Concurrent chemoradiotherapy in locally advanced lung cancer with cisplatin-etoposide or carboplatin-paclitaxel: An institutional analysis.

e20042 Background: In patients with unresectable locally advanced non-small cell lung cancer (NSCLC), chemotherapy given concurrently with radiation (CRT) is the standard of care. Two common chemotherapy regimens are etoposide-cisplatin (EP) and carboplatin-paclitaxel (PC), however, there is no consensus on the optimal CRT regimen for unresectable locally advanced disease. Our study compares CRT regimens using EP and PC in the treatment of unresectable locally advanced NSCLC. Methods: We conducted a retrospective analysis of patients with inoperable locally advanced NSCLC between 2015 and 2023, with institutional review board approval. We included adult patients with histologically confirmed, inoperable stage II-III NSCLC, who received either EP or PC concurrently with radiation. The primary end points were median progression free survival (mPFS) and median overall survival (mOS) while the secondary end points were overall response rate (ORR) and adverse event analyses. Descriptive studies were done in SPSS and Excel. Chi square and t-test analyses were used to find differences in means. mPFS and mOS were calculated using Kaplan-Meier method, comparison between groups by Mantel Cox log rank test and hazard ratios (HR) by Mantel Haenzel models. Results: Of 177 patients included in our study, 43 were treated with EP and 134 with PC. The ORR in the EP arm was 63% and 52% in the PC arm. The mPFS in the EP arm was 48 months versus 15 months in the PC arm (HR 0.65, 95% CI 0.43 - 0.90; p = 0.05). The mOS in the EP arm was 77 months versus 35 months in the PC arm (HR 0.71, 95% CI 0.44 - 1.12; p = 0.17). 34.9% patients in the EP arm had adverse events versus 34.3% in the PC arm. Grade 3 or 4 adverse events were noted in 25.6% patients in the EP arm and 9.7% patients in the PC arm. The most common adverse event in patients receiving EP was arthralgia and PC was pneumonitis. Rest of the results are noted in Table 1. Conclusions: Our study shows that patients who received EP had increased mPFS. They also had a higher ORR, prolonged PFS and OS, however, the findings did not reach statistical significance. The incidence of grade 3 or 4 adverse events was higher in patients who received EP. EP(n = 43) PC(n = 134) p-value Age, mean ± SD (years) 69.28 ± 8.63 65.02 ± 8.74 0.90 Gender (n, %) MaleFemale 22 (51) 21 (49) 76 (58) 58 (42) 0.43 Race (n, %) WhiteBlack Asian Other 39 (91) 4 (9) 00 123 (92) 8 (6) 1 (0.7) 2 (1.4) 0.83 Histology (n, %)Adenocarcinoma Squamous cell carcinoma Other 26 (60) 16 (38) 1 (2) 58 (44) 64 (48) 10 (8) 0.36 Stage (n, %)II III 4 (9) 39 (91) 12 (9) 122 (91) 0.16 Response (n, %)Complete response Partial response Stable disease Progressive disease Not evaluable 0 (0) 27 (63) 9 (21) 3 (7) 4 (9) 0 (0) 70 (52) 26 (19) 28 (21) 10 (8) 00.220.82 0.03 0.60 mPFS, months 48.07 14.93 0.05 Death (n, %)Yes No 21 (49) 22 (51) 72 (54) 62 (46) 0.41 mOS, months 76.97 34.60 0.17 Adverse events (n, %)Any grade Grade 3/4 15 (34.9)11 (25.6) 46 (34.3) 13 (9.7) 0.05