Frequent NFIB-associated Gene Rearrangement in Adenoid Cystic Carcinoma of the Vulva

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.

Human Papillomavirus-Associated Multiphenotypic Carcinoma: First Description of a Vulval Case

Human papillomavirus (HPV)-associated multiphenotypic sinonasal carcinoma is a rare and recently described epithelial neoplasm exhibiting myoepithelial differentiation and morphological overlap with salivary gland neoplasms, especially adenoid cystic carcinoma; it is commonly associated with HPV, especially type 33. It has mainly been reported in the nasal cavity and paranasal sinuses with a single case reported in the breast. Herein, we report the first vulval example in a 47-year-old patient who presented with a large craggy mass in the region of the Bartholin gland. The histologic features were of a high-grade carcinoma composed of basaloid cells arranged in sheets and nests, with occasional ductal formations, surrounded by densely hyalinised basement membrane-type material. There was diffuse block-type immunoreactivity with p16 and HPV genotyping revealed high-risk HPV type 16. In reporting this case, we highlight the propensity for "salivary gland-type" neoplasms to arise in the vulva, especially in the Bartholin gland, and stress that pathologists should consider salivary-type neoplasms when faced with a morphologically unusual vulval tumor.

Invasive Squamous Cell Carcinoma of the Cervix: A Review of Morphological Appearances Encountered in Human Papillomavirus-associated and Papillomavirus-independent Tumors and Precursor Lesions

Cervical cancer is the fourth most common cancer among women globally. Historically, human papillomavirus (HPV) infection was considered necessary for the development of both precursor and invasive epithelial tumors of the cervix; however, studies in the last decade have shown that a significant proportion of cervical carcinomas are HPV-independent (HPVI). The 2020 World Health Organization (WHO) Classification of Female Genital Tumors separates both squamous cell carcinomas (SCCs) and endocervical adenocarcinomas (ECAs) by HPV status into HPV-associated (HPVA) and HPVI tumors. The classification further indicates that, in contrast to endocervical adenocarcinomas, HPVI and HPVA SCCs cannot be distinguished by morphological criteria alone and suggests that HPV testing or correlates thereof are required for correct classification. Moreover, while HPVA SCC precursor lesions (ie, high-grade squamous intraepithelial lesion) are well known and characterized, precursors to HPVI SCCs have only been described recently in a small number of cases. We studied 670 cases of SCCs from the International Squamous Cell Carcinoma Project (ISCCP) to analyze the reproducibility of recognition of invasive SCC growth patterns, presence of lymphovascular space invasion, tumor grade, and associations with patient outcomes. Consistent with previous studies, we found histologic growth patterns and tumor types had limited prognostic implications. In addition, we describe the wide morphologic spectrum of HPVA and HPVI SCCs and their precursor lesions, including tumor growth patterns, particular and peculiar morphologic features that can lead to differential diagnoses, and the role of ancillary studies in the diagnosis of these tumors.

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.

MYB-NFIB fusion transcript in Adenoid Cystic Carcinoma: current state of knowledge and future directions

Adenoid cystic carcinoma (ACC) is the most common type of salivary gland cancer that can also arise in other primary sites. Regardless of the site, most ACC cases carry a recurrent chromosomal translocation - t(6;9)(q22-23;p23-24) - involving the MYB oncogene and the NFIB transcription factor. Generally, a long sequence of MYB is fused to the terminal exons of NFIB, yet the break can occur in different exons for both genes, resulting in multiple chimeric variants. The fusion status can be determined by a number of methods, each of them with particular advantages. In vitro and in vivo studies have been conducted to understand the biological consequences of MYB-NFIB translocation, and such findings could contribute to improving the current inefficient therapeutic options for disseminated ACC. This review provides a discussion on relevant evidence in the context of ACC MYB-NFIB translocations to determine the current state of knowledge and discuss future directions.

Primary cutaneous adenoid cystic carcinoma: a clinicopathologic, immunohistochemical, and fluorescence in-situ hybridisation study of 13 cases

AIMS

This study aimed to investigate the clinical, histological, immunohistochemical and chromosomal features of primary cutaneous adenoid cystic carcinoma (PCACC).

METHODS AND RESULTS

We retrospectively analysed 13 cases identified on their clinicopathological features and performed fluorescence in-situ hybridisation (FISH) on six available cases. Head and neck (46.2%) were most commonly involved. The median age was 53 years, with a male predilection. Histologically, tumours were classified as grades 1 (eight), 2 (four) and 3 with high-grade transformation (HGT) (one). The HGT component was demonstrated as poorly differentiated carcinoma with multifocal necrosis and myoepithelial differentiation. Patients with one of the following factors: longest diameter of the lesion (≥ 1 cm), involvement of subcutaneous fat tissue and widely infiltrative border had a relatively higher rate of local recurrence, distant metastasis and death. Five of six cases were confirmed to have MYB translocation, while nuclear staining for MYB proto-oncogene, transcription factor (MYB) protein was found in four cases. During the follow-up (median = 64 months), two patients experienced local recurrences. One patient, who was classified as grade III PCACC with HGT, developed multiple metastases and died of disease. Another patient was alive with multiple metastases.

CONCLUSIONS

This is the largest single-institution study, to our knowledge, of PCACC in an Asian population. We describe the first case of scalp PCACC with HGT, which is the only death case in our series. PCACC tends to recur locally and has metastatic potential. PCACC with HGT has a poor prognosis.

Nuclear factor I/B mediates epithelial-mesenchymal transition in human melanoma cells through ZEB1

The relationship between nuclear factor I/B (NFIB) and cancer attracts growing research interest. NFIB has diverse and specific roles in tumor progression and invasion. However, the potential effects and functions of this transcription factor in melanoma remain unclear. The present study sought to determine the distinguishing properties of NFIB in melanoma cells. Immunohistochemical examination of the tissues of 15 patients with melanoma indicated that the expression of NFIB was high in melanoma specimens, compared with the benign nevus and normal skin specimens. In addition, the relationship between high NFIB expression and low overall survival rate was assessed. Functional studies demonstrated that NFIB enhanced the malignancy of melanoma, including proliferation, migration and invasion. In addition, NFIB silencing in A375 and A875 cell lines inhibited the process of epithelial-mesenchymal transition (EMT), upregulated E-cadherin and zona occludens-1, but suppressed N-cadherin and vimentin expression. These findings may suggest a new function of NFIB in promoting the migration and invasion of melanoma cells. Therefore, the present study further evaluated the association between NFIB and zinc finger protein E-box binding homeobox-1 (ZEB1) in melanoma. Mechanistic experiments revealed that NFIB exerted its roles during EMT by regulating ZEB1. Overall, the present data indicates that NFIB promotes the malignancy of melanoma, particularly EMT, by modulating the ZEB1 axis, such as ZEB2, ATM and CHK1, which may represent a potential molecular therapeutic target in melanoma.

Clinicopathologic and survival analysis of patients with adenoid cystic carcinoma of vulva: single-institution experience

PURPOSE

The purpose of this study was to elucidate our experience in the diagnosis and treatment of adenoid cystic carcinoma of the vulva (ACC-vulva) and to assess the clinicopathological characteristics and prognosis among ACC-vulva patients.

METHODS

A retrospective study of seventeen patients was performed to illustrate the demographic information, clinical performance, pathological characteristics, treatment modality, and development of local recurrence or distant metastasis, as well as the survival outcome.

RESULTS

The median age at diagnosis was 56 years (range, 26-71 years). Radical local excision was performed on fifteen patients, and two patient received radical hemi-vulvectomy. Six patients received ipsilateral inguinal lymphadenectomy. Involvement of the resection margin was observed in six patients. The postoperative pathologic diagnosis showed no proof of inguinal lymph node metastasis in all the six patients receiving lymphadenectomy. However, the perineural invasion was observed in all patients. Postoperative adjuvant radiotherapy was applied to five patients who had positive resection margin. The mean survival time except for that in four patients (recent case) was 47.8 months (range, 23-78 months).

CONCLUSION

Radical resection towards negative margins seems to be acceptable as initial treatment. Adjuvant radiotherapy is a preferable treatment modality for patients with high-risk factors pathologically or patients with local recurrence.

Adenoid Cystic Carcinoma of Bartholin's Gland: What Is the Best Approach?

Background and summary: Among all vulvar cancers, primary adenoid cystic carcinoma (ACC) of Bartholin's gland is a very rare tumor characterized by a slow growth, a high local aggressiveness, and a remarkable recurrence rate. Due to its rarity, treatment remains a challenge for oncologists and gynecological surgeons. Key message: The present paper reports clinical, radiological, and histological features of ACC of Bartholin's gland and reviews the literature data on the treatment options with a particular focus on the potential role of particle radiation therapy.

Adenoid cystic carcinoma of the Bartholin gland is not HPV-related: A case report and review of literature

Adenoid cystic carcinoma (ACC) of the Bartholin gland is a rare gynaecological entity. Despite its slow growth and inconspicuous presentation, vulvar ACC has a propensity for perineural invasion and is therefore associated with high local recurrence rates. We report a case of vulvar ACC in a 61-year-old woman with a prolonged swelling of the Bartholin gland. This patient presented with pulmonary metastases at the moment of histological diagnosis. The vulvar and the pulmonary lesions showed identical histology. Despite a history of human papilloma virus (HPV)-related usual type vulvar intra-epithelial neoplasia and cervical squamous cell carcinoma, the vulvar ACC was negative for both p16 immunohistochemistry and HPV-DNA. We conclude that HPV is not involved in the pathogenesis of pure ACC of the Bartholin gland. Additionally, we advocate a low threshold for performing biopsies of vulvar swellings in women aged >40 years, to rule out malignancy and to prevent diagnostic delays.

Primary Mammary Analog Secretory Carcinoma (MASC) of the Vulva With ETV6-NTRK3 Fusion: A Case Report

Mammary analog secretory carcinoma is a primary salivary gland neoplasm with histologic, immunophenotypic, and molecular features identical to those of secretory carcinoma of the breast. Similar neoplasms have now been reported to occur in various nonmammary sites including the parotid gland, submandibular gland, sinuses, lip, skin, thyroid gland, and lung. We report, to our knowledge, the first example of a primary vulvar neoplasm with pathologic features identical to secretory carcinoma of the breast and an ETV6-NTRK3 fusion.

Small Subset of Adenoid Cystic Carcinoma of the Skin Is Associated With Alterations of the MYBL1 Gene Similar to Their Extracutaneous Counterparts

Adenoid cystic carcinoma (ACC) of the skin is a rare malignant neoplasm histologically identical to homonymous tumors in other organs. Cutaneous ACC has been found to harbor MYB gene activations, either through MYB chromosomal abnormalities or by generation of the MYB-NFIB fusion. In salivary gland ACC, in addition to the MYB gene, alterations in MYBL1, the gene closely related to MYB, have been reported. We studied 10 cases of cutaneous ACC (6 women, 4 men; and age range 51-83 years) for alterations in the MYB, NFIB, and MYBL1 genes, using FISH and PCR. MYB break-apart and NFIB break-apart tests were positive in 4 and 5 cases, respectively. MYB-NFIB fusions were found in 4 cases. The break of MYBL1 was found in 2 cases, and in one of them, the NFIB break-apart probe was positive, strongly indicating a MYBL1-NFIB fusion. In 2 cases, the MYB break-apart test was positive, whereas no MYB-NFIB was detected, strongly suggesting another fusion partner. It is concluded that MYBL1 alterations are detected in primary cutaneous ACC but are apparently less common compared with MYB and NFIB alterations.

c-MYB and DMTF1 in Cancer

The c-Myb gene encodes a transcription factor that regulates cell proliferation, differentiation, and apoptosis through protein-protein interaction and transcriptional regulation of signaling pathways. The protein is frequently overexpressed in human leukemias, breast cancers, and other solid tumors suggesting that it is a bona fide oncogene. c-MYB is often overexpressed by translocation in human tumors with t(6;7)(q23;q34) resulting in c-MYB-TCRβ in T cell ALL, t(X;6)(p11;q23) with c-MYB-GATA1 in acute basophilic leukemia, and t(6;9)(q22-23;p23-24) with c-MYB-NF1B in adenoid cystic carcinoma. Antisense oligonucleotides to c-MYB were developed to purge bone marrow cells to eliminate tumor cells in leukemias. Recently, small molecules that inhibit c-MYB activity have been developed to disrupt its interaction with p300. The Dmp1 (cyclin D binding myb-like protein 1; Dmtf1) gene was isolated through its virtue for binding to cyclin D2. It is a transcription factor that has a Myb-like repeat for DNA binding. The Dmtf1 protein directly binds to the Arf promoter for transactivation and physically interacts with p53 to activate the p53 pathway. The gene is hemizygously deleted in 35-42% of human cancers and is associated with longer survival. The significances of aberrant expression of c-MYB and DMTF1 proteins in human cancers and their clinical significances are discussed.

Distinctive clinicopathological features and disease‑specific survival of adenoid cystic carcinoma and adenoid basal carcinoma in the lower female genital tract

Adenoid cystic carcinomas (ACCs) and adenoid basal carcinomas (ABCs) in the lower female genital tract are very rare. Data on the clinicopathologic features and survival outcomes of ACCs and ABCs in the lower female genital tract are limited to case reports and small case series studies. The present study systemically analyzed 233 cases, including 84 cervical ACCs, 78 cervical ABCs and 71 vulvar ACCs, to identify clinicopathologic features and survival factors in a population‑based Surveillance, Epidemiology and End Results (SEER) study. Whereas cervical ACCs and ABCs tend to occur in the elderly (median, 72 and 69 years, respectively), vulvar ACCs commonly occurred in patients a decade younger (median, 59 years). The majority of patients with cervical ABC had localized disease and almost all received surgery. In contrast, cervical and vulvar ACC patients tended to have higher stage disease, and a significant proportion of these patients received radiotherapy, with or without surgery. The 5‑year cause‑specific survival (CSS) rates for patients with cervical ACC were 69.3%, vulvar ACC 87.7% and cervical ABC 96.6%. The 5‑year overall survival (OS) rate for patients with cervical ACC was 59.2%, significantly worse than that of cervical ABC (88.3%; P=0.002) and vulvar ACC (81.2%; P=0.01). Increased age and high stage were significantly associated with a worse prognosis in patients with cervical and vulvar ACCs by univariate and multivariate analysis (P<0.05). Tumor stage was the only significant factor associated with 5‑year overall survival in patients with cervical ABC (P<0.05). The present data demonstrated that the distinctive clinicopathologic features and survival outcomes differed significantly among ACCs and ABCs in the lower female genital tract, thus providing a rationale for location/pathologic type‑based treatment modalities.

The convergent roles of the nuclear factor I transcription factors in development and cancer

The nuclear factor I (NFI) transcription factors play important roles during normal development and have been associated with developmental abnormalities in humans. All four family members, NFIA, NFIB, NFIC and NFIX, have a homologous DNA binding domain and function by regulating cell proliferation and differentiation via the transcriptional control of their target genes. More recently, NFI genes have also been implicated in cancer based on genomic analyses and studies of animal models in a variety of tumours across multiple organ systems. However, the association between their functions in development and in cancer is not well described. In this review, we summarise the evidence suggesting a converging role for the NFI genes in development and cancer. Our review includes all cancer types in which the NFI genes are implicated, focusing predominantly on studies demonstrating their oncogenic or tumour-suppressive potential. We conclude by presenting the challenges impeding our understanding of NFI function in cancer biology, and demonstrate how a developmental perspective may contribute towards overcoming such hurdles.

Nuclear Factor I/B: A Master Regulator of Cell Differentiation with Paradoxical Roles in Cancer

Emerging evidence indicates that nuclear factor I/B (NFIB), a transcription factor required for proper development and regulation of cellular differentiation in several tissues, also plays critical roles in cancer. Despite being a metastatic driver in small cell lung cancer and melanoma, it has become apparent that NFIB also exhibits tumour suppressive functions in many malignancies. The contradictory contributions of NFIB to both the inhibition and promotion of tumour development and progression, corroborates its diverse and context-dependent roles in many tissues and cell types. Considering the frequent involvement of NFIB in cancer, a better understanding of its multifaceted nature may ultimately benefit the development of novel strategies for the management of a broad spectrum of malignancies. Here we discuss recent findings which bring to light NFIB as a crucial and paradoxical player in cancer.

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NFIB, a versatile regulator of cell differentiation, is emerging as a crucial driver of cancer metastasis.

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Paradoxically, NFIB also exhibits tumour suppressive functions in several cancer types.

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A deeper understanding of the multifaceted and context-dependent nature of NFIB has the potential to improve the clinical management of a variety of cancers.