Thyroid transcription factor-1 expression in ovarian epithelial neoplasms

Area of Science:

• Oncology
• Pathology
• Molecular Diagnostics

Background:

• Thyroid transcription factor-1 (TTF-1) is a key protein marker for diagnosing lung and thyroid carcinomas.
• Previous studies have reported TTF-1 expression in non-lung/thyroid tumors, but its role in ovarian neoplasms is under-investigated.

Purpose of the Study:

• To investigate the incidence and patterns of TTF-1 protein expression in various types of ovarian epithelial neoplasms.
• To assess the diagnostic implications of TTF-1 expression in ovarian cancers, particularly in cases of unknown primary origin.

Main Methods:

• Tissue microarrays and whole tissue sections from 138 ovarian serous carcinomas, 65 endometrioid adenocarcinomas, 35 mucinous adenocarcinomas, 30 mucinous neoplasms of low malignant potential, and 10 clear cell carcinomas were analyzed.
• Immunohistochemical staining using an anti-TTF1 antibody was performed to detect nuclear TTF-1 expression.

Main Results:

• TTF-1 nuclear expression was detected in 3% of endometrioid adenocarcinomas on tissue microarrays.
• In whole tissue sections, TTF-1 nuclear staining was observed in 37% of serous carcinomas, 20% of endometrioid adenocarcinomas, and 33% of clear cell carcinomas.
• Overall, TTF-1 expression was found in 0.7% of tumors on tissue microarrays and 26% on whole tissue sections, often focally, but sometimes diffusely.

Conclusions:

• While TTF-1 is primarily a marker for lung and thyroid neoplasms, its occasional expression in ovarian carcinomas warrants consideration.
• TTF-1 immunoreactivity in ovarian cancers may aid in the evaluation of neoplasms with unknown primary origin.
• This finding is also relevant when assessing lung adenocarcinomas in patients with a history of gynecologic malignancy.