuvant therapy or frequent follow‐up in patients with surgically resected stage I NSCLC with cN+ status.

A Radiomics Nomogram for Preoperative Prediction of Clinical Occult Lymph Node Metastasis in cT1-2N0M0 Solid Lung Adenocarcinoma

Background

Clinical occult lymph node metastasis (cOLNM) means that the lymph node is negatively diagnosed by preoperative computed tomography (CT), but has been proven to be positive by postoperative pathology. The aim of this study was to establish and validate a nomogram based on radiomics features for the preoperative prediction of cOLNM in early-stage solid lung adenocarcinoma patients.

Methods

A total of 244 patients with clinical T1-2N0M0 solid lung adenocarcinoma who underwent preoperative contrast-enhanced chest CT were divided into a primary group (n = 160) and an independent validation group from another hospital (n = 84). The records of 851 radiomics features of each primary tumor were extracted. LASSO analysis was used to reduce the data dimensionality and select features. Multivariable logistic regression was utilized to identify independent predictors of cOLNM and develop a predictive nomogram. The performance of the predictive model was assessed by its calibration and discrimination. Decision curve analysis (DCA) was performed to estimate the clinical usefulness of the nomogram.

Results

The predictive model consisted of a clinical factor (CT-reported tumor size) and a radiomics feature (Rad-score). The nomogram presented good discrimination, with a C-index of 0.782 (95% CI, 0.768–0.796) in the primary cohort and 0.813 (95% CI, 0.787–0.839) in the validation cohort, and good calibration. DCA showed that the radiomics nomogram was clinically useful.

Conclusion

This study develops and validates a nomogram that incorporates clinical and radiomics factors. It can be tailored for the individualized preoperative prediction of cOLNM in early-stage solid lung adenocarcinoma patients.

Clinicopathological and computed tomographic features associated with occult lymph node metastasis in patients with peripheral solid non-small cell lung cancer

OBJECTIVES

To investigate the value of combining clinicopathological characteristics with computed tomographic (CT) features of tumours for predicting occult lymph node metastasis (OLNM) in peripheral solid non-small cell lung cancer (PS-NSCLC).

METHODS

The study included 478 NSCLC clinically N0 (cN0) patients who underwent lobectomy and systemic lymph node dissection from January 2014 to August 2019. Patients were classified into OLNM and negative lymph node metastasis (NLNM) groups. The CT features of non-metastatic and metastatic lymph nodes with a largest short-diameter > 5 mm were compared in the OLNM group. Thereafter, the clinicopathological characteristics and CT morphological features of tumours were compared between both groups. Multivariable logistic regression analysis and receiver-operating characteristic curve were developed.

RESULTS

CT images detected 103 metastatic and 705 non-metastatic lymph nodes, and no significant differences in CT features of lymph nodes were found in all 161 OLNM patients (P > 0.05). For both groups, sex, carcinoembryonic antigen and pathological type differed significantly (all P < 0.05), while tumour size, necrosis, calcification, vascular convergence, pleural involvement, and the shortest interval of tumour-pleura differed significantly on CT images (all P < 0.05). Multivariable logistic regression analysis showed that carcinoembryonic antigen > 5.00 ng/ml, adenocarcinoma, absence of vascular convergence, and pleural involvement of Type II (one linear or cord-like pleural tag or tumour abut to the pleura with a broad base observed on both lung and mediastinal window images) were independent predicting factors of OLNM.

CONCLUSIONS

CT findings of lymph nodes can provide limited value and integrating clinicopathological characteristics with the CT morphological features of tumours is helpful in predicting OLNM in patients with PS-NSCLC.

Porfimer Sodium Versus PS785 for Photodynamic Therapy (PDT) of Lung Cancer Xenografts in Mice

BACKGROUND

Lung cancer is the greatest cause of cancer mortality in the United States, necessitating ongoing improvements in current treatment techniques. Photodynamic therapy (PDT) involves the interaction between a photosensitizer, light, and oxygen. The resulting release of reactive oxygen species causes tumor necrosis. It has been used as an endoscopic technique for the palliation of lung cancer. Porfimer sodium (Photofrin) is the only Food and Drug Administration-approved photosensitizer for PDT but has limited depth of penetration and produces prolonged skin phototoxicity. Multiple newer photosensitizers are in development, including PS785. The effectiveness of PS785 was compared with porfimer sodium in the treatment of human lung cancer xenografts in mice.

METHODS

Human non-small cell lung cancer (NSCLC) xenografts were established in severe combined immunodeficient mice and grouped into small (3-5 mm) and large tumors (6-10 mm). PS785 or porfimer sodium was administered intravenously, and PDT was executed at 24, 48, or 72 h after injection. The primary endpoint was the delay of tumor regrowth after PDT.

RESULTS

Porfimer sodium and PS785 produced statistically similar delays of tumor regrowth after PDT when small tumors were treated at 24 and 48 h. At 72 h, PS785 performed better in small tumors. However, for large tumors, PS785 produced no delay in tumor regrowth at any time point.

CONCLUSIONS

PS785 and porfimer sodium were able to effectively treat NSCLC to a depth of ≤5 mm. However, porfimer sodium was more effective in treating NSCLC tumors to a depth of 6-10 mm. Further efforts are required to produce photosensitizers that will facilitate PDT of larger tumors.

Circulatory shear stress induces molecular changes and side population enrichment in primary tumor-derived lung cancer cells with higher metastatic potential

Cancer is a leading cause of death and disease worldwide. However, while the survival for patients with primary cancers is improving, the ability to prevent metastatic cancer has not. Once patients develop metastases, their prognosis is dismal. A critical step in metastasis is the transit of cancer cells in the circulatory system. In this hostile microenvironment, variations in pressure and flow can change cellular behavior. However, the effects that circulation has on cancer cells and the metastatic process remain unclear. To further understand this process, we engineered a closed-loop fluidic system to analyze molecular changes induced by variations in flow rate and pressure on primary tumor-derived lung adenocarcinoma cells. We found that cancer cells overexpress epithelial-to-mesenchymal transition markers TWIST1 and SNAI2, as well as stem-like marker CD44 (but not CD133, SOX2 and/or NANOG). Moreover, these cells display a fourfold increased percentage of side population cells and have an increased propensity for migration. In vivo, surviving circulatory cells lead to decreased survival in rodents. These results suggest that cancer cells that express a specific circulatory transition phenotype and are enriched in side population cells are able to survive prolonged circulatory stress and lead to increased metastatic disease and shorter survival.

Tumor-to-liver standard uptake ratio using fluorine-18 fluorodeoxyglucose positron emission tomography computed tomography effectively predict occult lymph node metastasis of non-small cell lung cancer patients

OBJECTIVES

We aimed to investigate predictive factors of occult lymph node metastasis and to explore the diagnostic value of various standardized uptake value (SUV) parameters using fluorine-18 fluorodeoxyglucose (F-FDG) positron emission tomography computed tomography (PET/CT) in predicting occult lymph node metastasis of clinical N0 non-small cell lung cancer patients.

METHODS

We retrospectively analyzed PET/computed tomography parameters of tumor and clinical data of 124 clinical N0 non-small cell lung cancer patients who underwent both preoperative F-FDG PET/computed tomography and anatomical pulmonary resection with systematic lymph node dissections. The SUVmax, SUVmean, metabolic total volume, and total lesion glycolysis of the primary tumor was automatically measured on the PET/computed tomography workstation. Standardized uptake ratio (SUR) were derived from tumor standardized uptake value divided by blood SUVmean (B-SUR) or liver SUVmean (L-SUR), respectively.

RESULTS

According to postoperative pathology, 19 (15%) were diagnosed as occult lymph node metastasis among 124 clinical N0 non-small cell lung cancer patients. On univariate analysis, carcinoembryonic antigen, cytokeratin 19 fragment, lobulation, and all PET parameters were associated with occult lymph node metastasis. The area under the receiver operating characteristic curve, sensitivity, and negative predictive value of L-SURmax were the highest among all PET parameters (0.778, 94.7%, and 98.4%, respectively). On multivariate analysis, carcinoembryonic antigen, cytokeratin 19 fragment, and L-SURmax were independent risk factors for predicting occult lymph node metastasis. Compared to L-SURmax alone and the combination of carcinoembryonic antigen and cytokeratin 19 fragment, the model consisting of three independent risk factors achieved a greater area under the receiver operating characteristic curve (0.901 vs. 0.778 vs. 0.780, P = 0.021 and 0.0141).

CONCLUSIONS

L-SURmax showed the most powerful predictive performance than the other PET parameters in predicting occult lymph node metastasis. The combination of three independent risk factors (carcinoembryonic antigen, cytokeratin 19 fragment, and L-SURmax) can effectively predict occult lymph node metastasis in clinical N0 non-small cell lung cancer patients.

Molecular Nodal Restaging Based on CEACAM5, FGFR2b and PTPN11 Expression Adds No Relevant Clinical Information in Resected Non-Small Cell Lung Cancer

BACKGROUND

The relapse rate in non-small cell lung cancer (NSCLC) is high, even in localized disease, suggesting that the current approach to pathological staging is insufficiently sensitive to detect occult micrometastases present in resected lymph nodes. Therefore, we aimed to determine the prognostic value of the expression of embryonic molecular markers in histologically-negative lymph nodes of completely-resected NSCLC.

METHODS

76 completely-resected NSCLC patients were included: 60 pN0 and 16 pN1. Primary tumors and 347 lymph node were studied. CEACAM5, FGFR2b, and PTPN11 expression levels were evaluated through mRNA analysis using real-time RT-qPCR assay. Statistical analyses included the Kruskal-Wallis test, Kaplan Meier curves, and log-rank tests.

RESULTS

CEACAM5 expression levels were scored as high in of 90 lymph nodes (26%). The molecular-positive lymph nodes lead to the restaging of 37 (62%) pN0 patients as molecular N1 or N2 and 5 (31%) pN1 cases were reclassified as molecular-positive N2. Surprisingly, molecular-positive patients associated with a better OS (overall survival, p = 0,04). FGFR2b overexpression was observed in 41 (12%) lymph nodes leading to the restaging of 17 patients (22%). Again a trend was observed toward a better DFS (disease-free survival) in the restaged patients (p = 0,09). Accordingly, high expression levels of CEACAM5 or FGFR2b in the primary were related to better DFS (p = 0,06; p < 0,02, respectively).

CONCLUSION

Molecular nodal restaging based on expression levels of CEACAM5 and/or FGFR2b, does not add relevant clinical information to pathological staging of NSCLC likely related to the better prognosis of their overexpression in primary tumors.

A Circle RNA Regulatory Axis Promotes Lung Squamous Metastasis via CDR1-Mediated Regulation of Golgi Trafficking

Lung squamous carcinoma (LUSC) is a highly metastatic disease with a poor prognosis. Using an integrated screening approach, we found that miR-671-5p reduces LUSC metastasis by inhibiting a circular RNA (circRNA), CDR1as. Although the putative function of circRNA is through miRNA sponging, we found that miR-671-5p more potently silenced an axis of CDR1as and its antisense transcript, cerebellar degeneration related protein 1 (CDR1). Silencing of CDR1as or CDR1 significantly inhibited LUSC metastases and CDR1 was sufficient to promote migration and metastases. CDR1, which directly interacted with adaptor protein 1 (AP1) complex subunits and coatomer protein I (COPI) proteins, no longer promoted migration upon blockade of Golgi trafficking. Therapeutic inhibition of the CDR1as/CDR1 axis with miR-671-5p mimics reduced metastasis in vivo. This report demonstrates a novel role for CDR1 in promoting metastasis and Golgi trafficking. These findings reveal an miRNA/circRNA axis that regulates LUSC metastases through a previously unstudied protein, CDR1. SIGNIFICANCE: This study shows that circRNA, CDR1as, promotes lung squamous migration, metastasis, and Golgi trafficking through its complimentary transcript, CDR1.

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.

Comparative Age-Based Prospective Multi-Institutional Observations of 12,367 Patients Enrolled to the American College of Surgeons Oncology Group (ACOSOG) Z901101 Trials (Alliance)

BACKGROUND

The risk of surgery, particularly for older cancer patients with serious, extensive comorbidities, can make this otherwise curative modality precarious. Leveraging data from the American College of Surgeons Oncology Group, this study sought to characterize age-based comparative demographics, adverse event rates, and study completion rates to define how best to conduct research in older cancer patients.

METHODS

This study relied on clinical data from 21 completed studies to assess whether older patients experienced more grade 3 or worse adverse events and were more likely to discontinue study participation prematurely than their younger counterparts.

RESULTS

The study enrolled 12,367 patients. The median age was 60 years, and 36% of the patients were 65 years of age or older. Among 4008 patients with adverse event data, 1067 (27%) had experienced a grade 3 or worse event. The patients 65 years or older had higher rates of grade 3 or worse adverse events compared to younger patients [32% vs. 24%; odds ratio (OR), 1.5; 95% confidence interval (CI), 1.3-1.7; p < 0.0001]. This association was not observed in multivariate analyses. The study protocol was completed by 97% of the patients. No association was observed between age and trial completion (OR 0.8; 95% CI 0.7-1.1; p = 0.14). Only the older gastrointestinal cancer trial patients were less likely to complete their studies compared to younger patients (OR 0.50; 95% CI 0.30-0.70; p < 0.0001).

CONCLUSION

Despite higher rates of adverse events, the older patients typically completed the study protocol, thereby contributing relevant data on how best to render care to older cancer patients and affirming the important role of enrolling these patients to surgical trials.

Stereotactic Body Radiation Therapy for Operable Early-Stage Lung Cancer: Findings From the NRG Oncology RTOG 0618 Trial

Importance

Stereotactic body radiation therapy (SBRT) has become a standard treatment for patients with medically inoperable early-stage lung cancer. However, its effectiveness in patients medically suitable for surgery is unclear.

Objective

To evaluate whether noninvasive SBRT delivered on an outpatient basis can safely eradicate lung cancer and cure selected patients with operable lung cancer, obviating the need for surgical resection.

Design, Setting, and Participants

Single-arm phase 2 NRG Oncology Radiation Therapy Oncology Group 0618 study enrolled patients from December 2007 to May 2010 with median follow-up of 48.1 months (range, 15.4-73.7 months). The setting was a multicenter North American academic and community practice cancer center consortium. Patients had operable biopsy-proven peripheral T1 to T2, N0, M0 non-small cell tumors no more than 5 cm in diameter, forced expiratory volume in 1 second (FEV1) and diffusing capacity greater than 35% predicted, arterial oxygen tension greater than 60 mm Hg, arterial carbon dioxide tension less than 50 mm Hg, and no severe medical problems. The data analysis was performed in October 2014.

Interventions

The SBRT prescription dose was 54 Gy delivered in 3 18-Gy fractions over 1.5 to 2.0 weeks.

Main Outcomes and Measures

Primary end point was primary tumor control, with survival, adverse events, and the incidence and outcome of surgical salvage as secondary end points.

Results

Of 33 patients accrued, 26 were evaluable (23 T1 and 3 T2 tumors; 15 [58%] male; median age, 72.5 [range, 54-88] years). Median FEV1 and diffusing capacity of the lung for carbon monoxide at enrollment were 72.5% (range, 38%-136%) and 68% (range, 22%-96%) of predicted, respectively. Only 1 patient had a primary tumor recurrence. Involved lobe failure, the other component defining local failure, did not occur in any patient, so the estimated 4-year primary tumor control and local control rate were both 96% (95% CI, 83%-100%). As per protocol guidelines, the single patient with local recurrence underwent salvage lobectomy 1.2 years after SBRT, complicated by a grade 4 cardiac arrhythmia. The 4-year estimates of disease-free and overall survival were 57% (95% CI, 36%-74%) and 56% (95% CI, 35%-73%), respectively. Median overall survival was 55.2 months (95% CI, 37.7 months to not reached). Protocol-specified treatment-related grade 3, 4, and 5 adverse events were reported in 2 (8%; 95% CI, 0.1%-25%), 0, and 0 patients, respectively.

Conclusions and Relevance

As given, SBRT appears to be associated with a high rate of primary tumor control, low treatment-related morbidity, and infrequent need for surgical salvage in patients with operable early-stage lung cancer.

Trial Registration

ClinicalTrials.gov Identifier: NCT00551369.

Incidence and clinical relevance of non-small cell lung cancer lymph node micro-metastasis detected by staging endobronchial ultrasound-guided transbronchial needle aspiration

Background

Approximately twenty percent of lymph node (LN) negative non-small cell lung cancer (NSCLC) patients who undergo curative intent surgery have pan-cytokeratin immunohistochemistry (IHC)-detectable occult micro-metastases (MMs) in resected LNs. The presence of the MMs in NSCLC is associated worsened outcomes. As a substantial proportion of NSCLC LN staging is conducted using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), we sought to determine the frequency of detection of occult MMs in EBUS-TBNA specimens and to evaluate the impact of MMs on progression-free and overall survival.

Methods

We performed retrospective IHC staining for pan-cytokeratin of EBUS-TBNA specimens previously deemed negative by a cytopathologist based on conventional hematoxylin and eosin staining. The results were correlated with clinical variables, including survival outcomes.

Results

Of 887 patients screened, 44 patients were identified meeting inclusion criteria with sufficient additional tissue for testing. With respect to the time of the EBUS-TBNA procedure, 52% of patients were clinical stage I, 34% clinical stage II, and clinical 14% stage IIIa NSCLC. Three patients (6.8%) were found to have cytokeratin positive MMs. All 3 MMs detected were at N2 LN stations. The presence of MMs was associated with significantly decreased progression-free (median 210 vs. 1,293 days, P=0.0093) and overall survival (median 239 vs. 1,120 days, P=0.0357).

Conclusions

Occult LN MMs can be detected in EBUS-TBNA specimens obtained during staging examinations and are associated with poor clinical outcomes. If prospectively confirmed, these results have significant implications for EBUS-TBNA specimen analyses and possibly for the NSCLC staging paradigm.

Prediction of occult lymph node metastasis using SUV, volumetric parameters and intratumoral heterogeneity of the primary tumor in T1-2N0M0 lung cancer patients staged by PET/CT

OBJECTIVE

The aim of this study was to identify whether PET/CT-related metabolic parameters of the primary tumor could predict occult lymph node metastasis (OLM) in patients with T1-2N0M0 NSCLC staged by ¹⁸F-FDG PET/CT.

METHODS

215 patients with clinical T1-2N0M0 (cT1-2N0M0) NSCLC who underwent both preoperative FDG PET/CT and surgical resection with the systematic lymph node dissection were included in the retrospective study. Heterogeneity factor (HF) was obtained by finding the derivative of the volume-threshold function from 40 to 80% of the maximum standardized uptake value (SUVmax). Univariate and multivariate stepwise logistic regression analyses were used to identify these PET parameters and clinicopathological variables associated with OLM.

RESULTS

Statistically significant differences were detected in sex, tumor site, SUVmax, mean SUV (SUVmean), metabolic tumor volume (MTV), total lesion glycolysis and HF between patients with adenocarcinoma (ADC) and squamous cell carcinoma (SQCC). OLM was detected in 36 (16.7%) of 215 patients (ADC, 27/152 = 17.8% vs. SQCC, 9/63 = 14.3%). In multivariate analysis, MTV (OR = 1.671, P = 0.044) in ADC and HF (OR = 8.799, P = 0.023) in SQCC were potent associated factors for the prediction of OLM. The optimal cutoff values of 5.12 cm³ for MTV in ADC, and 0.198 for HF in SQCC were determined using receiver operating characteristic curve analysis.

CONCLUSIONS

In conclusion, MTV was an independent predictor of OLM in cT1-2N0M0 ADC patients, while HF might be the most powerful predictor for OLM in SQCC. These findings would be helpful in selecting patients who might be considered as candidates for sublobar resection or new stereotactic ablative radiotherapy.

Clinical Significance of Molecular Micrometastasis in the Sentinel Lymph Node of Early-stage Non-Small Cell Lung Cancer Patients

OBJECTIVES

Metastatic affectation of lymph node is the main prognostic factor in localized lung cancer. A pathologic study of the obtained samples, even after adequate lymphadenectomy, showed tumor relapses for 20% of stage I patients after oncological curative surgery. We evaluated the prognostic value of molecular micrometastasis in the sentinel lymph node of patients with early-stage lung cancer.

PATIENTS AND METHODS

The sentinel node was marked immediately after performing thoracotomy by peritumorally injecting 0.25 mCi of nanocoloid of albumin (Nanocol1) labeled with Tc-99m in 0.3 mL. Guided by a Navigator1 gammagraphic sensor, we proceeded to its resection. The RNA of the tissue was extracted, and the presence of genes CEACAM5, BPIFA1, and CK7 in mRNA was studied. The significant association between the presence of micrometastasis, clinicopathologic characteristics, and patients' outcome was assessed.

RESULTS

Eighty-nine stage I-II non-small cell lung cancer patients were included in the study. Of the 89 analyzed sentinel lymph nodes, 44 (49.4%) were positive for CK7, 24 (26.9%) for CEACAM5, and 17 (19.1%) for BPIFA1, whereas 10 (11.2%) were positive for the 3 analyzed genes. A survival analysis showed no significant relation between the presence of molecular micrometastasis in the sentinel node and patients' progression.

CONCLUSIONS

The molecular analysis of the sentinel node in patients with early-stage lung cancer shows node affectation in cases staged as stage I/II by hematoxylin-eosin or an immunohistochemical analysis. However, this nodal affectation was not apparently related to patients' outcome.

[Research Progress of Lymph Node Micrometastasis in Non-small Cell Lung Cancer]

The incidence and mortality of lung cancer rank top in China. One important factor is the occurrence of metastasis. With the development of science technology, the effect of surgical treatment on lung cancer is improved. Moreover, the use of targeted therapy has achieved a new height for the treatment of lung cancer. However, the recurrence rate remains high even the tumor was completely resected at early stage. The occurrence of lymph node micrometastasis is considered as one of the plausible explanations. The difficulty indetecting micrometastasis has been greatly reduced. Although studies dig deeper into the lymph node micrometastasis, there are still some controversies including the selection of surgical procedures, the pathological staging and prognosis about patients with lymph node micrometastasis. This review manages to generalize the latest research progress of lymph node micrometastasis.
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Prediction of Occult Lymph Node Metastasis Using Tumor-to-Blood Standardized Uptake Ratio and Metabolic Parameters in Clinical N0 Lung Adenocarcinoma

PURPOSE

We aimed to investigate whether the tumor-to-blood SUV ratio (SUR) and metabolic parameters of F-FDG uptake could predict occult lymph node metastasis (OLM) in clinically node-negative (cN0) lung adenocarcinoma.

MATERIALS AND METHODS

We retrospectively reviewed 157 patients with cN0 lung adenocarcinoma who underwent both preoperative F-FDG PET/CT and surgical resection with the systematic lymph node dissection. The SUVmax, SUVmean, MTV, and total lesion glycolysis (TLG) of the primary tumor was measured on the PET/CT workstation. SURmax, SURmean, and TLGsur were derived from each of them divided by descending aorta SUVmean. These PET parameters and clinicopathological variables were analyzed for OLM.

RESULTS

In our study, OLM was detected in 31 (19.7%) of 157 patients. Significantly higher values of tumor size, SUVmax, SUVmean, MTV, TLGsuv, SURmax, SURmean, and TLGsur were found in patients with OLM. In receiver operating characteristic curve analysis, the optimal cutoff values of the above parameters were 29.50, 4.38, 2.45, 6.37, 44.13, 5.30, 1.86, and 28.24, respectively. The multivariate analysis showed that TLGsur (odds ratio, 1.024; P = 0.002) was the most potent associated factor for the prediction of OLM in cN0 lung adenocarcinoma.

CONCLUSIONS

TLGsur showed the most powerful predictive performance than the other PET parameters for the prediction of OLM in cN0 lung adenocarcinoma. This normalized volumetric parameter would be helpful in selection of sublobar resection or aggressive tailored treatments in patients with cN0 lung adenocarcinoma.

Prognostic roles of lymph node micrometastasis in non-small cell lung cancer

OBJECTIVE

This study aimed to confirm the prognostic roles of lymph node (LN) micrometastasis (LNMM) in non-small cell lung cancer (NSCLC) through a meta-analysis.

METHODS

This study included 2026 NSCLC cases without detection of LN metastasis in histologic examination. We investigated the detection rate of LNMM in early-stage NSCLC and analyzed the correlation between LNMM and the rates of recurrence and survival.

RESULTS

The range of detection rates of LNMM was 3.8-68.8% in the eligible studies. The detection rate of LNMM in early-stage NSCLC was 25.3% (95% confidence interval [CI] 19.8-31.6%). In subgroup analysis based on detection method, polymerase chain reaction method had higher detection rate than immunohistochemistry (33.7%, 95% CI 25.5-43.0% vs. 23.1%, 95% CI 18.0-29.0%). The presence of LNMM was significantly correlated with a higher recurrence rate (odds ratio 3.913, 95% CI 1.595-9.600, P=0.003). In addition, there were significant correlations between LNMM and worse overall and disease-free survival rates (hazard ratio [HR] 2.345, 95% CI 1.863-2.951, and HR 1.606, 95% CI 1.170-2.206, respectively).

CONCLUSION

Taken together, our results showed that LNMM was detected in 25.3% of NSCLCs without nodal disease through ancillary test. In addition, the presence of LNMM was significantly correlated with a higher recurrence rate and worse survival rates in early-stage NSCLC.

Frequency and clinical impact of preoperative circulating tumor cells in resectable non-metastatic lung adenocarcinomas

OBJECTIVES

Despite successful surgery, 30-50% of patients with resectable non-small cell lung cancer develop tumor recurrence within 5 years of surgery.

MATERIALS AND METHODS

In this prospective study, we performed CTC enumerations in 40 patients with non-metastatic lung adenocarcinoma (NMLA) using a size-based microfilter. Additionally, cfDNA isolated from plasma was analyzed in 35 out of 40 patients.

RESULTS

CTCs were identified in 15 out of 40 patients (37.5%) with a range of 1-44 cells, whereas mutated cfDNA was only detected in 3 out of 35 patients (8.6%). Disease-free survival (DFS) was significantly associated with CTC positivity (log-rank p=0.025), grading (log-rank p=0.019), tumor stage (log-rank p=0.025) and lymph node status (log-rank p=0.029). Multivariate analysis, including tumor stage and grading, showed that CTC positivity (p=0.006), grading (0.039) and tumor stage (p=0.022) were independently associated with DFS.

CONCLUSION

Our study found that microfilter-based CTC enumeration in NMLA patients is an independent predictor of worse DFS. The used NGS-based cfDNA characterization had limited sensitivity to be clinically informative in our study cohort. CTC assessment before surgery can thus identify NMLA patients at high risk of disease recurrence.

Relationship of Lymph Node Micrometastasis and Micropapillary Component and Their Joint Influence on Prognosis of Patients With Stage I Lung Adenocarcinoma

This study aimed to investigate the relationship between lymph node micrometastasis and histologic patterns of adenocarcinoma, with a particular focus on their joint effect on prognosis. We retrospectively reviewed 235 patients with stage I adenocarcinoma from January 2009 to December 2009. Lymph node micrometastasis was evaluated by immunohistochemical staining for cytokeratin (AE1/AE3) and thyroid transcription factor-1. A logistic regression model was applied to confirm the predictive factors of micrometastasis. Survival analysis was performed to evaluate the effect of micrometastasis on prognosis. Lymph node micrometastasis was observed in 35 patients (15%). Patients with micrometastasis had significantly worse recurrence-free survival (P<0.001) and overall survival (P<0.001) compared with those without micrometastasis. Micropapillary component was confirmed as an independent predictor of increased frequency of micrometastasis (P<0.001). Among 62 patients with adenocarcinoma with a micropapillary component, 23 (37%) had lymph node micrometastasis. Micropapillary-positive/micrometastasis-positive patients had significantly worse survival compared with micropapillary-positive/micrometastasis-negative patients (RFS, P=0.039; OS, P=0.002) and micropapillary-negative patients (recurrence-free survival, P<0.001; overall survival, P<0.001). Moreover, the presence of micrometastasis correlated with a higher risk of locoregional recurrence (P=0.031) rather than distant recurrence (P=0.456) in micropapillary-positive patients. In summary, lymph node micrometastasis was more frequently observed in adenocarcinoma with a micropapillary component. Moreover, lymph node micrometastasis could provide helpful prognostic information in patients with resected stage I lung adenocarcinoma with a micropapillary component; thus, immunohistochemical detection of micrometastatic tumor cells in lymph nodes should be recommended.

Loss of β-arrestin-2 and Activation of CXCR2 Correlate with Lymph Node Metastasis in Non-small Cell Lung Cancer

Background: Although β-arrestin-2 (β-arr2) and CXCR2 have been shown to affect various malignant tumors, their exact roles in lung cancer remain unclear. We investigated expression of β-arr2 and CXCR2 in patients with non-small cell lung cancer (NSCLC) and their correlation with lymph node metastasis and prognosis.

Methods: We reviewed medical records of 136 patients with NSCLC who underwent surgical resection, and assessed their specimens immunohistochemically for expression of β-arr2 and CXCR2 in primary tumors and metastatic lymph nodes (MLNs), respectively.

Results: High β-arr2 expression was seen in 63 specimens (46.3%), and was significantly associated with male patients (P=0.011), squamous cell carcinoma (P=0.003), and lymph node metastasis (P<0.001). High CXCR2 expression was seen in 62 specimens (45.6%), and was significantly correlated only with lymph node metastasis (P<0.001). Expression of β-arr2 was significantly lower at MLNs than at primary lesions (Z=-2.315; P=0.021; Wilcoxon signed-rank), whereas CXCR2 expression was significantly higher in MLNs than in primary lesions (Z=-3.712; P<0.001; Wilcoxon signed-rank). No relationship was seen between β-arr2 and CXCR2 expression in primary lesions (r=-0.065, P=0.548; Spearman rank coefficient), but they were inversely related in MLNs (r=-0.263, P=0.012). Kaplan-Meier survival curve was shown that low β-arr2 and high CXCR2 expressions was associated with poor survival (log-rank: χ²=5.926, P=0.015).

Conclusions: β-arr2 may promote lymph node metastasis in NSCLC by modulating CXCR2 activation.

A Clinicopathological Study of Small Lung Adenocarcinoma 1 cm or Less in Size: Emphasis on Histological Subtypes Associated With Lymph Node Metastasis and Recurrence

BACKGROUND

The aim of this study was to assess the prognostic significance of the newly proposed 2015 World Health Organization (WHO) lung adenocarcinoma classification for patients undergoing resection for small (≤1 cm) lung adenocarcinoma. We also investigated whether lobectomy offers prognostic advantage over limited resection for this category of tumors.

METHODS

A retrospective study of resected pulmonary adenocarcinomas (n = 83) in sizes 1 cm or less was carried out in which comprehensive histologic subtyping was assessed according to the 2015 WHO classification on all consecutive patients who underwent lobectomy or limited resection between 2008 and 2015. Correlation between clinicopathologic parameters and the difference in recurrence between lobectomy and limited resection group was evaluated.

RESULTS

Our data show that the proposed 2015 WHO classification identifies histological subsets of small lung adenocarcinomas with significant differences in prognosis. No recurrence was noted for patients with adenocarcinoma in situ and minimally invasive adenocarcinoma. Invasive adenocarcinomas displayed high heterogeneity and the presence of micropapillary component of 5% or greater in adenocarcinomas was significantly related to lymph node involvement and recurrence ( P < .001). Stage Ia patients who underwent limited resection had a higher risk of recurrence than did those treated by lobectomy (P < .05).

CONCLUSIONS

Application of the 2015 WHO classification identifies patients with adenocarcinoma in situ and minimally invasive adenocarcinoma had excellent prognosis. Micropapillary pattern was associated with high risk of lymph node metastasis and recurrence.

Circulating tumor cells in peripheral and pulmonary venous blood predict poor long-term survival in resected non-small cell lung cancer patients

We tested the hypothesis that circulating tumor cells (CTCs) in preoperative peripheral blood (PPB) and intraoperative pulmonary venous blood (IPVB) could predict poor long-term survival in resected non-small cell lung cancer (NSCLC) patients. CTCs were separated from blood using magnetic beads coated with antibodies against epithelial-cell adhesion molecule (EpCAM) via magnetic-activated cell sorting (MACS). CTCs were quantified with fluorescence-labeled antibodies against pan-cytokeratin through flow cytometry. CTCs were quantified in PPB and IPVB in 23 consecutive stage I-IIIA patients with resected NSCLC. The association between CTCs and prognosis in these patients was evaluated after a 5-year follow-up. In NSCLC patients, outcomes were assessed according to CTC levels at surgery. NSCLC patients identified as high-risk groups exhibited >5 CTCs/15 mL in PPB and >50 CTCs/15 mL in IPVB. Univariate Cox proportional-hazards regression analysis showed that the CTC count in PPB or IPVB was an independent risk factor for tumor-free surivival (TFS) and overall survival (OS). The high-risk group of patients had a shorter median TFS (22 months vs. >60.0 months, p < 0.0012) and shorter OS (27 months vs. >60 months, p < 0.0015). The number of CTCs counted in PPB and IPVB was an independent risk factor for TFS and OS in resected NSCLC patients.

Adjuvant Chemotherapy Is Associated With Improved Survival in Locally Invasive Node Negative Non-Small Cell Lung Cancer

BACKGROUND

The objectives of this study are to explore factors that are associated with use of adjuvant chemotherapy and to evaluate its impact on overall survival in node-negative patients who undergo lung and chest wall resection for non-small cell lung cancer (NSCLC).

METHODS

Patients who underwent concomitant lung and chest wall resection for NSCLC were abstracted from the National Cancer Database. Clinical, pathologic, treatment, and follow-up data were obtained. Patients with pathologic nodal metastases or patients who received any radiation treatment were excluded, and the cohort was dichotomized based on administration of adjuvant postoperative chemotherapy.

RESULTS

Between 1998 and 2010, 824 patients met the inclusion criteria. This cohort exclusively consisted of pT3 N0 patients who did not receive any induction treatment or adjuvant radiation treatment. Adjuvant chemotherapy was administered to 255 patients (31%). Patients in the chemotherapy group were younger and had shorter inpatient length of stay. Both groups had similar comorbidities, tumor size, unplanned readmission rate, and incomplete resection rate. In multivariable analysis, younger age and shorter length of stay were associated with a greater likelihood of receiving adjuvant chemotherapy. Adjuvant chemotherapy was associated with improved survival (hazard ratio 0.74, 95% CI: 0.6 to 0.9), whereas increasing age, white race, length of inpatient stay, tumor size, and residual tumor were independently associated with greater risk of death.

CONCLUSIONS

Patients who undergo lobectomy with chest wall resection for locally advanced NSCLC should be strongly considered for postoperative adjuvant chemotherapy even in the absence of nodal disease. Actual selection of patients for adjuvant chemotherapy is affected by perioperative factors.

Nodal recurrence after stereotactic body radiotherapy for early stage non-small cell lung cancer: Incidence and proposed risk factors

Stereotactic body radiotherapy (SBRT) is an alternative to surgery for patients with early stage non-small cell lung cancer (NSCLC) who are inoperable due to comorbid disease or who refuse surgery. SBRT results in an excellent local control rate of more than 90%, which is comparable to surgery, while short and long-term overall toxicity is low. Surgically treated patients are often more extensively staged pre-operatively, e.g. with endobronchial ultrasound and/or mediastinoscopy, and typically undergo intra-operative lymph node dissection or sampling. Occult nodal metastases (ONM), detected by lymph node dissection, have been shown to increase the incidence of regional recurrence (RR) after surgery, which is associated with poor outcome. In patients undergoing SBRT, however, definite pathological nodal staging is lacking and so other ways to identify patients at high risk for ONM and RR are desirable. The aim of this systematic review is to summarize the incidence of, and risk factors for, RR after SBRT and compare these to those after surgery. The available evidence shows the incidence of RR after SBRT or surgery to be comparable, despite more elaborate pre- and intra-operative lymph node evaluation in surgical patients. However, the fact that this finding is based on mostly retrospective studies in which the majority of patients treated with SBRT were inoperable, needs to be taken into consideration. For now, there is no evidence that inoperable clinical stage I patients with no indication of pathological lymph nodes on PET/CT will benefit from more invasive lymph node staging prior to SBRT.

A novel technique for tumor localization and targeted lymphatic mapping in early-stage lung cancer

OBJECTIVE

To investigate safety and feasibility of navigational bronchoscopy (NB)-guided near-infrared (NIR) localization of small, ill-defined lung lesions and sentinel lymph nodes (SLN) for accurate staging in patients with non-small cell lung cancer (NSCLC).

METHODS

Patients with known or suspected stage I NSCLC were enrolled in a prospective pilot trial for lesion localization and SLN mapping via NB-guided NIR marking. Successful localization, SLN detection rates, histopathologic status of SLN versus overall nodes, and concordance to initial clinical stage were measured. Ex vivo confirmation of NIR⁺ SLNs and adverse events were recorded.

RESULTS

Twelve patients underwent NB-guided marking with indocyanine green of lung lesions ranging in size from 0.4 to 2.2 cm and located 0.1 to 3 cm from the pleural surface. An NIR⁺ "tattoo" was identified in all cases. Ten patients were diagnosed with NSCLC and 9 SLNs were identified in 8 of the 10 patients, resulting in an 80% SLN detection rate. SLN pathologic status was 100% sensitive and specific for overall nodal status with no false-negative results. Despite previous nodal sampling, one patient was found to have metastatic disease in the SLN alone, a 12.5% rate of disease upstaging with NIR SLN mapping. SLN were detectable for up to 3 hours, allowing time for obtaining a tissue diagnosis and surgical resection. There were no adverse events associated with NB-labeling or indocyanine green dye itself.

CONCLUSIONS

NB-guided NIR lesion localization and SLN identification was safe and feasible. This minimally invasive image-guided technique may permit the accurate localization and nodal staging of early stage lung cancers.