Exploration of High-Grade Transformation and Postoperative Radiotherapy on Prognostic Analysis for Primary Adenoid Cystic Carcinoma of the Head and Neck

[Research Progress of Cellular Lipid Droplets in Oral Diseases]

Lipid droplets are dynamic multifunctional organelles composed of a neutral lipid core and a phospholipid monolayer membrane modified by a specific set of proteins. PAT family proteins are the most characteristic lipid droplet proteins, playing an important role in regulating lipid droplet structure, function, and metabolism. The biogenesis of lipid droplets involves neutral lipid synthesis and the nucleation, budding, and growth of the lipid droplets. Lipid droplets not only serve as the energy metabolism reserve of cells but also participate in intracellular signal transduction and the development of inflammation and tumor. Lipid droplets are closely connected to and interact with various organelles, regulating the division, the transportation, and the genetics of organelles. The complexity of lipid droplets biogenesis and the diversity of their functions may have provided a physiological basis for the pathogenesis and development of diseases, but further research is needed in order to better understand the relevant processes. Published findings have helped elucidate the association between lipid droplets and diseases, such as obesity, non-alcoholic fatty liver disease, neurodegenerative disease, cancer, and cardiovascular disease, but the relationship between lipid droplets and oral diseases has not been fully studied. Topics that warrant further research include the role and mechanisms of lipid droplets in the pathogenesis and development of oral diseases, the relationship between oral diseases and systemic diseases, and translation of the effect of lipid droplets on oral diseases into valuable clinical diagnostic and treatment methods. Herein, we reviewed the biogenesis and functions of lipid droplets and the progress in research concerning lipid droplets in oral diseases, including mouth neoplasms, periodontitis, and dental caries.

Prognostic Significance of Histopathological Parameters for Salivary Gland Adenoid Cystic Carcinoma

Adenoid cystic carcinoma (ACC) is a rare salivary gland tumor that accounts for approximately 1% of all head and neck cancers. Despite its initial indolent behavior, long-term survival is poor due to locoregional recurrence in approximately 40% and distant metastasis in up to 60% of patients who undergo radical treatment. The histological parameters of ACC and the combination of these parameters in histopathological grading systems provide valuable prognostic information about the clinical course of the disease. Within this context, this review aims to analyze the impact of histopathological parameters, individual or combined in histopathological grading systems of malignancy, on ACC prognosis. Individual histopathological parameters such as solid pattern, presence of tumor necrosis, high-grade transformation, dominance of the epithelial component, presence of perineural and lymphovascular invasion, and positive surgical margins have negative impacts on the survival of patients with ACC. There are currently four histopathological grading systems for ACC; however, few studies have validated these systems and most of them explored small cohorts with short follow-up. Considering that the application of grading systems has been associated with ACC prognosis, a broader validation will allow not only their use for prognostic prediction but also assist in treatment planning.

Radiotherapy of skin adnexal carcinoma

Skin adnexal carcinomas are rare skin cancer, developing from pilosebaceous, eccrine and apocrine unit. Treatment of localised tumours usually includes surgery and radiotherapy. Indications and modalities of radiotherapy depend on the pathological subtype with a lack of consensus for some histologies. This review summarises the place of radiotherapy in terms of indication, dose and fractionation, volumes to irradiate and discuss ongoing studies.

MiR-29a-3p inhibits high-grade transformation and epithelial-mesenchymal transition of lacrimal gland adenoid cystic carcinoma by targeting Quaking

BACKGROUND

Lacrimal adenoid cystic carcinoma (LACC) is the most common orbital malignant epithelial neoplasm. LACC with high-grade transformation (LACC-HGT) has higher rates of recurrence, metastasis, and mortality than LACC without HGT. This study investigated the effects of microRNA-29a-3p (miR-29a-3p) in the pathogenesis of LACC-HGT.

METHODS

An Agilent human miRNA microarray was used to screen the differentially expressed miRNAs (DEMs) in LACC and LACC-HGT tumor tissues. Then, the primary cells obtained in previous studies were used to determine the effect of miR-29a-3p.

RESULTS

The expression of miR-29a-3p was abnormally lower in LACC-HGT than in LACC. miR-29a-3p can specifically target the 3' UTR of Quaking mRNA and down-regulate Quaking expression, thereby inhibiting the proliferation, migration, and epithelial-mesenchymal transition of LACC cells.

CONCLUSIONS

This study illustrated that miR-29a-3p functions as a tumor suppressor by down-regulating the expression of Quaking to inhibit the tumorigenesis of LACC cells. This study may also reveal the pathogenesis of HGT in LACC cells and provide a reference for LACC-HGT targeted diagnosis.

Polar Vessel: A New Ultrasound Sign for Complementary Diagnosis of Major Salivary Gland Adenoid Cystic Carcinoma

OBJECTIVES

To investigate the characteristic ultrasonographic findings of adenoid cystic carcinoma (ACC) in major salivary glands and identify the value of polar vessel in color Doppler flow imaging (CDFI) for the diagnosis of ACC.

METHODS

From January 2017 to December 2021, 76 patients with parotid and submandibular gland tumors, including 14 patients with ACC, as confirmed by surgery and histopathology, were enrolled. Their clinicopathologic information and ultrasound (US) features were recorded and analyzed. The performance of polar vessel in CDFI for differentiating ACC from non-ACC (benign tumors and mucoepidermoid carcinoma [MEC]) was analyzed.

RESULTS

ACC in the major salivary gland was more likely to be associated with pain symptoms (P = .027) and unclear borders and rough edges in grayscale US (P = .002, .015, respectively) than benign tumors. Compared to MEC, ACC tended to feature a homogeneous internal echo (P = .008). ACC of the major salivary gland had a significantly higher incidence of polar vessel sign than that of non-ACC (benign tumors and MEC) (P < .0001, .0001, respectively). The polar vessel sign showed good performance in distinguishing between ACC and non-ACC, with an area under the receiver operating characteristic curve of 0.857, a sensitivity of 71.4%, a specificity of 100%, and an accuracy of 94.7%. Positive predictive value and negative predictive value were calculated at 100% and 93.9%, respectively.

CONCLUSIONS

The US sign of polar vessel has high diagnostic efficiency, and it may have important potential for use as a new complementary sign for the diagnosis of ACC in major salivary glands.

Robotic resection of a single adenoid cystic tumor liver metastasis using ICG fluorescence. A case report and literature review

Adenoid cystic carcinoma (AdCC) is a rare tumor that typically develops in the salivary glands and less frequently in other sites of the head and neck region. Only a few cases of resected metachronous liver metastases have been reported. Minimally invasive surgery is currently the gold standard of care for liver resections; furthermore, the use of Indocyanine Green (ICG) is continuously increasing in surgical practice, especially in cases of primary liver tumors and colorectal liver metastases, due to its capacity to enhance liver nodules. We report the case of a 54-year-old male with a single liver metastasis of AdCC, located in SIII, who presented in our center 9 months after resection of a primary tumor of the laryngotracheal junction and adjuvant proton therapy. A 25-mg injection of ICG (0.3 mg/kg) was administered 48 h before surgery in order to highlight the tumor and perform an ICG-guided resection. The lesion was clearly visible during surgery, and, given its position and the proximity to the main lobar vessels of the left lobe, we opted for a left lateral sectionectomy. The outcome was unremarkable, with no major postoperative complications. The administration of ICG 48 h before surgery seems to be a valid tool even in cases of AdCC liver metastases, providing surgeons with better visualization of the lesion and improving the precision of the resection.

A pilot study of 68 Ga-PSMA-617 PET/CT imaging and 177Lu-EB-PSMA-617 radioligand therapy in patients with adenoid cystic carcinoma

BACKGROUND

This pilot study was designed to evaluate the diagnostic value of 68 Ga-PSMA-617 and 18F-FDG PET/CT in adenoid cystic carcinoma (ACC) and to assess the safety and therapeutic response to PSMA radioligand therapy (RLT) in ACC patients.

METHODS

Thirty patients pathologically diagnosed with ACC were recruited into the cohort. Each patient underwent 68 Ga-PSMA-617 and 18F-FDG PET/CT within 1 week. The number and SUVmax of PET-positive lesions were recorded and compared. Four patients accepted RLT using 177Lu-EB-PSMA-617, in a dosage of approximately 1.85 GBq (50 mCi) per cycle for up to 3 cycles.

RESULTS

Compared with 18F-FDG, 68 Ga-PSMA-617 revealed more PET-positive extrapulmonary tumors (157 vs. 141, P = 0.016) and higher SUVmax (8.8 ± 3.6 vs. 6.4 ± 4.2, P = 0.027). However, 68 Ga-PSMA-617 revealed less PET-positive pulmonary lesions (202 vs. 301, P < 0.001) and lower SUVmax of tumors (3.1 ± 3.0 vs. 4.2 ± 3.9, P < 0.001) than 18F-FDG. The combination of 68 Ga-PSMA-617 and 18F-FDG can detect 469 PET-positive lesions, which was superior to each alone (469 vs. 359 vs. 442, P < 0.001). Two patients achieved remarkable response after PSMA RLT, while the other two patients showed reduced tumor uptake of recurrent foci, lung and liver metastases, whereas increased SUVmax of bone metastases.

CONCLUSIONS

68 Ga-PSMA-617 PET/CT is a valuable imaging modality for the detection of ACC and combining with 18F-FDG PET/CT will achieve a higher detection efficiency. PSMA RLT may be a promising treatment for ACC and is worth of further investigation.

TRIAL REGISTRATION

Diagnosis of Adenoid Cystic Carcinoma on 68 Ga-PSMA-617 PET-CT and Therapy With 177Lu-EB-PSMA-617 (NCT04801264, Registered 16 March 2021, retrospectively registered). URL of registry: https://clinicaltrials.gov/ct2/show/NCT04801264 .