Abstract 56P
Background
KRAS in one of the most frequently altered oncogenes in NSCLC. The prognostic role of the KRAS mutations in early-stage NSCLC is still unclear. In this study we aim to analyze the overall survival (OS) and the disease free survival (DFS) of patients with early stage NSCLC underwent lobectomy and systematic lymphadenectomy.
Methods
Patients who underwent lobectomy and systematic lymphadenectomy for clinical stage I-II lung adenocarcinoma and next-generation sequencing (NGS) were evaluated. Exclusion criteria were the neoadjuvant treatment, an incomplete resection and the presence of EGFR mutations. Mutations were classified as KRASwild-type, KRASG12C, or KRASother.
Results
A total of 257 patients were included in the study (Table). The KRAS mutation status was: 161 KRASwild type, 42 KRASg12c and 54 KRASother. All the patients reported a resection of at least 4 nodal stations and the median of resected lymph nodes was 16 (11-36). After pathological examination 200 patients confirmed the N0, 30 patients was N1 and the remainder N2. Adjuvant therapy was administered to 25 patients (9.7%). The KRASg12c group showed a non-significant worst 3-year OS compared to KRASother group (p=0.2). OS was not statistically significant different between patients with any mutation and patient with KRASwild type. However, the 3-year DFS of the KRASg12c group was substantially worse compared to the KRASother group (62.5% vs 74.3%; p=0.04). Table: 56P
| Kras wild type (161) | Kras g12c (42) | Kras other (54) | |
| Age (years) | 68 (44-78) | 66 (50-77) | 67 (49-80) |
| Sex (m/f) | 94/67 | 33/9 | 28/26 |
| Smoking history (y/n) | 104/57 | 38/4 | 49/5 |
| Pack/years | 24 (15-68) | 29 (12-80) | 23 (14-78) |
| Side (right/left) | 99/62 | 30/12 | 34/20 |
| pN0 | 122 | 33 | 33 |
| pN1 | 16 | 7 | 11 |
| pN2 | 23 | 2 | 10 |
| Resected N stations | 6 (4-7) | 5 (4-8) | 6 (4-7) |
| Resected lymph nodes | 17 (12-33) | 19 (13-36) | 15 (11-31) |
| Metastatic lymph nodes | 2 (1-3) | 3 (1-4) | 2 (1-4) |
| PD-L1 (%) | 29 (0-90%) | 43 (0-70) | 37 (0-80) |
| Adjuvant treatment | 17 | 3 | 5 |
Conclusions
Our results showed that in a homogeneous cohort of stage I-III lung adenocarcinoma after radical surgery, the group of KRASg12c mutation had a worst DFS compared to the KRASwild type and KRASother. without differences in terms of OS.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.