However, the mOS in their study was 52

However, the mOS in their study was 52.0 months, which was higher than our mOS of 36.0 months. gefitinib retreatment beyond disease progression may be an effective and tolerable approach for NSCLC individuals with sensitive mutations. amplification.3 We previously4,5 showed that TKI retreatment beyond progression (TBP) could help to achieve long-term survival in selected patients. However, other studies6,7 have failed to support TBP, and its use thus remains controversial and the optimal therapeutic schedule for TBP remains undetermined. We, therefore, conducted a retrospective study to evaluate the effectiveness and safety of gefitinib retreatment in patients with NSCLC. Patients and methods Patients This study was approved by the Ethics Committee of the Peoples Hospital of Bishan District, Chongqing, China, in 2014. After the patients provided informed consent, we retrospectively analyzed patients with stage III/IV NSCLC with sensitive mutations treated with gefitinib at the Peoples Hospital of Bishan District of Chongqing City from August 2013 to November 2015. The inclusion criteria were as follows: histologically confirmed NSCLC; tumor biopsy tested for mutation; first-line treatment with oral gefitinib (250 mg/day); and first progression-free survival time (PFS-1) 3 months. We excluded patients who received chemotherapy alone or as combination therapy; however, radiotherapy for isolated lesions was permitted. After the first disease progression, which was defined in accordance with the Response Evaluation Criteria in Solid Tumors criteria (RECIST 1.1 version), retreatment with oral gefitinib 250 mg/day (TBP) was administered until a second progression, which was defined at the clinicians discretion. The patients baseline characteristics (TNM stage, location, histopathology, genotype) were noted. Follow-up Follow-up was performed on a clinical basis, including head/chest/abdominal computed tomography (CT) and assessment of tumor biomarkers every 2 months for the first 12 months and every 3 months thereafter. Follow-up data were updated in November 2015. Effect and toxicity evaluation The effect was evaluated 1 month after gefitinib treatment based on head/chest/abdominal CT and/or tumor biomarkers. Overall survival (OS) was calculated from the date of gefitinib initiation until the date of death or the date of last follow-up. The time to first progression-free survival (PFS-1) was defined in accordance with RECIST 1.1, and it was estimated from the date of gefitinib initiation to the time of RECIST failure; the time to second progression-free survival (PFS-2) was defined as the time interval between the first and second progressions, which was estimated from the date of gefitinib retreatment beyond RECIST progression to the date of death or last follow-up or second failure, based on the clinicians discretion. For survival calculations, patients who were alive at the end of the study period, who died from other causes, or who were lost to follow-up were censored. Treatment-related toxicities were recorded in accordance with the National Malignancy Institute (NCI)-Common Terminology Criteria (CTC) version 4.0. Statistical analysis Survival curves were generated using the KaplanCMeier method. Statistical analysis was performed using SPSS Statistics for Windows, version 19.0 (SPSS Inc., Chicago, IL, USA). Results Clinical characteristics Sixteen patients were included in CACNB2 the analysis (Table 1). Most patients had adenocarcinoma. The most frequent sensitive mutations were 19DEL and L858R, and other mutations included L861Q and G719X. The median follow-up period was 24.0 months. All patients completed gefitinib treatment and retreatment. Five patients (31.3%) also received radiotherapy for isolated lesions located in Olutasidenib (FT-2102) the lungs during the period of gefitinib retreatment. Table 1. Clinical characteristics of the patients (n?=?16). mutations who received TBP Olutasidenib (FT-2102) after the failure of first-line EGFR-TKI therapy. Adenocarcinoma (87.5%) was the dominant pathological type, and the most frequent genotypes were 19DEL (47.8%) and 21 exon L858R (37.5%). PFS following TKI retreatment has been reported to be positively correlated with the response to initial EGFR-TKI. 8 The present study found a slightly better response to initial TKI treatment to previous reports,2 with an overall response rate of 81%. TKI retreatment, thus, resulted in favorable outcomes. In our study, the 1- and 2-12 months OS rates were 100% and 75%, respectively, and the median PFS-2 was 14.0 months. However, the PFS-2 was worse in one patient with pleural effusion, Olutasidenib (FT-2102) suggesting that TBP should be administered Olutasidenib (FT-2102) with caution in patients with complications such as pleural metastasis and effusion. In another study, 9 PFS-2 was defined as the time from first gefitinib dose to off-gefitinib progression, which was similar to PFS-1 plus PFS-2 in our study. Their median PFS-2 of 27.7 months (95% CI, 21.6C33.9) was higher than the 24.0 months in the current study (PFS-1+PFS-2). This might have been due to the limited number of patients.