Abstract 4204
Background
The impact of bone metastasis on the patient’s response to EGFR-TKI therapy is yet to be determined in lung adenocarcinoma (LUAD) patients harboring EGFR mutations.
Methods
This is a retrospective analysis of the efficacy of EGFR-TKIs for LUAD patients with EGFR mutations, comparing patients with bone metastases (BM) and those with no bone metastases (NBM). Regular imaging that evaluated the bone metastasis response was required for patients with BM. Overall response, median progression-free survival (mPFS), and progression patterns were calculated.
Results
Of the 502 patients reviewed, 175 were evaluated (BM 96, NBM 79). Clinical characteristics were balanced between the groups. Median PFS was 11.0 months in the NBM group versus 7.0 months in the BM group, P = 0.013. The mPFS was significantly decreased in patients with multiple BM (≥4) compared with those having oligometastases (1-3) or NBM (7.0 months vs. 10.0 months vs. 11.0 months, P = 0.003). Multivariate analysis confirmed that bone metastasis was an independent negative predictive factor of PFS, hazard ratio 1.87, P = 0.003. The response rate was higher in the NBM group than in the BM group (70.9% vs. 56.3%), P = 0.046. Bone was one of the frequent sites of EGFR-TKIs failure, accounting for 52 of 125 (41.6%). Patients with NBM had a remarkably lower rate of bone failure compared to patients with BM, 11.8% vs. 62.2%, P < 0.001.
Conclusions
Bone metastasis and multiple metastases in particular, reduce the responsiveness to EGFR-TKIs for LUAD patients with EGFR mutations. Monitoring of bone metastases should be a routine clinical practice in patients with BM.
Clinical trial identification
Legal entity responsible for the study
Fujian Cancer Hospital.
Funding
Fujian Provincial health systemic youth backbone training projects [grant number 2015-ZQN-ZD-9].
Editorial Acknowledgement
Disclosure
All authors have declared no conflicts of interest.