ESTRO 2020 Abstract book

S585 ESTRO 2020

This monocentric retrospective study included 194 metastatic NSCLC patients treated by an anti-PD1 (nivolumab or pembrolizumab) between January 2015 and August 2018 in a French academic hospital. Patients with locally advanced NSCLC who had received local treatments (such as concurrent radiochemotherapy) were excluded. The primary endpoint was progression free survival (PFS) from the onset of immunotherapy. Secondary endpoints were overall survival (OS) from the onset of immunotherapy and safety. Statistical analyses was performed by Chi-squared or the student’s t-test, when indicated. Survival analyses were performed using the Kaplan-Meier method. Univariate and multivariate analyses were performed using the Cox regression model (stepwise for multivariate). Results Overall, 65 patients received previous or concurrent radiotherapy (RT+) and 129 did not (RT-) (Table 1). Patients RT+ had more frequently bone metastases (p<0.001) and brain metastases (p<0.01), but less pleural metastases (p ≤ 0.01). With respect to the RT site, 12% was the thoracic region, 62% was the bone, and 26% was the brain. In the RT+ group, 22% of patients received concurrent RT, and 14% received treatment with curative intent. Median PFS and OS were not significantly different between patients RT+ and RT-: 2.7 vs 3.3 months (p=0.99) and 6.3 vs 8.3 months (p=0.79), respectively. However, in multivariate analysis, previous or concurrent RT was associated with better PFS (HR = 0.63; CI 95%: 0.42-0.94, p = 0.02) and OS (HR = 0.60; IC 95%: 0.39-0.93; p = 0.02). An exploratory univariate analysis evaluating the timing of RT suggested that concurrent RT versus previous RT could be a favorable prognostic factor of PFS (HR : 0.44 ; IC 95% : 0.21-0.91, p = 0.027) (Figure 1). Tolerance was similar in both groups.

Conclusion Previous or concurrent radiotherapy seemed to be a favorable prognostic factor of PFS and OS in patients with metastatic NSCLC treated by immunotherapy. More studies are needed in order to determine which characteristic of RT, such as timing, may be important to enhance this effect. PO-1012 Prognostic Value of Anemia in Lung Cancer Patients Treated with Stereotactic Body Radiation Therapy H. Nonaka 1 , H. Onishi 1 , S. Funayama 1 , H. Watanabe 1 1 University of Yamanashi, Department of Radiology, Chuo city, Japan Purpose or Objective Previous studies showed that preoperative anemia predicts for poor clinical outcomes in lung cancer patients with surgical resection. However, little is known regarding the prognostic value of pretreatment anemia in patients with stage I non-small-cell lung cancer (NSCLC) treated with stereotactic body radiation therapy (SBRT). Hence, we assessed whether pretreatment anemia associated with prognosis in stage I NSCLC patients treated with SBRT. Material and Methods We retrospectively reviewed patients treated with SBRT for stage I NSCLC between 2007 and 2016. Patients who had no blood tests within three months before SBRT were excluded. We divided the patients into two groups according to cutoff value of hemoglobin level using receiver operating characteristic analysis. The clinical outcome was evaluated based on 3-year local progression- free survival (LPFS), progression-free survival (PFS) and overall survival (OS). LPFS, PFS and OS were calculated using the Kaplan-Meier method, and examined with the log-rank test. Prognostic factors including age, sex, histology, T stage and hemoglobin level were examined with multivariate analyses using Cox proportional hazards Totally 166 patients (112 men and 54 women) with stage I (UICC 7th, T1aN0M0: 59, T1bN0M0: 42, T2aN0M0: 65) were enrolled in this study. The median age was 79 years old (range, 52-89). The median follow-up time after SBRT was 44.5 months (range, 1-125). The histology was adenocarcinoma in 80, squamous cell carcinoma in 40, other carcinoma in 10, and no pathological diagnosis in 36 patients. Patients were divided into non-anemia group in 112, and anemia group in 54 patients based on cutoff value of hemoglobin level of 11.6 g/dl. Disease progression was model. Results