Rb1 Loss in Salivary Gland Anlage Tumors | Petr Slavík
Salivary Gland Anlage Tumor: A Study of Rb1 Expression and Molecular Genetic Analysis of 8 Cases
Authors: Petr Slavík (1,2), Nina Zidar (3), Jason Jarzembowski (4), Petr Grossmann (2), Göran Elmberger
(5), Hiroshi Minato (6), Miguel Rito (7), Tomáš Vaněček (2), Alena Skálová (1,2), Michal Michal (1,2)
Supervisor: Martina Bradová (1,2)
(1) Department of Pathology, Faculty of Medicine in Pilsen, Charles University and University
Hospital, Pilsen (2) Bioptická laboratoř, s.r.o., Pilsen (3) Institute of Pathology, Faculty of Medicine,
University of Ljubljana, Ljubljana, Slovenia (4) Medical College of Wisconsin, Milwaukee,
Wisconsin (5) Department of Laboratory Medicine, Pathology Orebro University Hospital, Orebro,
Sweden (6) Department of Diagnostic Pathology, Ishikawa Prefectural Central Hospital,
Kanazawa City, Ishikawa Prefecture, Japan (7) Serviço de Anatomia Patológica, Instituto Português
de Oncologia de Lisboa Francisco Gentil, Lisboa, Portugal
State-of-the-Art: Salivary gland anlage tumor (SGAT) is a very rare infantile tumor occurring in the nasopharynx, often presenting with respiratory distress syndrome, stridor, or feeding difficulties in the first few months of life. SGAT is a biphasic tumor combined of epithelial (tubules, ducts and solid or cystic squamous nests) and variably cellular myoepithelial tissue (spindle- shaped cells). The genetic background of this tumor remains poorly understood.
Objective: Eight cases of SGAT were selected from the authors‘ files. These cases underwent
histological and immunohistochemical (IHC) analysis (Rb1, and other IHC markers), as well as
molecular genetic analysis.
Material and Methods: For microscopy, the excised tissues were fixed in formalin, processed
routinely, embedded in paraffin, cut and stained with hematoxylin & eosin. For immunohistochemistry,
sections were cut from paraffin blocks and mounted on positively charged slides. The in-house customized version of Archer FusionPlex Sarcoma kit was used to construct a cDNA library for detecting fusion transcripts and point mutations in 88 and 14 genes respectively. The library was sequenced on an Illumina platform. Illumina TruSight Oncology 500 interrogating 523 genes for single nucleotide variants (SNVs) and indels and TruSight RNA Pan-Cancer Panel assays targeting 1385 genes were performed. For the detection of Rb1 loss the probe ZytoLight® SPEC Rb1/13q12 Dual Color Probe was used.
Results & Discussion: The cohort consisted of 8 patients, including 6 males, 1 female and in 1 case unknown, with an age range from 2 days to 5 years. One case was an incipient stage of SGAT, composed of cystically dilated ducts lined by cylindrical epithelium with a ciliated surface and squamous, partly cystic islands. Another case was a malignant SGAT composed of squamous, partly cystic nests along with a pleomorphic spindle cell component with multiple mitoses. All cases with available tissue blocks showed complete loss of Rb1 staining in tumor cells with positive internal and outer control. None of our cases showed a somatic genetic event; however, a clinically significant RICTOR mutation, potentially germline, was found in one case. FISH and DNA sequencing were negative/non-analyzable for Rb1 mutation.
Conclusion: Despite negative/non-analyzable molecular genetic results of Rb1 gene alterations,
Rb1 IHC is an important diagnostic tool in SGAT. Loss of Rb1 immunoexpression suggests an absence or malfunction of Rb1, likely through mechanisms other than direct genetic alterations detectable by FISH or NGS.
Funding: This study was supported by study grant SVV 260652 from the Ministry of Education.
Study program: Master´s degree – General Medicine | Year of study: 6
ID: 1088
PLAG1:LIFR Fusion in Pleomorphic Adenoma | Constantina Constantinou
SIGNIFICANCE OF PLAG1::LIFR GENE FUSION IN PLEOMORPHIC ADENOMA OF SALIVARY GLANDS: POTENTIALLY SIGNIFICANT PROGNOSTICATOR OF CLINICAL BEHAVIOUR
Author: Constantina Constantinou (1)
Supervisor: Alena Skálová (1, 2)
(1) Department of Pathology, Faculty of Medicine in Pilsen, Charles University and University Hospital, Pilsen (2) Biopticka Laboratory Ltd., Pilsen
State-of-the-Art: Pleomorphic adenoma (PA) is a benign epithelial neoplasm characterized by cytomorphological and architectural diversity, with an admixture of ductal and myoepithelial cells usually embedded in a chondromyxoid or fibrous stromal component. PAs harbor recurrent translocations or intrachromosomal rearrangements resulting in gene fusions involving PLAG1 on 8q12 (> 50%) or HMGA2 on 12q14.3 (10–15%). Seven recurrent fusion partner genes for PLAG1 have been reported (CTNNB1, FGFR1, LIFR, CHCHD7, TCEA1, NFIB, and BOC). Moreover, oncocytic PAs have been shown to contain PLAG1 gene fusions with GEM, CHCHD7, NTF3, FBXO32, and C1orf116.
Objective: Recently, it has been proposed that PLAG1::LIFR fusion might be associated with adverse prognosis of PA.
Material and Methods: A retrospective analysis of 1557 PA cases, retrieved from the Salivary gland tumor registry consultation files, was conducted. A total of 150 cases of PA positive for PLAG1 on immunohistochemistry (IHC) were selected. Fluorescence in situ hybridization (FISH) and/or targeted next generation sequencing (NGS) were performed in order to detect PLAG1 gene rearrangements and/or fusion. Fusions of the PLAG1 gene were identified in 42 PA cases, including PLAG1::LIFR (11/42), PLAG1::CTNNB1 (9/42), and variable other fusions (22/42).
Results & Discussion: PLAG1::LIFR fusions (n=11) were found in the palate (7), parotid (2), submandibular gland (1), and jaw (1). Patients were 82% female (9/11) and 18% male (2/11), with an average age of 54 (range 35–79). The PLAG1::LIFR tumors were benign in 5 cases: PA (3), recurrent PA (1), myoepithelioma (1), while 6 cases were malignant, such as myoepithelial carcinoma (MECa) (3), recurrent MECa ex PA (1), MECa ex PA (2). Lung metastases occurred in 2 cases. PLAG1::CTNNB1 fusions (n=9) were found in the parotid gland (7), submandibular gland (1) and palate (1). Patients were 67% male (6/9) and 33% female (3/9), with an average age of 46 (range 18–68). Tumors were benign in 4 cases: PA (2), atypical PA (2) while 5 cases showed malignant transformation of PA: MECa (4), salivary duct carcinoma ex PA (1).
Conclusion: PLAG1::LIFR and PLAG1::CTNNB1 fusions were both identified in a subset of PLAG1-positive pleomorphic adenomas. PLAG1::LIFR was notably associated with malignant transformation and metastatic behaviour of PA, thus indicating its potential utility as a prognostic marker.
Funding: The work was partly supported by the grant SVV No. 260 773.
Study program: Master´s degree – General Medicine | Year of study: 4
ID: 1107
Does the MDM2 Gene Predict the Behaviour of PA ? | Klára Bělohlávková
Significance of MDM2 gene amplification to predict an aggressive behaviour of Pleomorphic adenoma.
Author: Klára Bělohlávková (1)
Supervisor: Alena Skálová (1, 2)
(1) Department of Pathology, Faculty of Medicine in Pilsen, Charles University and University
Hospital, Pilsen (2) Bioptická laboratoř, s.r.o., Pilsen, Czech Republic
State-of-the-Art: Pleomorphic adenoma (PA) is a benign neoplasm characterized by cytomorphological
and architectural diversity, with an admixture of ductal and myoepithelial cells usually embedded in a chondromyxoid or fibrous stromal component. PAs harbor recurrent translocations or intrachromosomal rearrangements resulting in gene fusions involving PLAG1 or HMGA2 genes. Carcinoma ex pleomorphic adenoma (CXPA) is an aggressive epithelial and/or myoepithelial neoplasm that arises in association with a PA. Its etiopathogenesis remains poorly understood, but it is believed that the development of this tumor is due to the accumulation of genetic, protein, metabolic, and epigenetic alterations in a PA.
Objective: Recently, it has been proposed that the MDM2 gene amplifications could be useful
to predict an aggressive course of CXPA.
Material and Methods: A total amount of 14 Atypical PA cases (Group A), 29 Myoepithelial
and/or Epithelial-Myoepithelial carcinoma cases (Group B) and 16 CXPA cases (Group C) were
retrieved from the Salivary gland tumor registry consultation files. In these cases an immunohistochemical
(IHC) detection of MDM2 was conducted. In 12 immunohistochemically positive cases fluorescence in situ hybriditation (FISH) was performed to detect MDM2 gene amplification.
Results & Discussion: In all three groups (Group A,B,C), the distribution of sex (50% male, 50%
female patients) and age (average of 67 years) was equal. The immunohistochemical detection
of the MDM2 gene was positive in 1/14 atypical PA cases, 9/29 myoepithelial and/or epithelial-
myoepithelial carcinoma cases and 2/16 CXPA cases. A positive FISH detection of MDM2
amplification corelated with the IHC findings in Group B and Group C cases and was not found
in the one positive atypical PA case.
Conclusion: The MDM2 gene amplification could indeed predict an aggressive outcome of the
otherwise benign PA. Although the PA itself expresses this alteration very rarely, the malignant
neoplasms arising from PA were significantly more likely to show the MDM2 amplification.
Funding: The work was supported by the grant SVV (No.260773).
Study program: Master´s degree – General Medicine | Year of study: 5
ID: 1099
Journey of Breast Cancer Patients to Diagnosis | Sára Sedláčková
Mapping the journey of patients with breast cancer – understanding the causes, early detection and diagnosis of the disease
Author: Sára Sedláčková (1,2)
Supervisor: Samuel Vokurka (1,2)
(1) Department of Oncology and Radiotherapeutics, Faculty of Medicine in Pilsen, Charles University and University Hospital, Pilsen (2) Center for Palliative and Supportive Medicine, Faculty of Medicine in Pilsen, Charles University and University Hospital, Pilsen
State-of-the-Art: Early detection of breast cancer is a basic prerequisite for improving the prognosis of this oncological disease. Regular self-examination and screening mammography (MMG) from the age of 45 and every 2 years are the main methods for early detection. The trend in patient care and public education is cooperation with patient organizations and improving awareness of recommended procedures within the so-called patient‘s journey to prevention, early diagnosis and treatment of individual oncological diseases. At the same time, there is little awareness of the perception of the causes of the disease and the insight into the patient‘s journey from diagnosis to treatment by patients.
Objective: Patient‘s perception of the cause of the disease, methods of early detection of breast cancer, and the patient‘s journey from the first symptoms to treatment.
Material and Methods: Questionnaire survey conducted once a week at 8-9:00 on 4.11.-16.12.2024 among randomly selected patients with breast cancer within the Department of Oncology and Radiotherapeutics of the University Hospital Pilsen and Faculty of Medicine in Pilsen. Questions included: the patient‘s suspicion of a possible risk factor or influence leading to the development of cancer; availability and source of information on regular breast self-examination; performing self-examination; availability and source of information on screening MMG; attitude towards MMG examination; other procedures in prevention and detection; symptom of breast disease and reason for visiting a physician; course and perception of the patient‘s journey to cancer treatment.
Results & Discussion: 26 patients (24 women, 2 men), median age 51 (33-71), women age 45+ 18/26 (69%). Most frequently perceived risk factors: stress 54%, none 12%, many others 34%. Self-exam awareness and use in 96% and 54%, source of information physician 46% and media 31%. In women 45+ Screening MMG awareness and use in 89% and 83%, source of information physician 70%, MMG omission due to ignorance, lifestyle or resistance 25%. Other screenings: USG 15%, CT 4%. Initial symptom: breast lump 11/26 (42%), MMG and USG detection 27% and 8%, armpit lump 8%. Timeline and pathway perceived without problem in 23/26 (88%), slight mistake or underestimation by the patient or physicians in 12%. While the patient group is heterogeneous, the data reflects a real-world situation and provides a fundamental insight.
Conclusion: We observed strong patient perception of cancer causes and awareness of its early detection, with some patients not adhering to screening MMG. Patients‘ journeys were positively reviewed by the majority of them. Further research would be beneficial for a more comprehensive view.
Funding: Partially supported by: Faculty of Medicine in Pilsen Cooperatio-ONCO; NEXTIN Pilsen.
Study program: Master´s degree – General Medicine | Year of study: 4
ID: 1073