P2.17-28 Real-World Data: Survival Outcomes of Chemotherapy Regimens Given Concurrently with Radiotherapy for Locally Advanced NSCLC

Abstract

Initial management for inoperable Stage III non-small cell lung cancer (NSCLC) treated for curative intent is platinum-based chemotherapy with concurrent thoracic radiotherapy (TRT). However, a lack of consensus on the optimal chemotherapy regimen administered with TRT remains. In Alberta, Canada, cisplatin/etoposide (EP), given Days 1-5 + 8 of a 28-day cycle, and cisplatin/vinorelbine (VP), given Days 1 +8 of a 21-day cycle, have been the two regimens used preferentially. Weekly carboplatin/paclitaxel (CP) has historically been used as an alternative in patients (pts) with borderline performance status or contraindication to cisplatin. Here, we retrospectively compare survival outcomes of these chemotherapy regimens. The Alberta Cancer Registry identified pts diagnosed with locally advanced NSCLC between 2010 and 2015 and treated with EP, VP or CP chemotherapy with concurrent TRT. Patient and tumour characteristics were collected along with treatment parameters. Progression-free survival (PFS) and overal survival (OS) was determined for each chemotherapy regimen. Survival outcomes were compared using Kaplan-Meier analysis and Cox proportional hazard regression models adjusting for age, gender, tumour histological subtype (squamous vs. non-squamous NSCLC) and 7th edition TNM Stage (IIIA vs. IIIB). Of 148 pts reviewed, 44, 79, and 25 pts were treated with EP, VP, and CP, respectively, with median ages of 63, 62, and 68 years. Gender, tumour histological subtype, distribution of Stage IIIA vs. IIIB, and use of PET imaging for staging were balanced between regimens. Median PFS (EP 9.5 mo; VP 12.9 mo; CP 11.2 mo; p=0.875) and OS (EP 17.8 mo; VP 25.3 mo; CP 33.2 mo; p=0.509) were not significantly affected. Non-squamous median OS (EP 33.4 mo; VP 31.0 mo; CP 33.2 mo; p=0.997) and squamous median OS (EP 13.4 mo; VP 22.3 mo; CP not reached (N=11); p=0.406) also did not differ by regimen. Multivariate Cox regression analysis demonstrated Stage (IIIA vs. IIIB) as the only parameter that significantly altered PFS and OS. This retrospective analysis of real-word data from 2010 to 2015, in the absence of consolidation durvalumab, shows that PFS and OS in locally advanced NSCLC pts treated with concurrent chemoradiotherapy are similar for the EP, VP or CP regimens. Dose scheduling and respective toxicities will likely determine choice of chemotherapy regimen given with TRT. Further review of the CP regimen, given the small sample size in this study, and the use of next generation chemotherapy regimens such as platinum/pemetrexed for non-squamous NSCLC is warranted.