Effect of TTF-1 expression on progression free survival of immunotherapy and chemo-/immunotherapy in patients with non-small cell lung cancer

The choice between immunotherapy with a checkpoint inhibitor (CPI) and chemo-/immunotherapy (CIT) in patients with NSCLC stage IV is often discussed. There is some data that the effect of chemotherapy is influenced by TTF-1 expression. Little is known about the influence of thyreoid transcription factor 1 (TTF-1) expression on CIT and CPI therapy. We aimed to investigate the relationship between tumor TTF-1 expression and efficacy of CIT and CPI therapy.

We retrospectively analysed 130 patients (age 68 ± 7 y) with NSCLC stage IV. Only patients with lung adenocarcinoma were included. Patients with ALK, ROS1, RET, MET, NTRK, EGFR, BRAF mutation were excluded. Patients were treated according to the guidelines with either CPI alone (pembrolizumab, nivolumab, atezolizumab, cemiplimab) or CIT (Carboplatin/Pemetrexed/Pembrolizumab, Carboplatin/Paclitaxel/Atezolizumab). We registered patients’ characteristics including TTF-1 expression. Group 1 consisted of 40 patients with CPI and TTF-1 expression, group 2 were 26 patients with CPI and with no TTF-1 expression. Group 3 consisted of 41 patients with CIT and TTF-1 expression, group 4 were 23 patients with CIT and with no TTF-1 expression.

Group 1–4 showed comparable patients characteristics. Using cox-regression analysis, we found that TTF-1 expression resulted in an improved progression free survival (PFS) compared to patients with CPI and no TTF-1 expression (18 ± 3,15 vs. 5 ± 0,85 months, p = 0.004, 95% CI: 0,23 − 0,984). In patients, who were treated with CIT, PFS was also increased in patients with TTF-1 expression (9 ± 3,17 vs. 3 ± 0,399 months, p = 0.001, 95% CI: 0,23 − 0,85).

In a real-life setting, we found that TTF-1 expression is associated with an increased PFS. Patients with chemo-/immunotherapy and immunotherapy seem to have a better therapy response in pulmonary adenocarcinoma with TTF-1 expression.