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Kwon, Park, Kim, Song, Choi, Rho, and Lee: Predictive Factors for Switched EGFR-TKI Retreatment in Patients with EGFR-Mutant Non-Small Cell Lung Cancer
Original Article
Lung Cancer

Tuberculosis and Respiratory Diseases 2017; 80(2): 187-193.

Published online: 31 March 2017

DOI: https://doi.org/10.4046/trd.2017.80.2.187

Predictive Factors for Switched EGFR-TKI Retreatment in Patients with EGFR-Mutant Non-Small Cell Lung Cancer

Byoung Soo Kwon, M.D.1, Ji Hyun Park, M.D., Ph.D.2, Woo Sung Kim, M.D., Ph.D.1, Joon Seon Song, M.D., Ph.D.3, Chang-Min Choi, M.D., Ph.D.1, 2, Jin Kyung Rho, Ph.D.4, 5, Jae Cheol Lee, M.D., Ph.D.2

1Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

2Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

3Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

4Asan Institute for Life Sciences, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

5Department of Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.

Address for correspondence: Jae Cheol Lee, M.D., Ph.D. Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Korea. Phone: 82-2-3010-3208, Fax: 82-2-3010-6961, jclee@amc.seoul.kr

Received 13 September 2016       Revised 12 December 2016       Accepted 9 February 2017

Copyright©2017. The Korean Academy of Tuberculosis and Respiratory Diseases

(open-access):

It is identical to the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/)

Abstract

Background

Third-generation tyrosine kinase inhibitors of the epidermal growth factor receptor (EGFR-TKIs) have proved efficacious in treating non-small cell lung cancer (NSCLC) patients with acquired resistance resulting from the T790M mutation. However, since almost 50% patients with the acquired resistance do not harbor the T790M mutation, retreatment with first- or second-generation EGFR-TKIs may be a more viable therapeutic option. Here, we identified positive response predictors to retreatment, in patients who switched to a different EGFR-TKI, following initial treatment failure.

Methods

This study retrospectively reviewed the medical records of 42 NSCLC patients with EGFR mutations, whose cancers had progressed following initial treatment with gefitinib or erlotinib, and who had switched to a different first-generation EGFR-TKI during subsequent retreatment. To identify high response rate predictors in the changed EGFR-TKI retreatment, we analyzed the relationship between clinical and demographic parameters, and positive clinical outcomes, following retreatment with EGFR-TKI.

Results

Overall, 30 (71.4%) patients received gefitinib and 12 (28.6%) patients received erlotinib as their first EGFR-TKI treatment. Following retreatment with a different EGFR-TKI, the overall response and disease control rates were 21.4% and 64.3%, respectively. There was no significant association between their overall responses. The median progression-free survival (PFS) after retreatment was 2.0 months. However, PFS was significantly longer in patients whose time to progression was ≥10 months following initial EGFR-TKI treatment, who had a mutation of exon 19, or whose treatment interval was <90 days.

Conclusion

In patients with acquired resistance to initial EGFR-TKI therapy, switched EGFR-TKI retreatment may be a salvage therapy for individuals possessing positive retreatment response predictors.

Keywords: Carcinoma, Non-Small-Cell Lung, Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor, Retreatment, Predictive

Introduction

Lung cancer is the most common form of cancer and the leading cause of cancer-related mortality worldwide1. Because of changing in smoking habits such as cessation of smoking, increase in the number of female smokers, and use of filtered tobacco, the incidence of non-small cell cancer (NSCLC) continues to increase23. In the early 2000s, platinum-based doublet chemotherapy was the treatment of choice for NSCLC, with the median survival time being less than 8 months4.
The discovery that mutations in the tyrosine-kinase epidermal growth factor receptor (EGFR) gene were responsible for cell proliferation, cellular escape from apoptosis, and cell migration in NSCLC led to the development of a new class of therapeutic agents, the tyrosine kinase inhibitors (TKIs). Treatment with EGFR-TKI results in significantly prolonged progression-free survival (PFS) than platinum-based doublet therapy, particularly in Asian, female, non-smoking patients5.
In previous studies, the median PFS following EGFR-TKI treatment ranged from 10 to 14 months67. However, acquired resistance to EGFR-TKI is unavoidable because of several mechanisms and results in reduced treatment response. In 50%–60% of patients who acquire resistance to first-generation EGFR-TKIs, the mutation T790M is responsible8. Resistance can also develop via other mechanisms, such as c-MET amplification, transformation to small cell carcinoma, and AXL activation8910111213. Although third-generation EGFR-TKIs have proven efficacy in T790M-positive NSCLC patients, there are no effective therapeutic options for patients who acquire resistance by other mechanisms1415.
Several clinical trials have been conducted to investigate the efficacy of EGFR-TKI retreatment after first-line EGFR-TKI treatment failure161718192021. In most of these previous studies, a favorable outcome was achieved in patients who showed a good response to prior EGFR-TKI therapy. However, there are as yet no consistent data on whether factors such as age, sex, smoking history, and subtype of EGFR mutation can affect the outcomes of EGFR-TKI retreatment. In 2013, switched EGFR-TKI retreatment was approved in Korea for use in patients who develop acquired resistance to first-line EGFR-TKI. With this as a momentum, we conducted the present study to identify the predictors of improved outcomes following EGFR-TKI retreatment.

Materials and Methods

1. Study design

The inclusion criteria for this study were patients aged 18 years or older with NSCLC with activating EGFR mutations who underwent EGFR-TKI retreatment therapy at the Asan Medical Center between 2005 and 2016. Patients eligible for inclusion in the study were those who received once-daily doses of 250 mg gefitinib or 150 mg erlotinib for at least 1 month prior to disease progression and were then re-treated with a different first-generation EGFR-TKI after stopping the initial therapy. We included patients regardless of whether they were administered conventional chemotherapy between the two EGFR-TKI treatments. Patients must have had at least one measurable lesion and an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0–3. Excluded from the study were patients who switched EGFR-TKI owing to drug toxicity or intolerability, who were treated with second- or third-generation EGFR-TKIs as part of a clinical trial, or whose EGFR mutation status was unknown.

2. Treatment response evaluation

Demographic information and clinical data such as vital signs, results of physical examination, and blood test results were extracted from each patient's medical record. Disease progression was assessed by the examination of radiographic data available for each patient, such as chest X-rays and computed tomography scans, which were administered every 1–2 months during treatment. Drug response was assessed via Response Evaluation Criteria In Solid Tumors (RECIST).
Efficacy outcomes including overall response and survival following the second EGFR-TKI treatment were calculated. PFS was defined as the length of time from the start of treatment to the date of disease progression or death. Time to progression (TTP) was defined as the length of time from the start of treatment to the date of disease progression. Overall survival (OS) was defined as the length of time from the start of treatment to the date of all-cause death. Disease control rate (DCR) was defined as the percentage of patients who have achieved complete response (CR), partial response (PR), or stable disease. Response rate (RR) was defined as the percentage of patients who achieved either a CR or PR.

3. EGFR mutation analysis

The activating EGFR mutation in each enrolled patient was confirmed by nested polymerase chain reaction (PCR).

4. Statistical analysis

DCR and RR were compared using Fisher exact test. TTP, PFS, and OS were estimated by the Kaplan-Meier method. All analyses were performed using SPSS version 20 (IBM Corp., Armonk, NY, USA).

Results

1. Patient characteristics

A total of 42 patients who received switched EGFR-TKI retreatment between January 2005 and March 2016 were included in the study. Patient baseline characteristics are shown in Table 1. The median age of patients was 64 years (range, 48–86 years), 76.2% of the patients were women, and 95.2% were ex-smokers or had never smoked. The quality of life measured as ECOG PS was 0 or 1 for 35 patients (83.3%).
All patients had histologically-confirmed adenocarcinoma and possessed activating EGFR mutations as determined by nested PCR. With regard to EGFR genotypes, 24 patients (57.1%) had an exon 19 deletion mutation, 16 (38.1%) had an exon 21 point mutation, and two (4.8%) had an exon 18 point mutation. Stage at initial diagnosis was less than IIIA in seven patients, but their disease advanced to stage IV in 16 months (range, 6.5–37.3 months). Initial EGFR-TKI treatment was gefitinib for 30 patients (71.4%) and erlotinib for 12 patients (28.6%).

2. Efficacy of EGFR treatment and retreatment

RR was 73.8% (31/42) for the first EGFR-TKI treatment and 21.4% (9/42) for retreatment following treatment failure with the first EGFR-TKI. DCR for the first EGFR-TKI treatment was 97.6% (41/42) and 64.3% (27/42) for the second EGFR-TKI (Table 2). There was no significant association between overall RR and DCR of the first and second EGFR-TKI (p=0.676 and p=0.357, respectively).
The time interval between treatment and retreatment ranged from 0 to 34.5 months (median, 7.1 months; 95% confidence interval [CI], 4.6–9.3 months), with 32 of 42 patients receiving systemic chemotherapy prior to the second EGFR-TKI treatment. There was no association between PFS and the number of chemotherapy cycles (p=0.412).
For the first EGFR-TKI treatment, the median PFS was 10.4 months (95% CI, 6.4–13.9) and the median PFS was 2.0 months for the second EGFR-TKI (95% CI, 1.2–2.9). After the second EGFR-TKI, 38/42 patients (90.5%) had experienced a PFS event (disease progression or death).
Results of univariate and multivariate analysis of potential predictors of treatment response are shown in Table 3. The analysis showed that longer PFS following switching was significantly associated with EGFR mutation subtype (p<0.001) and with a TTP longer than 10 months (p=0.037). No significant association was found between PFS and the interval of time elapsed between the two EGFR-TKI treatments (p=0.056). There was no association between PFS and ECOG score (p=0.300), smoking history (p=0.089), or site of metastasis (p=0.594). In particular, no significant differences were noted in the PFS of patients having bone or brain metastases. Thirty-six patients had experienced an OS event, and median OS for EGFR-TKIs was 26.6 months (95% CI, 21.5–31.8 months).
After adjusting for sex, age, ECOG, PS, and response to EGFR-TKI, multivariate analysis showed that PFS was significantly longer in patients who had a TTP greater than 10 months following the first EGFR-TKI treatment (p=0.030) and for patients with an exon 19 mutation (p=0.008). Additionally, having a time interval between treatments of less than 90 days showed significantly longer PFS (p=0.019) (Figure 1).
The order of administration of gefitinib and erlotinib had no effect on the outcome. The median PFS was 2.3 months for patients treated with erlotinib after gefitinib failure, whereas the median PFS was 1.2 months for patients treated with gefitinib after erlotinib failure. The difference in median PFS did not achieve statistical significance (p=0.851).

Discussion

A number of mechanisms leading to EGFR-TKI resistance have been identified121415222324, and treatment options for patients with EGFR-TKI resistance are still being investigated. The T790M mutation, c-MET amplification, AXL activation, transformation to mesenchymal cells, and tumor heterogeneity are all possible mechanisms leading to resistance to first-generation EGFR-TKI121314. At present, there are no proven treatment options for patients with acquired resistance except for those with the T790M mutation.
Although no prospective, randomized controlled trials have been conducted examining retreatment efficacy, there is some evidence that retreatment is effective in some patients. While the median PFS of first-line EGFR-TKI treatment was 10–14 months67, PFS following EGFR-TKI re-administration was 2–13.8 months1825262728. The greater variability in PFS following EGFR-TKI retreatment compared to that of first-line therapy might be attributable to differences in the study populations and small sample sizes. However, it suggests that we should search for factors predicting favorable outcome and narrow down the indication of EGFR-TKI retreatment according to those factors.
In our study, RR for EGFR-TKI retreatment was 21.4% and DCR was 64.3%. Previous studies have reported RR percentages ranging from 9.5% to 27.3% and DCR percentages ranging from 28.6% to 77.3%17182125. Our results showed that the RR for EGFR-TKI retreatment was not correlated with the RR for first-line EGFR-TKI, while longer PFS for second-line EGFR-TKI was related to longer TTP for first-line EGFR-TKI. These data suggest that a favorable outcome from first-line EGFR-TKI should be considered when selecting patients as candidates for retreatment.
The type of retreatment protocol to use is another consideration. Retreating with the same EGFR-TKI2021252930, switching to another EGFR-TKI1718262728, and using EGFR-TKI therapy in combination with standard chemotherapy31 have all been attempted. Tang et al.32 conducted a prospective study in which patients who showed a response to gefitinib therapy were enrolled and divided into two categories based on whether the retreatment was with gefitinib or erlotinib. There was no significant difference in the outcome between the two groups. In general, efficacy does not seem to be associated with the kind of EGFR-TKI used for retreatment2032 but is associated with the response to prior EGFR-TKI treatment19212833.
The time interval between the two EGFR-TKI treatments also should be scrutinized. There have only been a few studies reporting effects of the time interval between the first and second EGFR-TKI treatment323334. These studies found that more favorable outcomes were associated with a time interval of more than 3 months. Longer intervals could provide more time for EGFR-TKI–sensitive cells to regrow and respond to the second EGFR-TKI treatment. However, the effect of the time interval should be evaluated in the context of any conventional chemotherapy administered during the interval period. Chemotherapy can alter both EGFR phosphorylation and the proportion of EGFR-TKI sensitive and resistant tumor cells and can therefore have an impact on the effect of the second EGFR-TKI treatment. Chin et al.35 showed that lung cancer cells exposed to cisplatin exhibited reduced sensitivity to erlotinib through down-regulation of PTEN.
In our study, chemotherapy during the EGFR-TKI–free interval was not related to PFS, but interval durations of less than 90 days were associated with longer PFS. Current National Comprehensive Cancer Network guidelines recommend continuation of EGFR-TKI in asymptomatic progression36, but the Korean regulations currently do not permit continued treatment. In the case of asymptomatic progression, continuation of EGFR-TKI might be helpful because the drug can still inhibit EGFR-TKI–sensitive clones having rapid growth potential regardless of the presence of slower-growing, resistant cancer cells14. Hence, our results may reflect the difference in growth rate between EGFR-TKI–sensitive and –resistant clones because the shorter time interval can be considered similar to continued treatment. However, the real effect of the time interval in retreatment should be further investigated.
Our study was retrospective and had a small sample size; therefore, it is not possible to draw any definitive conclusions regarding positive predictors of retreatment outcomes. However, our findings suggest that TTP longer than 10 months after first-line EGFR-TKI therapy, an EGFR-TKI–free interval less than 90 days, and having an exon 19 deletion mutation are predictors of a favorable response to retreatment.
Identification of positive retreatment outcome predictors may help guide selection of patients who are more likely to benefit from EGFR-TKI retreatment. Appropriate retreatment candidate selection also would reduce unnecessary medical costs and undesirable toxicity. Therefore, along with continuing efforts to elucidate the precise mechanisms of resistance in patients with mutations other than T790M, studies should also be conducted to identify the positive predictors of EGFR-TKI retreatment response.

Figures and Tables

Figure 1

(A) Progression-free survival of second epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) by time to progression (TTP). (B) Progression-free survival of second EGFR-TKI by interval duration. (C) Progression-free survival of second EGFR-TKI by EGFR mutation subtype.

trd-80-187-g001
Table 1

Baseline characteristics

trd-80-187-i001
Variable Total p-value
Gefitinib (n=30) Erlotinib (n=12)
Age, yr 0.315
 <60 14 (46.7) 8 (66.7) 22
 >60 16 (53.3) 4 (33.3) 20
Sex 0.040
 Male 10 (33.3) 0 10
 Female 20 (66.7) 12 (100) 32
Smoking 0.222
 Current* 1 (3.3) 1 (8.3) 2
 Ex-smoker† 6 (20.0) 0 6
 Never smoker‡ 23 (76.7) 11 (91.7) 34
Stage 0.545
 IB 3 (10) 0 3
 IIA 2 (6.7) 0 2
 IIIA 1 (3.3) 1 (3.3) 2
 IV 24 (80) 11 (91.7) 35
EGFR mutation 0.178
 Exon 18 1 (3.3) 1 (8.3) 2
 Exon 19 15 (50) 9 (75) 24
 Exon 21 14 (46.7) 2 (16.7) 16
ECOG PS 0.651
 0-1 24 (80) 11 (91.7) 35
 >2 6 (20) 1 (8.3) 7

Values are presented as number (%).

*Someone who was currently smoking or had stopped smoking less than 1 year ago. †Someone who had stopped smoking 1 year or more ago. ‡Someone who had never smoked cigarettes.

EGFR-TKI: epidermal growth factor receptor tyrosine kinase inhibitor; ECOG: Eastern Cooperative Oncology Group; PS: performance status.

Table 2

Response to EGFR-TKI

trd-80-187-i002
Variable Initial EGFR-TKI Second-line EGFR-TKI
Complete response 0 0
Partial response 31 (73.8) 9 (21.4)
Stable disease 10 (23.8) 18 (42.9)
Progressive disease 1 (2.4) 15 (35.7)
Response rate 31/42 (73.8) 9/42 (21.4)
Disease control rate 41/42 (97.6) 27/42 (64.3)
Response duration, mo 16.0 (1.1–83.3) 3.0 (0.3–11.2)

Values are presented as number (% or range).

Response rate=Complete response+Partial response, Disease control rate=Complete response+Partial response+Stable disease.

EGFR-TKI: epidermal growth factor receptor tyrosine kinase inhibitor.

Table 3

Univariate and multivariate analysis

trd-80-187-i003
Variable Univariate analysis
HR (95% CI) p-value HR (95% CI) p-value
Sex
 Male 1 0.889 1 0.867
 Female 0.95 (0.4–2.1) 1.1 (0.5–2.4)
ECOG PS
 0-1 1 0.300 1 0.477
 2-4 2.2 (1.0–4.8) 1.4 (0.6–3.3)
Initial TKI TTP, mo
 ≥10 1 0.037 1 0.030
 <10 2.0 (1.0–3.9) 2.3 (1.1–4.9)
Subtype of EGFR mutation
 Exon 19 1 <0.001 1 0.008
 Exon 21 2.4 (1.1–4.9) 1.8 (0.8–3.8)
 Exon 18 3.5 (3.5–143.2) 18.3 (2.7–123.7)
Interval duration*, day
 <90 1 0.056 1 0.019
 ≥90 2.14 (1.0–4.8) 2.8 (1.2–6.6)

*Time interval between first epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) and second EGFR-TKI.

HR: hazard ratio; CI: confidence interval; ECOG: Eastern Cooperative Oncology Group; PS: performance status; TTP: time to progression.

Acknowledgments

This work was supported by a grant of the Korea Health Technology R & D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant HI15C0516).

Notes

Conflicts of Interest No potential conflict of interest relevant to this article was reported.

References

1. Ferlay J, Soerjomataram I, Dikshit R, Eser S, Mathers C, Rebelo M, et al. Cancer incidence and mortality worldwide: sources, methods and major patterns in GLOBOCAN 2012. Int J Cancer. 2015; 136:E359–E386.
2. Charloux A, Quoix E, Wolkove N, Small D, Pauli G, Kreisman H. The increasing incidence of lung adenocarcinoma: reality or artefact? A review of the epidemiology of lung adenocarcinoma. Int J Epidemiol. 1997; 26:14–23.
3. Park JY, Jang SH. Epidemiology of lung vancer in Korea: recent trends. Tuberc Respir Dis. 2016; 79:58–69.
4. Schiller JH, Harrington D, Belani CP, Langer C, Sandler A, Krook J, et al. Comparison of four chemotherapy regimens for advanced non-small-cell lung cancer. N Engl J Med. 2002; 346:92–98.
5. Mok TS, Wu YL, Thongprasert S, Yang CH, Chu DT, Saijo N, et al. Gefitinib or carboplatin-paclitaxel in pulmonary adenocarcinoma. N Engl J Med. 2009; 361:947–957.
6. Maemondo M, Inoue A, Kobayashi K, Sugawara S, Oizumi S, Isobe H, et al. Gefitinib or chemotherapy for non-small-cell lung cancer with mutated EGFR. N Engl J Med. 2010; 362:2380–2388.
7. Zhou C, Wu YL, Chen G, Feng J, Liu XQ, Wang C, et al. Erlotinib versus chemotherapy as first-line treatment for patients with advanced EGFR mutation-positive non-small-cell lung cancer (OPTIMAL, CTONG-0802): a multicentre, open-label, randomised, phase 3 study. Lancet Oncol. 2011; 12:735–742.
8. Su KY, Chen HY, Li KC, Kuo ML, Yang JC, Chan WK, et al. Pretreatment epidermal growth factor receptor (EGFR) T790M mutation predicts shorter EGFR tyrosine kinase inhibitor response duration in patients with non-small-cell lung cancer. J Clin Oncol. 2012; 30:433–440.
9. Vikis H, Sato M, James M, Wang D, Wang Y, Wang M, et al. EGFR-T790M is a rare lung cancer susceptibility allele with enhanced kinase activity. Cancer Res. 2007; 67:4665–4670.
10. Kuang Y, Rogers A, Yeap BY, Wang L, Makrigiorgos M, Vetrand K, et al. Noninvasive detection of EGFR T790M in gefitinib or erlotinib resistant non-small cell lung cancer. Clin Cancer Res. 2009; 15:2630–2636.
11. Yu HA, Arcila ME, Rekhtman N, Sima CS, Zakowski MF, Pao W, et al. Analysis of tumor specimens at the time of acquired resistance to EGFR-TKI therapy in 155 patients with EGFR-mutant lung cancers. Clin Cancer Res. 2013; 19:2240–2247.
12. Gainor JF, Shaw AT. Emerging paradigms in the development of resistance to tyrosine kinase inhibitors in lung cancer. J Clin Oncol. 2013; 31:3987–3996.
13. Zhang Z, Lee JC, Lin L, Olivas V, Au V, LaFramboise T, et al. Activation of the AXL kinase causes resistance to EGFR-targeted therapy in lung cancer. Nat Genet. 2012; 44:852–860.
14. Lee JC, Jang SH, Lee KY, Kim YC. Treatment of non-small cell lung carcinoma after failure of epidermal growth factor receptor tyrosine kinase inhibitor. Cancer Res Treat. 2013; 45:79–85.
15. Nurwidya F, Takahashi F, Murakami A, Takahashi K. Epithelial mesenchymal transition in drug resistance and metastasis of lung cancer. Cancer Res Treat. 2012; 44:151–156.
16. Lee DH, Kim SW, Suh C, Yoon DH, Yi EJ, Lee JS. Phase II study of erlotinib as a salvage treatment for non-small-cell lung cancer patients after failure of gefitinib treatment. Ann Oncol. 2008; 19:2039–2042.
17. Wong AS, Soong R, Seah SB, Lim SW, Chuah KL, Nga ME, et al. Evidence for disease control with erlotinib after gefitinib failure in typical gefitinib-sensitive Asian patients with non-small cell lung cancer. J Thorac Oncol. 2008; 3:400–404.
18. Cho BC, Im CK, Park MS, Kim SK, Chang J, Park JP, et al. Phase II study of erlotinib in advanced non-small-cell lung cancer after failure of gefitinib. J Clin Oncol. 2007; 25:2528–2533.
19. Becker A, Crombag L, Heideman DA, Thunnissen FB, van Wijk AW, Postmus PE, et al. Retreatment with erlotinib: regain of TKI sensitivity following a drug holiday for patients with NSCLC who initially responded to EGFR-TKI treatment. Eur J Cancer. 2011; 47:2603–2606.
20. Song Z, Yu X, He C, Zhang B, Zhang Y. Re-administration after the failure of gefitinib or erlotinib in patients with advanced non-small cell lung cancer. J Thorac Dis. 2013; 5:400–405.
21. Oh IJ, Ban HJ, Kim KS, Kim YC. Retreatment of gefitinib in patients with non-small-cell lung cancer who previously controlled to gefitinib: a single-arm, open-label, phase II study. Lung Cancer. 2012; 77:121–127.
22. Sequist LV, Waltman BA, Dias-Santagata D, Digumarthy S, Turke AB, Fidias P, et al. Genotypic and histological evolution of lung cancers acquiring resistance to EGFR inhibitors. Sci Transl Med. 2011; 3:75ra26.
23. Arcila ME, Oxnard GR, Nafa K, Riely GJ, Solomon SB, Zakowski MF, et al. Rebiopsy of lung cancer patients with acquired resistance to EGFR inhibitors and enhanced detection of the T790M mutation using a locked nucleic acid-based assay. Clin Cancer Res. 2011; 17:1169–1180.
24. Kobayashi S, Boggon TJ, Dayaram T, Janne PA, Kocher O, Meyerson M, et al. EGFR mutation and resistance of non-small-cell lung cancer to gefitinib. N Engl J Med. 2005; 352:786–792.
25. Yokouchi H, Yamazaki K, Kinoshita I, Konishi J, Asahina H, Sukoh N, et al. Clinical benefit of readministration of gefitinib for initial gefitinib-responders with non-small cell lung cancer. BMC Cancer. 2007; 7:51.
26. Costa DB, Nguyen KS, Cho BC, Sequist LV, Jackman DM, Riely GJ, et al. Effects of erlotinib in EGFR mutated non-small cell lung cancers with resistance to gefitinib. Clin Cancer Res. 2008; 14:7060–7067.
27. Vasile E, Tibaldi C, Chella A, Falcone A. Erlotinib after failure of gefitinib in patients with advanced non-small cell lung cancer previously responding to gefitinib. J Thorac Oncol. 2008; 3:912–914.
28. Hata A, Katakami N, Yoshioka H, Fujita S, Kunimasa K, Nanjo S, et al. Erlotinib after gefitinib failure in relapsed non-small cell lung cancer: clinical benefit with optimal patient selection. Lung Cancer. 2011; 74:268–273.
29. Li J, Hao X, Wang Y, Zhang X, Shi Y. Clinical response to gefitinib retreatment of lung adenocarcinoma patients who benefited from an initial gefitinib therapy: a retrospective analysis. Zhongguo Fei Ai Za Zhi. 2012; 15:44–48.
30. Tomizawa Y, Fujita Y, Tamura A, Shirai M, Shibata S, Kawabata T, et al. Effect of gefitinib re-challenge to initial gefitinib responder with non-small cell lung cancer followed by chemotherapy. Lung Cancer. 2010; 68:269–272.
31. Zwitter M, Rajer M, Stanic K, Vrankar M, Doma A, Cuderman A, et al. Intercalated chemotherapy and erlotinib for non-small cell lung cancer (NSCLC) with activating epidermal growth factor receptor (EGFR) mutations. Cancer Biol Ther. 2016; 17:833–839.
32. Tang C, Li X, Guo W, Li J, Qin H, Wang W, et al. How to make the choice in the retreatment of EGFR-TKI for advanced NSCLC patients who benefited from prior gefitinib therapy: the original drug or switching to a second EGFR-TKI? Zhongguo Fei Ai Za Zhi. 2013; 16:345–352.
33. An T, Huang Z, Wang Y, Wang Z, Bai H, Wang J. Retreatment with epidermal growth factor receptor inhibitor after initial failure in advanced non-small cell lung cancer. Zhongguo Fei Ai Za Zhi. 2011; 14:261–265.
34. Xia GH, Zeng Y, Fang Y, Yu SR, Wang L, Shi MQ, et al. Effect of EGFR-TKI retreatment following chemotherapy for advanced non-small cell lung cancer patients who underwent EGFR-TKI. Cancer Biol Med. 2014; 11:270–276.
35. Chin TM, Quinlan MP, Singh A, Sequist LV, Lynch TJ, Haber DA, et al. Reduced Erlotinib sensitivity of epidermal growth factor receptor-mutant non-small cell lung cancer following cisplatin exposure: a cell culture model of second-line erlotinib treatment. Clin Cancer Res. 2008; 14:6867–6876.
36. Ettinger DS, Wood DE, Akerley W, Bazhenova LA, Borghaei H, Camidge DR, et al. NCCN guidelines insights: non-small cell lung cancer, version 4.2016. J Natl Compr Canc Netw. 2016; 14:255–264.
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