Pulmonary Adenoid Cystic Carcinoma Research Articles

Extrapleural Pneumonectomy for Treatment of Pulmonary Adenoid Cystic Carcinoma

Extrapleural Pneumonectomy for Treatment of Pulmonary Adenoid Cystic Carcinoma

Uncommon Presentation of Pulmonary Adenoid Cystic Carcinoma: A Case of Brain Metastasis in a Young Smoker

Abstract Introduction/Objective Pulmonary adenoid cystic carcinoma (PACC) is a rare entity, accounting for only 0.04-0.2% lung cancers, and mainly originating from the small salivary glands in the tracheobronchial tree. Due to slow-growing pattern and unspecific symptoms, the diagnosis is often delayed. While metastasis in PACC is uncommon, reports of brain metastasis are exceedingly rare. We present a case of PACC with metastasis to the brain in a young smoker. Methods/Case Report A 29-year-old female with history of smoking presented with headache, hypersomnia, episodes of vomiting and falling. Physical examination revealed multiple palpable nodes on the mid head, left temporal and right parietal area, left shoulder area were found. CT scan demonstrated complex cystic mass with a mural nodule within the left cerebellar hemisphere, with displacement of the cerebellar tonsils, as well as a 7.4 cm left infrahilar mass with heterogenous enhancement. Patient underwent craniotomy with tumor resection and left lower lobe endobronchial biopsy. Touch smear of the brain lesion showed clusters of hyperchromatic cells with myxoid like and hyalinized stroma. H&E stain showed cords of neoplastic cells embedded in a basophilic/myxoid stroma. Lung biopsy showed similar histological patterns. IHC stain showed the tumor cells were positive for epithelial and myoepithelial cells markers(CAM5.2, CK7, p63, Sox 10), retained INI1/BAF47 and BRG1 expression, negative for NUT and BCOR. Salivary Gland NGS Fusion Panel was performed and detected a MYBL1::NFIB [t(8;9)(8q13.1;9p23)] fusion alteration, which confirmed the diagnosis of adenoid cystic carcinoma. Considering no lesion was found in the patient’s head and neck, diagnosis of PACC was made. Results (if a Case Study enter NA) NA Conclusion PACC manifests three histologic subtypes: cribriform (most common), trabecular, and solid. In this case, brain and lung lesions exhibited similar patterns - nests of small, monomorphic cells within a myxoid-like and basophilic stroma background, consistent with trabecular pattern. Cytologically, densely packed cellular clusters were embedded in a myxoid like matrix. Distinguishing PACC from other salivary gland tumors is challenging. Immunostains for epithelial and myoepithelial cells, along with morphology, aid in diagnosis. The MYB::NFIB fusion helps differentiate from other lung salivary gland malignancies, but is found in a lower percentage of PACC cases (~40%) compared to other primary adnoid cystic carcinoma (~85%).

Primary pulmonary adenoid cystic carcinoma: A clinicopathological study of 64 patients.

This study aimed to investigate the clinicopathological features and prognostic indicators of primary pulmonary adenoid cystic carcinoma (PACC). Clinical data were collected from 64 primary PACC patients and analyzed retrospectively at the Tianjin Medical University General Hospital, the West China Hospital of Sichuan University, the First Affiliated Hospital of Guangxi Medical University, and the Bishan Hospital of Chongqing Medical University from January 2003 to August 2023. The 64 patients (28 males and 36 females) were aged from 20 to 73 years, with a median age of 49 years and an average age of 49.3 years. Immunohistochemical staining showed that the tumors expressed CK7, S-100 protein, CK5/6, CD117, and p63. Seven patients underwent fluorescence in situ hybridization (FISH) testing and three were found to have myeloblastosis (MYB) gene translocation. In total, 53 patients underwent surgery, among whom 31 received only surgery and 22 received both surgery and postoperative chemoradiotherapy. In addition, 10 patients received chemoradiotherapy only, while one patient underwent treatment with traditional Chinese medicine. The overall survival rates in the first, third, and fifth years were 98.4%, 95.3%, and 87.5%, respectively. Prognostic analysis revealed that age, tumor size, lymph node metastasis status, margin status, and choice of treatment modality significantly influenced the patients' prognosis.

Claudin expression in pulmonary adenoid cystic carcinoma and mucoepidermoid carcinoma.

Background: Although the expression of tight junction protein claudins (CLDNs) is well known in common histological subtypes of lung cancer, it has not been investigated in rare lung cancers. The aim of our study was to examine the expression of different CLDNs in pulmonary salivary gland tumors. Methods: 35 rare lung cancers including pathologically confirmed 12 adenoid cystic carcinomas (ACCs) and 23 mucoepidermoid carcinomas (MECs) were collected retrospectively. Immunohistochemical (IHC) staining was performed on formalin fixed paraffin embedded (FFPE) tumor tissues, and CLDN1, -2, -3, -4, -5, -7, and -18 protein expressions were analyzed. The levels of immunopositivity were determined with H-score. Certain pathological characteristics of ACC and MEC samples (tumor grade, presence of necrosis, presence of blood vessel infiltration, and degree of lymphoid infiltration) were also analyzed. Results: CLDN overexpression was observed in both tumor types, especially in CLDN2, -7, and -18 IHC. Markedly different patterns of CLDN expression were found for ACC and MEC tumors, especially for CLDN1, -2, -4, and -7, although none of these trends remained significant after correction for multiple testing. Positive correlations between expressions of CLDN2 and -5, CLDN3 and -4, and CLDN5 and -18 were also demonstrated. Tumors of never-smokers presented lower levels of CLDN18 than tumors of current smokers (p-value: 0.003). Conclusion: This is the first study to comprehensively describe the expression of different CLDNs in lung ACC and MEC. Overexpression of certain CLDNs may pave the way for targeted anti-claudin therapy in these rare histological subtypes of lung cancer.

Bronchial cytology of pulmonary adenoid cystic carcinoma – A multi-institute series with emphasis on immunocytochemistry

BackgroundPulmonary adenoid cystic carcinoma (AdCC) is a central and superficial primary lung neoplasm, well-suited for sampling by bronchial cytology. This study aims to review the cytologic features of pulmonary AdCC on bronchial cytology, and to report an experience of applying immunocytochemistry on this rare entity. MethodsA multi-institute review of bronchial cytology specimens from histologically proven pulmonary AdCCs was performed. Published cases of bronchial cytology of pulmonary AdCC were reviewed. The cytologic features and immunocytochemical profile for pulmonary AdCC was summarized and compared with pertinent differentials. ResultsA total of 16 specimens from eight patients were retrieved. The initial cytologic diagnoses were negative (n = 7), atypia (n = 6), suspicious (n = 2) and AdCC (n = 1). Retrospective review showed eight bronchial cytology specimens (including five cases of atypia) with tumor cells present. The tumor cells displayed small basaloid nuclei with occasional small nucleoli, mild nuclear atypia, and scanty cytoplasm. Architectural patterns observed included clusters, tubules, solid sheets, three-dimensional balls, papillary-like fronds, and complex cribriform structures. Basement-membrane-like material, free or associated with tumor cells, were seen in all cases. Immunocytochemistry was performed in one specimen. MYB was positive. TTF-1, synaptophysin and chromogranin were negative. Epithelial and basal markers demonstrated a dual cell population. Literature review yielded 28 cases. Cytologic features described were similar except for cytoplasmic vacuolation in one case. ConclusionBasement membrane-like material is specific for AdCC. MYB positivity, TTF-1 and neuroendocrine marker negativity, support a diagnosis of AdCC. Other immunocytochemistry and cytologic features overlap significantly with adenocarcinoma and small cell carcinoma of lung.

Primary pulmonary adenoid cystic carcinoma- clinicopathological features and predictors of poor outcome.

Primary pulmonary adenoid cystic carcinoma is a rare disease. Its clinico-pathological features, course of disease, therapeutic strategy, and survival data have not been fully elucidated. We aimed to study the clinicopathological characteristics of primary pulmonary adenoid cystic carcinomas in north India. This study was a retrospective, single-centre, cohort study. The database of the hospital was searched for a period of seven years to identify all patients with primary pulmonary adenoid cystic carcinoma. Out of 6050 lung tumors, 10 were primary adenoid cystic carcinomas. The mean age of diagnosis was 42 (±12) years. Six patients had the lesion in the trachea, main bronchus or truncus intermedius and four had parenchymal lesions. Seven patients had resectable tumours. Three patients achieved an R0 resection, two achieved R1 resection and two had R2 resection. On histopathological examination, almost all of the patients had cribriform pattern. Only four patients (57.1%) showed positivity for TTF-1 staining. The five-year survival of patients with resectable tumour and un-resectable tumour was 85.7% and 33.3%, respectively (P = 0.01). The predictors of poor outcome included non-operability of the tumour, presence of metastasis at the time of diagnosis, and macroscopically positive tumour margin during surgery. Primary pulmonary adenoid cystic carcinoma is a unique and rare tumour that affects relatively younger individuals, males and females, as well as smokers and non-smokers equally. The features of bronchial obstruction are the most common. Surgery is the primary modality of treatment and completely resectable lesions have the best prognosis.

A rare case of pulmonary adenoid cystic carcinoma with liver metastases treated effectively with stereotactic body radiation therapy

AbstractPulmonary adenoid cystic carcinoma (PACC) is an extremely rare neoplasm. Adenoid cystic carcinoma (ACC) usually occurs in the salivary glands of the head and neck. Given its rare occurrence, there are no established guidelines for the treatment of progressive and/or relapsed disease. We herein report a case of a 57‐year‐old female who was incidentally found to have biopsy confirmed PACC following trauma diagnostic workup. She underwent pneumonectomy and adjuvant radiation therapy with an initial good response. On follow‐up a year later, she was noted to have two metastatic liver lesions treated with stereotactic body radiation therapy (SBRT) and lenvatinib. This case report adds to the growing area of research on PACC, especially among patients requiring SBRT for oligometastatic disease.

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

PurposePrimary 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.MethodsThis 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.ResultsA 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).ConclusionThe 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.

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

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. 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. 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). 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.

A Case of Resected Pulmonary Adenoid Cystic Carcinoma Requiring a Differential Diagnosis from Small-cell Lung Carcinoma

A Case of Resected Pulmonary Adenoid Cystic Carcinoma Requiring a Differential Diagnosis from Small-cell Lung Carcinoma

Case Report: Efficacy of Pyrotinib in ERBB2 Amplification Pulmonary Adenoid Cystic Carcinoma

Primary pulmonary adenoid cystic carcinomas are salivary tumors that are low-grade malignant and prone to recurrence and metastasis. Surgery is currently the main treatment, but there is no standard with regard to postoperative adjuvant therapy. Adenoid cystic carcinoma is more sensitive to radiotherapy and patients benefit less from chemotherapy, but few studies have focused on targeted therapy, and their conclusions are inconsistent. With respect to primary pulmonary adenoid cystic carcinoma, large-scale studies cannot be conducted due to its low incidence, and studies on the targeted therapy of it are very scarce. A few case reports indicate that targeted therapy can be effective however, suggesting that it may be a good option. The current report is the first on the occurrence of human epidermal growth factor receptor 2 amplification in pulmonary adenoid cystic carcinoma. The patient was treated with pyrotinib for 6 months and achieved stable disease.

CT-guided palladium-103 seed brachytherapy for metastatic adenoid cystic carcinoma: a retrospective study to assess initial safety and effectiveness of percutaneous CT fluoroscopy-guided permanent seed brachytherapy.

PurposeMultiple pulmonary metastases present treatment difficulties in available treatment techniques, which are inconvenient or may damage sufficient pulmonary tissue to cause pulmonary crippling. This retrospective study of a single-community practice evaluated responses to computed tomography (CT)-guided 103Pd permanent seed brachytherapy (CTGPSB) in adenoid cystic carcinoma (ACC) synchronous pulmonary metastases. The purpose of the current study was to document that metastatic pulmonary ACC lesions can be controlled with CTGPSB.Material and methodsTwenty-nine discrete lesions in 14 patients were evaluated with serial CT scans. All were treated with CTGPSB. Lesions were tracked over serial CT scans and volumes measured. Primary endpoint was a reduction in tumor volume on subsequent CT scan. Secondary endpoint was occurrence of CTCAE grades 2-5.ResultsThere was a 100% measured reduction in tumor volume (n = 29) at follow-up. Follow-up was a mean of 3.13 years. Baseline tumor volume was a mean of 1.85 ml (range, 0.69-9.15 ml). There were two grade 1 and one grade 2 adverse events, which did not require hospitalization.ConclusionsCTGPSB for the treatment of multiple ACC pulmonary metastases is effective, with minimal acute complications, as shown in small cohort of subjects of the present study. Further studies evaluating specific dosimetry parameters in this free-hand technique are needed to specify minimal and maximal dose constraints.

An Overview of Pulmonary Adenoid Cystic carcinomas - Review Article

An Overview of Pulmonary Adenoid Cystic carcinomas - Review Article

SALIVARY ADENOID CYSTIC CARCINOMA: AN UNCOMMON SALIVARY-TYPE OF LUNG CANCER

SESSION TITLE: Medical Student/Resident Lung Cancer Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Adenoid cystic carcinoma (ACC) is a rare salivary gland-type lung malignancy with an estimated incidence of 0.04-0.2% [1]. Tumors typically occur in the major airways and may have submucosal invasion [2]. Common presenting symptoms include chest pain, hemoptysis, and dyspnea. We report a patient with non-specific chest pain found to have primary ACC of the lung. CASE PRESENTATION: A 55-year-old female non-smoker with history of hypertension and diabetes presented with worsening headache, neck, chest, and back pain following a motor vehicle accident four days prior. She further clarified that she had been experiencing left-sided chest pain radiating to her left shoulder for one year. Physical examination was remarkable only for midline neck and back tenderness. Initial labs were unremarkable. Chest radiography identified a left sided suprahilar opacity. This prompted a computed tomography (CT) scan of her chest which demonstrated a 2.9 x 2.3cm left sided suprahilar mass with splaying of the underlying vascular structures [Figure 1A]. Positron emission tomography CT scan showed avid fluorodeoxyglucose uptake in the left upper lobe [Figure 1B]. Bronchoscopy was performed which revealed a smooth mass within the left main bronchus that had increased vascularity with narrow band imaging [Figure 2]. Endobronchial biopsies confirmed ACC and prompted referral for a left upper lobe lobectomy. Pathological analysis was consistent with a Grade II, moderately differentiated adenoid cystic carcinoma. Surgical margins and 0/23 lymph nodes were negative for malignancy. She was ultimately staged pT2N0M0 with an R0 resection. On follow-up with hematology-oncology, it was determined that the patient would not require adjuvant chemoradiation. She remains on active surveillance without any evidence of tumor recurrence at 12-month follow-up. DISCUSSION: Diagnosis and staging for ACC requires a combination of radiographic imaging and bronchoscopy with biopsy. Histological sub-types include cribriform, tubular, and solid, the latter being more aggressive [2]. Surgical resection is the cornerstone of management providing the best prognosis. A case series of 26 patients who underwent R0 surgical resection of primary ACC observed an overall survival rate of 91.7% at 5-years [3]. A similar benefit was also seen with adjuvant radiotherapy in R1 resections. In those who are not surgical candidates, survival is 0% at 5-years. In non-surgical patients, chemoradiation is often ineffective as ACC responds poorly to currently available chemotherapeutics. CONCLUSIONS: ACC is an uncommon type of lung cancer. Tumors have a high likelihood of submucosal extension and local recurrence. Complete surgical resection offers the best prognosis. In contrast, chemoradiation has a limited role in non-surgical candidates. Reference #1: W. D. Travis, L. B. Travis, and S. S. Devesa, “Lung cancer,” Cancer, vol. 75, no. 1 S, pp. 191–202, 1995, doi: 10.1002/1097-0142(19950101)75:1+<191::AID-CNCR2820751307>3.0.CO;2-Y. Reference #2: H. Inoue, A. Iwashita, H. Kanegae, K. Higuchi, Y. Fujinaga, and I. Matsumoto, “Peripheral pulmonary adenoid cystic carcinoma with substantial submucosal extension to the proximal bronchus,” Thorax, vol. 46, no. 2, pp. 147–148, 1991, doi: 10.1136/thx.46.2.147. Reference #3: M. M. Hu, Y. Hu, J. B. He, and B. L. Li, “Primary adenoid cystic carcinoma of the lung: Clinicopathological features, treatment and results,” Oncol. Lett., vol. 9, no. 3, pp. 1475–1481, Mar. 2015, doi: 10.3892/ol.2015.2859. DISCLOSURES: No relevant relationships by Ethan Karle, source=Web Response No relevant relationships by Armin Krvavac, source=Web Response No relevant relationships by Michael Nance, source=Web Response No relevant relationships by Tarang Patel, source=Web Response

Adenoid cystic carcinoma of the lung — a case report

Adenoid cystic carcinoma (ACC) is a malignant neoplasm that frequently originates from the salivary glands of the head and neck. The majority of pulmonary adenoid cystic carcinomas develop centrally in the trachea. Primary ACC of the lung arising from the bronchial glands is a rare disease and accounts for only 0.09‑0.2% of all primary lung neoplasms [1]. Although their growth rate is often indolent, they sometimes show aggressive biologic behaviour. Local invasion with perineural infiltrations, and lymph node and hematogenous metastases have been reported for some of these neoplasms [2]. Treatment options for advanced disease are limited. We herein report a case of a 56-year-old male patient with adenoid cystic carcinoma of the lung, who received conventional chemotherapy and endobronchial irradiation. This review focuses on the palliative therapy in the treatment of metastatic ACC.

Clinicopathological features and prognostic factors of primary pulmonary adenoid cystic carcinoma: a study of 59 cases

Objective: To investigate the clinicopathological features and prognostic indicators of primary pulmonary adenoid cystic carcinoma. Methods: Fifty-nine cases of primary pulmonary adenoid cystic carcinoma were collected from August 2011 to December 2017 at the First Affiliated Hospital of Zhengzhou University. All cases were retrospectively studied by hematoxylin-eosin staining and immunohistochemistry. The clinicopathological features were reviewed and patient survival analysis was performed using Kaplan-Meier method and Cox regression model. Status of epidermal growth factor receptor (EGFR), KRAS, BRAF genes was analyzed in 15 of the 59 study cases. Results: Among 59 cases, there were 25 males and 34 females with male to female ratio of 1.0 to 1.4. The patient age ranged from 29 to 81 years with a mean age of 55 years. The tumor max diameters ranged from 1.0 to 9.6 cm with an average diameter of 2.8 cm. Fifteen (25.4%) patients were smokers while 44 patients (74.6%) were non-smokers. Tumors predominantly occurred in the trachea (28/59,47.5%), the left main bronchus (7/59,11.9%) and the right bronchus (5/59,8.5%). Grossly, the tumors were well circumscribed, greyish-white nodules. Microscopically the tumor cells were small and uniform, and arranged in tubular, cribriform, and solid patterns. Immunohistochemistry showed that the tumor cells were positive for CK7, S-100 protein, Sox-10, CD117 and p63. TTF1 was only positive in 2 cases and Ki-67 index ranged from 3% to 40%. Eighteen cases (30.5%) were gradeⅠ, 26 cases (40.1%) grade Ⅱ, and 15 cases (25.4%) grade Ⅲ. Overall, 39 cases (66.1%), 7 cases (11.9%), 10 cases (16.9%), and 3 cases (5.1%) were at stages Ⅰ, Ⅱ, Ⅲ, and Ⅳ, respectively. Twenty-three patients (39.0%) received surgical therapy, 3 patients (5.1%) surgery combined with radiotherapy, 9 patients (15.2%) surgery combined with chemotherapy, and 24 cases (40.7%) chemotherapy only. No mutation of EGFR, KRAS and BRAF was detected in all 15 tested cases. The overall survival rate at the first, third and fifth years was 94.9%, 86.4% and 84.7%, respectively. Prognostic analysis showed that patient's age and tumor size were statistically associated with the survival (P<0.05). Conclusions: Majority of the patients with primary pulmonary adenoid cystic carcinoma are at an early clinical stage with a favorable prognosis. The size of the tumor and the age of the patients are independent prognostic indicators.

CT features and differential diagnosis of primary pulmonary mucoepidermoid carcinoma and pulmonary adenoid cystic carcinoma.

The differential diagnosis of primary pulmonary mucoepidermoid carcinoma (PMEC) and pulmonary adenoid cystic carcinoma (PACC) is difficult, because both tumors could be similar in terms of certain characteristics on CT. The CT findings from 24 cases of PMEC and 30 cases of PACC were retrospectively analyzed. According to the position of the lesion in airway, we divided these cases into three types: central, hilar, and peripheral. In PMEC, there were 7 cases of central type, 14 cases of hilar type, and 3 cases of peripheral type. And, 57.1% PMEC cases of the hilar type were accompanied by distal bronchial dilatation with mucoid impaction. Patchy areas of low density were observed in 79.2% cases of PMEC. The solid part of most lesions showed moderate (37.5%) or severe enhancement (45.8%). However, in PACC, there were 24 cases of central type, 3 cases of hilar type, and 3 cases of peripheral type. PACC had more cases of central type than PMEC. Moreover, longitudinal extent greater than 3 cm was observed in 62.5% PACC cases of the central type, while infiltration of the luminal perimeter more than 1/2 perimeter was observed in 95.8% PACC cases of the central type. Patchy areas of low density were observed in 26.7% cases of PMEC. In PACC cases, the solid part of 76.7% lesions showed slight enhancement. Cavities could be observed in PMEC, but not in PACC. PMEC and PACC have different CT features in various airway locations. PMEC is usually the hilar type, accompanied by distal bronchial dilatation with mucoid impaction. However, PACC is usually the central type, with longitudinal extent greater than 3 cm and infiltration of the luminal wall more than 1/2 perimeter. Patchy areas of low density and moderate or severe enhancement are more prominent in PMEC. However, slight enhancement is more common in PACC.

P1.09-18 15 Cases of Clinical and Molecular Features Analysis in Pulmonary Adenoid Cystic Carcinoma

P1.09-18 15 Cases of Clinical and Molecular Features Analysis in Pulmonary Adenoid Cystic Carcinoma

Mutational landscape and clonal diversity of pulmonary adenoid cystic carcinoma

ABSTRACTPulmonary adenoid cystic carcinoma is a rare and indolent lung malignancy, characterized by a protracted but unpredictable growth behavior. Currently, the treatment of PACC relies on surgery and local radiotherapy. However, treatment options for advanced PACC patients are limited. A larger number of studies demonstrated that advanced PACC patients obtained limited benefit from chemotherapy. Moreover, only a few case reports revealed PACC patients were candidates for target therapy. Therefore, there is an urgent need to develop novel therapies. Due to its rareness, its mutational landscape remains largely elusive. In this study, we performed capture-based ultra-deep sequencing on multiregional surgical specimens obtained from 8 PACC patients using a panel consisting of 295 cancer-related genes. Our data revealed distinctive mutational spectrum of PACC, which differed from non-small cell lung cancer and adenoid cystic carcinomas originated from other anatomical sites. PACC, lacking mutations in a majority of non-small cell lung cancer driver genes, has frequent mutations in genes participating in chromatin remodeling and NOTCH signaling pathway. We also elucidated spatial intra-tumoral heterogeneity, which varied among cases. Most mutations in chromatin remodelers were subclonal. Collectively, our findings elucidated molecular signature associated with PACC and highlighted the potential for epigenetic therapy in this disease.

A Comparative Study of Primary Adenoid Cystic and Mucoepidermoid Carcinoma of Lung.

Pulmonary mucoepidermoid carcinoma (PMEC) and pulmonary adenoid cystic carcinoma (PACC) are the two major types of primary salivary gland-type (PSGT) lung cancers. The demographic profile, clinicopathological features, and predictors of survival as an overall group have not been described for PSGT cancers of lung. In this study, we analyzed demographic, clinical, and survival data from 1,032 patients (546 PMEC and 486 PACC) who were diagnosed of PSGT lung cancer in the Surveillance, Epidemiology and End Results database from 1973 to 2014. The PSGT constituted 0.09% of all lung cancers with age-adjusted incidence rate of 0.07 per 100,000 person-years and change of -32% from 1973 to 2014. The incidence of PMEC was slightly higher than PACC but there were no differences in the age and sex distribution. PACCs (55%) were significantly higher at trachea and main bronchus while PMECs were more common at peripheral lungs (85%). Most of the tumors were diagnosed at an early stage and were low grade irrespective of histology. As compared to PMEC, significantly higher number of patients with PACC underwent radical surgery and received adjuvant radiation. The 1- and 5-year cause-specific survival was 76.6 and 62.8%, respectively. On multivariate analysis, the survival was affected by age at diagnosis, tumor stage, histological grade, period of diagnosis, and surgical resection. The histology showed strong interaction with time and hazard ratio of patients with PACC was significantly worse than patients with PMEC only after 5 years. The incidence of pulmonary PSGT cancer is 7 cases per 10 million population in the United States and is decreasing. There was no difference between demographic profile of patients with PMEC and PACC but pathological features were diverse. The difference in the survival of patients with the two histological types surfaced only after 5 years when survival of patients with PMEC was better than PACC.