Adenoid Cystic Carcinoma Research Articles

NanoString nCounter-Based Assay for Detection of Fusion-Associated Salivary Gland Tumors.

Salivary gland tumors include numerous subtypes that vary from benign to highly aggressive, with many showing overlapping histopathological features that can make diagnosis challenging. Most subtypes express driver fusion genes that are tumor specific, and detection of such fusions is useful for differentiating amongst specific diagnoses, determining appropriate tumor grading, and guiding effective treatment. Currently, fusions can be detected by FISH, RT-PCR or through next-generation sequencing approaches, all of which are highly effective methodologies but can be costly or time consuming. We developed a rapid NanoString nCounter platform-based assay to detect salivary gland tumor fusions using a combination of fusion junction-specific probes and an approach through differential exon expression analysis. The assay includes 68 junction-specific probes and analysis of exon expression across 9 fusion-associated genes in a single multiplex assay. Out of 55 retrospective and 171 prospective cases assayed, we accurately detected the majority of cases of pleomorphic adenoma, adenoid cystic carcinoma, cribriform adenocarcinoma, clear cell carcinoma, secretory carcinoma and NUT-rearranged carcinoma, including cases of these tumor types arising in non-salivary gland sites, with the major drawback being an inability to detect MAML2-containing mucoepidermoid samples. With mucoepidermoid carcinoma excluded, the assay shows an overall sensitivity of 96.1% and specificity of 100%. We show that the majority of salivary gland tumor fusions can be effectively detected with a single rapid NanoString based assay, which can serve as a useful adjunctive tool for routine diagnostic head and neck pathology. The assay is low cost with a rapid turnaround time (30h total assay time per sample batch, with minimal technician input required) compared to alternate detection methods.

Comparative Analysis of MYB Expression by Immunohistochemistry and RNA Sequencing in Clinical Gene Fusion Detection in Adenoid Cystic Carcinoma.

MYB has been shown to play a central role in oncogenesis in a majority of adenoid cystic carcinomas (ACC). Testing for MYB expression via immunohistochemistry (IHC) or testing for the MYB gene fusion by next-generation sequencing(NGS) have become useful tools for the diagnosis of ACC. In addition, detection of MYB expression may have implications for patient management. A cohort of 35 ACC cases was identified from the archival pathology files of the Massachusetts General Hospital. Cases were tested for MYB expression using a panel of 4 different commercially available MYB antibodies and scored using a modified Allred system. RNA-based NGS for MYB gene fusion detection was also performed. Among 4 different MYB antibodies, the sensitivity for MYB detection ranged from 26 to 97%. When a 30% threshold for determination of MYB immunohistochemical positivity was used, the AB_10900735 IHC clone showed the maximum sensitivity (97%). RNA sequencing revealed 19 (54%) cases positive for MYB fusions, and expression analysis derived from the sequencing data confirmed a significant association between MYB expression and fusion status (p = 0.036). Although less sensitive, the AB_778878 MYB clone showed a significant positive association between IHC staining and MYB RNA expression (R2 = 0.15, p = 0.023). The detection of MYB expression using immunohistochemistry varies significantly depending on the antibody used. Comparison with MYB fusion and transcription levels, as determined by NGS, reveals that MYB has a complex relationship between genetic alterations, transcript levels, and protein abundance.

Salivary Gland Tumours in Children and Adolescents-A Study in Shaheed Monsur Ali Medical College & Hospital, Uttara, Dhaka, Bangladesh

Introduction: Salivary gland carcinomas (SGCs) are rare neoplasms in adults, but are exceedingly infrequent in children, with a reported annual incidence of 0.8–1.4 per million populations under 20 years old. Like other pediatric very rare tumors, SGCs in children and adolescents often present diagnostic and therapeutic challenges for pathologists, surgeons, and pediatric oncologists. Objective: To assess the salivary gland tumours in children and adolescents. Methods: A cross-sectional observational study was carried out at Dept. of ENT, Shaheed Monsur Ali Medical College & Hospital, Uttara, Dhaka, Bangladesh from January to June 2023. Total 60 patients included in our study. Our pre-operative clinical diagnoses were based on size, shape, mobility, fixity of the tumour to the underlying structures, ulceration of overlying skin, involvement of facial nerve by its malignant transformation and fine needle aspiration cytology. All patients, or their guardians, gave their informed consent for data collection within the national rare tumour group and analysis. Results: Total sixty (60) cases of salivary gland tumours were available for our study. Out of 55% were male and 45% were female patients. Incidence of tumours is highest in the age group of 41-50 with 13 cases (21.6% of the total). The least affected age group was the 0-10 group with only one patient (3.3%). Women accounted for 16 cases of the total 33 benign neoplasias (55% of the total). Of the 33 benign tumour, 18 were in males (54.5% of all benign tumours) and 15 were in females (45.5%). Total 60 operated cases). Of these, 32 were pleomorphic adenomas (53.3%) and 1 was an adenolymphoma (1.6%). the total number of malignant tumours confirmed by HPE were 27 (45%). Of these, most numerous was adenoid cystic carcinoma in 8 cases (13.3%). squamous cell carcinoma and muco epidermoid carcinoma were found in 6 cases each (10%). There were 4 and 3 cases of adenocarcinoma (6.6%) and acinic cell carcinoma (5%) respectively. The parotid glands were also the sole location for the 3 acinic cell carcinomas. No tumours were found in the sublingual gland. The majority of the tumours found in the parotid gland were benign tumours, mainly pleomorphic adenomas with 24 cases (75% of the total parotid tumours). Conclusions: The tumours were equally distributed between males and females. The tumours were most commonly found in the third to fifth decades of life. The most common benign tumour and the most common tumour overall was pleomorphic adenoma making up 54.5% of all tumours. Surgical excision was the most commonly done treatment. The most commonly done surgical procedure was superficial parotidectomy.

Non-invasive miRNAs for early detection and diagnosis of lacrimal adenoid cystic carcinoma.

Lacrimal adenoid cystic carcinoma (LACC) is one of the most common malignant epithelial tumors of the lacrimal gland, characterized by high rates of local recurrence, distant metastases, and tumor-related mortality. This malignancy impairs the lacrimal gland's ability to secret tears, thereby disrupting the normal function of the ocular surface. Due to ineffective diagnostic approaches and the complex anatomical location of the lacrimal gland within the orbit, many LACC patients are often diagnosed at the later stages. Therefore, it is urgent to develop a simple and convenient method for early detection of LACC through biomarker analysis by liquid biopsies, such as blood or tears. Various microRNAs (miRNAs) derived from liquid biopsies have been shown to serve as biomarkers for early diagnosis of tumors. In the present study, we screened LACC-specific miRNAs using miRNA microarray analysis in both primary and recurrent patient groups. We then validate their expression by qPCR experiments conducted in tissues, cell lines, tear fluid and serum to explore the association between these miRNAs and LACC development and prognosis. Our findings reveal that hsa-miR-200b-3p, hsa-miR-200c-3p and hsa-miR-141-3p are significantly upregulated in LACC, and the microarray data showed that these three miRNAs were significantly elevated in the recurrence group compared to the primary group. In conclusion, detecting miRNA expression in tear fluid and serum provides non-invasive biomarkers for the early diagnosis of LACC and may facilitate monitoring outcomes related to lacrimal gland diseases.

Nuclear staining for pan-Trk by immunohistochemistry is highly specific for secretory carcinoma of breast: pan-Trk in various subtypes of breast carcinoma

AimsSecretory carcinoma of breast (SCB) typically harbours ETV6-NTRK3 gene fusion. Pan-Trk immunohistochemistry analysis (IHC) has been shown to be sensitive for SCB diagnosis. However, weak focal pan-Trk nuclear staining was...

Cancer cell-derived exosomal miRNA induces and reprograms Schwann cells to augment the perineural invasion of salivary adenoid cystic carcinoma.

Cancer cell-derived exosomal miRNA induces and reprograms Schwann cells to augment the perineural invasion of salivary adenoid cystic carcinoma.

Optimizing surgical approaches for lacrimal gland adenoid cystic carcinoma to minimize cross-organ invasion.

To evaluate the outcomes of eye-sparing surgery for lacrimal gland adenoid cystic carcinoma and the impact on tumor recurrence and orbital integrity. The study enrolled four patients with recurrent lacrimal gland adenoid cystic carcinoma. The outcome focused on the relevance of the integrity of the lateral orbital wall to the occurrence of extraorbital metastasis in the local recurrence of lacrimal gland adenoid cystic carcinoma. Three patients underwent eye-sparing surgery via lateral orbitotomy without postoperative radiotherapy, and one patient who underwent eye-sparing surgery via sub-brow approach. These four patients all demonstrated a recurrence involving the invasion of extraorbital tissues as metastatic form through surgical bone seams. Preserving intact orbital bone tissue is crucial for mitigating direct cross-organ metastasis of lacrimal gland adenoid cystic carcinoma. The findings suggest avoiding the lateral orbitotomy approach with no or limited orbital bone wall invasion.

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.

Clinical and molecular epidemiology of malignant salivary gland tumors

Salivary gland carcinomas are a rare and heterogeneous group of malignant tumors, accounting for 3-6% of all malignant tumors in the head and neck region. The 1-, 3- and 5-year survival rates are 83%, 69% and 63% respectively. Due to new molecular pathological and genetic findings, new entities are constantly being defined as part of the recurring WHO classification of salivary gland carcinomas, so that the incidence rates of the entities are subject to constant change. The only certain risk factor for the development of salivary gland carcinomas is ionizing radiation. In addition, large tumors, cervical lymph node involvement and perineural sheath involvement significantly worsen the prognosis. Today, molecular pathology is coming to the fore, with which potential targets have been identified that can offer prognosis-improving treatment options, particularly in recurrent or distant metastatic stages. Entity-specific tyrosine kinase inhibitors such as axitinib in adenoid cystic carcinoma or larotrectinib in secretory carcinoma and cross-entity therapies such as HER2 inhibition and androgen deprivation can prolong median and progression-free survival with a favorable side effect profile.

Solid-basaloid Variant of Mammary Adenoid Cystic Carcinoma – Report of an Unusual Case with Literature Review

Abstract Introduction/Objective Adenoid cystic carcinoma (AdCC) of breast is a rare subtype of malignancy, constituting approximately 0.1% of all breast carcinomas. The solid-basaloid variant (SB-AdCC) is exceedingly uncommon. Here, we present such an unusual case of SB-AdCC. Methods/Case Report A 64-year-old woman who underwent screening mammography presented with abnormal findings, revealing a hypoechoic ovoid, lobulated nodule at 7:00 of the left breast, which prompted an ultrasound- guided biopsy. Histologically, the biopsy cores demonstrated a 9 mm infiltrative round, solid nests with focal “cribriforming” areas. It was composed of monomorphic basaloid epithelial cells with marked nuclear atypia and high mitotic count. High-grade ductal carcinoma in situ, solid papillary carcinoma, and nonspecific invasive carcinoma were in differentials. Immunohistochemical (IHC) staining expressed positivity for CD117 and CK 5/6, while p63, SMMHC, and synaptophysin were negative. MYB gene rearrangement confirmed by fluorescence in situ hybridization. As expected, the tumor lacked ER, PR, and HER2 expression by IHC. Left breast mastectomy and axillary lymph node dissection have been scheduled. Results (if a Case Study enter NA) NA Conclusion Per literature review, the mean age of SB-AdCC at diagnosis was 68 years (33-84 years) with an average tumor size of 25 mm (12-70 mm). It had more aggressive behavior, with a higher propensity for lymph node metastasis, locally recurrence, and distant metastasis. The median disease-free survival was 46.5 months versus 151.8 months in those with class AdCC. Notably, neovascularization has emerged as a strong independent predictor of outcome in SB-AdCC. Most patients were treated with surgical excision, axillary lymph node dissection, and/or adjuvant chemotherapy. Limited studies demonstrated that neoadjuvant chemotherapy may induce an excellent response. Furthermore, a distinct molecular mutation enriched in NOTCH and CREBBP genes has been identified, which could be novel potential therapeutic target. Thus, awareness of this extremely rare breast cancer subtype and accurate differentiation from other entities are paramount for appropriate management strategies.

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&amp;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%).

Synchronous endometrial and minor salivary gland carcinomas – role of molecular diagnostics amid lack of clinical suspicion

Abstract Introduction/Objective Synchronous malignancies account for 3-5% of all tumor diagnoses but can be challenging to detect if one or both tumors are rare histologic subtypes and clinical suspicion is lacking. Molecular diagnostics are critical for accurate diagnosis in these difficult cases to guide appropriate patient care. Methods/Case Report We report the case of a 49-year-old female who was diagnosed with a high-grade, mixed- histology endometrial adenocarcinoma a few years back. She was found to have hilar and mediastinal nodal carcinoma of uncertain differentiation a couple of months after her initial diagnosis, clinically labelled as metastatic endometrial carcinoma. Following neoadjuvant chemotherapy, her hysterectomy showed complete pathologic response, and was found to be POLE ultramutated on NGS. Follow-up PET scan in 2023 showed progression of hilar/endobronchial thickening, as well as interval increase in size of mediastinal nodes, again presumed to be endometrial metastases, despite the POLE mutant status. Repeat sampling was performed from both the sites, along with comprehensive molecular profiling. Cytology from the nodes and surgical pathology from the endobronchial lesion showed similar morphology consisting of hyperchromatic basaloid cells in cribriform arrangement with tubular structures containing myxoid stromal material, negative for PAX-8, ER, p40, and TTF1 immunostains, inconsistent with endometrial metastasis. Molecular studies including FISH and NGS showed MYB1::NFIB fusion characteristic of adenoid cystic carcinoma and absence of POLE mutation, definitively refuting the clinically suspected progression of endometrial metastasis. Molecular testing confirmed that the endobronchial tumor and mediastinal nodal involvement were caused by a second primary, distinct from her POLE-ultramutated endometrial carcinoma which disappeared with chemotherapy. Her extended molecular workup also revealed a pathogenic mutation in BRIP1, suggesting a genetic cancer predisposition syndrome requiring referral for genetic counseling. Results (if a Case Study enter NA) NA Conclusion Molecular pathology is an invaluable tool for unravelling diagnostic complexity. Pathologists must integrate cytomorphology, molecular genetics and knowledge of cancer biology to steer the clinical teams towards the best patient care.

Clinical pathological features and radiotherapy treatment for adenoid cystic carcinoma of the head and neck

Clinical pathological features and radiotherapy treatment for adenoid cystic carcinoma of the head and neck

Sinonasal adenoid cystic carcinoma: preoperative apparent diffusion coefficient histogram analysis in prediction of prognosis and Ki-67 proliferation status.

To investigate the value of preoperative apparent diffusion coefficient (ADC) histogram analysis in predicting the prognosis of patients with sinonasal adenoid cystic carcinoma (ACC) and the correlation between ADC histogram parameters and Ki-67 labeling index (LI). The study enrolled 66 patients with sinonasal ACC who were surgically resected and confirmed by histopathology. The disease-free survival (DFS) was evaluated with clinical-pathologic and radiologic characteristics using the Cox proportion hazard model. Spearman correlation analysis was used to evaluate the correlation between ADC histogram parameters and Ki-67 LI. The predictive performance of ADC histogram parameters for Ki-67 LI was assessed using the receiver operating characteristic (ROC) curve. Multivariable analysis showed Ki-67 LI (hazard ratio: 9.279; 95% confidence interval 1.099-78.338; P = 0.041) and ADCskewness (hazard ratio: 5.942; 95% confidence interval 1.832-19.268; P = 0.003) were significant independent predictors of DFS. The combination of these two variables achieved the predictive ability with a C-index of 0.717 (95% confidence interval 0.607-0.826). ADCmean and all ADC percentiles (10th, 50th, and 90th) significantly and inversely correlated with Ki-67 LI of ACC (Correlation coefficients = -0.574 to -0.591, Ps < 0.001). Among the ADC histogram parameters, the ADC50th showed superior performance for the differentiation of the high from low Ki-67 LI groups with an area under the curve (AUC) of 0.834 and an accuracy of 80.30%. ADC histogram analysis had predictive value for DFS and Ki-67 LI, which may be a valuable biomarker for prognosis and proliferation status for ACC in clinical practice.

Role of microscope in parotidectomy for identification and preservation of facial nerve: An institutional experience at Tertiary Care Hospital.

Objective: This study presents the authors' experience with performing parotidectomy while using the microscope and its outcomes, particularly concerning the identification and preservation of the facial nerve and its branches. Study Design: Prospective study. Setting: Tertiary Care Hospital; in Rawalpindi. Period: January 2020 to December 2023. Methods: Enrolled 70 patients with parotid lesions treated patient selection was based on the presence of parotid lesions. Data was entered and analysed by using SPSS V.26. Results: The gender distribution was 29 males (41.43%) and 41 females (58.57%), with a mean age of 38.2 years. The majority of cases involved pleomorphic adenoma, constituting 74.28% (n=52) of the total cases. Other tumor types included Warthin tumor (5.71%, n=4), monomorphic adenoma (2.86%, n=2), Mucoepidermoid carcinoma (14.29%, n=10), and adenoid cystic carcinoma (2.86%, n=2). In terms of the type of surgery performed, 82.86% (n=58) of cases underwent superficial parotidectomy, while 17.14% (n=12) underwent total conservative parotidectomy. Regarding facial nerve outcomes, temporary facial nerve paralysis was observed in 8.57% (n=6) of cases, while permanent facial nerve palsy occurred in 2.86% (n=2) of cases. Conclusion: We have seen that a microscope is a very valuable assistant in the identification and preservation of the facial nerve. Thus, we can recommend its use during the procedure in order to prevent morbidity of the patient.

Prognostic factors and survival in adenoid cystic carcinoma of the head and neck: A retrospective study

Prognostic factors and survival in adenoid cystic carcinoma of the head and neck: A retrospective study

8042 A Rare Case of Papillary Thyroid Carcinoma in a Patient with Li-Fraumeni Syndrome

Abstract Disclosure: K.M. Bakhtawar: None. G. Jaiswal: None. Li-Fraumeni syndrome (LFS) is an autosomal dominant syndrome with a high lifetime probability of cancer at an early age. The spectrum of cancers primarily includes osteosarcoma, soft tissue sarcoma, breast cancer, brain tumors, leukemia, and Adenoid cystic carcinoma. Prior studies have estimated the cumulative cancer risk to be about 50% by age 40 and as high as 90% by age 60. As screening for TP53 mutations has improved and more patients are identified, the LFS cancer spectrum has expanded to include thyroid cancer. However, the occurrence of thyroid cancer in LFS has not been extensively assessed in the literature. A recent study examined cancer patients carrying the Brazilian p.R337H TP53 mutation which demonstrated that out of 101 patients, 11 had thyroid cancer (10.9%). In our case, a 45-year-old female with a past medical history of Li-Fraumeni syndrome, Von Willebrand disease, Pulmonary embolism, HER-2 positive invasive ductal carcinoma of the left breast status post chemotherapy, and bilateral mastectomy presented for evaluation of papillary thyroid carcinoma (PTC). An enlarged thyroid was initially identified on physical exam by the PCP with a follow-up thyroid ultrasound showing bilateral nodules. The right upper pole 1.9 x 1.3 x 1.6 cm nodule was biopsied revealing PCT. Following neck ultrasound demonstrated mildly enlarged lymph nodes on the right side, level 2A 1.5 cm and level 3 1.6 cm. The patient subsequently underwent total thyroidectomy and lymph node dissection. The pathology report revealed a 1.4 cm PTC in the upper right pole, a 0.9 cm PCT in the isthmus, and a 0.8 cm PTC in the left midpole. 4/62 lymph nodes were positive with the largest deposit of 1 cm. All margins were negative for carcinoma with no angioinvasion or lymphatic invasion. She was staged as T1bN1bM0. We are awaiting post-operative Thyroglobulin level to assess the need for Radioactive iodine. BRAFV600E and P53 mutation was identified. The patient carries known heterozygous mutation p.R1755H in the TP53 gene with an estimated lifetime cancer risk of 93%. This particular mutation has not been associated with thyroid cancer in prior studies. Although thyroid cancer is an uncommon manifestation of LFS, this case begs the importance of further studies to explore this association which may then lead to early screening and treatment of thyroid cancer in individuals with founder TP53 mutations. Presentation: 6/1/2024

Epidemiological Study of Adenoid Cystic Carcinoma and Its Outcomes: Insights from the Surveillance, Epidemiology, and End Results (SEER) Database

Objective: Adenoid cystic carcinoma (ACC) is a rare malignant tumor that mainly arises in the head and neck area. We aimed to compare the long-term survival of patients with ACC based on their geographic regions within the United States using the Surveillance, Epidemiology, and End Results (SEER) registry data. Methods: We queried the SEER database to evaluate the geographic distribution of ACC patients based on inpatient admissions. The states included in the study were divided into four geographical regions (Midwest, Northeast, South, and West) based on the U.S. Census Bureau-designated regions and divisions. Demographic and clinical variables were compared between the groups. Kaplan–Meier curves and Cox regression were used to assess late mortality. Results: A total of 5150 patients were included (4.2% from the Midwest, 17.2% from the Northeast, 22.5% from the South, and 56.1% from the West regions). The median follow-up was 12.3 (95% CI: 11.6–13.1 years). Median overall survival was 11.0 (95% CI: 9.2-NR years), 14.3 (95% CI: 12.4–16.4 years), 11.3 (95% CI: 9.7–14.8 years), and 12.0 (95% CI: 11.3–13.0 years) for Midwest, Northeast, South, and West regions, respectively. In multivariable analysis, older age, male sex, thoracic cancer, the presence of regional and distal disease, receiving chemotherapy, not undergoing surgical resection, and being treated in the West vs. Northeast region were found to be independent predictors of poor survival. We identified a significant survival difference between the different regions, with the West exhibiting the worst survival compared to the Northeast region. Conclusions: In addition to the well-known predictors of late mortality in ACC (tumor location, stage, and treatment modalities), our study identified a lack of social support (being unmarried) and geographic location (West region) as independent predictors of late mortality in multivariable analysis. Further research is needed to explore the causal relationships.

Immunostaining for Mismatch Repair Complex Proteins Impacts on Clinical-Pathological Characteristics and Prognosis of Adenoid Cystic Carcinoma of Salivary Glands.

To evaluate the influence of MMR proteins on clinicopathological characteristics and prognosis of salivary gland adenoid cystic carcinoma (ACC). The solid pattern of ACC showed lower expression for MSH2 (p = 0.039). Significant imbalance in MSH2/MSH6 immunostaining was observed in all histological patterns (p < 0.001), and imbalance in PMS2/MLH1 immunostaining was observed in the cribriform pattern (p = 0.011). The presence of capsule was associated with high expression of MSH6 (p = 0.019), MLH1 (p = 0.045) and PMS2 (p = 0.009). The absence of cribriform pattern (p = 0.002) and capsule pattern (p = 0.025), as well as low expression for MSH6 (p = 0.006) and PMS2 (p = 0.037) were associated with lower overall survival. In multivariate analysis, loss of MSH2 (p = 0.039) and MLH1 (p = 0.017) were significantly associated with worse overall survival. Twenty-four ACC were clinical-pathologically evaluated and we perform immunohistochemistry for MSH2, MSH6, PMS2 and MLH1. Percentage counting of positive cells was performed in 10 fields of each histological pattern (cribriform, tubular and solid) and the averages of the 30 fields were considered for evaluation with other clinical-pathological variables (Kruskal-Wallis/Dunn, Friedman/Dunn, chi-square, Log-Rank Mantel-Cox tests and Cox regression; SPSS v20.0, p < 0.05). Salivary glands' ACC shows imbalance of the MMR complex and loss of expression of its components is associated with the overall survival of these patients.

Phase 2 trial of regorafenib in recurrent or metastatic adenoid cystic carcinoma.

There is a significant need for effective therapies to treat recurrent/metastatic (R/M) adenoid cystic carcinoma (ACC). This study evaluated the multi-targeted, vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor (TKI) regorafenib in patients with R/M ACC. Patients with progressive R/M ACC were treated with regorafenib until disease progression, consent withdrawal, or excessive toxicity. The primary endpoints were best overall response (BOR) and 6-month progression-free survival (PFS). Genomic and transcriptomic biomarker analyses were performed in tumors from trial participants. Thirty-eight patients were enrolled, including 7 (18%) patients with prior VEGFR-TKIs. No objective responses were observed. Six-month PFS was 45%, and median PFS was 7.2 months (95%CI 5.2-11.9 months). Presence of either activating NOTCH1 (22%) or KDM6A alterations (24%) was associated with decreased PFS (HR 2.6, 95%CI 1.1-6.1, p=0.03). Bulk RNA sequencing of pre-treatment tumors revealed that regorafenib clinical benefit (CB; PFS≥6 months; n=11) was associated with native enrichment of immune-related signatures. Immune deconvolution revealed a greater degree of macrophage and T-cell infiltration in CB tumors. Tumors from patients with no clinical benefit (NCB; PFS<6 months; n=9) had greater expression of signatures related to cell cycle progression (E2F targets, G2/M checkpoint). The trial failed to meet the pre-specified 6-month PFS and BOR targets. We hypothesize that TKI efficacy may be reliant upon an interplay between kinase inhibition and the ACC immune microenvironment, while programs promoting cell cycle progression may contribute to TKI resistance. These observations suggest that trials evaluating CDK4/6 inhibition plus a VEGFR-TKI should be considered.