ABSTRACT
Objective:To compare clinicopathologic parameters of uncommon mutations of epidermal growth factor receptor (EGFR) and preliminary therapeutic effects of EGFR-TKI treatment in patients with non-small cell lung cancer. Methods:We collected clinico-pathological data from 29 patients with non-small cell lung cancer who carry uncommon mutations of EGFR, which were pathological-ly confirmed in the Tumor Hospital Affiliated to Xinjiang Medical University, from January 2012 to April 2016. Then we analyzed the re-lationship between the clinicopathologic characteristics of uncommon mutations and therapeutic effects of EGFR-TKIs. Results:Among the 29 cases of patients with uncommon mutations, the most common distant metastasis organs were ipsilateral/contralateral lung tissue, bone, brain, liver, and adrenal gland;the most common metastatic lymph nodes were hilar lymph node, supraclavicular/subclavian lymph node, neck-root lymph node, and mediastinal lymph node. In seldom mutations, 16 cases of single mutation were found:5 cases of L861Q, 5 cases of G719X, 4 cases of 20ins, and 2 cases of S768I. By contrast, 11 cases of double mutations were found:4 cases of S768I and 20ins, 1 case of double mutation of L858R and S768I, 1 case of double mutation of 19Del and T790M, 2 cases of double mutations of L861Q and G719X, 1 case of 19Del and S768I, 1 case of 20ins and G719X, and 1 case of T790M and G719X. Moreover, 2 cases of triple mutation were found:1 case of L858R, L861Q, and G719X;1 case of S768I, 20ins, and G719X. The objective response rate (ORR) of the first-line EGFR-TKI therapy was 43.75%, the disease control rate (DCR) was 50%, and the median progression-free survival (mPFS) was 5.5 months. Furthermore, the ORR of the second-line EGFR-TKI therapy was 28.57%, the DCR was 42.85%, and the mPFS was 4 months. Moreover, the ORR of the third-line EGFR-TKI therapy was 33.33%, the DCR was 50.00%, and the mPFS was 2.67 months. Conclusion:Great individual differences were found on EGFR uncommon mutations for effective rate and sur-vival time of EGFR-TKI treatment;in general, ORR and mPFS of EGFR seldom mutations were lower than classical mutations and partly higher than wild types. The first-line therapeutic effects of EGFR-TKI therapy was slightly better than the second-line or third-line thera-peutic effects;however, no significant statistical difference was observed .