Survival comparison of adenosquamous, squamous cell, and adenocarcinoma of the lung after lobectomy

Differences in postoperative prognosis between early-stage lung adenocarcinoma and squamous cell carcinoma

BACKGROUND

Although prognosis and treatments differ between small-cell- and nonsmall-cell carcinoma, comparisons of the histological types of NSCLC are uncommon. Thus, we investigated the oncological factors associated with the prognosis of early-stage adenocarcinoma and squamous cell carcinoma.

METHODS

We retrospectively compared the clinicopathological backgrounds and postoperative outcomes of patients diagnosed with pathological stage I-IIA adenocarcinoma and squamous cell carcinoma primary lung cancer completely resected at our department from January 2007 to December 2017. Multivariable Cox regression analysis for overall survival and recurrence-free survival was performed.

RESULTS

The median follow-up duration was 55.2 months. The cohort consisted of 532 adenocarcinoma and 96 squamous cell carcinoma patients. A significant difference in survival was observed between the two groups, with a 5-year overall survival rate of 90% (95% confidence interval 86-92%) for adenocarcinoma and 77% (95% CI 66-85%) for squamous cell carcinoma (P < 0.01) patients. Squamous cell carcinoma patients had worse outcomes compared to adenocarcinoma patients in stage IA disease, but there were no significant differences between the two groups in stage IB or IIA disease. In multivariate analysis, invasion diameter was associated with overall survival in adenocarcinoma (hazard ratio 1.76, 95% confidence interval 1.36-2.28), but there was no such association in squamous cell carcinoma (hazard ratio 0.73, 95% confidence interval 0.45-1.14).

CONCLUSIONS

The importance of tumor invasion diameter in postoperative outcomes was different between adenocarcinoma and squamous cell carcinoma. Thus, it is important to consider that nonsmall-cell carcinoma may have different prognoses depending on the histological type, even for the same stage.

First insight about the ability of specific glycerophospholipids to discriminate non-small cell lung cancer subtypes

Introduction: Discrimination between adenocarcinoma (ADC) and squamous cell carcinoma (SCC) subtypes in non-small cell lung cancer (NSCLC) patients is a significant challenge in oncology. Lipidomics analysis provides a promising approach for this differentiation. Methods: In an accompanying paper, we explored oxPCs levels in a cohort of 200 NSCLC patients. In this research, we utilized liquid chromatography coupled with mass spectrometry (LC-MS) to analyze the lipidomics profile of matching tissue and plasma samples from 25 NSCLC patients, comprising 11 ADC and 14 SCC cases. This study builds upon our previous findings, which highlighted the elevation of oxidised phosphatidylcholines (oxPCs) in NSCLC patients. Results: We identified eight lipid biomarkers that effectively differentiate between ADC and SCC subtypes using an untargeted approach. Notably, we observed a significant increase in plasma LPA 20:4, LPA 18:1, and LPA 18:2 levels in the ADC group compared to the SCC group. Conversely, tumour PC 16:0/18:2, PC 16:0/4:0; CHO, and plasma PC 16:0/18:2; OH, PC 18:0/20:4; OH, PC 16:0/20:4; OOH levels were significantly higher in the ADC group. Discussion: Our study is the first to report that plasma LPA levels can distinguish between ADC and SCC patients in NSCLC, suggesting a potential role for LPAs in NSCLC subtyping. This finding warrants further investigation into the mechanisms underlying these differences and their clinical implications.

Estimating the risk of brain metastasis for patients newly diagnosed with cancer

BACKGROUND

Brain metastases (BM) affect clinical management and prognosis but limited resources exist to estimate BM risk in newly diagnosed cancer patients. Additionally, guidelines for brain MRI screening are limited. We aimed to develop and validate models to predict risk of BM at diagnosis for the most common cancer types that spread to the brain.

METHODS

Breast cancer, melanoma, kidney cancer, colorectal cancer (CRC), small cell lung cancer (SCLC), and non-small cell lung cancer (NSCLC) data were extracted from the National Cancer Database to evaluate for the variables associated with the presence of BM at diagnosis. Multivariable logistic regression (LR) models were developed and performance was evaluated with Area Under the Receiver Operating Characteristic Curve (AUC) and random-split training and testing datasets. Nomograms and a Webtool were created for each cancer type.

RESULTS

We identify 4,828,305 patients from 2010-2018 (2,095,339 breast cancer, 472,611 melanoma, 407,627 kidney cancer, 627,090 CRC, 164,864 SCLC, and 1,060,774 NSCLC). The proportion of patients with BM at diagnosis is 0.3%, 1.5%, 1.3%, 0.3%, 16.0%, and 10.3% for breast cancer, melanoma, kidney cancer, CRC, SCLC, and NSCLC, respectively. The average AUC over 100 random splitting for the LR models is 0.9534 for breast cancer, 0.9420 for melanoma, 0.8785 for CRC, 0.9054 for kidney cancer, 0.7759 for NSCLC, and 0.6180 for SCLC.

CONCLUSIONS

We develop accurate models that predict the BM risk at diagnosis for multiple cancer types. The nomograms and Webtool may aid clinicians in considering brain MRI at the time of initial cancer diagnosis.

Surgical Options for Resectable Lung Adenosquamous Carcinoma: A Propensity Score-Matched Analysis

Background

Surgery is the primary treatment option for Lung adenosquamous carcinoma (ASC) patients. However, no study compares the benefits of lobectomy and sublobar resection in ASC patients.

Methods

A total of 1379 patients in the Surveillance, epidemiology, and End Results (SEER) database and 466 patients in Shanghai Pulmonary Hospital (SPH) were enrolled. Survival benefits were evaluated after possible confounders were eliminated by propensity score matching (PSM).

Results

After 1:3 PSM, 463 SEER database patients and 244 SPH patients were enrolled. Lobectomy was associated with better overall survival (OS) and disease-free survival (DFS) than sublobar resection for ASC patients (5-year OS of SEER: 46.9% vs. 33.3%, P =0.017; 5-year OS of SPH: 35.0% vs. 16.4%, P =0.002; 5-year DFS of SPH: 29.5% vs. 14.8%, P =0.002). Similar results were observed in stage I patients. Univariate and multivariate Cox regression analyses showed that sublobar resection was an adverse prognostic factor independently (SEER: HR: 1.40, 95%CI: 1.08-1.81, P =0.012; SPH: HR: 1.73, 95%CI: 1.11-2.70, P =0.015). Subgroup analysis showed that all of the ASC patient subtypes tended to benefit more from lobectomy than sublobar resection.

Conclusions

Lobectomy remains the primary option for ASC patients compared to sublobar resection, including stage I.

Clinicopathological characteristics and prognosis of resectable lung adenosquamous carcinoma: a population-based study of the SEER database

OBJECTIVE

Adenosquamous carcinoma is a rare subtype of non-small cell lung cancer characterized by aggressive behavior, with combination of adenocarcinoma and squamous cell carcinoma components. The clinicopathological characteristics and prognosis of resectable adenosquamous carcinoma are incompletely understood and this study aimed to depict those in a large population.

METHODS

A total of 805 adenosquamous carcinoma, 7875 squamous cell carcinoma and 23 957 adenocarcinoma patients who underwent lobectomy or sublobectomy were queried from the Surveillance, Epidemiology, and End Results database (2010-17). Clinicopathological characteristics of adenosquamous carcinoma patients were compared with those of squamous cell carcinoma and adenocarcinoma patients. Prognostic factors were identified by univariable and multivariable Cox regression analyses. Propensity score matching was applied to reduce confounding effects.

RESULTS

Adenosquamous carcinoma was associated with higher pleural invasion incidence and poorer differentiation compared with squamous cell carcinoma or adenocarcinoma (P values < 0.001). The independent risk factors of cancer-specific survival of adenosquamous carcinoma patients were increasing age, male sex, invading through visceral pleura, poor differentiation and higher stage. Stage IB adenosquamous carcinoma patients whose tumor invaded through visceral pleura had significantly worse survival than those not (P = 0.003). Adenosquamous carcinoma patients had worse survival compared with squamous cell carcinoma (5-year-survival: 64.55 vs. 69.09%, P = 0.003) and adenocarcinoma (5-year-survival: 64.55 vs. 76.79%, P < 0.001) patients before match. And this difference persisted after match.

CONCLUSIONS

Resectable adenosquamous carcinoma patients had higher pleural invasion incidence, poorer differentiation and worse survival compared with squamous cell carcinoma and adenocarcinoma patients. Visceral pleural invasion status and differentiation grade were vital prognostic factors of adenosquamous carcinoma patients on the basis of stage.

Multimodal analysis suggests differential immuno-metabolic crosstalk in lung squamous cell carcinoma and adenocarcinoma

Immunometabolism within the tumor microenvironment is an appealing target for precision therapy approaches in lung cancer. Interestingly, obesity confers an improved response to immune checkpoint inhibition in non-small cell lung cancer (NSCLC), suggesting intriguing relationships between systemic metabolism and the immunometabolic environment in lung tumors. We hypothesized that visceral fat and ¹⁸F-Fluorodeoxyglucose uptake influenced the tumor immunometabolic environment and that these bidirectional relationships differ in NSCLC subtypes, lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). By integrating ¹⁸F-FDG PET/CT imaging, bulk and single-cell RNA-sequencing, and histology, we observed that LUSC had a greater dependence on glucose than LUAD. In LUAD tumors with high glucose uptake, glutaminase was downregulated, suggesting a tradeoff between glucose and glutamine metabolism, while in LUSC tumors with high glucose uptake, genes related to fatty acid and amino acid metabolism were also increased. We found that tumor-infiltrating T cells had the highest expression of glutaminase, ribosomal protein 37, and cystathionine gamma-lyase in NSCLC, highlighting the metabolic flexibility of this cell type. Further, we demonstrate that visceral adiposity, but not body mass index (BMI), was positively associated with tumor glucose uptake in LUAD and that patients with high BMI had favorable prognostic transcriptional profiles, while tumors of patients with high visceral fat had poor prognostic gene expression. We posit that metabolic adjunct therapy may be more successful in LUSC rather than LUAD due to LUAD's metabolic flexibility and that visceral adiposity, not BMI alone, should be considered when developing precision medicine approaches for the treatment of NSCLC.

Clinical-pathological and molecular characterization of long-term survivors with advanced non-small cell lung cancer

Objective: Long-term survivors (LS) of non-small cell lung cancer (NSCLC) without driver alterations, displaying an overall survival (OS) of more than 3 years, comprise around 10% of cases in several series treated with chemotherapy. There are classical prognosis factors for these cases [stage, Eastern Cooperative Oncology Group (ECOG), etc.], but more data are required in the literature. In this multi-center study, we focused on LS of advanced NSCLC with OS above 36 months to perform a clinical-pathological and molecular characterization.

Methods: In the first step, we conducted a clinical-pathological characterization of the patients. Afterwards, we carried out a genetic analysis by comparing LS to a sample of short-term survivors (SS) (with an OS less than 9 months). We initially used whole-genome RNA-seq to identify differentiating profiles of LS and SS, and later confirmed these with reverse transcription-polymerase chain reaction (RT-PCR) for the rest of the samples.

Results: A total of 94 patients were included, who were mainly men, former smokers, having adenocarcinoma (AC)-type NSCLC with an ECOG of 0–1. We obtained an initial differential transcriptome expression, displaying 5 over- and 33 under-expressed genes involved in different pathways: namely, the secretin receptor, surfactant protein, trefoil factor 1 (TFF1), serpin, Ca-channels, and Toll-like receptor (TLRs) families. Finally, RT-PCR analysis of 40 (20 LS/20 SS) samples confirmed that four genes (surfactant proteins and SFTP) were significantly down-regulated in SS compared to LS by using an analysis of covariance (ANCOVA) model: SFTPA1 (P = 0.023), SFTPA2 (P = 0.027), SFTPB (P = 0.02), and SFTPC (P = 0.047).

Conclusions: We present a sequential genetic analysis of a sample of NSCLC LS with no driver alterations, obtaining a differential RNA-seq/RT-PCR profile showing an abnormal expression of SF genes.

Metachronous Isolated Contralateral Lung Metastasis from Pulmonary Adenosquamous Carcinoma with EGFR Mutation

Lung metastasis and metachronous double primary lung cancer are both common and often present diagnostic challenges. We present a case of metachronous isolated contralateral lung metastasis from pulmonary adenosquamous carcinoma with EGFR mutation. A 75-yearold woman presented with left lung nodule on a routine follow-up chest radiograph. She had had surgery for pulmonary adenocarcinoma with EGFR Ex21 L858R mutation 6 years ago. She underwent surgical resection, and histologic findings revealed adenosquamous carcinoma with the same EGFR mutation. Re-assessment of the resected specimen of the primary tumor resected 6 years ago revealed the morphologically similarity to the left lung tumor. Based on morphological and genetic identity, final diagnosis was adenosquamous cell carcinoma and metachronous isolated contralateral lung metastasis. The diagnosis of metachronous isolated metastasis is difficult but important for appropriate management and prediction of prognosis. A careful pathological examination and evaluation of genetic abnormality are needed to make the correct diagnosis.

Clinical significance of visceral pleural and lymphovascular invasion in surgically resected adenosquamous lung cancer

OBJECTIVES

The aim of this study was to assess the relationship between visceral pleural invasion (VPI), lymphovascular invasion (LVI) and other clinicopathological characteristics and their prognostic impact on surgically resected adenosquamous carcinoma (ASC).

METHODS

We retrospectively reviewed 256 patients with radically resected ASC between January 2010 and December 2015. Patients were divided into 2 groups: those with VPI and those with LVI. The effects of VPI and LVI on disease-free survival and overall survival were evaluated, further stratified by tumour size and lymph node status.

RESULTS

Finally, 213 patients with ASC were enrolled in our study. VPI was correlated with tumour location (P < 0.001), pT stage (P < 0.001) and pN stage (P = 0.012). LVI was related to age (P = 0.005) and pN stage (P = 0.003). Both VPI and LVI were adverse prognostic factors for disease-free survival (P = 0.008, P = 0.028) and overall survival (P = 0.005, P = 0.009) using the Kaplan-Meier method. In multivariable analysis only, VPI was an independent risk factor for disease-free survival [hazard ratio (HR) 0.61, 95% confidence interval (CI) 0.42-0.87; false discovery rate, adjusted P = 0.020] and overall survival (HR 0.60, 95% CI 0.42-0.86; false discovery rate, adjusted P = 0.017). When the prognostic value of VPI was stratified by tumour size and lymph node status, we observed that only patients with VPI in tumours ≤4 cm and patients with N0 status had a worse prognosis than those without visceral invasion (P < 0.05).

CONCLUSIONS

VPI and LVI were poor prognostic factors in patients with ASC, but only VPI was an independent factor for survival, especially in patients with tumours ≤4 cm and pN0 status.

Notch1 Deficiency Induces Tumor Cell Accumulation Inside the Bronchiolar Lumen and Increases TAZ Expression in an Autochthonous Kras LSL-G12V Driven Lung Cancer Mouse Model

Purpose: Abrogation of Notch signaling, which is pivotal for lung development and pulmonary epithelial cell fate decisions was shown to be involved in the aggressiveness and the differentiation of lung carcinomas. Additionally, the transcription factors YAP and TAZ which are involved in the Hippo pathway, were recently shown to be tightly linked with Notch signaling and to regulate the cell fate in epidermal stem cells. Thus, we aim to elucidate the effects of conditional Notch1 deficiency on carcinogenesis and TAZ expression in lung cancer. Methods: We investigated the effect of conditional Cre-recombinase mediated Notch1 knock-out on lung cancer cells in vivo using an autochthonous mouse model of lung adenocarcinomas driven by Kras ^LSL-G12V and comprehensive immunohistochemical analysis. In addition, we analyzed clinical samples and human lung cancer cell lines for TAZ expression and supported our findings by publicly available data from The Cancer Genome Atlas (TCGA). Results: In mice, we found induction of papillary adenocarcinomas and protrusions of tumor cells from the bronchiolar lining upon Notch1 deficiency. Moreover, the mutated Kras driven lung tumors with deleted Notch1 showed increased TAZ expression and focal nuclear translocation which was frequently observed in human pulmonary adenocarcinomas and squamous cell carcinomas of the lung, but not in small cell lung carcinomas. In addition, we used data from TCGA to show that putative inactivating NOTCH1 mutations co-occur with KRAS mutations and genomic amplifications in lung adenocarcinomas. Conclusion: Our in vivo study provides evidence that Notch1 deficiency in mutated Kras driven lung carcinomas contributes to lung carcinogenesis in a subgroup of patients by increasing TAZ expression who might benefit from TAZ signaling blockade.

A predictive model for identifying candidates for adjuvant chemotherapy based on recurrence risk profile of resected, node-negative (N0) non-small cell lung cancer

Background

The decision for administering adjuvant chemotherapy (AC) in completely resected node-negative non-small cell lung cancer (NSCLC) is guided by likelihood of disease recurrence or death based on tumor, node, metastasis (TNM) stage. However, within each TNM stage are sub-groups of patients that are more or less likely to relapse than stage alone predicts.

Methods

In this retrospective cohort study, prospective data from 394 consecutive patients who underwent complete resection of node-negative NSCLC without adjuvant therapies, between 2002 and 2019 was retrospectively analyzed. Independent tumor and host risk factors for recurrence were subjected to multivariate analysis to develop a predictive risk model distributing patients into low-risk or high-risk categories.

Results

Recurrence risk was independently predicted by a neutrophil:lymphocyte ratio (NLR) of ≥3.5 [hazard ratio (HR), 1.9; 95% confidence interval (CI), 1.1–3.5], visceral pleural invasion (HR, 2.2; 95% CI, 1.3–3.8), histopathology other than adenocarcinoma or squamous cell (HR, 2.6; 95% CI, 1.2–5.5) and tumor size >33 mm (HR, 3.9; 95% CI, 2.3–6.7). The specific combination of risk factors contributed to a score for a risk model which classified 9% of Stage I and 69% of Stage ≥II patients as high-risk. The predicted 5-year disease-free survival (DFS) for high-risk and low-risk patients as scored by the predictive model was 30% and 85%, respectively.

Conclusions

Our readily reproducible, low-technology model, developed from individually validated tumor/host risk factors, identified sub-groups of resected node-negative NSCLC patients at significantly discordant risk of recurrence to their TNM stage category.

Risk factors of postoperative recurrence and potential candidate of adjuvant radiotherapy in lung adenosquamous carcinoma

Background

Adenosquamous carcinoma (ASC) is a rare and aggressive histologic subtype of non-small cell lung cancer (NSCLC). Little is known about the prognostic significance of routine immunohistochemical (IHC) markers and clinical value of adjuvant radiotherapy in completely resected lung ASC.

Methods

Consecutive patients with pathologically confirmed lung ASC receiving curative resection from January 2007 to December 2017 at our center were retrospectively reviewed. The prognostic significance of 14 routine IHC markers and potential candidate of adjuvant radiotherapy were investigated.

Results

With a median follow up of 35 (range, 3.0–138) months, 95 out of the 176 enrolled patients had disease recurrence. The 1-, 3- and 5-year cumulative rate of recurrence was 25.8%, 55.8% and 63.1%, respectively. Using the Cox proportional hazard regression model, T stage, N stage, lymphovascular invasion (LVI), expression of CEA, expression of p53, but not EGFR mutations or expression of the other 12 IHC markers (CK20, CK5/6, PE10, ERCC1, Napsin A, RRM1, Ki67, CK7, P63, EGFR, HER2, TTF1), were significantly associated with postoperative recurrence. N stage, expression of CEA and LVI were identified as independent prognosticators of overall recurrence. Using competing risk methodology and distant recurrence chosen as a competing risk, T stage and N stage were identified as significant risk factors of loco-regional recurrence. Moreover, adjuvant radiotherapy significantly improved disease-free survival (DFS) (P=0.002) and was associated with non-significant longer overall survival (OS) (P=0.078) among 95 patients with either pathological T3–4 or N⁺ disease (collectively defined as pT_3–4/N⁺ disease).

Conclusions

This study provides the proof of concept for using routine IHC markers, along with common clinic-pathological parameters, in predicting postoperative recurrence and identifying potential candidate for adjuvant radiotherapy in completely resected lung ASC.

GLI1 activation is a key mechanism of erlotinib resistance in human non-small cell lung cancer

Lung cancer is the leading cause of cancer-associated death worldwide. In recent years, the advancement of epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) targeted therapies has provided clinical benefits for lung cancer patients with EGFR mutations. The response to EGFR-TKI varies in patients with lung cancer, and resistance typically develops during the course of the treatment. Therefore, understanding biomarkers which can predict resistance to EGFR-TKI is important. Overexpression of GLI causes activation of the Hedgehog (Hh) signaling pathway and plays a critical role in oncogenesis in numerous types of cancer. In the present study, the role of GLI1 in erlotinib resistance was investigated. GLI1 mRNA and protein expression levels were determined using reverse transcription-quantitative PCR and immunohistochemistry (IHC) in lung cancer cell lines and tumor specimens, respectively. GLI1 mRNA expression levels were found to be positively correlated with the IC₅₀ of erlotinib in 15 non-small cell lung cancer (NSCLC) cell lines. The downregulation of GLI1 using siRNA sensitized lung cancer cells to the erlotinib treatment, whereas the overexpression of GLI1 increased the survival of lung cancer cells in the presence of erlotinib, indicating that Hh/GLI activation may play a critical role in the development of TKI resistance in lung cancer. Combined treatment with erlotinib and a GLI1 inhibitor reduced the cell viability synergistically. A retrospective study of patients with NSCLC treated with erlotinib revealed that those with a high IHC score for GLI1 protein expression had a poorer prognosis. These results indicated that GLI1 is a key regulator for TKI sensitivity, and patients with lung cancer may benefit from the combined treatment of TKI and GLI1 inhibitor.

Matrix metalloproteinase-9 (MMP-9) Expression in Non-Small Cell Lung Carcinoma and Its Association with Clinicopathologic Factors

Background & Objective:

Matrix metalloproteinases-9 (MMP-9) is one of the most important enzymes to breakdown extracellular matrix which plays a major role in tumor invasion and metastasis. This study aimed to determine tumor MMP-9 expression in non-small-cell lung carcinoma (NSCLC) and whether it is associated with histopathologic factors and has prognostic value to affect overall survival (OS).

Methods:

The specimens of 92 patients with NSCLC diagnosis were included. Tumor sections were stained by immunohistochemistry method. Using scores for the percentage of cells positively stained and the intensity of staining, MMP-9 expression total score was classified as low-score (scores of 0 to 2), moderate-score (scores of 3 to 5), or high-score (scores of 6 or 7). OS was defined as the time interval since the diagnosis of NSCLC to the status at the last follow-up (dead or alive). The follow up period was up to 70 months.

Results:

About 74% of undifferentiated specimens (grade III tumors) showed high scores for MMP-9 expression which was significantly higher than moderately differentiated tumors (25% had high scores for MMP-9 expression) and well differentiated ones which did not have high scores (P<0.001). A total of 74 patients (80.4%) died during the follow-up period. Of this, 36% had high scores for MMP-9 expression. In contrast, none of the patients who were alive at the last follow-up had high scores for MMP-9 expression (P<0.001). Median OS was significantly lower in high score group (6 months) compared to moderate score (9 months) and high score group (15 months) (P<0.001).

Conclusion:

MMP-9 expression may serve as a significant prognostic factor for mortality and overall survival in NSCLC. Undifferentiated tumors significantly express higher MMP-9 immunohistochemically.

A nomogram to predict prognosis of patients with lung adenosquamous carcinoma: a population-based study

Background

Adenosquamous carcinoma (ASC) of the lung is an infrequent variant of lung cancer. This study aimed to identify independent risk factors and to develop a predictive model for the prognosis of ASC patients.

Methods

Patient data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database (2004 to 2016) and database in our department (2010 to 2014). Overall survival (OS) was evaluated by the Kaplan-Meier method. Significant prognostic factors were identified by univariate analysis (UVA) and multivariate analysis (MVA) using the Cox proportional hazards regression. Competing risk model analyses were performed using cancer-specific survival outcomes. A nomogram was developed to predict patient 3-year and 5-year OS and was validated using data from the two databases.

Results

A total of 4,600 patients with ASC were included and divided into a training cohort (n=3,202) and two validation cohorts (n=1,372, n=26). Patients with ASC had significantly older age, lower grades of tumor differentiation or incidences of nodal, and distant invasions than adenocarcinoma and squamous cell carcinoma (SCC) of the lung (P<0.001), while the median survival time of ASC patients was intermediate [21.0 (19.3-22.7) months]. Age, sex, primary site of tumor, histological grade, T stage, N stage, M stage of the tumor, as well as surgery to the primary tumor site and chemotherapy were identified as independent factors for ASC (P<0.001). A reliable nomogram was established with a group of validation plots and concordance indices (C-indices) (internal: 0.755±0.010; external: 0.748±0.049 and 0.721±0.045).

Conclusions

Age, sex, primary site of tumor, histological grade, T stage, N stage, M stage of the tumor, as well as surgery to the primary site of tumors and chemotherapy were independent risk factors for ASC patients. A validated nomogram was constructed to predict the prognosis based on the patient clinical characteristics.

A competing risk nomogram predicting cause-specific mortality in patients with lung adenosquamous carcinoma

Background

Adenosquamous carcinoma (ASC) is an uncommon histological subtype of lung cancer. The purpose of this study was to assess the cumulative incidences of lung cancer-specific mortality (LC-SM) and other cause-specific mortality (OCSM) in lung ASC patients, and construct a corresponding competing risk nomogram for LC-SM.

Methods

Data on 2705 patients with first primary lung ASC histologically diagnosed between 2004 and 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The cumulative incidence function (CIF) was utilized to calculate the 3-year and 5-year probabilities of LC-SM and OCSM, and a competing risk model was built. Based on the model, we developed a competing risk nomogram to predict the 3-year and 5-year cumulative probabilities of LC-SM and the corresponding concordance indexes (C-indexes) and calibration curves were derived to assess the model performance. To evaluate the clinical usefulness of the nomogram, decision curve analysis (DCA) was conducted. Furthermore, patients were categorized into three groups according to the tertile values of the nomogram-based scores, and their survival differences were assessed using CIF curves.

Results

The 3-year and 5-year cumulative mortalities were 49.6 and 55.8% for LC-SM and 8.2 and 11.8% for OCSM, respectively. In multivariate analysis, increasing age, male sex, no surgery, and advanced T, N and M stages were related to a significantly higher likelihood of LC-SM. The nomogram showed good calibration, and the 3-year and 5-year C-indexes for predicting the probabilities of LC-SM in the validation cohort were both 0.79, which were almost equal to those of the ten-fold cross validation. DCA demonstrated that using the nomogram gained more benefit when the threshold probabilities were set within the ranges of 0.24–0.89 and 0.25–0.91 for 3-year and 5-year LCSM, respectively. In both the training and validation cohorts, the high-risk group had the highest probabilities of LC-SM, followed by the medium-risk and low-risk groups (both P < 0.0001).

Conclusions

The competing risk nomogram displayed excellent discrimination and calibration for predicting LC-SM. With the aid of this individualized predictive tool, clinicians can more expediently devise appropriate treatment protocols and follow-up schedules.

Radiographic patterns of symptomatic radiation pneumonitis in lung cancer patients: Imaging predictors for clinical severity and outcome

OBJECTIVE

Investigate the spectrum of radiographic patterns of radiation pneumonitis (RP) in lung cancer patients and identify imaging markers for high-grade RP and RP-related death.

METHODS

Eighty-two patients with lung cancer treated with conventional chest radiotherapy who had symptomatic RP were identified from the radiation oncology database. The imaging features of RP were studied for association with high-grade RP (Grade ≥3) and RP-related death (Grade 5).

RESULTS

RP was Grade 2 in 60 (73%), Grade 3 in 15 (18%), and Grade 5 in 7 patients (9%). Lower performance status (p = 0.04), squamous cell histology (p = 0.03), and FEV1 ≤ 2 (p = 0.009) were associated with high-grade pneumonitis. Older age (p = 0.03) and squamous cell histology (p = 0.03) were associated with RP-related death. The CT findings included ground-glass and reticular opacities in all patients, with traction bronchiectasis in 77 (94%) and consolidation in 74 (90%). The most common radiographic pattern of RP was cryptogenic organizing pneumonia (COP) pattern (n = 54), followed by acute interstitial pneumonia (AIP)/acute respiratory distress syndrome (ARDS) pattern (n = 10). Higher extent of lung involvement, diffuse distribution, and AIP/ARDS pattern were associated with high-grade pneumonitis and RP-related death. AIP/ARDS pattern was a significant factor for high-grade pneumonitis (OR:12.62, p = 0.01) in multivariable analyses adjusting for clinical variables.

CONCLUSION

COP pattern was the most common radiographic pattern for symptomatic RP in lung cancer patients. AIP/ARDS pattern was significantly associated with high-grade RP and RP-related deaths, and was an independent marker for high-grade RP. The recognition of the radiographic patterns of RP can help to effectively contribute to patient management.

Treatment for Patients With Early Stage Adenosquamous Lung Cancer

Introduction

Adenosquamous lung cancer (ASC) is a rare type of NSCLC with poor prognosis. There is no consensus on the necessity of adjuvant chemotherapy and the selection of surgical procedures for patients with early stage lung cancer. Few studies have investigated the treatment for early stage ASC.

Methods

All cases of TNM stage I ASC as per the seventh edition of the American Joint Committee on Cancer staging system were identified from the Surveillance, Epidemiology, and End Results database from 2004 to 2016. The prognostic factors of the primary cohort were identified. Clinical characteristics, first-line treatments, surgical procedures, and survival data, including overall survival and cancer-specific survival, were analyzed.

Results

A total of 1251 patients were included. The mean age of the patients was 70 years (±9.5 y). Male and white patients accounted for larger proportions. There were 656 and 595 patients with stages IA and IB, respectively. The mean tumor size was 26.2 mm (±10.7 mm). With respect to the treatment, 139 patients who received only chemotherapy had the worst prognosis. Similar outcomes were observed in both the surgery and adjuvant therapy groups. Nevertheless, adjuvant chemotherapy could improve survival outcomes of patients with a tumor size of 4 to 5 cm. Of the 1075 patients who underwent surgery, there were 224 cases of sublobar resection, 834 cases of lobectomy, and 17 cases of extended or sleeve lobectomy. The results revealed that patients who underwent lobectomy had better prognosis.

Conclusions

Early stage ASC has a poor prognosis. Adjuvant chemotherapy was found to have no considerable benefit in patients with stage I disease (eighth edition). Lobectomy or other radical surgeries are recommended as they can improve overall survival of patients with ASC.

18F-FDG PET/CT in lung adenosquamous carcinoma and its correlation with clinicopathological features and prognosis

OBJECTIVE

Lung adenosquamous carcinoma (ASC) is a rare histological subtype of non-small cell lung cancer (NSCLC). Due to its rarity, the studies about ¹⁸F-FDG PET/CT in this kind of pulmonary tumor were quite limited. Thus, this study investigated ¹⁸F-FDG PET/CT findings in ASC and its correlation with clinicopathological features and clinical outcomes.

METHODS

Preoperative ¹⁸F-FDG PET/CT findings and parameters of maximum standard uptake value (SUV_max), metabolic tumor volume and total lesion glycolysis of primary lesion (MTV-P, TLG-P), combination of primary lesion and metastases (MTV-C, TLG-C), and clinicopathological features were retrospectively investigated in patients with ASC. Moreover, progression-free survival (PFS) was also analyzed.

RESULTS

All 41 patients (25 men; 16 women; age: 60 ± 7 years) had single ASC with the mean diameter of 33 ± 14 mm. Six lesions were located centrally and 35 peripherally. Serum tumor markers were abnormally increased sporadically. Twenty-two cases were at TNM stage I, 9 at II, and 10 at III. The primary tumors were FDG-avid in all cases, with the average SUV_max of 11.5 ± 6.0. SUV_max was significantly associated with tumor location, size, and TNM stage (P < 0.05). Forty-one lesions were subgrouped into 23 AC-predominant and 18 SCC-predominant lesions, and significant differences were observed for age, tumor size, and SUV_max in two groups (P < 0.05). The median PFS of 41 cases was 19 months, and 12-month and 24-month PFS rates were 72.1% and 36.1%, respectively. SUV_max, MTV-P, and TLG-C were significantly associated with PFS (P < 0.05).

CONCLUSIONS

ASC of the lung displayed high SUV_max on ¹⁸F-FDG PET/CT, which was associated with tumor location, size, TNM stage, and predominant histologic component. Moreover, metabolic parameters of ¹⁸F-FDG PET/CT were independent prognostic factors of this rare lung malignancy.

Development and validation of a nomogram for predicting cancer-specific survival of surgical resected stage I-II adenosquamous carcinoma of the lung

OBJECTIVES

Primary lung adenosquamous carcinoma (ASC) is a rare cancer subtype and has a poor prognosis. The prognostic factors for resected early-stage ASC remain unclear. We aimed to develop a nomogram to predict lung cancer-specific survival (LCSS) of patients undergoing surgical resection for stage I-II ASC.

METHODS

Data of patients undergoing resection for stage I-II ASC and diagnosed between 2004-2015 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. All the included patients were randomized at a 7:3 ratio into a training and a validation cohort. We selected and integrated significant prognostic factors based on competing for risk regression to build a nomogram. The performance of the nomogram was evaluated using Harrell's concordance index (C-index) and calibration plots.

RESULTS

A total of 988 patients (530 men and 458 women) undergoing surgical resection for stage I-II ASC were identified and randomized into a training (692, 70%) cohort and a validation cohort (296, 30%). The baseline characteristics were similar in the training and validation cohorts. Age, T stage, N stage, and the number of examined lymph nodes were independent prognostic factors for LCSS and were used in the nomogram. The calibration plots showed that the 3- and 5-year LCSS probabilities were consistent between the nomogram prediction and the actual observation. The C-index of the nomogram was 0.671 (95%CI: 0.618-0.724) and 0.635 (95%CI: 0.557-0.713) in the training cohort and validation cohort, respectively. We developed a risk classification system based on the nomogram to stratify patients into high- and low-risk of cancer-specific death groups. Patients with a similar risk shared similar prognostic prediction regardless of the stage category and patients with the same risk shared similar prognoses despite the different stage category.

CONCLUSIONS

We developed a competing risk nomogram to reliably predict cancer-specific survival of patients undergoing surgical resection for stage I-II ASC. The nomogram might be a useful tool to identify patients undergoing surgical resection for ASC who could be suitable candidates for adjuvant chemotherapy.

High CXCR4 Expression Predicts a Poor Prognosis in Resected Lung Adenosquamous Carcinoma

Background: Primary adenosquamous carcinoma (ASC) is a rare malignant tumor in the lung and its biological behavior has not yet been thoroughly described. In this study, we aimed to explore the clinical and biological role of CXCR4 in patients with resected lung ASC. Methods: We retrospectively reviewed the clinical records of patients with histologically confirmed lung ASC who underwent surgical resection with systematic lymph node dissection. Immunohistochemical staining was performed to detect the expression of CXCR4 in tumor tissues. The correlation between CXCR4 expression and clinicopathological characteristics were evaluated. The association between CXCR4 expression and patients' prognosis was analyzed by Kaplan-Meier and Cox regression. Moreover, we performed in vitro studies including CCK8, transwell and cell apoptosis to explore the potential role of CXCR4 in lung ASC. Results: A total of 78 patients with resected lung ASC were reviewed. Seventy (89.7%) patient tumors expressed CXCR4, with high level of CXCR4 expression observed in 45 (57.7%) cases. In vitro, CXCR4 conferred no difference in proliferative capacity but increased invasive potential, enhanced chemoresistance and inhibited apoptosis of lung ASC. Clinically, high CXCR4 expression was significantly associated with solid ASC, lymph node metastasis and advanced TNM stage. Patients with high CXCR4 expression and solid ASC had decreased disease-free survival and overall survival.Conclusions: CXCR4 was commonly expressed in lung ASC tumors. High CXCR4 expression might be a novel marker in predicting a poor prognosis in resected lung ASC and might serve as a potential therapeutic target.

A qualitative transcriptional signature for the histological reclassification of lung squamous cell carcinomas and adenocarcinomas

Background

Targeted therapy for non-small cell lung cancer is histology dependent. However, histological classification by routine pathological assessment with hematoxylin-eosin staining and immunostaining for poorly differentiated tumors, particularly those from small biopsies, is still challenging. Additionally, the effectiveness of immunomarkers is limited by technical inconsistencies of immunostaining and lack of standardization for staining interpretation.

Results

Using gene expression profiles of pathologically-determined lung adenocarcinomas and squamous cell carcinomas, denoted as pADC and pSCC respectively, we developed a qualitative transcriptional signature, based on the within-sample relative gene expression orderings (REOs) of gene pairs, to distinguish ADC from SCC. The signature consists of two genes, KRT5 and AGR2, which has the stable REO pattern of KRT5 > AGR2 in pSCC and KRT5 < AGR2 in pADC. In the two test datasets with relative unambiguous NSCLC types, the apparent accuracy of the signature were 94.44 and 98.41%, respectively. In the other integrated dataset for frozen tissues, the signature reclassified 4.22% of the 805 pADC patients as SCC and 12% of the 125 pSCC patients as ADC. Similar results were observed in the clinical challenging cases, including FFPE specimens, mixed tumors, small biopsy specimens and poorly differentiated specimens. The survival analyses showed that the pADC patients reclassified as SCC had significantly shorter overall survival than the signature-confirmed pADC patients (log-rank p = 0.0123, HR = 1.89), consisting with the knowledge that SCC patients suffer poor prognoses than ADC patients. The proliferative activity, subtype-specific marker genes and consensus clustering analyses also supported the correctness of our signature.

Conclusions

The non-subjective qualitative REOs signature could effectively distinguish ADC from SCC, which would be an auxiliary test for the pathological assessment of the ambiguous cases.

The importance of EGFR mutation testing in squamous cell carcinoma or non-small cell carcinoma favor squamous cell carcinoma diagnosed from small lung biopsies

Background

Adenosquamous carcinoma (ADSC) of the lung, a rare but aggressive subtype of non-small cell lung cancer (NSCLC), is defined as a carcinoma containing components of adenocarcinoma (ADC) and squamous cell carcinoma (SqCC). Mutations of epidermal growth factor receptor (EGFR) are found at a frequency of 15 to 44% in Asian ADSC, and EGFR tyrosine kinase inhibitors (EGFR-TKIs) are a more effective treatment for EGFR-mutated ADSC compared to chemotherapy. However, ADSC in small lung biopsies could be misdiagnosed as SqCC or non-small cell carcinoma (NSCC) favor SqCC due to undersampling, which may result in neglecting of EGFR mutation testing and affecting patients’ clinical management, particularly in Asian patients that relatively have high prevalence of EGFR mutation.

Methods

A total of 148 small lung biopsy cases with pathological diagnosis of SqCC or NSCC favor SqCC were retrospectively enrolled. The frequency of EGFR mutations and the correlation between patients’ EGFR mutation status and clinicopathological characteristics were evaluated.

Results

EGFR mutations were found in 8.8% (13 /148) of all cases with 5.2% (7/135) in SqCC and 46.2% (6/13) in NSCC favor SqCC. There were 7 (53.8%) L858R mutation, 4 (30.8%) exon 19 deletions, and 2 (15.4%) cases with coexistent L858R and T790 M mutations. Multivariate analysis showed that EGFR mutations were more prevalent in never-smokers (83.3% versus 16.7%, p = 0.006) and patients diagnosed as NSCC favor SqCC (46.2% versus 5.2%, p = 0.001). Moreover, 75% (3/4) of EGFR mutation-positive cases with subsequent surgical resection or rebiopsy were further diagnosed as ADSC.

Conclusions

EGFR mutation testing should be performed in Asian patients with SqCC diagnosed from small lung biopsies, especially in never-smokers and patients with diagnosis of NSCC favor SqCC, which have a high probability of being ADSC.

Prognostic Significance of Mean Platelet Volume on Local Advanced Non-Small Cell Lung Cancer Managed with Chemoradiotherapy

Mean platelet volume (MPV), the most commonly used measure of platelet size, and is altered in patients with malignancies. The aim of this study was to investigate the effect of MPV on overall survival (OS) of patients with locally advanced (Stage IIIA/B) inoperable non-small cell lung cancer (NSCLC). This retrospective study included patients who received concomitant chemoradiotherapy (CCRT) with cisplatin + etoposide regimen due to locally advanced stage IIIA/B NSCLC. The study included a total of 115 cases, consisting of 110 (95.7%) male and 5 (4.2%) female patients. The mean age of the patients was 61.3 ± 10.4 (22-82) years. ROC curve generated by MPV for OS yielded an AUC of 0.746 (95% CI 0.659-0.833), (p < 0.001). MPV was detected as >9 fL with a sensitivity of 74.4% and a specificity of 72.0%. In patients with stage IIIA, median OS was 45.0 months (95% CI 17.3-74.1) and 21 months (95% CI 10.6-31.3) in groups with MPV > 9.0 fL and ≤9.0 fL, respectively (p = 0.013). In patients with stage IIIB, median OS was 44.0 months (95% CI 13.8-60.6) and 16 months (95% CI 9.5-22.4) in groups with MPV > 9.0 fL and ≤9.0 fL, respectively (p = 0.036). ECOG performance score, total platelet count, and MPV were found as the most significant independent factors affecting survival (p < 0.001, p = 0.008, and, p = 0.034, respectively). In this study, we showed that decreased pre-treatment MPV was an independent risk factor for survival in NSCLC patients who were administered CCRT. As part of routine complete blood count panel, MPV may represent one of the easiest measuring tools as an independent prognostic marker for survival in locally advanced NSCLC.

ICD-10-CM/PCS: potential methodologic strengths and challenges for thoracic surgery researchers and reviewers

The recent implementation of the International Classification of Diseases, 10^th Revision, Clinical Modification and Procedure Coding System (ICD-10-CM/PCS) provides a robust classification of diagnoses and procedures for hospital systems. As researchers begin using ICD-10-CM/PCS for outcomes research from administrative datasets, it is important to understand ICD-10-CM/PCS, as well as the strengths and challenges of these new classifications. In this review, we describe the development of ICD-10-CM/PCS and summarize how it applies specifically to thoracic surgery patients undergoing pulmonary lobectomy, sublobar resection (segmentectomy or wedge resection) and esophagectomy. This myriad of ICD-10-CM/PCS codes presents challenges and questions for thoracic surgery researchers and medical journal reviewers and editors when evaluating thoracic surgical outcomes research utilizing ICD-10-CM/PCS. Additional work is needed to develop consensus guidelines and uniformity for accurate and coherent research methods to utilize ICD-10-CM/PCS in future outcomes research efforts.

Adenosquamous carcinoma of the lung

Adenosquamous carcinoma of the lung (ASC), a relatively rare subtype of non-small-cell lung cancer, is defined as a malignancy containing components of lung adenocarcinoma (ADC) and lung squamous cell carcinoma (SCC). Although ASC has biological characteristics of ADC and SCC, it is not by any means a simple hybrid of two components above. It is extremely difficult to diagnose preoperatively; pathology of surgically resected gross specimen is the most effective means for adequate diagnosis of ASC. Platinum-based postoperative adjuvant chemotherapy for at least four cycles can significantly improve the survival in stage III patients with ASC. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) such as erlotinib and gefitinib can be the effective therapeutic strategies for advanced EGFR-mutant ASC. The studies of crizotinib in the treatment of patients with ASC are very limited. Immune checkpoint blockade therapy may be a potential treatment choice for ASC patients.

Expression of phosphatase and tensin homolog and programmed cell death ligand 1 in adenosquamous carcinoma of the lung

BACKGROUND

Lung adenosquamous carcinoma (ASC) is a rare variant of non-small cell lung cancer (NSCLC) with poor prognosis. Certain biological differences may exist between these tumors and other common histological types of NSCLC, including adenocarcinoma (ADC) and squamous cell carcinoma (SCC). The phosphoinositide 3-kinase (PI3K) pathway, which links oncogenes and multiple receptor classes to essential cellular functions, is activated by phosphatase and tensin homolog (PTEN) loss. The PTEN loss has been suggested to induce programmed cell death ligand 1 (PD-L1) expression in various cancer types.

OBJECTIVE

Here, we sought to determine the relationships between the expression of PTEN and PD-L1 in each component of ASC with ADC and SCC, and clinical parameters.

MATERIAL AND METHODS

Tissue microarrays of 148 cases of surgically resected lung ADC and 102 cases of SCC, as well as full sections from 28 ASC cases, were analyzed immunohistochemically for the expression of PTEN and PD-L1.

RESULTS

PD-L1 expression was similar between the adenocarcinoma component of ASC vs. lung ADC and between the squamous component of ASC vs. lung SCC. PTEN loss was higher in lung ADC than in the adenocarcinoma component of ASC and significantly higher in lung SCC than in the squamous component of ASC. PD-L1 expression was higher in the squamous component than in the glandular component of the 28 ASC cases, but PTEN loss was similar. Overall, PTEN loss was higher in lung SCC than in lung ADC and both components of ASC. In lung SCC and glandular portions of ASC, PD-L1 expression levels were significantly associated with those of PTEN. The loss of PTEN correlated with smoking status in patients with lung ADC.

CONCLUSIONS

Our results implied that both squamous and glandular components of ASC may share the same oncogenic driver pathway for carcinogenesis. However, the squamous cell components of ASC likely escape the immune surveillance better than the glandular components due to higher PD-L1 expression.

Surgical significance and efficacy of epidermal growth factor receptor tyrosine kinase inhibitors in patients with primary lung adenosquamous carcinoma

Background

Primary adenosquamous carcinoma (ASC) of the lung is a rare and aggressive disease. The accurate diagnosis of ASC based on small biopsies is challenging because of the mixed components within the tumor, and this may lead to suboptimal treatment. Furthermore, information about the efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in lung ASC is limited.

Patients and methods

Data on a cohort of patients with lung ASC who underwent surgery between October 2008 and December 2016 at a single institution were retrospectively reviewed.

Results

This study analyzed 148 patients. Differences between the pre- and post-resection diagnosis were observed. Based on the results of preoperative biopsy, patients were diagnosed as having squamous cell carcinoma (n=26), adenocarcinoma (n=20), poorly differentiated carcinoma (n=20), and large cell carcinoma (n=1), and finally diagnosed as having ASC based on histopathological examination of the surgical specimens. Thirty patients (20.3%) with EGFR-sensitizing mutations (TKI group) were treated with EGFR-TKIs after surgery, whereas the remaining patients (79.7%) with unknown EGFR-mutation status received chemotherapy or chemoradiotherapy alone (non-TKI group). TKI treatment was associated with better median overall survival (OS) (HR=0.619; p=0.034). Multivariate analysis identified the presence of EGFR-TKI treatment as an independent prognostic factor for OS (HR=0.471; p=0.003).

Conclusion

Discrepancies between the pre- and post-operative diagnosis reflect the inadequacy of non-resection approaches to the diagnosis of ASC. ASC patients harboring EGFR-sensitizing mutations who were treated with EGFR-TKIs showed a significantly better prognosis than those receiving chemotherapy or chemoradiotherapy alone.

Clinical characteristics and prognosis of patients with lung adenosquamous carcinoma after surgical resection: results from two institutes

Background

Adenosquamous carcinoma (ASC) is a mixed glandular and squamous cell carcinoma (SCC) with more aggressive behavior than the other histologic subtypes of lung cancer. We aim to evaluate the prognosis of patients with ASC after surgical resection.

Methods

We reviewed records of patients who underwent surgical resection for lung cancer in two institutes between January 2010 and December 2015. Survival data were collected with a median follow-up of 59 (range from 10 to 85) months. Kaplan-Meier survival curve was determined for all patients.

Results

Patients with ASC accounted for 1.6% of all NSCLC patients (33 males, 25 females). The cumulative postoperative 3- and 5-year survival rates were 56% and 48%, respectively. Overall survival (OS) was significantly lower in ASC patients than in adenocarcinoma (AC) patients operated during the same period (P<0.01). Patients with ASC containing acinar predominant AC had better survival than those with non-acinar predominant ASC (P=0.03). No difference of OS was found in patients with or without visceral pleural invasion (VPI), vascular invasion (VI) or EGFR mutation status. Multivariate analysis showed gender, pathological subtype, and TNM staging to be independent prognostic factors.

Conclusions

We demonstrated that ASC were uncommon and aggressive lung tumors. Predominant histological subtype of AC might be an independent prognostic factor for ASC. Further prospective studies are warranted to clarify the characteristics of this rare tumor.

Clinicopathological characteristics and survival outcomes in adenosquamous carcinoma of the lung: a population-based study from the SEER database

Adenosquamous carcinoma (ASC) of the lung is an unusual histology type in non-small-cell lung cancers. Due to its rarity, the clinicopathological characteristics and survival outcomes of the lung ASC are incompletely understood. We used the Surveillance, Epidemiology, and End Results (SEER) database to enroll 203,208 eligible patients, including 4,245 ASC, 124,253 adenocarcinoma (ADC) and 74,710 squamous cell carcinoma (SCC) patients. To date, this is the largest cohort in a study for ASC of the lung. With regard to age, sex, race, year of diagnosis, tumor size and SEER stage, ASC was intermediate between ADC and SCC. However, compared with ADC and SCC patients, ASC patients presented with a higher tumor grade and lower prevalence of nodal metastasis. More ASC patients underwent surgery and a lower proportion underwent radiation treatment and chemotherapy. Kaplan-Meier analysis showed that ASC patients had a better prognosis than ADC and SCC patients, but stratified analysis showed that the prognosis of ASC patients was worse than that of ADC and SCC patients in surgery and non-surgery subgroup. Multivariate analysis further confirmed that the ASC histology type was a risk factor for poor prognosis with respect to ADC and SCC. Using the propensity score matching to 1:1 match ASC with ADC or SCC, we found that ASC patients had worse survival than ADC and SCC patients. Subgroup analysis further demonstrated that ASC was a more aggressive histology type with a worse prognosis. These results provided a deep understanding of ASC, which contributed to better clinical diagnosis and treatment.

Characteristics of lymph node metastasis in resected adenosquamous lung cancer

The aim of this study was to retrospectively analyze the clinical data of resected adenosquamous lung cancer (ASLC) and to explore the influencing factors and clinicopathological characteristics of the metastasis lymph nodes. A total of 1156 consecutive patients with surgically resected lung cancer from January 2009 to June 2014 were studied. Fifty-four previously diagnosed ASLC patients were re-evaluated by experienced pathologists. IHC and H&E staining were employed to examine the primary focus and metastasis lymph nodes. The relationship between lymph node metastasis and clinicopathological characteristics of ASLC patients was then analyzed and the pathological type of metastasis lymph node was also determined. Forty-nine cases of typical ASLC were included in the study. Of the 49 ASLC patients, 26 cases presented lymph node metastasis. Lymph node metastasis was not associated with gender, smoking, tumor distribution, histological type of primary focus, and preoperative CEA level, but was associated with age ≥ 65 (P < .05) and tumor size ≥ 3 cm (P < .05). Lymph node metastasis adenocarcinoma was the main type in ASLC patients, and was related to the age and tumor size of the primary focus. Further large sample studies are necessary to identify influencing factors and clinicopathological characteristics of metastasis lymph nodes.

Pathology Issues in Thoracic Oncology: Histologic Characterization and Tissue/Plasma Genotyping May Resolve Diagnostic Dilemmas

Lung cancer is a heterogeneous diagnosis that encompasses a spectrum of histologic and molecular subgroups. A paradigm shift favoring selection of treatment based on histologic and molecular makeup has positively affected prognosis for patients with metastatic lung cancer, with select patients experiencing durable responses to treatment. However, prognosis remains poor for the majority of patients. Furthermore, oncologists are increasingly faced with challenging dilemmas related to histopathologic and molecular characterization of tumors, both at diagnosis and during treatment. In this review, we focus on three particular challenges: (1) management of mixed histology tumors, a particularly aggressive group of lung cancers, (2) distinguishing multiple primary lung tumors from intrapulmonary metastases, and (3) incorporation of liquid biopsies into the diagnostic algorithm and subsequent follow-up of patients with advanced lung cancer. This review will summarize the existing literature and highlight the potential for molecular genotyping to help refine approaches to each of these challenges.

The status of immunosuppression in patients with stage IIIB or IV non-small-cell lung cancer correlates with the clinical characteristics and response to chemotherapy

BACKGROUND

Indoleamine 2,3-dioxygenase (IDO) catalyzes the rate-limiting step of tryptophan (Trp) degradation via the kynurenine (Kyn) pathway, which inhibits the proliferation of T cells and induces the apoptosis of T cells, leading to immune tolerance. Therefore, IDO has been considered as the most important mechanism for tumor cells to escape from immune response. Previous studies suggested that IDO might be involved in the progression of tumor and resistance to chemotherapy. Several preclinical and clinical studies have proven that IDO inhibitors can regulate IDO-mediated tumor immune escape and potentiate the effect of chemotherapy. Thus, the present study investigated the correlation between the clinical parameters, responses to chemotherapy, and IDO activity to provide a theoretical basis for the clinical application of IDO inhibitors to improve the suppression status and poor prognosis in cancer patients.

METHODS

The serum concentrations of Trp and Kyn were measured by high-performance liquid chromatography in 252 patients with stage IIIB or IV non-small-cell lung cancer, and 55 healthy controls. The IDO activity was determined by calculating the serum Kyn-to-Trp (Kyn/Trp) ratio.

RESULTS

The IDO activity was significantly higher in the lung cancer patients than in the controls (median 0.0389 interquartile range [0.0178-0.0741] vs 0.0111 [0.0091-0.0133], respectively; P<0.0001). In addition, patients with adenocarcinoma had higher IDO activity than patients with nonadenocarcinoma (0.0449 [0.0189-0.0779] vs 0.0245 [0.0155-0.0563], respectively; P=0.006). Furthermore, patients with stage IIIB disease had higher IDO activity than patients with stage IV disease (0.0225 [0.0158-0.0595] vs 0.0445 [0.0190-0.0757], respectively; P=0.012). The most meaningful discovery was that there was a significant difference between the partial response (PR) patients and the stable disease (SD) and progressive disease (PD) patients (0.0240 [0.0155-0.0381] vs 0.0652 [0.0390-0.0831] vs 0.0868 [0.0209-0.0993], respectively, P<0.0001).

CONCLUSION

IDO activity was increased in lung cancer patients. Higher IDO activity correlated with histological types and disease stages of lung cancer patients, induced the cancer cells' resistance to chemotherapy, and decreased the efficacy of chemotherapy.

[Clinicopathologic Features and Prognostic Implications in 72 Cases with Lung Adenosquamous Carcinoma]

背景与目的

肺腺鳞癌是肺癌中的一种少见类型，混合有腺癌和鳞癌两种恶性组织成分，侵袭性高、预后差。本研究旨在探讨腺鳞癌的临床病理特点和预后影响因素。

方法

对72例肺腺鳞癌患者的临床病理资料进行回顾性分析，探讨影响患者预后的因素。

结果

全组患者中位生存期位34.7个月，5年生存率为14.9%，肿瘤长径、转移（metastasis, M）分期、肿瘤-淋巴结-转移（tumor-node-metastasis, TNM）病理分期、基因突变、手术对患者预后的影响有统计学意义。

结论

肺腺鳞癌恶性程度高、预后差，应采取手术为主的综合治疗，小分子酪氨酸激酶抑制剂治疗有助于延长患者生存期。

Clinical outcomes of epidermal growth factor receptor tyrosine kinase inhibitors in recurrent adenosquamous carcinoma of the lung after resection

PURPOSE

The therapeutic efficacy of targeted therapy for adenosquamous carcinoma (ASC) of the lung remains unclear and the role of epidermal growth factor receptor (EGFR) testing in patients with ASC also remains controversial. We aimed to analyze the efficacy of EGFR tyrosine kinase inhibitors (EGFR-TKIs) in ASC.

METHODS

Clinical records of patients with ASC who received treatment with EGFR-TKIs between January 2006 and December 2014 at two institutions were retrospectively reviewed.

RESULTS

A total of 27 EGFR mutation-positive patients with ASC who received TKI therapy were enrolled in this study. EGFR mutations included a deletion in exon 19 in 15 cases and a point mutation at codon 858 (L858R) in exon 21 in 12 cases. Among the 27 ASC patients who received treatment with EGFR-TKIs, nine had a partial response and 11 achieved stable disease, accounting for a disease control rate of 74.1% (20/27). The median postoperative overall survival (OS) of the EGFR-mutant patients who received TKI therapy was 39 months (95% confidence interval [CI]: 25.6-52.4). The median progression-free survival for EGFR mutation-positive patients was 15 months (95% CI: 12.9-17.1), and the median relapse OS was 19 months (95% CI: 0.9-37.1). In addition, the 3- and 5-year postoperative survival rate was 51.9% and 15.3%, respectively.

CONCLUSION

ASC patients harboring EGFR mutations had a good response to TKI therapy. Routine EGFR testing for ASCs was recommended. Further studies on TKI therapy versus chemotherapy alone for EGFR-mutant ASCs are required.

Molecular profiling of lung adenosquamous carcinoma: hybrid or genuine type?

Lung adenosquamous carcinoma is a particular subtype of non-small cell lung carcinoma that is defined by the coexistence of adenocarcinoma and squamous cell carcinoma components. The aim of this study was to assess the mutational profile in each component of 16 adenosquamous carcinoma samples from a Caucasian population by a combination of next generation sequencing using the cancer hotspot panel as well as the colon and lung cancer panel and FISH. Identified mutations were confirmed by Sanger sequencing of DNA from cancer cells of each component collected by Laser Capture microdissection. Mutations typical for adenocarcinoma as well as squamous cell carcinoma were identified. Driver mutations were predominantly in the trunk suggesting a monoclonal origin of adenosquamous carcinoma. Most remarkably, EGFR mutations and mutations in the PI3K signaling pathway, which accounted for 30% and 25% of tumors respectively, were more prevalent while KRAS mutations were less prevalent than expected for a Caucasian population. Surprisingly, expression of classifier miR-205 was intermediate between that of classical adenocarcinoma and squamous cell carcinoma suggesting that adenosquamous carcinoma is a transitional stage between these tumor types. The high prevalence of therapy-relevant targets opens new options of therapeutic intervention for adenosquamous carcinoma patients.

Improved survival associated with a balanced structure between adenomatous and squamous components in patients with adenosquamous carcinoma of the lung

BACKGROUND

Primary adenosquamous carcinoma (ASC) of the lung is rare and its biological behavior has not yet been thoroughly described. The aim of this study was to analyze the clinicopathological characteristics and prognostic factors associated with ASC.

MATERIALS

Clinical records of patients with ASC of the lung who underwent surgery between October 2008 and December 2014 in a single institution were retrospectively reviewed.

RESULTS

A total of 205 patients were identified. Patients with balanced structural components had significantly better prognosis than those with squamous (p = 0.014) or adenomatous (p < 0.001) predominance, and those with N0, N1, and N2 ASC (N0 vs. N1 [ p = 0.031] and N1 vs. N2 [p = 0.037], respectively), or stage I, II and IIIA ASC (stage I vs. II [p = 0.021] and stage II vs. IIIA [p = 0.007], respectively) had significant differences with respect to overall survival (OS). Multivariate analysis identified structural components (p = 0.011), tumor, node and metastasis (TNM) status (p < 0.001), and adjuvant chemotherapy (p = 0.008) as significantly prognostic factors for OS, and structural components (p = 0.030), TNM stage (p < 0.001) and adjuvant chemotherapy (p = 0.005) as the corresponding variables for disease-free survival.

CONCLUSIONS

A balanced structure between adenomatous and squamous components in patients with primary ASC of the lung was associated with better prognosis.

Correlation between FDG-PET/CT findings and solid type non-small cell cancer prognostic factors: are there differences between adenocarcinoma and squamous cell carcinoma?

OBJECTIVES

The maximum standardized uptake value (SUVmax) of FDG-PET/CT is commonly used as an indicator to evaluate the invasiveness and prognosis of non-small-cell lung cancers (NSCLC). We investigated the correlation between SUVmax and tumor invasiveness or postoperative recurrence of solid type NSCLC and compared squamous cell carcinoma (SCC)/adenosquamous carcinoma (ASC) to adenocarcinoma (AC).

METHODS

A retrospective review of preoperative PET/CT, thin-section CT, and postoperative pathological records obtained over a 5-year period was conducted. Solid type NSCLC tumors on thin-section CT with confirmed diagnosis from surgical resection (diameter ≤3 cm) were included. Multivariate logistic regression was used to evaluate the correlation between tumor characteristics and pathological prognostic factors or postoperative recurrence.

RESULTS

150 patients (111 males, 39 females; mean age 67 years; 106 cases of AC, 36 cases of SCC, and 8 cases of ASC) were included. SUVmax was significantly correlated with pleural involvement (p = 0.047), lymphatic permeation (p = 0.003), lymph node metastasis (p = 0.027), and tumor invasiveness (p < 0.001). Receiver operating characteristic analysis indicated an optimal SUVmax threshold of 5.0 for tumor invasiveness. Histopathological type was significantly correlated with pleural involvement (p = 0.042), but not with other types of invasiveness. Twenty-nine patients experienced postoperative recurrence. SUVmax was significantly correlated with tumor recurrence (p = 0.004), but size and histopathological type were not (p = 0.502 and p = 0.351, respectively).

CONCLUSION

SUVmax of the primary lesion in solid type NSCLC was significantly correlated with tumor invasiveness and postoperative recurrence. No differences in tumor invasiveness were observed between solid type AC and SCC/ASC. However, in solid type AC, SUVmax of the primary lesion was more significantly correlated with recurrence.

Duodeno-colic fistula as a rare presentation of lung cancer - surgical treatment of a stage IV oligometastatic lung disease

•

Atypical presentation of stage IV oligometastatic lung disease in a young patient.

•

Diagnostic challenge complicated by rapid evolution to a life-threatening condition.

•

Difficult assessment of the risk/benefit of surgery due to absence of guidelines.

•

Importance of multidisciplinary therapeutic approach in rare clinical presentations.

•

Successful outcome at 18 month follow-up of malignancy with rare presentation.

Introduction

Rare adenosquamous carcinomas have no defined standard approach given their low incidence. They present with nonspecific imaging characteristics and are described as having worse prognosis than other lung malignancies, with greater likelihood of local invasion and early metastasis.

Presentation of case

Male caucasian patient, 43 years, 26 pack-year smoking history, presented with watery diarrhea, early emesis and loss of 25% body weight (20 kg) in four weeks. Colonoscopy identified a left colonic mass. Abdominal CT/ultrasound showed a large fistulous lesion between the 4th portion of the duodenum and left colon. CT showed a solid mass in the right upper lung lobe. Endoscopy and transthoracic biopsy were inconclusive. En bloc D3 and D4 duodenectomy, proximal enterectomy and left hemicolectomy were performed, with inconclusive histology of the specimen. Three months later, a right upper lung lobectomy with lymphadenectomy was performed, revealing an adenosquamous carcinoma of lung origin, R0, staged as pT2pN0pM1b. Six months later, a single dural metastasis in the left cerebellopontine angle was detected and resected, with subsequent holocranial radiotherapy and systemic adjuvant chemotherapy. Patient is currently with 18 months follow-up, in good general health and with no evidence of recurrent disease.

Discussion

There are no specific guidelines to treat oligometastatic adenosquamous lung carcinoma. Our approach was abdominal surgery as a life-saving procedure and, months later, oncological resection of primary lung tumor and metachronous metastasis to the brain.

Conclusion

A systematic, patient-oriented, patient-shared, multidisciplinary approach is particularly relevant when dealing with atypical presentations of rare diseases in young patients.

Lineage factors and differentiation states in lung cancer progression

Lung cancer encompasses a heterogeneous group of malignancies. Here we discuss how the remarkable diversity of major lung cancer subtypes is manifested in their transforming cell of origin, oncogenic dependencies, phenotypic plasticity, metastatic competence and response to therapy. More specifically, we review the increasing evidence that links this biological heterogeneity to the deregulation of cell lineage-specific pathways and the transcription factors that ultimately control them. As determinants of pulmonary epithelial differentiation, these poorly characterized transcriptional networks may underlie the etiology and biological progression of distinct lung cancers, while providing insight into innovative therapeutic strategies.

Stereotactic aspiration combined with gamma knife radiosurgery for the treatment of cystic brainstem metastasis originating from lung adenosquamous carcinoma: A case report

Brainstem metastases have a poor prognosis and are difficult to manage. The present study describes the first case of histopathologically-confirmed brainstem metastasis originating from lung adenosquamous carcinoma, and discusses the outcomes of treatment by stereotactic aspiration combined with gamma knife radiosurgery (GKRS). A 59-year-old female presented with a cystic mass (15×12×13 mm; volume, 1.3 cm³) located in the pons, two years following surgical treatment for adenosquamous carcinoma of the lung. The patient received initial GKRS for the lesion in the pons with a total dose of 54.0 Gy, however, the volume of the mass subsequently increased to 3.9 cm³ over a period of three months. Computed tomography-guided stereotactic biopsy and aspiration of the intratumoral cyst were performed, yielding 2.0 cm³ of yellow-white fluid. Histology confirmed the diagnosis of adenosquamous carcinoma. Aspiration provided immediate symptomatic relief, and was followed one week later by repeat GKRS with a dose of 12.0 Gy. The patient survived for 12 months following the repeat GKRS; however, later succumbed to the disease after lapsing into a two-week coma. The findings of this case suggest that stereotactic aspiration of cysts may improve the effects of GKRS for the treatment of cystic brainstem metastasis; the decrease in tumor volume allowed a higher radiation dose to be administered with a lower risk of radiation-induced side effects. Therefore, stereotactic aspiration combined with GKRS may be an effective treatment for brainstem metastasis originating from adenosquamous carcinoma.

Analysis of major known driver mutations and prognosis in resected adenosquamous lung carcinomas

INTRODUCTION

Genotyping for driver mutations is now routinely used to guide clinical care of patients with lung cancer. Adenosquamous lung carcinoma (AdSqLC) is a subtype of cancer that contains both adenocarcinoma and squamous cell carcinoma. However, the incidence, clinicopathologic characteristics, and prognostic implications of major driver mutations in AdSqLCs are not well established.

METHODS

Seventy-six resected AdSqLCs and 646 lung adenocarcinomas were screened for known genetic alterations involving EGFR, ERBB2, KRAS, BRAF, PIK3CA, AKT1, RET, and ALK. Tumors showing acinar, lepidic, micropapillary, or papillary growth in glandular component were classified as classical AdSqLC.

RESULTS

Of the 76 AdSqLCs, 43 (56.6%) harbored known mutant kinases, including 24 (31.6%) with EGFR mutations, eight (10.5%) with KRAS mutations, two (2.6%) with AKT1 (2.6%) mutations, one (1.3%) with ERBB2 insertion mutation, one (1.3%) with PIK3CA mutation, four (5.3%) with ALK fusions, and three (4%) with KIF5B-RET fusions. No mutation was found in BRAF. The mutational profiles and clinicopathologic characteristics of classical AdSqLC were strikingly similar to that of poorly differentiated adenocarcinoma. However, AdSqLCs with solid growth pattern in glandular component had high frequency of ALK or RET fusions and low EGFR mutation rate.

CONCLUSIONS

To our knowledge, this is the first comprehensive study investigating major oncogenic driver mutations in a large cohort of AdSqLC patients in a Chinese population. The findings suggest that it will be clinically valuable to investigate the growth pattern of glandular component in AdSqLCs.

Biomarker expression and druggable gene alterations for development of an appropriate therapeutic protocol for pulmonary adenosquamous carcinoma

AIMS

Pulmonary adenosquamous carcinoma (ASC) is more aggressive than adenocarcinoma (AC) and squamous cell carcinoma (SCC). The genetic features and biomarkers of ASC are not well known. Here, we attempted to identify potential therapeutic markers for ASC.

METHODS AND RESULTS

Surgically resected ASC samples from 65 patients were analysed. We examined the expression of β III-tubulin, thymidylate synthase, breast cancer susceptibility gene 1 and ribonucleotide reductase M1 (RRM1); identified mutations in epidermal growth factor receptor (EGFR), KRAS, BRAF and HER2; and detected ALK, ROS1 and RET rearrangements. Gene amplification and expression of EGFR, human epidermal growth factor receptor 2 (HER2), fibroblast growth factor receptor-1 and MET were also examined. β III-Tubulin showed the highest expression (P = 0.002), and its expression was more frequent in the AC than in the SCC component (P = 0.013). RRM1 expression was more frequent in the SCC component (P = 0.046). EGFR and KRAS mutations were detected in both components (21.5 and 10.9%, respectively). ALK and ROS1 rearrangements and MET amplification were detected in both components in one (1.5%) case.

CONCLUSIONS

In ASC, drug response-specific gene alterations could occur in both AC and SCC components, suggesting that patients with confirmed or suspected ASC should undergo further testing for driver gene analyses.

Pulmonary adenosquamous carcinoma with mucoepidermoid carcinoma-like component with characteristic p63 staining pattern: either a novel subtype originating from bronchial epithelium or variant mucoepidermoid carcinoma

BACKGROUND

Our previous study found unique adenosquamous carcinomas (ADSQs) containing a mucoepidermoid carcinoma (MEC)-like component and a characteristic p63 staining pattern. This study focused on these unique ADSQs.

METHODS

Thirty ADSQ cases were studied histologically and by immunohistochemistry for TTF-1 and p63. Of these 30 ADSQs, eight were selected as unique ADSQs. The clinicopathological characteristics of these ADSQs were further studied, and the gene rearrangement of mammalian mastermind-like 2 (MAML2) was investigated by fluorescence in situ hybridization (FISH) for differentiation from pulmonary MEC.

RESULTS

The clinicopathological characteristics between the eight ADSQs and the other ADSQ cases showed no statistically significant differences, except for serum CEA level. Histologically, the eight ADSQs contained varying degrees of the MEC-like component, which consisted of solid nests with mucin-filled cysts or a cribriform-like structure. Immunohistochemically, p63-positive nuclei characteristically encircled the tumor nests, although TTF-1 was completely negative. All unique ADSQs not only had a variable degree of squamous cell carcinoma component in addition to the MEC-like component, but also contained a small tubular adenocarcinoma component in three tumors. FISH analysis revealed no MAML2 gene rearrangement in the eight ADSQs.

CONCLUSIONS

Of the 30 ADSQs investigated in this study, eight contained a MEC-like component with a characteristic p63 basilar staining pattern similar to that of bronchial basal cells. These unique ADSQs shared clinical characteristics with ordinary ADSQs, but clinicopathologically differed from pulmonary ordinary MEC. Therefore, these unique ADSQs may be either a novel ADSQ subtype originating from bronchial epithelium or variant-type MEC.

Does Immunohistochemistry Affect Response to Therapy and Survival of Inoperable Non–Small Cell Lung Carcinoma Patients? A Survey of 145 Stage III-IV Consecutive Cases

Whether non–small cell lung carcinoma (NSCLC) unveiled by immunohistochemistry (IHC) has the same clinical outcome as those typed by morphology is still matter of debate. A total of 145 stage III-IV, consecutive inoperable NSCLC patients treated by chemotherapy (133 cases) or EGFR tyrosine kinase inhibitor (12 cases) and including 100 biopsies, 11 surgical specimens, and 34 cytological samples had originally accounted for 120 adenocarcinomas (ADs), 19 squamous cell carcinomas (SQCs), and 6 adenosquamous carcinomas (ADSQCs) by integrating morphology and thyroid transcription factor-1 (TTF1)/p40 IHC. Thirty-two NSCLC–not otherwise specified (NSCLC-NOS) cases were identified by morphology revision of the original diagnoses, which showed solid growth pattern ( P < .001), 22 ADs, 5 SQCs, and 5 ADSQCs by IHC profiling ( P < .001), and 10 gene-altered tumors (3 EGFR, 5 KRAS, and 2 ALK). While no significant relationships were observed between response to therapy and original, morphology or IHC diagnoses, driver mutations and tumor differentiation by TTF1 expression, AD run better progression-free survival (PFS) or overall survival (OS) than other tumor types by morphology ( P = .010 and P = .047) and IHC ( P = .033 and P = .046), respectively. Furthermore, patients with NSCLC-NOS confirmed as AD by IHC tended to have poorer OS ( P = .179) and PFS ( P = .193) similar to that of ADSQC and SQC ( P = .702 and P = .540, respectively). A category of less differentiated AD with poorer prognosis on therapy could be identified by IHC, while there were no differences for SQC or ADSQC. The terminology of “NSCLC-NOS, favor by IHC” is appropriate to alert clinicians toward more aggressive tumors.

Isolation of cancer stem like cells from human adenosquamous carcinoma of the lung supports a monoclonal origin from a multipotential tissue stem cell

There is increasing evidence that many solid tumors are hierarchically organized with the bulk tumor cells having limited replication potential, but are sustained by a stem-like cell that perpetuates the tumor. These cancer stem cells have been hypothesized to originate from transformation of adult tissue stem cells, or through re-acquisition of stem-like properties by progenitor cells. Adenosquamous carcinoma (ASC) is an aggressive type of lung cancer that contains a mixture of cells with squamous (cytokeratin 5+) and adenocarcinoma (cytokeratin 7+) phenotypes. The origin of these mixtures is unclear as squamous carcinomas are thought to arise from basal cells in the upper respiratory tract while adenocarcinomas are believed to form from stem cells in the bronchial alveolar junction. We have isolated and characterized cancer stem-like populations from ASC through application of selective defined culture medium initially used to grow human lung stem cells. Homogeneous cells selected from ASC tumor specimens were stably expanded in vitro. Primary xenografts and metastatic lesions derived from these cells in NSG mice fully recapitulate both the adenocarcinoma and squamous features of the patient tumor. Interestingly, while the CSLC all co-expressed cytokeratins 5 and 7, most xenograft cells expressed either one, or neither, with <10% remaining double positive. We also demonstrated the potential of the CSLC to differentiate to multi-lineage structures with branching lung morphology expressing bronchial, alveolar and neuroendocrine markers in vitro. Taken together the properties of these ASC-derived CSLC suggests that ASC may arise from a primitive lung stem cell distinct from the bronchial-alveolar or basal stem cells.

Pneumonectomy: risk factor or innocent bystander?

Background

Pneumonectomy is associated with a higher operative mortality rate and worse 5-year survival after resection for non-small-cell lung cancer, compared to lobectomy. We investigated whether pneumonectomy is an independent risk factor for hospital mortality and poor long-term survival, after risk factor adjustment.

Methods

We analyzed a prospectively validated thoracic surgery database. Kaplan-Meier survival curves were constructed for patients who had undergone lobectomy ( n = 1484) or pneumonectomy ( n = 266). Logistic and Cox multivariate regression analysis and propensity matching were performed on hospital mortality and long-term survival data.

Results

Univariate analysis demonstrated that pneumonectomy was a significant risk factor for hospital death ( p = 0.02) and long-term survival ( p < 0.001). Logistic regression failed to demonstrate pneumonectomy as a risk factor for hospital mortality. Cox regression analysis failed to identify pneumonectomy as a statistically significant risk factor. Propensity analysis ( n = 266 in each group with 1:1 matching) demonstrated that pneumonectomy was not associated with hospital mortality ( p = 0.37) or poorer long-term survival ( p = 0.19) compared to lobectomy.

Conclusion

Pneumonectomy is not an independent risk factor for hospital mortality or long-term survival, after adjustment for confounding factors.