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.

BACKGROUND: Adenoid cystic carcinoma is a rare subtype of triple-negative breast carcinoma. These low-grade tumours, which are treated by simple mastectomy and have an excellent prognosis compared to other triple-negative breast carcinomas. Solid-variant adenoid cystic carcinomas have basaloid features and are difficult to distinguish morphologically from other triple-negative breast cancers. Breast adenoid cystic carcinoma exhibits MYB protein overexpression, which can be detected by immunohistochemistry (IHC).
OBJECTIVE: We compared the IHC expression of MYB in solid-variant adenoid cystic carcinoma with that in other triple-negative breast cancers.
METHODS: We conducted IHC staining of 210 samples of triple-negative breast cancers, including solid-variant adenoid cystic carcinoma (n = 17), metaplastic breast carcinoma (n = 44), basaloid triple-negative breast cancer (n = 21), and other triple-negative invasive ductal carcinoma (n = 128). We classified nuclear staining of MYB as diffuse/strong (3+), focal moderate (2+), focal weak (1+), or none (0).
RESULTS: All 17 solid/basaloid adenoid cystic carcinoma cases exhibited 3+ MYB expression. Of the 21 solid/basaloid triple-negative breast cancers, one (5%) had 2+ expression, seven (33%) 1+ expression, and 13 (62%) 0 expression. Of the 44 metaplastic carcinoma cases, 39 cases (89%) had no (0) staining, and the other five cases had focal weak (1+) or moderate (2+) staining. Among the 128 triple-negative invasive ductal carcinoma cases, 92 cases (72%) had no (0) staining, 36 cases (28%) exhibited focal weak (1+) or moderate (2+) staining.
CONCLUSIONS: Our study revealed diffuse/strong MYB staining (3+) only in solid/basaloid adenoid cystic carcinomas. Thus, we recommend routine MYB IHC staining in triple-negative breast carcinoma with solid/basaloid morphology to improve diagnostic accuracy.

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.

UNASSIGNED: Salivary gland tumours are rare cancers with variable course and prognosis. There is a paucity of data, especially for the advanced stages.
UNASSIGNED: This is a retrospective analysis carried out in our institute. All patients seeking treatment for incurable advanced salivary gland tumours from October 2018 to September 2022 were included. Relevant clinical data were collected and appropriate statistical analysis was applied.
UNASSIGNED: 30 patients were included in the analysis. The parotid gland was the most common site of origin (73%). Adenoid cystic carcinoma (ACC) and salivary duct carcinoma (SDC) were equally (37%) the most common pathological subtypes. The majority of patients were males (73%) and lungs (57%) were the most common site of metastases. On molecular analysis, SDC had high rates of androgen receptor (AR) (90%) and human epidermal growth factor receptor 2 (HER2) (55%) positivity. Mucoepidermoid carcinoma (MEC) had AR and HER2 positivity rates of 17% and 20%, respectively, while for ACC it was even lower. A variety of treatment regimens including hormonal therapy, anti-HER2 targeted therapy and chemotherapy were used in first-line treatment. With an overall response rate (ORR) of 10/21 (48%), only 9/21 (43%) went on to receive second-line treatment with an ORR of 4/9 (44%). The progression-free survival (PFS) with first-line treatment (PFS1) was a median of 5 months. The median PFS1 was worst for MEC. The median overall survival (OS) was 10 months. Median OS for ACC, SDC and MEC were 11, 10 and 7 months, respectively. At 24 months, ACC had much higher survival (50%) than others (10%) indicating a proportion of ACC with an indolent course.
UNASSIGNED: Our analysis highlights the variable disease biology of advanced salivary gland tumours and throws light on the various possible treatment targets and strategies. Molecular profiling and advancement in targeted therapies are expected to increase survival in this group of rare cancers.

Primary cutaneous adenoid cystic carcinoma (PCACC) is a rare form of adenoid cystic carcinoma (ACC) arising commonly from the salivary gland. Less often they originate outside the head and neck region, with the scalp being the commonest cutaneous site in 40% of the cases. The presentation on the chest wall is rare, with no reports to date on axillary lymph node metastases. Here we report a case of a 65-year-old female with previously operated PCACC of the chest wall at a different center, showing uptake on positron emission tomography imaging at the site of surgical scar that w as inconclusive on needle biopsy metastasized to the axillary lymph node confirmed by needle biopsy managed with wide local excision, axillary lymph node dissection, and chest wall reconstruction with keystone island flap. The postoperative outcome was uneventful with no recurrence or axillary complications at one year\'s follow-up. She was advised to receive adjuvant radiotherapy; however, she refused. To conclude, though PCACC is rare, they can have an aggressive presentation, and a multidisciplinary approach is necessary for a better outcome.

BACKGROUND: High-grade transformation Adenoid cystic carcinoma (HGT-AdCC) of the parotid gland is a rare transformation noted in slow growing low grade AdCC. Perineural invasion and spread is an important feature of this tumor. Temporal bone involvement is rare. A total of only 10 cases of HGT-AdCC in parotid gland has been reported in literature so far predominantly in the elderly with peak incidence in 5th-6th decade.
METHODS: We present a young lady of HGT-AdCC of right parotid gland with temporal bone involvement in the form of isolated perineural invasion (PNI) of facial nerve till the tympanic segment. She underwent right radical parotidectomy with modified radical neck dissection with modified lateral temporal bone resection and pectoralis major myocutaneous flap reconstruction. Histopathological examination revealed both low- and high-grade areas. Sections from facial nerve showed tumor invasion.
CONCLUSIONS: The radiological features of isolated perineural spread in intratympanic part of facial nerve can be easily missed if not specifically looked for. Every attempt should be made preoperatively and intraoperatively to determine the complete extent of the tumor for adequate disease clearance. A combined clinico-radiological approach aided by histopathology examination helps in early detection of this carcinoma and in better patient management.

OBJECTIVE: Modern intensity-modulated radiotherapy (IMRT) is frequently applied to treat patients with nasal cavity and paranasal sinus (NC/PNS) malignancies.
METHODS: One hundred and four patients who underwent radiotherapy (RT) between 1994 and 2020 were recognized. This analysis compared conventional-radiotherapy (CRT) and image-guided IMRT outcomes for NC/PNS malignancies.
RESULTS: The median follow-up was 69 months. Eighty-eight patients (85%) were managed with image-guided IMRT. The median initial radiation dose was 65 Gy, with 68 Gy applied for patients treated with primary RT versus 63 Gy applied for adjuvant therapy (p=0.1). The 5-year locoregional control (LRC) was 85%. The locoregional recurrence rate was 18% following IMRT versus 31% in the 2D/3D-conventional RT group (p=0.09). Moreover, IMRT was associated with a lower inner-ear toxicity rate (8% vs. 20%, respectively; p=0.045).
CONCLUSIONS: IMRT appears to be linked with higher LRC and lower inner-ear acute toxicities compared to conventional RT.

Adenoid cystic carcinoma of head and neck (AdCCHN) is an uncommon salivary gland cancer characterized for infrequent neck metastases, and high rate of local and distant recurrence. The aim of this meta-analysis was to analyse the significance of elective neck dissection (END) in terms of overall survival (OS) in patients with AdCCHN. A systematic literature search and meta-analysis was performed. Endpoint assessed by this meta-analysis included 5-year OS (death from any cause). Statistical heterogeneity was assessed using the Cochrane Q test and I2 statistic. A pooled odds ratio (OR) was reported with 95% confidence interval (CI). There were 1934 patients in the END arm and 3083 in the observation group. The pooled OR, calculated for END vs. observation, was 0.94. Patients receiving END had similar risk for death compared to observation cohort (P=0.76). No significant difference in final outcome after patient stratification based on T stage was identified (OR for T1/T2 1.27, P=0.39; OR for T3/T4 0.95, P=0.90). Observation for cN0 neck is a reasonable option in AdCCHN. These findings suggest the need for prospective trials on indications and extent of END in AdCCHN.

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.