Publication-only abstracts (abstract number preceded by an "e"), published in conjunction with the 2019 ASCO Annual Meeting but not presented at the Meeting, can be found online only.
Radiotherapy with continued EGFR-TKIs for oligoprogressive disease in non-small cell lung cancer: A real-world study.
Metastatic Non-Small Cell Lung Cancer
Lung Cancer—Non-Small Cell Metastatic
2019 ASCO Annual Meeting
J Clin Oncol 37, 2019 (suppl; abstr e20640)
Author(s): Fang Wu, Sixuan Wu, Chunhong Hu; Department of Oncology, The Second Xiangya Hospital, Central South University, Changsha, China
Background: Almost all epidermal growth factor recept (EGFR)-mutated non-small-cell lung cancer (NSCLC) will develop tyrosine kinase inhibitors (TKIs) resistance. The treatment of oligoprogression is debatable after TKIs resistance. We conducted a real-world retrospective study to evaluate the efficacy of radiotherapy and continuation of TKIs in advanced NSCLC patients with oligoprogressive disease after EGFR-TKIs. Methods: From January 2011 to January 2019, we retrospectively analyzed EGFR-mutated NSCLC patients with oligoprogression in our institution. 33 patients were treated by radiotherapy and continuation of TKIs after oligoprogression. We used Kaplan-Meier and Cox regression model to analyse the prognostic factors of median progression-free survival (PFS) and median overall survival (OS) from the time of oligoprogression. Variables we selected for analyses included gender, age, smoking status, performance status (PS) score, stage at initial diagnosis, initial resectable, radiotherapy dose, EGFR mutation type, number of metastasis, sites of radiation, T790M status and the time of oligometastasis to radiotherapy. Results: 33 patients develop resistance to EGFR-TKIs at a median time of 11.0 months. The mPFS and mOS were 6.5 (95%CI, 1.4-11.6) and 21.8 (95%CI, 14.8-28.8) months, respectively. T790M mutation was tested in nine patients, four of which were mutation negative and five were positive. The mPFS was 15.5 (95%CI, 7.4-23.6) months in T790M mutation positive patients and 6.0 (95%CI, 0-14.0) months in negative patients. The mPFS in patients who started radiotherapy within or beyond 1 month after oligometastasis was 10.8 months (95% CI, 4.9-16.7 months) and 5.3 months (95% CI, 2.4-8.2 months). Cox regression model showed no variables significantly correlated with PFS difference. Univariate analysis identified female patients have longer OS (P = 0.038). The results of Multivariate analysis indicated that there was no OS-related prognostic factors. Conclusions: Radiotherapy with continued TKIs is an efficacious treatment option in advanced NSCLC patients with oligoprogressive disease after EGFR-TKIs. T790M mutation is a common mutation in NSCLC patients with oligoprogression. Gender was prognostic factors for OS. Moreover, there was a better prognosis in patients with T790M mutation positive or radiotherapy within 1 month after oligometastasis. However, this was not statistically significant. Larger sample size studies are needed to validate these clinical results.