KRT18 as a Novel Biomarker of Urothelial Papilloma while Evaluating Low-Grade Papillary Urothelial Neoplasms: Bi-Center Analysis.

INTRODUCTION: Although urothelial papilloma (UP) is an indolent papillary neoplasm that can mimic the morphology of low-grade papillary urothelial carcinoma (PUC), there is no immunomarker to differentiate reliably these two entities. In addition, the molecular characteristics of UP are not fully understood. METHODS: We conducted an in-depth proteomic analysis of papillary urothelial lesions (n = 31), including UP and PUC along with normal urothelium. Protein markers distinguishing UP and PUC were selected with machine learning analysis, followed by internal and external validation using immunohistochemistry. RESULTS: In the proteomic analysis, UP and PUC showed overlapping proteomic profiles. We identified EHD4 and KRT18 as candidate diagnostic biomarkers of UP. Through immunohistochemical validation in two independent cohorts (n = 120), KRT18 was suggested as a novel UP diagnostic marker, able to differentiate UP from low-grade PUC. We also found that 3.5% of patients with UP developed urothelial carcinoma in subsequent resections, supporting the malignant potential of UP. KRT18 downregulation was significantly associated with UPs subsequently progressing to urothelial carcinoma, following their initial diagnosis. CONCLUSION: This is the first study that successfully revealed UPs comprehensive proteomic landscape, while it also identified KRT18 as a potential diagnostic biomarker of UP.

Quantitative proteomics and immunohistochemistry uncover NT5DC2 as a diagnostic biomarker for papillary urothelial carcinoma.

The accurate diagnosis of papillary urothelial carcinoma (PUC) is frequently challenging due to benign mimickers. Other than morphology-based diagnostic criteria, reliable biomarkers for differentiating benign and malignant papillary urothelial neoplasms remain elusive, so we sought to discover new markers to address this challenge. We first performed tandem mass spectrometry-based quantitative proteomics using diverse papillary urothelial lesions, including PUC, urothelial papilloma (UP), inverted urothelial papilloma, and cystitis cystica. We prioritized potential diagnostic biomarkers using machine learning, and subsequently validated through immunohistochemistry (IHC) in two independent cohorts. Metabolism, transport, cell cycle, development, and immune response functions were differentially enriched between malignant and benign papillary neoplasms. RhoB and NT5DC2 were shortlisted as optimal candidate markers for PUC diagnosis. In our pilot study using IHC, NT5DC2 was subsequently selected as its expression consistently differed in PUC (p = 0.007). Further validation of NT5DC2 using 49 low-grade (LG) urothelial lesions, including 15 LG-PUCs and 17 UPs, which are the most common mimickers, concordantly revealed lower IHC expression levels in LG-PUC (p = 0.0298). Independent external validation with eight LG-PUCs and eight UPs confirmed the significant downregulation of NT5DC2 in LG-PUC (p = 0.0104). We suggest that NT5DC2 is a potential IHC biomarker for differentiating LG-PUC from its benign mimickers, especially UP.

Deciphering Breast Origin in Malignant Effusions: The Diagnostic Utility of an MGP, GATA-3, and TRPS-1 Immunocytochemical Panel.

INTRODUCTION: Defining the origin of metastatic cancer is crucial for establishing an optimal treatment strategy, especially when obtaining sufficient tissue from secondary malignancies is limited. While cytological examination is often used in this diagnostic setting, morphologic analysis alone often fails to differentiate metastases derived from the breast from other primaries. The hormone receptor, human epidermal growth factor receptor-2, gross cystic disease fluid protein 15, and mammaglobin immunohistochemistry are often used to diagnose metastatic breast cancer. However, their effectiveness decreases in estrogen receptor (ER)-negative breast cancers, including the triple-negative breast cancer (TNBC) subtype. METHODS: We conducted a comprehensive evaluation of GATA-binding protein 3 (GATA-3), trichorhinophalangeal syndrome type 1 (TRPS-1), and Matrix Gla Protein (MGP) immunochemistry across 140 effusion cytology specimens with metastatic adenocarcinoma derived from various primaries, including the breast, colon, pancreaticobiliary, lung, tubo-ovarian, and stomach. RESULTS: The expression rates of these immunomarkers were significantly higher in metastatic cancers originating from the breast than other primaries. In TNBC, TRPS-1 (80.00%) and MGP (65.00%) exhibited higher positivity rates compared to GATA-3 (40.00%). Additionally, our data suggest that an immunohistochemical panel comprising MGP, GATA-3, and TRPS-1 significantly enhances the detection of metastatic breast cancer in effusion cytology specimens, including TNBC in particular. When considering dual-marker positivity, the diagnostic accuracy was found to be 89.29% across all breast cancer subtypes and 92.93% for TNBC. CONCLUSIONS: MGP appears to be a robust marker for identifying metastatic breast cancer in malignant effusions, especially TNBC. MGP notably enhances diagnostic accuracy when incorporated together with GATA-3 and TRPS-1 in an immunohistochemical panel.

Comparison of Breast Fine-Needle Aspiration Cytology and Tissue Sampling for High-Throughput Proteomic Analysis and Cancer Biomarker Detection.

INTRODUCTION: Fine-needle aspiration cytology (FNAC) specimens are widely utilized for the diagnosis and molecular testing of various cancers. We performed a comparative proteomic analysis of three different sample types, including breast FNAC, core needle biopsy (CNB), and surgical resection tissues. Our goal was to evaluate the suitability of FNAC for in-depth proteomic analysis and for identifying potential therapeutic biomarkers in breast cancer. METHODS: High-throughput proteomic analysis was conducted on matched FNAC, CNB, and surgical resection tissue samples obtained from breast cancer patients. The protein identification, including currently established or promising therapeutic targets, was compared among the three different sample types. Gene Ontology (GO) enrichment analysis was also performed on all matched samples. RESULTS: Compared to tissue samples, FNAC testing revealed a comparable number of proteins (7,179 in FNAC; 7,196 in CNB; and 7,190 in resection samples). Around 85% of proteins were mutually identified in all sample types. FNAC, along with CNB, showed a positive correlation between the number of enrolled tumor cells and identified proteins. In the GO analysis, the FNAC samples demonstrated a higher number of genes for each pathway and GO terms than tissue samples. CCND1, CDK6, HER2, and IGF1R were found in higher quantities in the FNAC compared to tissue samples, while TUBB2A was only detected in the former. CONCLUSION: FNAC is suitable for high-throughput proteomic analysis, in addition to an emerging source that could be used to identify and quantify novel cancer biomarkers.

Tailored radiation dose according to margin width for patients with ductal carcinoma in situ after breast-conserving surgery.

A 2 mm resection margin is considered adequate for ductal carcinoma in situ (DCIS). We assessed the effectiveness of a tailored radiation dose for margins < 2 mm and the appropriate margin width for high-risk DCIS. We retrospectively evaluated 137 patients who received adjuvant radiotherapy after breast-conserving surgery for DCIS between 2013 and 2019. The patients were divided into three- positive, close (< 2 mm), and negative (≥ 2 mm) margin groups. Radiation dose to the tumor bed in equivalent dose in 2 Gy fractions were a median of 66.25 Gy, 61.81 Gy, and 59.75 Gy for positive, close, and negative margin groups, respectively. During a median follow-up of 58 months, the crude rates of local recurrence were 15.0%, 6.7%, and 4.6% in the positive, close, and negative margin groups, respectively. The positive margin group had a significantly lower 5-year local recurrence-free survival (LRFS) rate compared to the close and negative margin groups in propensity-weighted log-rank analysis (84.82%, 93.27%, and 93.20%, respectively; p = 0.008). The difference in 5-year LRFS between patients with the high- and non-high-grade tumors decreased as the margin width increased (80.4% vs. 100.0% for margin ≥ 2 mm, p < 0.001; 92.3% vs. 100.0% for margin ≥ 6 mm, p = 0.123). With the radiation dose tailored for margin widths, positive margins were associated with poorer local control than negative margins, whereas close margins were not. Widely clear margins (≥ 2 mm) were related to favorable local control for high-grade DCIS.

Clinical Impact of Genomic and Pathway Alterations in Stage I EGFR-Mutant Lung Adenocarcinoma.

PURPOSE: We investigated the clinical impact of genomic and pathway alterations in stage I epidermal growth factor receptor (EGFR)-mutant lung adenocarcinomas, which have a high recurrence rate despite complete surgical resection. MATERIALS AND METHODS: Out of the initial cohort of 257 patients with completely resected stage I EGFR-mutant lung adenocarcinoma, tumor samples from 105 patients were subjected to analysis using large-panel next-generation sequencing. We analyzed 11 canonical oncogenic pathways and determined the number of pathway alterations (NPA). Survival analyses were performed based on co-occurring alterations and NPA in three patient groups: all patients, patients with International Association for the Study of Lung Cancer (IASLC) pathology grade 2, and patients with recurrent tumors treated with EGFR-tyrosine kinase inhibitor (TKI). RESULTS: In the univariate analysis, pathological stage, IASLC grade, TP53 mutation, NPA, phosphoinositide 3-kinase pathway, p53 pathway, and cell cycle pathway exhibited significant associations with worse recurrence-free survival (RFS). Moreover, RPS6KB1 or EGFR amplifications were linked to a poorer RFS. Multivariate analysis revealed that pathologic stage, IASLC grade, and cell cycle pathway alteration were independent poor prognostic factors for RFS (p=0.002, p < 0.001, and p=0.006, respectively). In the grade 2 subgroup, higher NPA was independently associated with worse RFS (p=0.003). Additionally, in patients with recurrence treated with EGFR-TKIs, co-occurring TP53 mutations were linked to shorter progression-free survival (p=0.025). CONCLUSION: Genomic and pathway alterations, particularly cell cycle alterations, high NPA, and TP53 mutations, were associated with worse clinical outcomes in stage I EGFR-mutant lung adenocarcinoma. These findings may have implications for risk stratification and the development of new therapeutic strategies in early-stage EGFR-mutant lung cancer patients.

The prognostic value of a combined immune score in tumor and immune cells assessed by immunohistochemistry in triple-negative breast cancer.

BACKGROUND: This study aimed to develop a novel combined immune score (CIS)-based model assessing prognosis in triple-negative breast cancer (TNBC). METHODS: The expression of eight immune markers (PD-1, PD-L1, PD-L2, IDO, TIM3, OX40, OX40L, and H7-H2) was assessed with immunohistochemistry on the tumor cells (TCs) and immune cells (ICs) of 227 TNBC cases, respectively, and subsequently associated with selected clinicopathological parameters and survival. Data retrieved from The Cancer Genome Atlas (TCGA) were further examined to validate our findings. RESULTS: All immune markers were often expressed in TCs and ICs, except for PD-1 which was not expressed in TCs. In ICs, the expression of all immune markers was positively correlated between one another, except between PD-L1 and OX40, also TIM3 and OX40. In ICs, PD-1, PD-L1, and OX40L positive expression was associated with a longer progression-free survival (PFS; p = 0.040, p = 0.020, and p = 0.020, respectively). In TCs, OX40 positive expression was associated with a shorter PFS (p = 0.025). Subsequently, the TNBC patients were classified into high and low combined immune score groups (CIS-H and CIS-L), based on the expression levels of a selection of biomarkers in TCs (TCIS-H or TCIS-L) and ICs (ICIS-H or ICIS-L). The TCIS-H group was significantly associated with a longer PFS (p < 0.001). Furthermore, the ICIS-H group was additionally associated with a longer PFS (p < 0.001) and overall survival (OS; p = 0.001), at significant levels. In the multivariate analysis, both TCIS-H and ICIS-H groups were identified as independent predictors of favorable PFS (p = 0.012 and p = 0.001, respectively). ICIS-H was also shown to be an independent predictor of favorable OS (p = 0.003). The analysis of the mRNA expression data from TCGA also validated our findings regarding TNBC. CONCLUSION: Our novel TCIS and ICIS exhibited a significant prognostic value in TNBC. Additional research would be needed to strengthen our findings and identify the most efficient prognostic and predictive biomarkers for TNBC patients.

Effect of high-dose radiation therapy on positive margins after breast-conserving surgery for invasive breast cancer.

PURPOSE: Positive margins after breast-conserving surgery are associated with poor oncological outcomes and warrant additional surgery. This study aimed to evaluate the effectiveness of high-dose radiation therapy for positive margins by comparing local recurrence between patients with positive and negative margins. METHODS: We retrospectively evaluated 550 patients treated with adjuvant radiation therapy after breast-conserving surgery for invasive breast cancer between 2013 and 2019. The total equivalent dose in 2 Gy fractions (EQD2) to the tumor bed ranged from 65.81 to 66.25 Gy for positive margins and 59.31-61.81 Gy for negative margins. The differences in local recurrence between the positive and negative margin groups were analyzed. RESULTS: After a median follow-up of 58 months, the crude local recurrence rate was 7.3% in the positive margin group (n = 55) and 2.4% in the negative margin group (n = 495). Positive margins were associated with higher local recurrence without statistical significance in the entire cohort (p = 0.062). Among patients aged <60 years, those with positive margins had a significantly lower 5-year local recurrence-free survival rate than those with negative margins (89.16% vs. 97.57%, respectively; p = 0.005). In contrast, there was no significant difference in the 5-year local recurrence-free survival rate between patients with positive and negative margins among those aged ≥60 years (100.00% vs. 94.38%, respectively; p = 0.426). CONCLUSION: In this study, positive margins were not associated with poor local control in older patients after a high-dose boosts. Further prospective studies are needed to verify our findings.

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Epithelioid hemangioendothelioma (EHE) is a low-grade malignant vascular neoplasm that can occur anywhere in the body. EHE has a low annual incidence (0.38/106) and prevalence (< 1/106), and primary mediastinal EHE is exceedingly rare. We report a case of EHE in a 53-year-old female which manifested as an incidentally discovered mass in the right paratracheal region. In this report, authors describe the pathological and radiological findings of primary mediastinal EHE invading the superior vena cava in the right paratracheal area.

High expression of the phosphoinositide 3-kinase p11γ isoform can predict poor prognosis of non-small cell lung cancer.

The protein p110γ is an isoform of the catalytic subunit of class I phosphoinositide 3-kinases (PI3Ks). PI3Ks are involved in the regulation of cell survival, growth, proliferation, and migration and have been implicated in the oncogenesis of various cancers. In this study, p110γ expression in non-small cell lung cancer (NSCLC) and its association with clinicopathological factors and patient survival were evaluated. A total of 230 NSCLC tumors were immunohistochemically stained for p110γ. Of these, 174 (75.7%) and 56 (24.3%) were placed in the low and high expression groups, respectively. The positive rate of p110γ was significantly higher in adenocarcinoma than in squamous cell carcinoma (p⟨0.001). Advanced stage NSCLCs showed higher p110γ expression than those at an early stage (p=0.002). Irrespective of the histological tumor type, the patients with high p110γ expression had significantly worse overall survival than those with low p110γ expression (p=0.004). p110γ expression was an independent poor prognostic factor in the multivariate analysis. Our results suggest that p110γ may be involved in the development and progression of NSCLC, and that p110γ has promising potential as a prognostic factor or novel therapeutic target for NSCLC.

Pyoderma Gangrenosum Mimicking Wound Infection after Breast Cancer Surgery.

Postoperative pyoderma gangrenosum (PPG) is rare, and its diagnosis is often delayed because of its wound infection-mimicking course. A 53-year-old breast cancer patient who underwent breast-conserving surgery of the right breast presented with fever, leukocytosis, C-reactive protein elevation, and redness of the right breast on postoperative day (POD) 3. The breast wound showed desquamation with painful ulcerative changes from POD 6, and fever was sustained under antibiotic administration. Wound irrigation was attempted; however, inflammatory skin damage progressed to involvement of the entire skin overlying the breast. With clinical suspicion of PPG, skin biopsy and systemic corticosteroid initiation were performed on POD 12. Wound damage progression ceased, and the systemic inflammation subsided. The patient underwent split-thickness skin grafting under intravenous corticosteroid administration, and the wound healed after 30 days. PPG is a rare clinical scenario. Early diagnosis is critical to avoid unnecessary treatment and aggravation of the surgical wound.

Clinical outcomes of laparoscopic versus open surgery for repairing colonoscopic perforation: a multicenter study.

PURPOSE: We conducted this study to compare the perioperative outcomes of laparoscopic surgery (LS) vs. open surgery (OS) for repairing colonoscopic perforation, and to evaluate the possible predictors of complications. METHOD: We reviewed the medical records of patients who underwent surgical repair of colonoscopic perforation by LS or OS between January 2005 and June 2019 at six Hallym University-affiliated hospitals. Multivariable analysis was performed to identify the predictors of postoperative complications. RESULTS: Of the total 99 patients, 40 underwent OS and 59 underwent LS. The postoperative hospital stay and the time to resuming a soft diet were shorter in the LS group than in the OS group (P = 0.017 and 0.026, respectively). The complication rate and Clavien-Dindo classification were not significantly different between the two groups. Multivariable analysis revealed that an American Society of Anesthesiologists score (ASA) ≥ 3 and switching from non-operative management to surgical treatment were independently associated with complications (P = 0.025 and 0.010, respectively). CONCLUSION: LS may be a safe alternative to OS for repairing colonoscopic perforation with a shorter postoperative hospital stay and time to resuming a soft diet. Patients with an ASA score ≥ 3 and those with changes to their planned treatment should be monitored carefully to minimize their risk of complications.

Comprehensive Immuno-Molecular Profiles for Liposarcoma: Roles of Programmed Death Ligand 1, Microsatellite Instability, and PIK3CA.

BACKGROUND: Developing personalized strategies for cancer has shown good efficacies. METHODS: We assessed the molecular targets programmed death ligand 1 (PD-L1), microsatellite instability (MSI), and PIK3CA. Seventy-four patients with liposarcomas who underwent curative resection were assessed for PD-L1 expression in the tumor and tumor-infiltrating lymphocytes (TILs), mismatch repair proteins (MLH1, PMS2, MSH2, and MSH6) by immunohistochemistry, MSI using polymerase chain reaction, and PIK3CA mutation/amplification using pyrosequencing and fluorescence in situ hybridization. RESULTS: Seventeen (23%) cases were TIL+ (≥1 + expression) and associated with longer 5-year overall survival than those with TIL- tumors (84.4 vs. 60.8%, p = 0.007). Six (35.3%) PD-L1+ tumors were detected only in TIL+ cases, with none detected in tumor cells. Two well-differentiated liposarcomas showed MSI, one low and one high with concurrent loss of MLH1, MSH6, and PMS2. PIK3CA mutation was detected in 7 (9.5%) [exon 9 (n = 4) and exon 20 (n = 3)] and only 1 Q546K mutation was a PD-L1+ tumor. PIK3CA copy number gain was detected in 18 (24.4%) and was associated with TIL+ tumors (p = 0.045). CONCLUSIONS: Our comprehensive immuno-molecular panel suggests that liposarcoma should be categorized based on the molecular genomic subtype for precision medicine.

Prognostic significance of glucose-related protein 94 in colorectal cancer.

AIMS: The expression of glucose-related protein 94 (GRP94), a member of the heat shock protein 90 family, was correlated with a variety of clinicopathological factors and patient survival in a large colorectal cancer (CRC) cohort. We aimed to elucidate the role of GRP94 in the prognosis of CRC patients. METHODS: Tissue microarray blocks were generated from 709 CRC samples and immunohistochemically stained for GRP94. RESULTS: Of the 709 tumours, 164 (23.1%) and 545 (76.9%) were classified in the low and high expression groups, respectively. GRP94 expression was high in CRC cases with larger tumours (p =  0.005) and advanced pT stage (p =  0.021). GRP94 expression was higher in females than males (p =  0.024). In univariate and multivariate survival analyses, high GRP94 expression was unexpectedly associated with better overall survival in CRC patients younger than 65 years of age (p =  0.001) CONCLUSION: Our conflicting results indicate that GRP94 has the ability to switch between oncogenic and tumour-suppressive roles depending on the conditions and microenvironment of the tumour cells. Furthermore, GRP94 could be a candidate biomarker to predict better prognosis in CRC patients.

Moesin (MSN) as a Novel Proteome-Based Diagnostic Marker for Early Detection of Invasive Bladder Urothelial Carcinoma in Liquid-Based Cytology.

Bladder urothelial carcinoma (BUC) is the most lethal malignancy of the urinary tract. Treatment for the disease highly depends on the invasiveness of cancer cells. Therefore, a predictive biomarker needs to be identified for invasive BUC. In this study, we employed proteomics methods on urine liquid-based cytology (LBC) samples and a BUC cell line library to determine a novel predictive biomarker for invasive BUC. Furthermore, an in vitro three-dimensional (3D) invasion study for biological significance and diagnostic validation through immunocytochemistry (ICC) were also performed. The proteomic analysis suggested moesin (MSN) as a potential biomarker to predict the invasiveness of BUC. The in vitro 3D invasion study showed that inhibition of MSN significantly decreased invasiveness in BUC cell lines. Further validation using ICC ultimately confirmed moesin (MSN) as a potential biomarker to predict the invasiveness of BUC (p = 0.023). In conclusion, we suggest moesin as a potential diagnostic marker for early detection of BUC with invasion in LBC and as a potential therapeutic target.

Utility of Human Papillomavirus Testing for Cervical Cancer Screening in Korea.

(1) Background: Cervical cancer is one of the most common cancers in Korean women. This study was performed to discover the utility of HPV (Human Papillomavirus) testing in screening of cervical lesions and to provide the prevalence of HPV and the genotype distribution in a single center of Korea. (2) Methods: A total of 15,141 women who underwent both HPV testing and cervical cytology were enrolled in this retrospective medical record review study. (3) Results: HPV testing showed higher sensitivity than cytology for the detection of histological high-grade squamous lesions. Furthermore, the sensitivity and specificity of HPV testing varied depending on the method used. The BD Onclarity™ HPV assay had higher sensitivity (90%) than the MyHPV CHIP™ kit (all types of HPV: 82%; high-risk HPV: 76%) for high-grade squamous lesions. A combination of MyHPV CHIP™ and cytology detected 90.9% (30/33) of histological high-grade squamous lesions. A combination of BD Onclarity™ HPV assay and cytology detected 96.55% (84/87) of histological high-grade squamous lesions. In addition, HPV prevalence and genotype distribution were different depending on the HPV testing method used. (4) Conclusion: HPV testing showed higher sensitivity than cytology, but the sensitivity and specificity of HPV testing had variation depending on the method used.

Differential expression of HSP90 isoforms and their correlations with clinicopathologic factors in patients with colorectal cancer.

Heat shock protein 90 (HSP90), a molecular chaperone, plays critical roles in cellular protection against various stressful stimuli and in the regulation of cellular growth and apoptosis. HSP90 has four human isoforms; HSP90α, HSP90ß, glucose related protein 94 (GRP94), and tumor necrosis factor (TNF) receptor-associated protein 1 (TRAP1). We evaluated the differential expression of these HSP90 isoforms in colorectal cancer (CRC) and correlated their expression levels with clinicopathological factors and patient survival rates. We performed immunohistochemical staining for HSP90α, HSP90ß, GRP94, and TRAP1 in 129 CRC tumor samples and found that HSP90α expression was significantly associated with advanced pT stage (P = 0.011) and shorter recurrence-free survival (RFS) (P = 0.010), whereas GRP94 expression was correlated with low grade (P = 0.029) and better RFS (P < 0.001). HSP90ß and TRAP1 had no prognostic impact, although HSP90ß expression was positively correlated with tumor size (P = 0.008). Based on our results, HSP90α and GRP94 are potential prognostic biomarkers of CRC. In addition, the differences in expression and functional activities among four HSP90 isoforms imply that isoform selectivity should be seriously considered when HSP90 inhibitors are studied or adopted for the treatment of CRC.

Genetic and clinicopathologic characteristics of lung adenocarcinoma with tumor spread through air spaces.

OBJECTIVE: The World Health Organization Classification of Lung Tumors considers "Spread Through Air Spaces (STAS)" as a form of invasion in lung adenocarcinoma. However, its existence as an independent pathologic entity rather than an artifact caused by spreading through a knife surface is still controversial. Therefore, we performed comprehensive analyses on the genetic and clinicopathologic characteristics of lung adenocarcinoma with STAS. MATERIALS AND METHODS: A total of 316 surgically resected lung adenocarcinoma cases were analyzed retrospectively. Detailed analyses were performed on clinical-histological-molecular features. Tumor STAS was defined as tumor cells within air spaces in the lung parenchyma beyond the edge of the main tumor. RESULTS: STAS was observed in 160 cases (50.6%). STAS was significantly related to lymphovascular invasion, lymph node metastasis, higher stage, and high-grade histologic subtype. STAS was frequently found in tumors with wild-type EGFR or ALK-rearrangement. Logistic regression analysis showed that STAS was significantly associated with absence of lepidic component, presence of micropapillary component, cribriform predominant type, lymphovascular invasion, and wild-type EGFR. Multivariate survival analysis demonstrated that STAS was independently associated with shorter recurrence-free survival. STAS was also associated with recurrences to extrathoracic sites as well as intrathoracic sites. CONCLUSION: STAS is associated with certain pathological and molecular subtypes. STAS might be a parameter for tumor aggressiveness in that it is strongly associated with poor prognostic factors and recurrence, including to extrathoracic sites.