Abstract 158P
Background
We compare the results of a multicenter protocol of Neoadjuvant Treatment (NT) in resectable stage III (rsIII) (AJCC, 8th) NSCLC to NADIM2 trial results.
Methods
We analyzed 67 patients who received NT per protocol in four centers (2013-2020), defined as concurrent chemotherapy and Radiotherapy (NTChRT) or chemotherapy alone (NTCh). Single-center surgery and Pathological Response (PR) evaluation by two pathologists was performed.
Results
40 patients received NTChRT and 27 NTCh. NTChRT arm had a higher proportion of stage IIIB (12 vs. 6), higher multinodal disease (7 vs 0), and one stage IV (resected M1 CNS). NADIM2 reported similar characteristics in the immunotherapy+Ch arm (ICh), more stage IIIB (14 vs 11) and multinodal disease (22 vs 11). Maximum PR (≤ 10% viable cells) was 54.5% vs. 9.5% (p= 0.001), favoring NTChRT. Complete PR (cPR) was 17.1% vs 4.8% (p= 0.23) in NTChRT vs NTCh respectively. NADIM2 Major PR (<15% viable cells) were 53% vs. 14% in favor of ICh and significantly improved cPR (37% vs.7%). Progression free survival (PFS) at 24 months was non-significantly different between NTChRT vs NTCh (41 vs 31%). ICh PFS was significantly better in NADIM2 (67.2% vs. 40.9%). Overall survival (OS) at 24 months was significantly improved in the NTChRT vs. NTCh arm (77% vs 45 % (p<0.02). In the NADIM2 OS was 85.0% and 63.6% favoring ICh.
Conclusions
NADIM2 sets the gold standard in rsIII NSCLC. Our trial is the first study on NT for rsIII NSCLC with a true comparison between concurrentNTChRt vs. NTCh performed by highly specialized oncologist team. Our results offer real-world NT data for rsIII patients. Compared with NADIM2 show similar results for cPR, Maximum/Major PR and OS for both NTCh arms. The NTChRT arm shown better overall results in PR and OS compared to both NTCh arms. Compared to sequential ChRT, concurrent ChRT has shown signifficant better outcomes (phase III trials). In the NT setting, this improvement has not been assessed. We report an improvement of OS and PR with “true” NTChRt compared to NTCh alone, in contrast to previous Thomas et al. and Pless et all. phase III trials which show data of sequential NTCh follow by ChRT vs. NTCh alone.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.