Primary Salivary Type Lung Cancers in the National Cancer Database

[Rare subtypes of lung cancer]

In Europe, a rare cancer is defined as having an incidence rate of less than 6/100,000. Rare lung cancers encompass many entities defined by the 2021 WHO classification of thoracic tumors, and represent around 10% of all lung cancers. Rare lung cancers involve several histological types (carcinoma, sarcoma and lymphoma), each of which comprises several entities. The management of these patients with rare cancers requires specific medical expertise at every level (diagnosis, treatment and follow-up). These patients should therefore be referred to expert centers affiliated with national networks, giving them appropriate care and better access to innovative treatments. The deployment of systematic molecular characterization of these tumors has allowed for the identification and better characterization of specific entities. Some entities are specific to the lung, while others are more commonly found in other organs. In this review, we will only consider malignant lung tumors with an incidence of less than 1%.

Defining the needle in a haystack: A compendium of genomic, pathologic, and clinical characteristics of rare pulmonary tumors

A major paradigm shift in the diagnosis, management, and survival outcomes of early and advanced non-small cell lung cancer has transpired over the past few decades in thoracic oncology with the incorporation of molecular testing, targeted therapy, immunotherapy, neoadjuvant, and adjuvant approaches. However, transformation in the management and survival outcomes of rare lung tumors is lacking. Given the scarcity of these tumor types, randomized trials are rarely performed, and treatment is extrapolated from case series, tumor-agnostic trials, or cancers with similar histology. Literature informing the management of rare pulmonary tumors is typically limited to a single histology, unique features, or extraordinary responses to therapy. Few resources detailing genomic characteristics and delineating features of these tumors are available, often resulting in suboptimal treatment. Here, we explore the clinical, histopathologic, genomic features and potential therapies of five rare pulmonary tumors, namely adenosquamous, basaloid squamous, mucoepidermoid, carcinosarcoma, and NUT carcinoma, to build a resource for rare histological subtypes of the lung and emphasize knowledge gaps in the management of these tumors. Our recommendations are based on a comprehensive review of case reports and series, clinical trials, and the "Indiana University Experience."

Salivary gland-type cancers: cross-organ demographics of a rare cancer

BACKGROUND

Salivary gland-type cancers (SGTCs) are histologically heterogeneous and can affect organs other than the salivary glands. Some tumors outside the salivary glands are diagnosed on their unique histological characteristics. Comprehensive cross-organ studies on SGTCs are limited.

METHODS

We retrospectively analyzed the data of patients with salivary duct carcinoma (SDC), adenoid cystic carcinoma (AdCC), mucoepidermoid carcinoma (MEC), epithelial-myoepithelial carcinoma (EMC), acinic cell carcinoma (AcCC), and polymorphous adenocarcinoma (PAC) who visited our institution between 2009 and 2019. The primary tumor sites were classified into four categories; major salivary glands, head/neck (H/N) excluding (exc) major salivary glands (MSG) regions, broncho-pulmonary regions, and "others". H/N exc MSG was further divided into three subcategories, nasal/paranasal sinus, oral and pharynx/larynx.

RESULTS

We identified 173 patients with SGTCs, with SDC, AdCC, MEC, EMC, AcCC, and PAC accounting for 20%, 42%, 27%, 3%, 8%, and 1% of the cases, respectively. The most frequent primary site was the major salivary glands (64%), followed by H/N exc MSG regions (27%), broncho-pulmonary regions, and "others", thus non-salivary gland origins accounted for 9% of all cases. Patients with SDC, MEC, AcCC, or SGTC of the major salivary glands and broncho-pulmonary regions were more frequently treated by surgery. The overall survival time of the patients with MEC was significantly better than that of patients with SDC or EMC.

CONCLUSIONS

This cross-organ study highlights the clinical significance of SGTCs, underscoring the need for developing novel therapies for this rare disease entity.

Evolving Diagnostic Approach of Pulmonary Salivary Gland-type Tumors

Pulmonary salivary gland-type, although bear resemblance to their salivary gland counterparts, present a diagnostic challenge due to their rarity. Clinical features overlap with lung carcinoma; however, management strategies and outcomes are distinct. Onus falls on the pathologist to avoid misinterpretation of small biopsies especially in young, nonsmokers with slow growing or circumscribed endobronchial growths. A combination of cytokeratin, myoepithelial immunohistochemical markers, and identification of signature molecular alteration is invaluable in differentiation from lung cancers and subtyping the pulmonary salivary gland-type tumor.

Current diagnosis and treatment of salivary gland-type tumors of the lung

Salivary gland-type tumors of the lung are thought to originate from the submucosal exocrine glands of the large airways. Due to their rare occurrence, reports of their study are limited to small-scale or case reports. Therefore, daily clinical practices often require a search for previous reports. In the last 20 years, several genetic rearrangements have been identified, such as MYB::NF1B rearrangements in adenoid cystic carcinoma, CRTC1::MAML2 rearrangements in mucoepidermoid carcinoma, EWSR1::ATF1 rearrangements in hyalinizing clear cell carcinoma and rearrangements of the EWSR1 locus or FUS (TLS) locus in myoepithelioma and myoepithelial carcinoma. These molecular alterations have been useful in diagnosing these tumors, although they have not yet been linked to molecularly targeted therapies. The morphologic, immunophenotypic, and molecular characteristics of these tumors are similar to those of their counterparts of extrapulmonary origin, so clinical and radiologic differential diagnosis is required to distinguish between primary and metastatic disease of other primary sites. However, these molecular alterations can be useful in differentiating them from other primary lung cancer histologic types. The management of these tumors requires broad knowledge of the latest diagnostics, surgery, radiotherapy, bronchoscopic interventions, chemotherapy, immunotherapy as well as therapeutic agents in development, including molecularly targeted agents. This review provides a comprehensive overview of the current diagnosis and treatment of pulmonary salivary gland tumors, with a focus on adenoid cystic carcinoma and mucoepidermoid carcinoma, which are the two most common subtypes.

Renal Metastasis Arising From a Pulmonary Adenoid Cystic Carcinoma: A Rare Case Report and Literature Review

Adenoid cystic carcinoma (ACC), a rare malignancy, typically originates in salivary glands and is rarely found in other locations. In this case report, we describe a 54-year-old male patient who was presented to the Urology Department of Yantai Yuhuangding hospital with right-sided waist pain. The patient underwent percutaneous ultrasound-guided biopsies of lesions in the kidney and lung, which were histologically confirmed as primary adenoid cystic carcinoma of the lung and metastatic renal adenoid cystic carcinoma, respectively. Given the presence of multiple metastases, the patient received systemic palliative chemotherapy, which was well-tolerated and effectively controlled the tumor. At the last follow-up, there was no evidence of tumor progression in the patient.

SALTT study: A retrospective analysis of 111 SAlivary gland tumors of Lung and Tracheobronchial Tree

INTRODUCTION

Primary pulmonary salivary gland-type tumours (PPSGT) are rare lung neoplasms arising from submucosal seromucinous glands in the central airway.

METHODS AND RESULTS

We retrospectively analysed the clinicopathological features of 111 PPSGTs diagnosed at our institute between 2003 and 2021. The mean age at diagnosis was 43.8 years(range 6-78 years) and a male-to-female ratio of 2:1. On imaging, 92 % of cases had centrally located tumours and 37.3 % were early stage. The histopathological types included 70 cases (63 %) of mucoepidermoid carcinoma (MEC), 31 cases (27.7 %) of adenoid cystic carcinoma (ADCC), two cases of myoepithelial carcinoma, one case each of acinic cell carcinoma (ACC), clear cell carcinoma (CCC), epithelial myoepithelial carcinoma (EMC) and 5 others [including adenocarcinoma of minor salivary gland origin(n = 3), carcinoma with sebaceous differentiation(n = 1) and poorly differentiated carcinoma of salivary gland type(n = 1)]. The size of the tumours found in the resection specimens ranged from 1 cm to 13 cm, with an average size of 4.9 cm. High-risk attributes such as lymphovascular invasion (LVI), perineural invasion (PNI), pleural involvement, positive resection margins, and nodal metastasis were identified in 15.3 %, 15.3 %, 13.6 %,15.2 % and 6.7 % of cases, respectively. These attributes were found to be more frequent in ADCC than in MEC. Surgery was the main treatment modality [68/84 (80 %) cases]. ADCC cases had more recurrence and distant metastasis than MEC cases. The 3- year overall-survival (OS) and recurrence-free survival(RFS) were better in patients with age lesser than 60 years(p-value <0.0001), low pT stage (p-value 0.00038) and lower grade of MEC(p-value-0.0067).

CONCLUSION

It is crucial to have an acquaintance with the morphologic spectrum and immunophenotypic characteristics of PPSGT to recognize them in this unusual location. In tandem, it is crucial to differentiate them from conventional primary non-small cell lung carcinoma, as the management protocols and prognostic implications differ significantly.

Rare but clinically important salivary gland-type tumor of the lung: A review

Salivary gland-type tumor (SGT) of the lung, which arises from the bronchial glands of the tracheobronchial tree, was first recognized in the 1950s. SGT represents less than 1% of all lung tumors and is generally reported to have a good prognosis. Mucoepidermoid carcinoma (MEC) and adenoid cystic carcinoma (ACC) are the two most common subtypes, comprising more than 90% of all SGTs. The reported 5-year survival rate of patients with SGT is 63.4%. Because this type of tumor develops in major bronchi, patients with SGT commonly present with symptoms of bronchial obstruction, including dyspnea, shortness of breath, wheezing, and coughing; thus, the tumor is usually identified at an early stage. Most patients are treated by lobectomy and pneumonectomy, but bronchoplasty or tracheoplasty is often needed to preserve respiratory function. Lymphadenectomy in the surgical resection of SGT is recommended, given that clinical benefit from lymphadenectomy has been reported in patients with MEC. For advanced tumors, appropriate therapy should be considered according to the subtype because of the varying clinicopathologic features. MEC, but not ACC, is less likely to be treated with radiation therapy because of its low response rate. Although previous researchers have learned much from studying SGT over the years, the diagnosis and treatment of SGT remains a complex and challenging problem for thoracic surgeons. In this article, we review the diagnosis, prognosis, and treatment (surgery, chemotherapy, and radiotherapy) of SGT, mainly focusing on MEC and ACC. We also summarize reports of adjuvant and definitive radiation therapy for ACC in the literature.

Primary Mucoepidermoid Carcinoma of the Lung Coexisting With Pulmonary Tuberculosis: A Rare Case Report

Mucoepidermoid carcinoma (MEC) is a well-established neoplasm of the salivary glands. However, the MEC of the lung is an exceedingly rare neoplasm that falls under the category of salivary gland-type tumors of the lung. Pulmonary MEC is recognized for its indolent progression. Pulmonary tuberculosis (TB) is a prevalent infectious disease in India and ranks among the leading causes of death from infectious diseases. Nevertheless, the co-occurrence of pulmonary MEC with pulmonary TB is a rare phenomenon that has not been documented in the literature. In this report, we describe a 54-year-old male patient who presented with symptoms of dysphagia, weight loss, and fever. Histopathological examination diagnosed him with pulmonary MEC, and concurrent cytology and Gene-Xpert tests confirmed tuberculosis. This case represents the first documented instance of this particular co-occurrence. It underscores the limitations of radiology in diagnosing such a rare neoplasm, especially when there is an absence of lung parenchyma infiltration and a mass lesion. Additionally, this case supports the possibility of an interdependent relationship between malignancies and tuberculosis.

Pulmonary adenoid cystic carcinoma: molecular characteristics and literature review

BACKGROUND

Pulmonary adenoid cystic carcinoma (PACC) is an exceptionally rare salivary gland-type malignant neoplasm. Because of its clinical manifestations, imaging features are not different from other types of non-small cell lung cancer, which is a diagnostic challenge for most doctors.

CONCLUSIONS

A review of the literature shows that high amounts of immunohistochemical (IHC) markers, such as CK7, CD117, P63, SMA, CK5/6, and S-100 are helpful for PACC diagnosis. Surgical resection is the main treatment of PACC, but treatment options for advanced PACC patients are limited and the research of molecular targeted drugs is ongoing in advanced cases not eligible for surgery. Currently, research on PACC targeted therapy mainly focuses on the exploration of v-myb avian myeloblastosis virus oncogene homolog (MYB) and its downstream target genes. In addition, median tumor mutation burden and PD-1/PD-L1 were lower in PACC, which may indicate poor efficacy of immunotherapy in PACC patients. This review focuses on the pathologic features, molecular characteristics, diagnosis, treatment and prognosis of PACC to establish a comprehensive understanding of PACC.

Clinical, laboratory, pathological, and radiological characteristics and prognosis of patients with pulmonary salivary gland-type tumors

PURPOSE

Primary pulmonary salivary gland-type tumor (PSGT) included two main subtypes, pulmonary adenoid cystic carcinoma (PACC) and pulmonary mucoepidermoid carcinoma (PMEC). The purpose of this study was to compare the similarities and differences between these two subtypes and to identify independent risk factors for the prognosis of PSGT patients.

METHODS

This study screened patients with a pathological diagnosis of PSGT in Beijing Chaoyang Hospital between 2010 and 2021. The clinical, pathological, radiological, laboratory test, and other characteristics were collected, and t, nonparametric and chi-squared tests were used to compare the differences in clinical characteristics of the two subtypes. COX univariate and multivariate analyses were used to explore prognostic-related risk factors.

RESULTS

A total of 62 patients with PSGT were included in our center over a 12-year period. There were 26 PMEC patients and 36 PACC patients. There were differences in the clinical, pathological, and radiological features of the two tumor subtypes. Univariate analysis showed that weight loss, chemotherapy, white blood cells, lymphocytes, red blood cells, total protein, and total bilirubin might be related to the prognosis in PSGT patients. Multivariate results showed that lymphocytes (p = 0.031), red blood cells (p = 0.047), total protein (p = 0.032), and total bilirubin (p = 0.010) were independent prognostic risk factors. Chemotherapy (HR 4.452; 95% CI 1.723-11.503; p = 0.002) might be associated with progression-free survival (PFS).

CONCLUSION

The two subtypes of PSGT had significantly different clinical, laboratory, pathological, and radiological features. However, there was no significant difference in the prognosis of patients with PMEC and PACC subtypes. Cox univariate and multivariate analyses showed that levels of lymphocytes, erythrocytes, total protein and total bilirubin in the peripheral blood of PSGT patients might be related to patient overall survival. Chemotherapy might also be associated with PFS.

Pulmonary mucoepidermoid carcinoma: A clinicopathological study of 45 patients

Pulmonary mucoepidermoid carcinoma (PMEC) is uncommon. The purpose of this study was to evaluate the clinicopathological features, diagnostic criteria, treatment options, and prognostic factors relating to primary PMEC. Clinical data on 45 patients with primary PMEC were collected and analyzed retrospectively at Tianjin Medical University General Hospital and the First People' Hospital of Longquanyi District Chengdu from January 2008 to December 2020. The 45 patients (25 males and 20 females) ranged in age from 22 to 72 years, with a median age of 49 and an average age of 47.7. All the patients underwent surgery, with 32 receiving only surgery and 13 receiving both surgery and postoperative chemotherapy. A total of 34 instances of low-grade tumors and 11 cases of high-grade tumors were discovered during postoperative pathological diagnosis. Forty-five patients were followed for 13 to 78 months, and four died during this period. In all four instances, a lung infection unrelated to the tumor was determined to be the cause of death. The MAML2 gene translocation was detected in 40 of 45 patients, with 34 of them testing positive. Radical surgery with lymph node dissection is an efficient treatment for PMEC. The prognosis is poor for patients with advanced disease, a negative MAML2 gene translocation, lymph node metastases, and high-grade tumors.

Adenoid Cystic Carcinoma of Lobar Bronchial Origin: 20-Year Experience at a Single Institution

BACKGROUND

Pulmonary adenoid cystic carcinoma (ACC) is a rare type of lung malignancy. The prevalence of ACC of lobar bronchial origin is lower than that of other lung malignancies, and studies investigating it are lacking. This study aimed to evaluate survival of patients with ACC of the lobar bronchus after surgical resection and to explore its prognostic factors.

METHODS

Between January 2000 and December 2019, 35 patients at the National Cancer Center/Cancer Hospital with a diagnosis of ACC of the lobar bronchus were included in the retrospective analysis.

RESULTS

During a median follow-up period of 61 months (range, 10-194 months), the analysis showed a 5-year overall survival (OS) rate of 81.4%, a 5-year locoregional recurrence-free survival rate of 84.0%, and 5-year disease-free survival rate of 60.1%. The univariate analysis exclusively identified the surgical margin as a predictor of OS, and survival was significantly longer for the patients with negative surgical margins than for those with positive surgical margins (R0 vs. R1: 94.4% vs. 66.0%; p = 0.014). Adjuvant radiotherapy was administered to most of the patients with positive surgical margins, which might have contributed to prolonged OS (R0 vs. R1+RT: 94.4% vs. 66.7%, p = 0.173; R0 vs. R1+no RT: 94.4% vs. 62.5%, p = 0.007).

CONCLUSIONS

For ACC of lobar bronchial origin, complete resection is the radical treatment, and the OS rate was significantly higher for the R0 patients than for the R1 patients. Adjuvant radiotherapy for patients with R1 may prolong survival.

Salivary Gland-type Tumors of the Lung

CONTEXT.—

Salivary gland-type tumors (SGTs) of the lung represent a distinct group of lung neoplasms. Pulmonary SGTs often pose diagnostic challenges, especially in small biopsy and cytology samples because of limited sample volume and overlapping morphology among pulmonary SGTs, metastatic SGTs of head and neck origin, and other lung tumors.

OBJECTIVE.—

To identify the clinical characteristics, histomorphology, immunophenotypic features, and molecular alterations that are crucial for the diagnosis and differential diagnosis of pulmonary SGTs, especially in small biopsy and cytology specimens.

DATA SOURCES.—

Literature review and authors' personal practice experience.

CONCLUSIONS.—

An accurate diagnosis of pulmonary SGTs can be achieved by careful evaluation of clinical findings and histomorphology in conjunction with immunohistochemical studies and molecular analysis.

Outcomes of surgically managed primary lung sarcomas: a National Cancer Database analysis

Background

Primary lung sarcoma (PLS) represents a rare form of lung cancer with outcomes that are poorly defined by small datasets. We sought to characterize clinical and pathological characteristics and associated survival within the surgically managed subgroup of these unusual pulmonary malignancies.

Methods

We performed a retrospective analysis of the National Cancer Database (NCDB), which was queried for cases of surgically managed PLS diagnosed between 2004–2014. Adjusted mortality was evaluated in a multivariable Cox proportional hazards model and compared to surgically manage non-small cell lung cancer (NSCLC) patients from the same time period.

Results

A total of 695 patients with surgically managed PLS were identified with 37 different histologic subtypes. The mean age of diagnosis was 57.7 years (range, 18–90 years). A majority of patients underwent surgical resection alone (64.3%) with an estimated 5-year overall survival (OS) of 51%. The multivariable Cox model identified increasing age, Charlson-Deyo score ≥2, high tumor grade, tumor size >5 cm, positive margins, and positive lymph nodes to be associated with higher risk for mortality (P<0.05). Compared to 101,428 surgically managed patients with adenocarcinoma, PLS patients were younger with fewer comorbidities but had larger tumors, higher grade tumors, and were more likely node negative (P<0.001). Surgery with adjuvant chemotherapy was associated with worse survival than surgery alone (HR 1.41, 95% CI: 1.05–1.88). The extent of parenchymal resection (lobar vs. sublobar) was not predictive for survival. Five-year OS was lower for patients with PLS (44%) than adenocarcinoma (53.6%, P<0.001).

Conclusions

The survival of surgically managed PLS is reasonable and impacted by tumor attributes and the completeness of surgical resection. Further study to define the role of multimodal therapy is indicated.

Sialadenoma Papilliferum of the Bronchus: An Unrecognized Bronchial Counterpart of the Salivary Gland Tumor With Frequent BRAF V600E Mutations

Sialadenoma papilliferum (SP) is a rare benign tumor of the salivary glands, and only 3 unequivocal cases of SP arising in the bronchus have been reported. We herein describe the histomorphologic and molecular features of 4 bronchial SP cases and discuss the differential diagnosis of this entity and the relationship with its clinicopathologic mimics, in particular, glandular papilloma and mixed squamous cell and glandular papilloma (GP/MP). We encountered 2 male and 2 female patients with bronchial SP (mean: 66.8 y old). All 4 tumors arose in the central bronchus and were characterized by a combination of surface exophytic endobronchial papillary proliferation and a submucosal multicystic component with complex architecture. The neoplastic epithelium consisted predominantly of nonciliated stratified columnar cells with ciliated, squamous, and mucinous cells present focally. While 2 tumors (50%) harbored a BRAF V600E mutation by molecular and immunohistochemical analysis, similar to GP/MP, no KRAS, HRAS, AKT1, or PIK3CA mutations were detected in any of the cases. Two patients were treated with limited resection, while 2 patients underwent lobectomy based on the diagnosis of adenocarcinoma or possible squamous cell carcinoma in situ in the preoperative biopsy. All survived without recurrence or metastasis for 23 to 122 months after treatment. SP can develop in the central bronchus as the bronchial counterpart of the salivary gland tumor and should be considered in the differential diagnosis of endobronchial tumors. In addition, some histologic resemblance and frequent BRAF V600E mutation raise the possibility of SP and GP/MP being on the same disease spectrum.

Solitary Renal Metastasis Arising from a Pulmonary Adenoid Cystic Carcinoma: A Case Report and Review of the Literature

Adenoid cystic carcinoma (ACC) is a malignancy affecting the salivary glands and rarely involving the lung. Due to its rarity, primary lung ACC remains incompletely understood. We herein report the case of a 57-year-old female patient who was initially diagnosed with primary lung ACC and was treated by lobectomy. Seven years later, an abdominal computed tomography scan performed in the context of surveillance revealed the presence of a solid lesion arising from the lower pole of the left kidney. The patient underwent left partial nephrectomy, and histopathology confirmed a completely excised metastatic ACC.

Clinical Characteristics and Prognosis of Patients With Pulmonary Mucoepidermoid Carcinoma: A SEER-Based Analysis

BACKGROUND

Primary pulmonary mucoepidermoid carcinoma (PMEC) is an extremely rare malignancy. Its clinical characteristics and prognosis are not fully understood. This study evaluated clinical characteristics and prognostic factors of PMEC and established a nomogram to predict its 1-, 3-, 5- and 10-year cancer-specific survival (CSS) rates.

METHODS

In the Surveillance, Epidemiology, and End Results database from January 1, 1975 to December 31, 2016, patients pathologically diagnosed with PMEC were identified. Kaplan-Meier analysis and Cox regression were performed to evaluate the CSS stratified by different covariates. A predictive nomogram model was built and validated by the concordance index (C-index) and calibration curves.

RESULTS

A total of 585 PMEC patients were identified. A total of 408 (70%) of patients were placed into the training cohort, and 177 (30%) patients were placed into the validation cohort. The 5- and 10-year CSS rates of stage I-II PMEC patients were 91.4 and 88.9, respectively. The 1-, 3- and 5-year CSS rates of stage III-IV PMEC were 56.5, 39.45, and 32.1%, respectively. Survival curves showed that older age, large tumor size, poor differentiation, and high TNM stage were associated with a significantly worse prognosis. CSS outcomes were significantly better in patients who received surgical treatments (surgical alone, surgery plus radiation and/or chemotherapy). Patients who received radiation and/or chemotherapy had the worst prognosis. Multivariate Cox results revealed that covariates, including age, tumor laterality, tumor sizes, pathological differentiation, lymph node metastasis, distant metastasis, TNM stage and therapy, were independent prognostic factors for PMEC. These factors were used to construct a nomogram. The C-index of the nomogram was 0.921. The calibration curve presented favorable consistency between the predicted CSS and actual observations. This nomogram was validated by the validation cohort. The C-index of the validation cohort was 0.968.

CONCLUSION

Age, bilateral tumors, tumor size, pathological differentiation grade, lymph node metastasis, distant metastasis, TNM stage and therapy were independent prognostic factors of PMEC patients. The first nomogram for predicting the CSS of PMEC was built and validated, showing its potential value in practice.

Clinical outcomes and the role of bronchoscopic intervention in patients with primary pulmonary salivary gland-type tumors

OBJECTIVES

Primary pulmonary salivary gland-type tumors (PSGT) are rare among all types of lung cancer. The purpose of this study was not only to evaluate the clinical outcomes and prognostic factors after treatment, but also to assess the role for bronchoscopic intervention in PSGT.

METHODS

We analyzed the medical data of 181 PSGT patients who were treated between 1995 and 2018. Patients were divided into three groups according to the initial treatment, as follows: surgical resection with/without adjuvant therapy including bronchoscopic intervention (surgery group, n = 116); bronchoscopic intervention without surgical resection (bronchoscopic intervention group, n = 51); and other treatments group (n = 14). A multivariable Cox proportional hazard regression analysis was used to identify the independent prognostic factors associated with overall survival (OS) and progression free survival (PFS) after the first treatment. In addition, subgroup analysis was performed according to the clinical stage.

RESULTS

Among the 181 patients, 104 (57.5%) patients were diagnosed with adenoid cystic carcinoma (ACC), 71 (39.2%) with mucoepidermoid carcinoma, and 6 (3.3%) with epithelial-myoepithelial carcinoma. In the surgery group, 21 patients underwent bronchoscopic intervention as a bridge therapy before surgery because of respiratory distress. Poor OS was associated with older age, the existence of other malignancy, higher clinical stages, larger tumor size, and non-surgical treatments. Lower PFS was associated with ACC, larger tumor size, and non-surgical treatments. The surgery group had the best OS and PFS among all treatment groups. However, there was no significant difference in the OS between the surgery and bronchoscopic intervention groups (p = 0.66) in patients at high clinical stages.

CONCLUSIONS

Surgical resection was the best initial treatment choice. However, bronchoscopic intervention may be useful as the initial treatment in patients at high clinical stage and as a bridge therapy prior to surgery.

Treatment outcomes of patients with tracheobronchial mucoepidermoid carcinoma compared with those with adenoid cystic carcinoma

OBJECTIVE

Tracheobronchial mucoepidermoid carcinoma (TMEC) is an extremely rare salivary gland-type neoplasm. We aimed to explore the clinical characteristics and prognosis of TMEC and to compare them with those of another rare salivary gland-type neoplasm, tracheobronchial adenoid cystic carcinoma (TACC).

METHOD

We performed a retrospective review of all patients pathologically diagnosed with TMEC between 1965 and 2017 at our institution. We reviewed the patients' clinical characteristics, treatment methods and outcomes and compared the results of TMEC and TACC patients.

RESULTS

A total of 115 consecutive patients, including 107 who underwent surgery and 8 who received nonoperative therapy, were included in our study. The 1-, 2-, and 5-year survival rates were 97.89%, 94.17%, and 90.50%, respectively, in the surgical group and 83.33%, 41.67% and 0.00%, respectively, in the nonoperative group. The multivariate analysis showed that N stage was an independent prognostic factor for overall survival (OS). TMEC patients were younger, had a shorter complaint duration, had fewer symptoms, had more bronchial tumors, and were more likely to undergo surgical treatment and achieve an R0 resection (surgically treated patients) than TACC patients; furthermore, TMEC patients had a significantly better OS than TACC patients (P < 0.050).

CONCLUSIONS

TMEC has different characteristics and a better prognosis than TACC, which may reflect the different biological behaviors of these two salivary gland neoplasms. Radical treatment and close follow-up are critical for surgically treated TMEC patients with lymph node metastasis.

Big data, big contributions: outcomes research in thoracic surgery

In recent years, analysis of registry data has defined clinically significant practice patterns and treatment strategies that optimize cancer care for thoracic surgery patients. These higher-order outcome studies rely on large patient cohorts that minimize the risk of selection bias and allow for a powered analysis that is not achievable with single- or multi-institutional data. This review uses recent study examples to highlight important contributions to our knowledge of thoracic surgery and describes how outcomes research using large data can address high impact clinical questions.

Prophylactic cranial irradiation is associated with improved survival following resection for limited stage small cell lung cancer

Background

Brain metastases are a major cause of mortality in patients with small cell lung cancer (SCLC). Prophylactic cranial irradiation (PCI) may improve survival among patients that respond to chemotherapy. Less is known about the outcomes of PCI following surgical resection of SCLC. The purpose of this study was to determine if patients who underwent initial surgical resection of SCLC benefit from PCI.

Methods

Adult patients in the National Cancer Database (NCDB) who underwent complete resection for primary, non-metastatic SCLC between 2004 and 2015 were identified. Patients that received preoperative chemotherapy or who did not receive appropriate adjuvant chemotherapy were excluded. Patients were grouped by treatment with or without cranial radiation within 8 months of resection. Survival was estimated using Kaplan-Meier and Cox multivariable analysis, adjusting for patient and tumor characteristics.

Results

A total of 859 patients met inclusion criteria (202 received PCI and 657 did not). Kaplan-Meier analysis demonstrated that patients treated with PCI had significantly improved survival compared to no PCI (5-year survival 59% vs. 50%, logrank P=0.0038). Multivariable cox models confirmed a significantly decreased hazard of death for patients receiving PCI (HR: 0.70, 95% CI: 0.55-0.89, P=0.003). In subset analyses, PCI was associated with significantly improved survival for node positive patients, but not node negative patients.

Conclusions

PCI is associated with increased survival for patients following surgical resection of SCLC. Patients with positive lymph nodes appear to benefit the most, while it remains unclear if patients with negative lymph nodes derive a benefit. Further study is warranted to clarify which subsets of patients should be treated with PCI.