Expression of CUG2, βIGH3 (TGFBI), and TGF-β in bronchoscopic biopsy specimens of lung cancer patients
| ISRCTN | ISRCTN52550559 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN52550559 |
| Süleyman Demirel University Scientific Research Projects Coordination Unit (SDÜ-BAP) Grant No | TDK-2019-6958 |
| Sponsor | Süleyman Demirel University |
| Funder | Süleyman Demirel Üniversitesi |
- Submission date
- 06/06/2026
- Registration date
- 11/06/2026
- Last edited
- 11/06/2026
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Cancer
Plain English summary of protocol
Background and study aims
Lung cancer is one of the most common and deadly cancers worldwide. When patients are first diagnosed, doctors need to know whether the cancer has spread (metastasized) to other parts of the body, and whether the tumor in the chest is a primary lung cancer or a cancer that has spread from elsewhere. This information is critical for choosing the right treatment.
This study investigates whether three proteins — CUG2, βIGH3 (also called TGFBI), and TGF-β — measured in tissue samples taken during a bronchoscopy (a routine procedure where a thin flexible tube is passed into the airways to take small tissue samples) can help answer these questions.
Who can participate?
Adults aged 18 years or older who are undergoing diagnostic bronchoscopy for suspected lung cancer or suspected spread of another cancer to the chest. Patients must have a confirmed tissue diagnosis and adequate biopsy sample quality for laboratory analysis.
What does the study involve?
Participants undergo routine diagnostic bronchoscopy as part of their standard clinical care. A small additional portion of the biopsy sample obtained during this procedure is used for laboratory analysis. Gene expression levels of three biomarkers (CUG2, βIGH3/TGFBI, and TGF-β) are measured using a technique called quantitative PCR (qPCR). No additional procedures, medications, or interventions are administered. Cancer spread (metastatic status) is determined by PET/CT scan as part of routine staging.
What are the possible benefits and risks of participating?
There are no direct benefits or risks to participants from this study. The biopsy is performed as part of standard diagnostic care. The biomarker measurements are performed on existing tissue samples and do not require any additional procedures. Results are not used to guide individual patient treatment in this study.
Where is the study run from?
Süleyman Demirel University Faculty of Medicine, Department of Pulmonology, Turkey.
When is the study starting and how long is it expected to run for?
January 2019 to June 2022
Who is funding the study?
Süleyman Demirel University Scientific Research Projects Coordination Unit, Turkey.
Who is the main contact?
Dr. Önder Öztürk, Süleyman Demirel University Faculty of Medicine, Department of Pulmonology, Turkey, dronderozturk@gmail.com
Contact information
Principal investigator, Scientific, Public
Department of Pulmonology, Faculty of Medicine, Süleyman Demirel University
Isparta, Merkez
32200
Türkiye
 ORCID ID |
0000-0001-8570-2172 |
|---|---|
| Phone | +905322677973 |
| dronderozturk@gmail.com |
Study information
| Primary study design | Observational |
|---|---|
| Observational study design | Prospective observational diagnostic accuracy study |
| Scientific title | Expression of CUG2, βIGH3 (TGFBI), and TGF-β in bronchoscopic biopsy specimens of lung cancer patients: predictive value for metastasis and differential diagnosis from other thoracic malignancies — a pilot study |
| Study objectives | 1. To evaluate the diagnostic accuracy of CUG2, βIGH3 (TGFBI), and TGF-β gene expression in bronchoscopic biopsy specimens for predicting metastatic status at the time of lung cancer diagnosis (primary objective). 2. To assess the utility of CUG2, βIGH3 (TGFBI), and TGF-β expression for differential diagnosis of primary lung cancer from other thoracic malignancies. 3. To examine correlations between biomarker expression levels and clinical variables including age, smoking history, PET/CT stage, and overall survival. 4. To evaluate the prognostic significance of biomarker expression for overall survival using Kaplan-Meier and Cox regression analyses. 5. To compare biomarker expression across histopathological subtypes (squamous cell carcinoma, adenocarcinoma, and small cell lung cancer). |
| Ethics approval(s) |
Approved 13/12/2018, Süleyman Demirel University Faculty of Medicine Clinical Research Ethics Committee (Süleyman Demirel Üniversitesi Tıp Fakültesi Dekanlığı Morfoloji Binası İdari Ofisler 2. Kat Doğu Kampüsü Çünür, Isparta, Merkez, 32260, Türkiye; +90246 211 32 30; tipetik@sdu.edu.tr), ref: 239 |
| Health condition(s) or problem(s) studied | Lung cancer; thoracic malignancy; lung neoplasms; bronchoscopic biopsy; metastasis; differential diagnosis |
| Methodology | This is a prospective observational diagnostic accuracy study. No intervention was administered to participants. Index test: Quantitative real-time PCR (qPCR) measurement of CUG2, βIGH3 (TGFBI), and TGF-β gene expression using the 2^−ΔΔCt method with β-actin as reference gene, performed on RNA extracted from bronchoscopic biopsy specimens obtained during routine diagnostic fiberoptic bronchoscopy. Reference standard: Metastatic status determined by PET/CT imaging and thoracic CT in accordance with the 8th edition TNM classification; histopathological diagnosis confirmed from bronchoscopic biopsy specimens. Non-randomised. Participants were assigned to study groups (primary lung cancer vs. other thoracic malignancies; metastatic vs. non-metastatic) based on histopathological diagnosis and PET/CT findings at the time of diagnostic bronchoscopy, not by randomisation. |
| Intervention type | Other |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) |
|
| Completion date | 20/06/2022 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 99 Years |
| Sex | All |
| Target sample size at registration | 49 |
| Total final enrolment | 57 |
| Key inclusion criteria | 1. Adult patients aged 18 years or older 2. Undergoing diagnostic fiberoptic bronchoscopy (FOB) for suspected primary lung cancer or suspected thoracic involvement by an extrapulmonary malignancy 3. Histopathologically confirmed diagnosis from bronchoscopic biopsy specimen 4. Adequate RNA yield from biopsy specimen (A260/A280 ratio 1.7–2.0) 5. Written informed consent obtained prior to enrollment |
| Key exclusion criteria | 1. Benign histology on bronchoscopic biopsy specimen 2. Insufficient RNA yield from biopsy specimen (A260/A280 ratio outside 1.7–2.0 range) 3. Non-evaluable biomarker measurements 4. Duplicate patient records 5. Age under 18 years 6. Refusal to provide written informed consent |
| Date of first enrolment | 01/01/2019 |
| Date of final enrolment | 01/01/2022 |
Locations
Countries of recruitment
- Türkiye
Study participating centres
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Statistical Analysis Plan | version 1.0 | 01/06/2026 | 11/06/2026 | No | No |
Additional files
- 49667_SAP_v1.0_01June2026.pdf
- Statistical Analysis Plan
Editorial Notes
08/06/2026: Study’s existence confirmed by the Süleyman Demirel University Faculty of Medicine Clinical Research Ethics Committee, Turkey.
