Adenoid cystic carcinoma. An indolent but aggressive tumour. Part A: from aetiopathogenesis to diagnosis

Adenoid cystic carcinoma of the Bartholin's gland is underpinned by MYB- and MYBL1- rearrangements

OBJECTIVE

Adenoid cystic carcinoma (AdCC) of the Bartholin's gland (AdCC-BG) is a very rare gynecologic vulvar malignancy. AdCC-BGs are slow-growing but locally aggressive and are associated with high recurrence rates. Here we sought to characterize the molecular underpinning of AdCC-BGs.

METHODS

AdCC-BGs (n = 6) were subjected to a combination of RNA-sequencing, targeted DNA-sequencing, reverse-transcription PCR, fluorescence in situ hybridization (FISH) and MYB immunohistochemistry (IHC). Clinicopathologic variables, somatic mutations, copy number alterations and chimeric transcripts were assessed.

RESULTS

All six AdCC-BGs were biphasic, composed of ductal and myoepithelial cells. Akin to salivary gland and breast AdCCs, three AdCC-BGs had the MYB::NFIB fusion gene with varying breakpoints, all of which were associated with MYB overexpression by IHC. Two AdCC-BGs were underpinned by MYBL1 fusion genes with different gene partners, including MYBL1::RAD51B and MYBL1::EWSR1 gene fusions, and showed MYB protein expression. Although the final AdCC-BG studied had MYB protein overexpression, no gene fusion was identified. AdCC-BGs harbored few additional somatic genetic alterations, and only few mutations in cancer-related genes were identified, including GNAQ, GNAS, KDM6A, AKT1 and BCL2, none of which were recurrent. Two AdCC-BGs, both with a MYB::NFIB fusion gene, developed metastatic disease.

CONCLUSIONS

AdCC-BGs constitute a convergent phenotype, whereby activation of MYB or MYBL1 can be driven by the MYB::NFIB fusion gene or MYBL1 rearrangements. Our observations further support the notion that AdCCs, irrespective of organ site, constitute a genotypic-phenotypic correlation. Assessment of MYB or MYBL1 rearrangements may be used as an ancillary marker for the diagnosis of AdCC-BGs.

TGFβ signaling pathway in salivary gland tumors

OBJECTIVE

Pleomorphic adenoma (PA), mucoepidermoid carcinoma (MEC), and adenoid cystic carcinoma (ACC) are the most prevalent salivary gland tumors. Their pathogenesis has been recently associated with complex molecular cascades, including the TGFβ signaling pathway. The aim of this study was to evaluate the expression of genes associated with the TGFβ signaling pathway (TGFB1, ITGB6, SMAD2, SMAD4, FBN1, LTBP1, and c-MYC) to map possible downstream alterations in the TGFβ cascade.

DESIGN

Thirteen PA, 17 MEC, 13 ACC, and 10 non-neoplastic salivary gland samples were analyzed by real-time RT-PCR.

RESULTS

Cases of PA presented increased TGFB1, LTPB1, c-MYC, and FBN1 expressions, whereas SMAD2 expression was decreased when compared to non-neoplastic tissue. MEC patients displayed increased expressions of TGFB1, ITGB6, FBN1, and c-MYC and decreased expressions of SMAD2 and SMAD4. ACC cases exhibited elevated expressions of the investigated genes except TGFB1. The present results suggest that decreased expression of SMAD2 and SMAD4 does not impede the transcriptional regulation of c-MYC, especially in PA and MEC. Increased expressions of ITGB6, TGFB1, LTBP1, and FBN1 appear to be related to the regulation of the TGFβ signaling pathway in these tumors. Additionally, we observed a higher expression of SMAD4 in ACC and a raised expression of ITGB6 and lowered expression of SMAD2 in MEC.

CONCLUSIONS

Our study demonstrated the differential expression of TGFβ cascade members in salivary gland tumors such as SMAD2/SMAD4 and c-MYC as well as the participation of ITGB6, TGFB1, LTBP1, and FBN1, contributing to the understanding of the mechanisms involved in tumor progression.

Molecular Aspects of Mucoepidermoid Carcinoma and Adenoid Cystic Carcinoma of the Salivary Gland

BACKGROUND

Salivary gland tumors (SGTs) are rare and highly heterogeneous lesions, making diagnosis a challenging activity. In addition, the small number of studies and samples evaluated difficults the determination of prognosis and diagnosis. Despite the solid advances achieved by research, there is still an intense need to investigate biomarkers for diagnosis, prognosis and that explain the evolution and progression of SGTs.

METHODS

We performed a comprehensive literature review of the molecular alterations focusing on the most frequent malignant SGTs: mucoepidermoid carcinoma and adenoid cystic carcinoma.

RESULTS

Due to the importance of biomarkers in the tumorigenenic process, this review aimed to address the mechanisms involved and to describe molecular and biomarker pathways to better understand some aspects of the pathophysiology of salivary gland tumorigenesis.

CONCLUSIONS

Molecular analysis is essential not only to improve the diagnosis and prognosis of the tumors but also to identify novel driver pathways in the precision medicine scenario.

Novel Epigenetic Modifiers of Histones Presenting Potent Inhibitory Effects on Adenoid Cystic Carcinoma Stemness and Invasive Properties

Adenoid cystic carcinoma (ACC) is a rare neoplasm known for its indolent clinical course, risk of perineural invasion, and late onset of distant metastasis. Due to the scarcity of samples and the tumor's rarity, progress in developing effective treatments has been historically limited. To tackle this issue, a high-throughput screening of epigenetic drugs was conducted to identify compounds capable of disrupting the invasive properties of the tumor and its cancer stem cells (CSCs). ACC cells were screened for changes in tumor viability, chromatin decondensation, Snail inhibition along tumor migration, and disruption of cancer stem cells. Seven compounds showed potential clinical interest, and further validation showed that Scriptaid emerged as a promising candidate for treating ACC invasion. Scriptaid demonstrated a favorable cellular toxicity index, effectively inhibited Snail expression, induced hyperacetylation of histone, reduced cell migration, and effectively disrupted tumorspheres. Additionally, LMK235 displayed encouraging results in four out of five validation assays, further highlighting its potential in combating tumor invasion in ACC. By targeting the invasive properties of the tumor and CSCs, Scriptaid and LMK235 hold promise as potential treatments for ACC, with the potential to improve patient outcomes and pave the way for further research in this critical area.

Epidemiology of and factors associated with overall survival for patients with head and neck adenoid cystic carcinoma

BACKGROUND

Updated epidemiologic and survival data of head and neck adenoid cystic carcinoma (HNACC) are lacking. This retrospective study aimed to clarify the incidence, prevalence, and overall survival (OS) of patients with HNACC and establish relevant nomogram.

METHODS

Trends in incidence, limited-duration prevalence, and relative survival (RS) rates were evaluated using data from the Surveillance, Epidemiology, and End Results (SEER) database, and annual percent change (APC) in rates was calculated using joinpoint regression. Data on age, sex, site, stage, and surgery were used in construction and validation of the nomogram.

RESULTS

The study included 6474 patients; 57.7% were female and 78.6% were white. The age-adjusted incidence rates of HNACC decreased significantly from 0.41 to 0.25 per 100,000 [1975-2018; average annual percent change (AAPC): - 1.37, P < 0.001], which was dominated by the localized stage. The 20-year limited duration prevalence increased from 0.00028% to 0.00262%. The 5- and 10-year RS rates of all HNACC patients were 80.0% and 65.5%, respectively. RS rates in HNACC showed a slight increase over time, with APC values of 0.03 for 5-year (P < 0.05) and 0.13 for 10-year (P < 0.05) RS. A prognostic model was constructed. The C-indices for the training and testing sets were both 0.734. The nomogram's discrimination efficiency was evaluated using the receiver operating characteristic curve and had moderate predictive power.

CONCLUSIONS

Over the past 40 years, the incidence of HNACC decreased accompanied by slightly improved survival rates. Nomogram was capable of predicting the 5- and 10-year OS rates with moderate accuracy.

Extracting Potential New Targets for Treatment of Adenoid Cystic Carcinoma using Bioinformatic Methods

Background

Adenoid cystic carcinoma is a slow-growing malignancy that most often occurs in the salivary glands. Currently, no FDA-approved therapeutic target or diagnostic biomarker has been identified for this cancer. The aim of this study was to find new therapeutic and diagnostic targets using bioinformatics methods.

Methods

We extracted the gene expression information from two GEO datasets (including GSE59701 and GSE88804). Different expression genes between adenoid cystic carcinoma (ACC) and normal samples were extracted using R software. The biochemical pathways involved in ACC were obtained by using the Enrichr database. PPI network was drawn by STRING, and important genes were extracted by Cytoscape. Real-time PCR and immunohistochemistry were used for biomarker verification.

Results

After analyzing the PPI network, 20 hub genes were introduced to have potential as diagnostic and therapeutic targets. Among these genes, PLCG1 was presented as new biomarker in ACC. Furthermore, by studying the function of the hub genes in the enriched biochemical pathways, we found that insulin-like growth factor type 1 receptor and PPARG pathways most likely play a critical role in tumorigenesis and drug resistance in ACC and have a high potential for selection as therapeutic targets in future studies.

Conclusion

In this study, we achieved the recognition of the pathways involving in ACC pathogenesis and also found potential targets for treatment and diagnosis of ACC. Further experimental studies are required to confirm the results of this study.

Unraveling the Role of Epithelial-Mesenchymal Transition in Adenoid Cystic Carcinoma of the Salivary Glands: A Comprehensive Review

Salivary adenoid cystic carcinoma (SACC) is considered a challenging malignancy; it is characterized by a slow-growing nature, yet a high risk of recurrence and distant metastasis, presenting significant hurdles in its treatment and management. At present, there are no approved targeted agents available for the management of SACC and systemic chemotherapy protocols that have demonstrated efficacy remain to be elucidated. Epithelial-mesenchymal transition (EMT) is a complex process that is closely associated with tumor progression and metastasis, enabling epithelial cells to acquire mesenchymal properties, including increased mobility and invasiveness. Several molecular signaling pathways have been implicated in the regulation of EMT in SACC, and understanding these mechanisms is crucial to identifying new therapeutic targets and developing more effective treatment approaches. This manuscript aims to provide a comprehensive overview of the latest research on the role of EMT in SACC, including the molecular pathways and biomarkers involved in EMT regulation. By highlighting the most recent findings, this review offers insights into potential new therapeutic strategies that could improve the management of SACC patients, especially those with recurrent or metastatic disease.

Malignant neoplasm of lacrimal gland with pulmonary metastasis

Adenoid cystic carcinomas (ACC) make up 3%-5% of head and neck malignancies. They have a high propensity to metastasise, in particular to the lungs. A 65-year-old male diagnosed with a right lacrimal gland ACC T2N0M0 (surgically resected 12 years prior) presented with an incidentally noted 1.2 cm right lower lobe lung nodule seen on MRI liver. Subsequent imaging confirmed a non-FDG avid 1.6 cm solitary ovoid subpleural lesion, percutaneous biopsy confirmed adenocarcinoma. A surgical metastasectomy was performed and recovery was complete. Prognosis in ACC is improved with radical management of metastatic disease. Rather than a simple chest radiograph, more detailed imaging, such as MRI or CT scanning may increase the probability of early detection of pulmonary metastasis and, thereby facilitate radical treatment and improve survival.

Translocations and Gene Fusions in Sinonasal Malignancies

PURPOSE OF REVIEW

During the past few years there has been an expansion in our understanding of gene fusions and translocations involved in cancer of the sinonasal tract. Here we review the downstream biologic effects, clinical characteristics, and pathologic features of these tumors. The molecular consequences and neo-antigens resulting from these chromosomal aberrations are considered and targets for current and future clinical trials discussed.

RECENT FINDINGS

Several new, clinically relevant, chromosomal aberrations have been discovered and evaluated to varying degrees in sinonasal tumors including DEK::AFF2, BRD4::NUT, ADCK4::NUMBL, and ETV6::NTRK3. Sinonasal malignancies demonstrate a diverse genetic landscape and varying clinical courses. Recent studies illustrate that gene fusions and translocations may play a role in carcinogenesis in certain sinonasal tumor subtypes and may be used to develop new biomarker-driven and patient-centered treatments.

Adenoid cystic carcinoma of Bartholin's gland, a case report with genomic data and literature review

Adenoid cystic carcinoma of the Bartholin's gland (ACCBG) is a rare, slowly but aggressive malignancy. We reported the case of a 31-year-old woman who was treated by local excision and then hemi-vulvectomy, with positive margins and perineural invasion. Radiation therapy (RT) was then performed delivering 45Gy in 25 fractions in bilateral inguinal lymph nodes and 64.8Gy in 36 fractions on the vulvar area. After 30 months, there was no local relapse (LR) but the patient presented a histologically documented lung recurrence. Genomic profiling of the tumor showed a MYB-NFIB fusion transcript and a somatic mutation of PLCG1. A treatment by Lenvatinib was started. We conducted a literature review of 100 published cases. Patients were mainly treated by radical vulvectomy (30%), hemi-vulvectomy (17%), wide or local excision (21% and 24%, respectively) or other. Forty-four percent of patients received postoperative RT, more frequently in case of positive margin (71.9% versus 29.5%). RT may reduce the risk of LR regardless of margin status, with 15.4% vs. 41.9% of LR with or without RT, respectively, in patients with negative margins, and 13% vs. 33.3% of LR with or without RT, respectively, in patients with positive margins. The risk of relapse of any type was 40.9% in patients who received adjuvant RT vs. 48.2% in patients who did not. Median time to relapse was 24 months (range 6-156 months). The most frequent metastatic sites were lung (76.7%) and bone (26.7%). Optimal treatment for ACCBG is still not clearly defined but pooling the data from published case report help us better understand this rare disease and help in the therapeutic decision.

Case report: First case of early adenoid cystic carcinoma and squamous cell carcinoma collision cancer treated by endoscopic submucosal dissection

Background

Collision cancer, a rare tumor, rarely occurs in the esophagus. Most reported cases of esophageal collision cancers are advanced cancers that can only be treated with surgery or palliative chemoradiotherapy. Here, we report a rare case of collisional squamous cell carcinoma (SqCC) and adenoid cystic carcinoma (AdCC) that was detected in the early stages by endoscopy.

Case summary

A 66-year-old man presented with retrosternal pain after swallowing and underwent endoscopy. Pathological biopsy showed high-grade squamous intraepithelial neoplasia. The lesion was removed by endoscopic submucosal dissection (ESD) after magnification and endoscopic ultrasonography. Postoperative pathology proved that the lesion was collision cancer comprising SqCC and AdCC. After six months of postoperative follow-up, there was no recurrence of esophageal cancer.

Conclusions

We provided a case report related to the diagnosis and treatment of esophageal collision cancer, especially early collision cancer. More research is needed to provide insights into the management of collision cancers.

[Molecular and genetic studies of polymorphic adenocarcinoma of the salivary gland: literature review and description of a clinical case]

The article summarizes the literature data on the results of clinical, histological and molecular genetic studies of polymorphic adenocarcinoma. It is shown that the diagnosis of polymorphic adenocarcinoma presents difficulties due to the variety of morphological structure of its various components, which may correspond to the characteristics of other tumors of the salivary glands, such as pleomorphic adenoma and adenoid cystic carcinoma. Immunohistochemical markers characteristic of this pathology of the salivary glands are described. The article presents a rare clinical case of a male patient with polymorphic adenocarcinoma. Histological examination revealed perineural invasion and a characteristic immunohistochemical profile of tumor cells: low cell proliferative activity for the Ki-67 protein, a positive reaction to antigens: S100, SOX10, P63 and reverse transcriptase TERT. A study conducted by the FISH method revealed the amplification of the TERC gene, which indicates the malignant nature of this neoplasm. Conducting molecular genetic studies is of paramount importance for the diagnosis of polymorphic adenocarcinoma.

Male Adenoid Cystic Carcinoma of the Breast

Adenoid cystic carcinoma (ACC) of the breast, a rare malignancy that makes up less than 0.1% of all breast malignancies, is much rarer in males than in females. Due to the rarity of this disease, an optimal treatment strategy for male breast ACC has not been established, and therapy for male patients is currently based on guidelines for female patients. According to previous reported cases, some authors believe that male breast ACC may have higher invasive potential than female breast ACC and the prognoses in male patients may be worse than those in female patients. Therefore, a more proactive diagnosis and treatment regimen may be required. However, the clinical feature of our case is inconsistent with this view. Herein we report the case of a 24-year-old male without any antecedent medical or family history who presented with a slow-growing lump on his left chest wall for 5 years. The patient initially underwent lumpectomy, and the mass was pathologically diagnosed as breast ACC. Systemic examination was performed, and no evidence of distant metastasis was found. Then, he received modified radical mastectomy and ipsilateral axillary lymph node dissection. The mastectomy pathological examination revealed that no cancerous tissue was detected around the primary tumor bed, and all 22 axillary lymph nodes were negative. The patient did not receive postoperative chemotherapy, radiotherapy or endocrine therapy and remained well after 28 months of follow-up. In this study, we review the literature and summarize the clinical manifestations, imaging and histopathological characteristics, treatments and outcomes of male breast ACC. We share our experience in the hopes that this evidence will aid in the development of better therapeutics.

Adenoid cystic carcinoma of the sublingual gland developing lung metastasis 20 years after primary treatment: A case report and literature review

RATIONALE

Adenoid cystic carcinoma (ACC) is a rare malignant tumor that primarily occurs in the salivary glands. Distant metastases can develop despite favorable local control. Moreover, distant metastasis of ACC can occur after a long time interval without local recurrence. We report the first case of ACC of the sublingual gland that developed lung metastasis 20 years after primary treatment.

PATIENT CONCERNS

A 52-year-old man was referred to our department with a 1-year history of painful swelling on the right oral floor.

DIAGNOSIS

An incisional biopsy was performed, and histopathological examination revealed malignancy.

INTERVENTIONS

Surgical excision of the right oral floor and right supra-omohyoid neck dissection with postoperative chemoradiation therapy were performed, and ACC of the sublingual gland was diagnosed. Left pulmonary metastasis was detected 20 years after the primary treatment. Metastasectomy was performed; however, subsequently, skin and bone metastases developed.

OUTCOMES

After receiving palliative care, the patient died of multiple organ failure.

LESSONS

As late distant metastasis of salivary ACC can develop, patients who undergo primary treatment need a long-term, strict follow-up plan even if locoregional control is favorable.