Prognostic relevance of TTF-1 expression in stage I adenocarcinoma

Tyroid transcription factor-1 (TTF-1) motivates the differentiation and development of bronchioloalveolar cells. The association of TTF-1 expression with prognosis in stage I adenocarcinoma is unclear. This study enrolled patients with resected stage I pulmonary adenocarcinoma who had TTF-1 immunostaining. All the corresponding clinicopathologic data including sex, age, smoking history, pathologic T stage, pathologic disease stage, surgical procedure, subtypes, follow-up records and adjuvant chemotherapy were investigated. Totally, 126 adenocarcinomas with TTF-1- and 2687 adenocarcinomas with TTF-1+ were subjected to the study. Among adenocarcinomas with TTF-1-, the major subtype was acinar-predominant adenocarcinomas, followed by invasive mucinous and papillary subtypes while acinar, papillary and minimally invasive adenocarcinoma were in the majority among adenocarcinomas with TTF-1+. The status of TTF-1 expression was not a significant factor for relapse-free survival (RFS) and overall survival (OS). Furthermore, there was no survival difference between the two groups (RFS: p = 0.2474; OS: p = 0.1480). When confined to stage IB adenocarcinomas with TTF-1-, whether received adjuvant chemotherapy made no difference to RFS and OS (RFS: p = 0.2707; OS: p = 1.000), as was the case in stage IB adenocarcinomas with TTF-1+ (RFS: p = 0.9161; OS: p = 0.1100). Within follow-up period, there was significant difference in post-recurrence survival (PRS) for TTF-1- patients compared with those TTF-1+ patients (Log-rank p = 0.0113). However, regarding to the recurrence site, there was no difference between TTF-1- patients and TTF-1+ patients in patients with stage I adenocarcinoma (p = 0.771) In conclusion, there is no significant difference in RFS and OS between TTF-1- group and TTF-1+ group, but TTF-1 negative adenocarcinoma has significantly worse PFS in patients with stage I adenocarcinoma. Moreover, chemotherapeutic efficacy between TTF-1+ and TTF-1- stage IB adenocarcinomas did not differ.