OBJECTIVE: Although parotid gland malignancies are uncommon, they nevertheless represent a cause of morbidity and mortality in the pediatric population. Few studies have sought to identify disparities related to their presentation, treatment, and survival. There is a need to understand these variations to improve care for historically underrepresented groups.
METHODS: Retrospective Cohort Study.
METHODS: Surveillance, Epidemiology, and End Results (SEER) Program Database.
METHODS: Analysis of pediatric patients with parotid gland malignancies between 2000 and 2019. Race and ethnicity were classified as Non-Hispanic White, Non-Hispanic Black, Asian, and Hispanic for multivariable analysis. Outcomes included tumor size and stage at diagnosis, survival, and need for facial nerve sacrifice. Kaplan-Meier analysis was used to analyze survival. Multivariable logistic regression was conducted to identify predictors of outcomes.
RESULTS: 149 patients met the criteria for inclusion. Stratified by race/ethnicity, Non-Hispanic Black (Median 23 mm, IQR 15-33), Asian (30 mm, 14-32), and Hispanic (23 mm, 20-28) patients had larger tumors at presentation than Non-Hispanic White patients (18 mm, 12-25, p = 0.017). Disease-specific survival differed by time-to-treatment (log-rank, p = 0.01) and overall survival differed by income (p < 0.001). On multivariable analysis, Hispanic patients were more likely to experience facial nerve sacrifice (OR 3.71, 95%CI 1.25-11.6, p = 0.020), and Non-Hispanic Black (OR 3.37, 0.95-11.6, = 0.053) and Asian (OR 5.67, 1.46-22.2, p = 0.011) patients presented with larger tumors compared to Non-Hispanic White patients.
CONCLUSIONS: Variations in presentation and treatment exist across race and ethnicity in pediatric parotid cancer. Identifying these disparities may help improve access and outcomes for underserved patient populations.
METHODS: III.

UNASSIGNED: This study aims to evaluate the treatment approaches and locoregional patterns for Adenoid cystic carcinoma (ACC) in the breast, which is an uncommon malignant tumor with limited clinical data.
UNASSIGNED: A total of 93 patients diagnosed with primary ACC in the breast between 1992 and 2022 were collected from multi-institutions. All patients underwent surgical resection, including breast-conserving surgery (BCS) or total mastectomy (TM). The recurrence patterns and locoregional recurrence-free survival (LRFS) were assessed.
UNASSIGNED: Seventy-five patients (80.7%) underwent BCS, and 71 of them (94.7%) received post-operative radiation therapy (PORT). Eighteen patients (19.3%) underwent TM, with 5 of them (27.8%) also receiving PORT. With a median follow-up of 50 months, the LRFS rate was 84.2% at 5 years. Local recurrence (LR) was observed in 5 patients (5.4%) and 4 cases (80%) of the LR occurred in the tumor bed. Three of LR (3/75, 4.0%) had a history of BCS and PORT, meanwhile, two of LR (2/18, 11.1%) had a history of mastectomy. Regional recurrence occurred in 2 patients (2.2%), and both cases had a history of PORT with (n=1) and without (n=1) irradiation of the regional lymph nodes. Partial breast irradiation (p=0.35), BCS (p=0.96) and PORT in BCS group (p=0.33) had no significant association with LRFS.
UNASSIGNED: BCS followed by PORT was the predominant treatment approach for ACC of the breast and local recurrence mostly occurred in the tumor bed. The findings of this study suggest that partial breast irradiation might be considered for PORT in primary breast ACC.

OBJECTIVE: Currently, no systemic treatments are approved for patients with recurrent and/or metastatic (R/M) adenoid cystic carcinoma (ACC). PRT543, a protein arginine methyltransferase 5 inhibitor that downregulates NOTCH1 and MYB signalling in tumours, is a potential candidate for R/M ACC treatment. We report the safety, tolerability and preliminary efficacy of PRT543 in a dose-expansion cohort of patients with R/M ACC.
METHODS: This phase I multicentre, open-label, sequential-cohort, dose-escalation and dose-expansion study (NCT03886831) enrolled patients with advanced solid tumours and select haematologic malignancies. Dose-escalation study design and results were reported previously. In the dose expansion, patients with R/M ACC received recommended phase II doses of 35 or 45 mg PRT543 orally on days 1-5 of each week. Primary objectives were to establish the safety and tolerability of PRT543. Secondary objectives included efficacy.
RESULTS: Between February 2019 and May 2022, 56 patients with ACC were enrolled across 23 US sites and received either 35 mg (n = 28) or 45 mg (n = 28) of PRT543. Overall, 23% of patients experienced a grade 3 treatment-related adverse event, most commonly anaemia (16%) and thrombocytopaenia (9%). No grade 4/5 treatment-emergent adverse events were reported. Median progression-free survival was 5.9 months (95% CI: 3.8-8.3). The clinical benefit rate was 57% (95% CI: 43-70). Overall response rate (per Response Evaluation Criteria in Solid Tumours v1.1) was 2%, with 70% of patients having stable disease.
CONCLUSIONS: In this analysis, PRT543 was tolerable, and the observed efficacy was limited in patients with R/M ACC.

OBJECTIVE: Combined photon intensity-modulated radiotherapy (IMRT) and sequential dose-escalated carbon ion beam therapy (IBT) is a technically advanced treatment option for head and neck malignancies. We proposed and evaluated an integrated planning strategy as opposed to an established and largely separated planning workflow.
METHODS: Ten patients with representative malignancies of the head and neck region underwent combined carbon-photon radiotherapy (RT) in our facilities. Clinical plans were created according to the separated workflow with independent optimization stages for both modalities. Experimental plans incorporated the existing carbon IBT dose distribution into the optimization stage of a step-and-shoot photon IMRT (bias dose planning).
RESULTS: Cumulative dose distributions showed statistically significant differences between the two planning strategies and were predominantly in favor of the integrated approach. As such, target irradiation was generally maintained or even improved in a subset of metrics, while normal tissue sparing was widely enhanced; for instance, in the ipsilateral temporal lobe with median Dmean of -16% (p < 0.001). Maximum doses D1% (with adjustment for different fractionation) fell below thresholds for toxicity risk in a minority of instances, where they were previously exceeded. Integral dose did not differ significantly.
CONCLUSIONS: Our findings indicate that combination planning of carbon-photon RT for head and neck malignancies may benefit from a proposed bias dose method, yielding favorable dose distribution characteristics and a streamlined planning workflow with fewer plan revisions. Further research is necessary to validate these observations in terms of robustness and their potential for higher tumor control.

Adenoid cystic carcinoma (ACC) is a rare salivary gland neoplasm with a poor long-term prognosis due to multiple recurrences and distant metastatic spread. Circulating tumour cells (CTCs) are tumour cells shed from a primary, recurrent, or metastatic cancer that are detectable in the blood or lymphatics. There is no literature to date confirming the presence of CTCs in ACC. The aim of this study was to determine whether CTCs are detectable in ACC. Blood samples were collected from eight patients with histologically confirmed ACC. The TNM stage of the tumour was recorded, as well as any prior treatment. CTCs were isolated by spiral microfluidics and detected by immunofluorescence staining. Three of the eight patients recruited (32.5%) had staining consistent with the presence of CTCs. Of these three patients with detectable CTCs, one had confirmed pulmonary metastasis, one had suspected pulmonary metastasis and was awaiting confirmation, and one had local recurrence confirmed on re-resection. One patient with known isolated pulmonary metastasis had previously undergone a lung metastasectomy and did not have CTCs detected. CTCs are detectable in ACC. In this small patient sample, CTCs were found to be present in those patients with recurrent local disease and known distant metastatic disease. CTCs in ACC should be investigated further for their potential use as an adjunct in staging, prognosis, and the detection of recurrence.

OBJECTIVE: Vorinostat is a histone deacetylase inhibitor (HDACi). Based on a confirmed partial response (PR) in an adenoid cystic carcinoma (ACC) patient treated with vorinostat in a prior phase 1 trial, we initiated this phase 2 trial.
METHODS: Vorinostat was administered orally 400 mg daily, 28 day cycles. The primary objective was to evaluate response rate (RR). Exploratory studies included whole exome sequencing (WES) of selected patients.
RESULTS: Thirty patients were enrolled. Median age of patients was 53 years (range 21-73). Median number of cycles was 5 (range 1-66). Lymphopenia (n = 5), hypertension (n = 3), oral pain (n = 2), thromboembolic events (n = 2) and fatigue (n = 2) were the only grade 3 adverse events (AEs) that occurred in more than 1 patient. Eleven patients were dose reduced secondary to drug-related AEs. Two patients had a partial response (PR), with response durations of 53 and 7.2 months. One patient had a minor response with a decrease in ascites (for 19 cycles). Stable disease was the best response in 27 patients. Targeted and WES of 8 patients in this trial identified mutations in chromatin remodeling genes highlighting the role of the epigenome in ACC.
CONCLUSIONS: Vorinostat demonstrated efficacy in patients with ACC supporting the inclusion of HDACi in future studies to treat ACC.

BACKGROUND: The objective was to assess demographic and survival patterns in patients with adenoid cystic carcinoma of the base of tongue.
METHODS: Patients were extracted from the Surveillance, Epidemiology and End Results (SEER) database from 1973 through 2012 and were categorized by age, gender, race, historical stage A, and treatment. Incidence and survival were compared with Kaplan Meier curves and mortality hazard ratios.
RESULTS: A total of 216 patients were included. After adjusting for age, gender, race and tumor-directed treatment, patients over the age of 70years had a significantly increased mortality [HR=2.847, 95% CI (1.499, 5.404) p=0.0014]. Furthermore mortality among patients with distant disease was significantly increased [HR=2.474 95% CI (1.459, 4.195) p=0.00008].
CONCLUSIONS: By examining the largest collection of patients we have demonstrated that there is a significant difference in mortality based on both the age at diagnosis and in the setting of distant disease.

BACKGROUND: Adenoid cystic carcinoma (ACC) is a locally aggressive tumor with a high prevalence of distant metastases. The purpose of this study was to identify independent predictors of outcome and to characterize the patterns of failure.
METHODS: An international retrospective review was conducted of 489 patients with ACC treated between 1985 and 2011 in 9 cancer centers worldwide.
RESULTS: Five-year overall-survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) were 76%, 80%, and 68%, respectively. Independent predictors of OS and DSS were: age, site, N classification, and presence of distant metastases. N classification, age, and bone invasion were associated with DFS on multivariate analysis. Age, tumor site, orbital invasion, and N classification were independent predictors of distant metastases.
CONCLUSIONS: The clinical course of ACC is slow but persistent. Paranasal sinus origin is associated with the lowest distant metastases rate but with the poorest outcome. These prognostic estimates should be considered when tailoring treatment for patients with ACC.

BACKGROUND: Ceruminal gland carcinomas are rare neoplasms confined to the skin lining the cartilaginous part of the external auditory canal.
METHODS: Retrospective.
RESULTS: The patients included 11 men and 6 women, aged 33-82 years (mean, 59.5 years). Patients presented clinically with a mass of the outer half of the external auditory canal (n = 14), hearing changes (n = 5), drainage (n = 4), or paralysis of the facial nerve (n = 3). The polypoid masses ranged in size from 0.5 to 3 cm in greatest dimension (mean, 1.8 cm). Histologically, the tumors demonstrated a solid to cystic pattern, composed of an infiltrating glandular to cribriform arrangement of epithelial cells. Histologic features included a dual cell population (although not the dominant histology), increased cellularity, moderate to severe nuclear pleomorphism, irregular nucleoli, increased mitotic figures (mean, 3/10 HPF), including atypical forms, and tumor necrosis (n = 2). Tumors were divided into three types of adenocarcinoma based on pattern of growth and cell type (ceruminous, NOS [n = 12], adenoid cystic [n = 4], mucoepidermoid [n = 1]). CK7 and CD117 highlighted the luminal cells, while S1-00 protein showed a predilection for the basal cells of ceruminous and adenoid cystic carcinomas. Metastatic adenocarcinoma or direct extension from salivary gland neoplasms are the principle differential considerations. Surgical resection was used in all patients with radiation used in four patients. Eleven patients were alive or had died of unrelated causes without evidence of disease (mean, 11.2 years); six patients had died with disease (mean, 4.9 years), all of whom had developed local recurrence.
CONCLUSIONS: Ceruminous-type carcinomas, with the exception of ceruminous mucoepidermoid carcinoma, all demonstrated a dual cell population of basal myoepithelial-type cells and luminal apocrine cells. The specific histologic sub-type does not influence the long-term patient outcome.

Adenoid cystic carcinoma (ACC) constitutes about 4% of salivary epithelial tumors and is the second common malignant epithelial salivary gland tumor involving both the major and minor salivary glands. High grade transformation in ACC is a recently recognized entity with only a few cases reported in literature. We report the first case of ACC with high grade transformation involving the parotid. A 54-year-old man with a history of right parotid painful swelling from 1.5 years presented with recent increase in size of the swelling and facial paresis of 2 months duration. The locally invasive salivary neoplasm was composed predominantly of an undifferentiated carcinoma with foci of conventional ACC occupying less than 10% of tumor area. Immunohistochemical study of the undifferentiated component as compared to conventional ACC showed greater over-expression of p53 and Ki-67. Her-2/Neu was negative in both components. Recognition of occasional clusters of basaloid cells and hyaline globules in association with larger poorly differentiated malignant cell population in aspiration smears can help in cytological diagnosis. The acquisition of high proliferation index and over-expression of p53 may be the probable factors involved in the pathogenesis of high grade transformation in a conventional ACC.