Abstract 205P
Background
In limited-stage small cell lung cancer (LS-SCLC), there is scarce evidence of the effectiveness and safety of the combinations in the neoadjuvant setting. We conducted a study to evaluate neoadjuvant chemoimmunotherapy in LS-SCLC.
Methods
Patients from Beijing Chest Hospital, Capital Medical University, between April 2019 and March 2023, received etoposide-based chemotherapy with (neoCIT group) or without (neoCT group) programmed death-ligand 1/programmed death 1 (PD-L1/PD-1) inhibitors followed by surgery for LS-SCLC were retrospectively studied. The primary objectives were to assess the pathological complete response (pCR) and the major pathological response (MPR). Secondary endpoints included event-free survival (EFS) and safety.
Results
A total of 31 cases with LS-SCLC stage IIB-IIIB were included, 16 cases in the neoCIT group and 15 patients in the neoCT group. A pCR occurred in eight cases (50.0%; 95% CI, 28.0 to 72.0) in the neoCIT group and in one patient (6.7%; 95% CI, 0.3 to 29.8) in the neoCT group (odds ratio, 14.00; 95% CI, 1.71 to 164.20; P = 0.016). An MPR occurred in 14 cases (87.5%; 95% CI, 64.0 to 97.8) in the neoCIT group and in three patients (20.0%; 95% CI, 7.0 to 45.2) in the neoCT group (odds ratio, 28.00; 95% CI, 4.23 to 150.50; P < 0.001). The median follow-up was 25.0 months. Event-free survival at 24.0 months was 87.5% in the neoCIT group and 46.2% in the neoCT group (hazard ratio, 0.20; 95% CI, 0.06 to 0.78). Grade 3 or 4 adverse events occurred in five patients in the neoCIT group (30.0%) and five patients in the control group (33.3%).
Table: 205P
Pathological response and imaging response of resected patients
| Pathological response and imaging response of resected patients | |||
| Response | Chemoimmunotherapy (N=16) | Chemotherapy Alone (N=15) | P value |
| Pathological response, n (%) | |||
| MPR | 14 (87.5) | 3 (20.0) | <0.001 |
| pCR | 8 (50.0) | 1 (6.7) | 0.02 |
| Imaging overall response, n (%) | >0.99 | ||
| CR | 1 (6.3) | 0 | |
| PR | 13 (81.3) | 13 (86.7) | |
| SD | 2 (12.5) | 2 (13.3) | |
| PD | 0 | 0 | |
| ORR | 14 (87.5) | 13 (86.7) | >0.99 |
Conclusions
Among the resectable SCLC patients, neoadjuvant chemoimmunotherapy significantly improved pathological complete response, major pathological response, and event-free survival as compared with neoadjuvant chemotherapy alone.
Legal entity responsible for the study
The authors.
Funding
This study was supported by Beijing Tongzhou District High Level Talent Project [Grant number: YH201910 to ZL and YH201916 to LS] and Beijing Municipal Administration of Hospitals Incubating Program [Grant number: PX2023057 to HX-L].
Disclosure
All authors have declared no conflicts of interest.