Apoptotic Marker Expression of Resected Lacrimal Gland Adenoid Cystic Carcinoma Tumor Margins After Intra-arterial Chemotherapy and Globe-Sparing Excision.

PURPOSE: Lacrimal gland adenoid cystic carcinoma (LGACC) is a rare orbital malignancy with devastating lethality. Neoadjuvant intra-arterial chemotherapy (IACC) has demonstrated cytoreductive effects on LGACC macroscopically, but limited studies have examined cellular and molecular determinants of the cytoreductive effect. This post hoc study assessed apoptotic marker expression on excised tumor specimens after neoadjuvant IACC and globe-sparing resection, emphasizing the examination of tumor margins. METHODS: This retrospective study identified LGACC specimens resected in a globe-sparing technique after neoadjuvant IACC by reviewing the Florida Lions Ocular Pathology database at Bascom Palmer Eye Institute. Histopathology slides of the specimens were re-examined to confirm the diagnosis and identify the tumor margin. Immunofluorescent staining was performed for apoptotic markers, including P53, cleaved caspase-3, cleaved PARP-1, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). Positive expression was determined by comparison to the negative control. RESULTS: Tumor specimens from 5 patients met inclusion criteria. All 5 cases were positive at the center and the margin for TUNEL, p53, and cleaved caspase-3. One case did not show positive expression of cleaved PARP-1 at the margin but was positive for the other apoptotic markers. CONCLUSIONS: This post hoc study demonstrated positive staining for multiple apoptotic markers in post-IACC tumor specimens at the tumor center and margin. Apoptotic marker expression along the margins of post-treatment specimens is important, as it may offer surrogate information to speculate on the state of residual cancer cells adjacent to the excision margin inadvertently remaining in the orbit.

Circulating Adenoid Cystic Carcinoma associated MYB transcripts enable rapid and sensitive detection of metastatic disease in blood liquid biopsies.

Adenoid cystic carcinoma (ACC) is a rare and lethal malignancy that originates in secretory glands of the head and neck. A prominent molecular feature of ACC is the overexpression of the proto-oncogene MYB. ACC has a poor long-term survival due to its high propensity for recurrence and protracted metastasis. Currently, clinical technologies lack the efficiency to distinguish patient prognosis prior to its redevelopment. We hypothesize that metastatic ACC can be detected by monitoring tumor-specific MYB expression in patients' blood. We developed a quantitative polymerase chain reaction (qPCR) assay for MYB transcripts and screened blood samples from four patient cohorts: no history or evidence of ACC (n=23), past history of ACC and no evidence of disease (NED) for greater than three years (n=15), local ACC (n=6), and metastatic ACC (n=5). Our assay detected significantly elevated levels of MYB transcripts in the metastatic ACC cohort (p < 0.01). Receiver operating characteristic (ROC) curves comparing metastatic to NED and metastatic to local disease were significant, with p values < 0.0001 and 0.0008, respectively. Single-cell RNA sequencing (scRNA-seq) of blood from metastatic ACC identified a cluster of circulating tumor cells (CTCs) expressing MYB. Here, we report a sensitive, cost-effective, and minimally invasive diagnostic test that leverages tumor-specific signatures to screen for metastatic ACC disease, potentially enhancing detection earlier than the current clinical standard.

Mass spectrometry database of lacrimal gland adenoid cystic carcinoma and normal lacrimal gland tissue identifies extracellular matrix remodeling in these tumors.

Adenoid cystic carcinoma of the lacrimal gland (LGACC) is a slow-growing but aggressive orbital malignancy. Due to the rarity of LGACC, it is poorly understood, which makes diagnosing, treating, and monitoring disease progression difficult. The aim is to understand the molecular drivers of LGACC further to identify potential targets for treating this cancer. Mass spectrometry was performed on LGACC and normal lacrimal gland samples to examine the differentially expressed proteins to understand this cancer's proteomic characteristics. Downstream gene ontology and pathway analysis revealed the extracellular matrix is the most upregulated process in LGACC. This data serves as a resource for further understanding LGACC and identifying potential treatment targets. This dataset is publicly available.

Spatial Transcriptomics Identifies Expression Signatures Specific to Lacrimal Gland Adenoid Cystic Carcinoma Cells.

Although primary tumors of the lacrimal gland are rare, adenoid cystic carcinoma (ACC) is the most common and lethal epithelial lacrimal gland malignancy. Traditional management of lacrimal gland adenoid cystic carcinoma (LGACC) involves the removal of the eye and surrounding socket contents, followed by chemoradiation. Even with this radical treatment, the 10-year survival rate for LGACC is 20% given the propensity for recurrence and metastasis. Due to the rarity of LGACC, its pathobiology is not well-understood, leading to difficulties in diagnosis, treatment, and effective management. Here, we integrate bulk RNA sequencing (RNA-seq) and spatial transcriptomics to identify a specific LGACC gene signature that can inform novel targeted therapies. Of the 3499 differentially expressed genes identified by bulk RNA-seq, the results of our spatial transcriptomic analysis reveal 15 upregulated and 12 downregulated genes that specifically arise from LGACC cells, whereas fibroblasts, reactive fibrotic tissue, and nervous and skeletal muscle account for the remaining bulk RNA-seq signature. In light of the analysis, we identified a transitional state cell or stem cell cluster. The results of the pathway analysis identified the upregulation of PI3K-Akt signaling, IL-17 signaling, and multiple other cancer pathways. This study provides insights into the molecular and cellular landscape of LGACC, which can inform new, targeted therapies to improve patient outcomes.