Abstract 1191P
Background
Thyroid transcription factor-1 (TTF-1), is expressed in thyroid and lung tissue. TTF-1, assessed by immunohistochemistry (IHC), is a specific biomarker for lung adenocarcinoma, and is commonly used to confirm the pulmonary origin of neuroendocrine tumors (NET), as well. The majority of the available data suggest that TTF-1 is a favourable prognostic biomarker for lung adenocarcinomas, whereas its role in lung NET is controversial.
Methods
A multicenter retrospective study, including 155 Lung NET, all surgically removed, all with available IHC assessment for TTF-1.
Results
Median age was 59.5 years (13–86), N= 58 patients (37.4%) were males, N=40 (25.8%) were smokers, N=31 (20%) were atypical carcinoids, N=85 (54.8%) were centrally-located, N=89 (57.4%) were located in the right lung, N=4 patients (2.6%) presented a TNM stage IV at the diagnosis. Mitotic count was ≥2 per 10 high-power field (HPF) in N=35 cases (22.6%), necrosis was present in N=20 (12.9%). Grade 1 was reported in 103 cases (66.5%), whereas Ki-67 was >20% in N=5 (3.2%). TTF-1 was positive in 78 cases (50.3%), cromogranin A in 139 (89.7%) and synaptophysin in 137 (88.4%), respectively. The most common type of surgery was lobectomy in 91 patients (58.7%). Median overall survival (OS) was 46.9 months (0.6–323), median progression-free survival (PFS) was 39.1 months (0.6–323). Statistically significant associations were found between (i) TTF-1 positivity and female sex (p=0.007), and among (ii) TTF-1 positivity and the absence of necrosis (p=0.018). No other relevant associations were detected between TTF-1 and the remaining clinical or pathological variables.
Conclusions
This study highlights that TTF-1 positivity differs according to sex in lung NET patients, with a more common TTF-1 positive staining in female. Moreover, TTF-1 was associated with the absence of necrosis. These data suggest that TTF-1 could potentially represent a gender-related biomarker in this population. Further analyses are needed to establish the value of this observation, and to determine the value of TTF-1 as prognostic biomarker for lung NET.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
1119P - Stage IIIA melanoma with isolated tumor cells in lymph nodes: Time for reviewing the AJCC v8 classification
Presenter: Teresa Amaral
Session: Poster session 13
1120P - Development and external validation of a clinical prediction model to predict recurrence-free survival and melanoma-specific survival in patients with melanoma after sentinel lymph node biopsy
Presenter: Robert Stassen
Session: Poster session 13
1121P - Interferon-gamma (IFNy) gene signature as a predictive biomarker for response in lactate dehydrogenase (LDH) low advanced melanoma patients
Presenter: Lotte Hoeijmakers
Session: Poster session 13
1122P - Neutrophil/lymphocyte ratio and systemic inflammatory index as prognostic biomarkers in metastatic melanoma patients under immune checkpoint inhibitors: Could any of them be used?
Presenter: Maria Menezes
Session: Poster session 13
1123P - Baseline tumor-infiltrating lymphocytes and response to immune checkpoint inhibition in advanced melanoma
Presenter: Mark Schuiveling
Session: Poster session 13
1124P - IL-6 as prognostic factor in adjuvant or metastatic skin cancer patients treated with immunotherapy: A deep biomarker analysis
Presenter: Domenico Mallardo
Session: Poster session 13
1125P - Identification of a subset of metastatic melanoma patients demonstrating germline determined insensitivity to immunotherapy
Presenter: Benjamin Fairfax
Session: Poster session 13
1126P - REtrospective Study of definitive therapy for head and neck mUcosal MElanoma: The RESUME study
Presenter: Motoo Nomura
Session: Poster session 13
1127P - Efficacy of immune checkpoint inhibitors (ICIs) in advanced mucosal melanoma (MM): A systematic review and meta-analysis
Presenter: James Pham
Session: Poster session 13
1128P - A phase I dose escalation and expansion study of FHD-286, a novel BRG1/BRM (SMARCA4/SMARCA2) inhibitor, for the treatment of metastatic uveal melanoma
Presenter: Sapna Patel
Session: Poster session 13