Five-Year Survival in EGFR-Mutant Metastatic Lung Adenocarcinoma Treated with EGFR-TKIs.

INTRODUCTION: Activating mutations in the epidermal growth factor receptor gene (EGFR) predict for prolonged progression-free survival in patients with advanced non-small cell lung cancer (NSCLC) treated with EGFR tyrosine kinase inhibitors (EGFR-TKIs) versus chemotherapy. Long-term survival outcomes, however, remain undefined. The objective of this study was to determine the 5-year survival in these patients and identify clinical factors associated with overall survival (OS). METHODS: Patients with EGFR-mutant metastatic lung adenocarcinoma who had been treated with erlotinib or gefitinib at Dana-Farber Cancer Institute between 2002 and 2009 were included. OS was analyzed. RESULTS: Among 137 patients, median progression-free survival and OS were 12.1 months (95% CI: 10.2-13.5) and 30.9 months (95% CI: 28.2-35.7), respectively. Twenty patients (14.6%) were 5-year survivors. In multivariate analysis, exon 19 deletions (hazard ratio [HR] = 0.63, 95% CI: 0.44-0.91, p = 0.01), absence of extrathoracic (HR = 0.62, 95% CI: 0.41-0.93, p = 0.02) or brain metastasis (HR = 0.48, 95% CI: 0.30-0.77, p = 0.002), and not a current smoker (HR = 0.23, 95% CI: 0.09-0.59, p = 0.002) were associated with prolonged OS. Age; sex; stage at diagnosis; liver, bone, or adrenal metastasis; specific TKI; and line of TKI therapy were not associated with OS. CONCLUSIONS: Our data suggest that the rate of 5-year survival among patients with EGFR-mutant metastatic lung adenocarcinoma treated with erlotinib or gefitinib is 14.6%. Exon 19 deletions and absence of extrathoracic or brain metastasis are associated with prolonged survival. On the basis of our findings, clinicians can gain an enhanced estimation of long-term outcomes in this population.

Interstitial lung abnormalities in treatment-naïve advanced non-small-cell lung cancer patients are associated with shorter survival.

OBJECTIVE: Interstitial lung diseases are associated with increased risk of lung cancer. The prevalence of ILA at diagnosis of advanced non-small-cell lung cancer (NSCLC) and its impact on overall survival (OS) remain to be investigated. MATERIALS AND METHOD: The study included 120 treatment-naïve stage IV NSCLC patients (53 males, 67 females). ILA was scored on CT prior to any systemic therapy using a 4-point scale [0=no evidence of ILA, 1=equivocal for ILA, 2=suspicious for ILA, 3=ILA] by a sequential reading method previously reported. ILA scores of 2 or 3 indicated the presence of ILA. RESULTS: ILA was present in 17 patients (14%) with advanced NSCLC prior to any treatment (score3: n=2, score2: n=15). These 17 patients were significantly older (median age: 69 vs. 63, p=0.04) and had a heavier smoking history (median: 40 vs. 15.5 pack-year, p=0.003) than those with ILA score 0 or 1. Higher ILA scores were associated with shorter OS (p=0.001). Median OS of the 17 patients with ILA was 7.2 months [95%CI: 2.9-9.4] compared to 14.8 months [95%CI: 11.1-18.4] in patients with ILA score 0 or 1 (p=0.002). In a multivariate model, the presence of ILA remained significant for increased risk for death (HR=2.09, p=0.028) after adjusting for first-line systemic therapy (chemotherapy, p<0.001; TKI, p<0.001; each compared to no therapy) and pack years of smoking (p=0.40). CONCLUSION: Radiographic ILA was present in 14% of treatment-naïve advanced NSCLC patients. Higher ILA scores were associated with shorter OS, indicating that ILA could be a marker of shorter survival in advanced NSCLC.

Cost-effectiveness of multiplexed predictive biomarker screening in non-small-cell lung cancer.

INTRODUCTION: Population-wide screening for epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) gene rearrangements to inform cancer therapy in non-small-cell lung cancer (NSCLC) is recommended by guidelines. We estimated cost-effectiveness of multiplexed predictive biomarker screening in metastatic NSCLC from a societal perspective in the United States. METHODS: We constructed a microsimulation model to compare the life expectancy and costs of multiplexed testing and molecularly guided therapy versus treatment with cisplatin-pemetrexed (CisPem). All testing interventions included a two-step algorithm of concurrent EGFR mutation and ALK overexpression testing with immunohistochemistry followed by ALK rearrangement confirmation with a fluorescence in situ hybridization assay for immunohistochemistry-positive results. Three strategies were included: "Test-treat" approach, where molecularly guided therapy was initiated after obtainment of test results; "Empiric switch therapy," with concurrent initiation of CisPem and testing and immediate switch to test-result conditional treatment after one cycle of CisPem; and "Empiric therapy" approach in which CisPem was continued for four cycles before start of a tyrosine kinase inhibitor. RESULTS: The incremental cost-effectiveness ratio for "Test-treat" compared with treatment with CisPem was $136,000 per quality-adjusted life year gained. Both empiric treatment approaches had less favorable incremental cost-effectiveness ratios. "Test-treat" and "Empiric switch therapy" yielded higher expected outcomes in terms of quality-adjusted life years and life-years than "Empiric therapy." These results were robust across plausible ranges of model inputs. CONCLUSION: From a societal perspective, our cost-effectiveness results support the value of multiplexed genetic screening and molecularly guided therapy in metastatic NSCLC.

Volumetric tumor growth in advanced non-small cell lung cancer patients with EGFR mutations during EGFR-tyrosine kinase inhibitor therapy: developing criteria to continue therapy beyond RECIST progression.

BACKGROUND: The objective of this study was to define the volumetric tumor growth rate in patients who had advanced nonsmall cell lung cancer (NSCLC) with sensitizing epidermal growth factor receptor (EGFR) mutations and had initially received treatment with EGFR-tyrosine kinase inhibitor (TKI) therapy beyond progression. METHODS: The study included 58 patients with advanced NSCLC who had sensitizing EGFR mutations treated with first-line gefitinib or erlotinib, had baseline computed tomography (CT) scans available that revealed a measurable lung lesion, had at least 2 follow-up CT scans during TKI therapy, and had experienced volumetric tumor growth. The tumor volume (in mm3) of the dominant lung lesion was measured on baseline and follow-up CT scans during therapy. In total, 405 volume measurements were analyzed in a linear mixed-effects model, fitting time as a random effect, to define the growth rate of the logarithm of tumor volume (log(e)V). RESULTS: A linear mixed-effects model was fitted to predict the growth of log(e)V, adjusting for time in months from baseline. Log(e)V was estimated as a function of time in months among patients whose tumors started growing after the nadir: log(e)V = 0.12*time + 7.68. In this formula, the regression coefficient for time, 0.12/month, represents the growth rate of log(e)V (standard error, 0.015/month; P < .001). When adjusted for baseline volume, log(e)V0, the growth rate was also 0.12/month (standard error, 0.015/month; P < .001; log(e)V = 0.12*months + 0.72 log(e)V0 + 0.61). CONCLUSIONS: Tumor volume models defined volumetric tumor growth after the nadir in patients with EGFR-mutant, advanced NSCLC who were receiving TKI, providing a reference value for the tumor growth rate in patients who progress after the nadir on TKI therapy. The results can be studied further in additional cohorts to develop practical criteria to help identify patients who are slowly progressing and can safely remain on EGFR-TKIs.

Clinical, pathologic, and biologic features associated with BRAF mutations in non-small cell lung cancer.

PURPOSE: BRAF mutations are found in a subset of non-small cell lung cancers (NSCLC). We examined the clinical characteristics and treatment outcomes of patients with NSCLC harboring BRAF mutations. EXPERIMENTAL DESIGN: Using DNA sequencing, we successfully screened 883 patients with NSCLC for BRAF mutations between July 1, 2009 and July 16, 2012. Baseline characteristics and treatment outcomes were compared between patients with and without BRAF mutations. Wild-type controls consisted of patients with NSCLC without a somatic alteration in BRAF, KRAS, EGFR, and ALK. In vitro studies assessed the biologic properties of selected non-V600E BRAF mutations identified from patients with NSCLC. RESULTS: Of 883 tumors screened, 36 (4%) harbored BRAF mutations (V600E, 18; non-V600E, 18) and 257 were wild-type for BRAF, EGFR, KRAS, and ALK negative. Twenty-nine of 36 patients with BRAF mutations were smokers. There were no distinguishing clinical features between BRAF-mutant and wild-type patients. Patients with advanced NSCLC with BRAF mutations and wild-type tumors showed similar response rates and progression-free survival (PFS) to platinum-based combination chemotherapy and no difference in overall survival. Within the BRAF cohort, patients with V600E-mutated tumors had a shorter PFS to platinum-based chemotherapy compared with those with non-V600E mutations, although this did not reach statistical significance (4.1 vs. 8.9 months; P = 0.297). We identified five BRAF mutations not previously reported in NSCLC; two of five were associated with increased BRAF kinase activity. CONCLUSIONS: BRAF mutations occur in 4% of NSCLCs and half are non-V600E. Prospective trials are ongoing to validate BRAF as a therapeutic target in NSCLC.

The impact of genomic changes on treatment of lung cancer.

The remarkable success of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors in patients with EGFR mutations and ALK rearrangements, respectively, introduced the era of targeted therapy in advanced non-small cell lung cancer (NSCLC), shifting treatment from platinum-based combination chemotherapy to molecularly tailored therapy. Recent genomic studies in lung adenocarcinoma identified other potential therapeutic targets, including ROS1 rearrangements, RET fusions, MET amplification, and activating mutations in BRAF, HER2, and KRAS in frequencies exceeding 1%. Lung cancers that harbor these genomic changes can potentially be targeted with agents approved for other indications or under clinical development. The need to generate increasing amounts of genomic information should prompt health-care providers to be mindful of the amounts of tissue needed for these assays when planning diagnostic procedures. In this review, we summarize oncogenic drivers in NSCLC that can be currently detected, highlight their potential therapeutic implications, and discuss practical considerations for successful application of tumor genotyping in clinical decision making.

RECIST 1.1 in NSCLC patients with EGFR mutations treated with EGFR tyrosine kinase inhibitors: comparison with RECIST 1.0.

OBJECTIVE: Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 has been rapidly accepted in clinical trials as a standard measure to assess tumor response to therapy and is expected to improve response assessment, especially in genomically defined patients. The impact of RECIST 1.1 was compared with RECIST 1.0 in non-small cell lung cancer (NSCLC) patients with sensitizing epidermal growth factor receptor (EGFR) mutations treated with EGFR tyrosine kinase inhibitors. MATERIALS AND METHODS: Seventy patients with advanced NSCLC harboring sensitizing EGFR mutations treated with a first-line EGFR tyrosine kinase inhibitor were retrospectively studied. Tumor measurements and response assessment were performed using RECIST 1.0 and RECIST 1.1. The number of target lesions, the percentage change at the initial follow-up, best response, and time to progression were compared between RECIST 1.1 and RECIST 1.0. RESULTS: The number of target lesions identified using RECIST 1.1 was significantly lower compared with that using RECIST 1.0 (mean, 2.7 and 2.0, respectively; p < 0.0001; paired Student t test), with a decrease in 31 patients (44%). The initial proportional changes of the target lesion measurements had high correlation between the two criteria (R(2) = 0.8070), with concordant response assessment in 66 patients (94%). The best response showed almost perfect agreement (κw = 0.970). Time to progression (TTP) did not differ between the two criteria in 52 patients (74%), was longer by RECIST 1.1 in 15 patients (21%), and was shorter by RECIST 1.1 in three patients (4%). CONCLUSION: RECIST 1.1 provided highly concordant response assessment with a decreased number of target lesions compared with RECIST 1.0 in advanced NSCLC patients harboring sensitizing EGFR mutations treated with an EGFR tyrosine kinase inhibitor. RECIST 1.1 altered TTP in 25% of patients compared with RECIST 1.0.

Tumor volume decrease at 8 weeks is associated with longer survival in EGFR-mutant advanced non-small-cell lung cancer patients treated with EGFR TKI.

BACKGROUND: The study investigated whether tumor volume changes at 8 weeks of therapy is associated with outcomes in advanced non-small-cell lung cancer (NSCLC) patients harboring sensitizing epidermal growth factor receptor (EGFR) mutations treated with EGFR tyrosine kinase inhibitors (TKIs). METHODS: In 56 advanced NSCLC patients with sensitizing EGFR mutations treated with first-line erlotinib or gefitinib, tumor volumes of dominant lung lesions were measured on baseline and follow-up computed tomography, and were analyzed for association with survival. RESULTS: Among 56 eligible patients, the median tumor volume was 17.8 cm (range, 1.3-172.7 cm) on the baseline scans. Forty-nine patients had follow-up computed tomography at approximately 8 weeks; the median tumor volume at 8 weeks was 7.1 cm (range, 0.4-62.3 cm), with the median proportional volume change of -59% (range, -90% to +91%) from baseline. The proportional volume change at 8 weeks was associated with survival (p = 0.02). Using the cutoff value of 38% volume decrease (75th percentile) at 8 weeks, patients with volume decrease more than 38% (n = 37) had a median overall survival of 43.5 months compared with 16.3 months among those with volume decrease of 38% or less (n = 12; p = 0.01). The median progression-free survival for patients with more than 38% volume decrease was 12.6 months, compared with 5.5 months for those with 38% or lesser volume decrease (p = 0.2). CONCLUSION: The proportional volume change at 8 weeks is associated with overall survival in EGFR-mutant advanced NSCLC patients treated with first-line EGFR-TKIs. The observation of the study, if confirmed in larger study cohorts, indicates that tumor volume analysis at 8 weeks may provide an early marker for survival, and contribute to therapeutic decision making by identifying patients who may benefit from additional anticancer therapy after 8 weeks of EGFR-TKI therapy.

Radiographic assessment and therapeutic decisions at RECIST progression in EGFR-mutant NSCLC treated with EGFR tyrosine kinase inhibitors.

PURPOSE: Advanced NSCLC harboring epidermal growth factor receptor (EGFR) mutations treated with EGFR tyrosine kinase inhibitors (TKIs) typically progresses after initial response due to acquired resistance. TKIs are often continued beyond progressive disease by RECIST. We investigated the practice of continuing EGFR-TKIs after RECIST-PD via CT findings. METHODS: Among 101 advanced NSCLC patients with sensitizing EGFR mutations treated with first-line EGFR-TKIs, 70 patients had baseline and at least one follow-up CT for retrospective radiographic assessments using RECIST1.1; 56 patients had experienced PD by the data closure date of June 2011. RESULTS: Among 56 patients experiencing PD, 82% were female, median age was 63 years, 50% were never-smokers, 57% had distant metastasis, 57% had exon 19 deletion, and 89% were treated with erlotinib. 49 patients (88%) continued TKI therapy beyond retrospectively assessed PD. 31/32 (97%) patients who progressed by an increase in their target lesions continued TKI. 13/16 (81%) patients who progressed by appearance of a new lesion remained on TKI. 5/6 (83%) patients with both increase of target lesions and new lesion at PD continued TKI. Two patients with PD in non-target lesions discontinued therapy at PD. In 49 continuing patients, the median time from retrospectively assessed RECIST-PD to termination of TKI was 10.1 months. CONCLUSIONS: 88% of EFGR-mutant NSCLC patients who progressed on first-line TKI continued therapy beyond RECIST-PD, which is not the single determining factor for terminating TKI in EGFR-mutant NSCLC patients. Additional radiographically defined progression criteria are needed for this population.

The introduction of systematic genomic testing for patients with non-small-cell lung cancer.

BACKGROUND: Genomic testing to identify driver mutations that enable targeted therapy is emerging for patients with non-small-cell lung cancer (NSCLC). We report the implementation of systematic prospective genotyping for somatic alterations in BRAF, PIK3CA, HER2, and ALK, in addition to EGFR and KRAS, in NSCLC patients at the Dana-Farber Cancer Institute. METHODS: Patients with NSCLC were prospectively referred by their providers for clinical genotyping. Formalin-fixed, paraffin embedded tumor samples were analyzed by Sanger sequencing for mutations in selected exons of EGFR, KRAS, BRAF, PIK3CA, and HER2. ALK rearrangements were detected by fluorescence in situ hybridization or immunohistochemistry. RESULTS: Between July 1, 2009 and August 1, 2010, 427 specimens from 419 patients were referred for genomic characterization; 344 (81%) specimens were successfully genotyped with a median turnaround time of 31 days (range, 9-155). Of the 344 specimens, 185 (54%) had at least one identifiable somatic alteration (KRAS: 24%, EGFR: 17%, ALK: 5%, BRAF: 5%, HER2: 4%, PIK3CA: 2%). As of August 1, 2011, 63 of 288 advanced NSCLC patients (22%) had received molecularly targeted therapy based on their genotypic results, including 34 of 42 patients (81%) with EGFR mutations, 12 of 15 (80%) with ALK rearrangements, and 17 of 95 (18%) with KRAS, BRAF, or HER2 mutations. CONCLUSIONS: Large-scale testing for somatic alterations in EGFR, KRAS, BRAF, PIK3CA, HER2, and ALK is feasible and impacts therapeutic decisions. As the repertoire for personalized therapies expands in lung cancer and other malignancies, there is a need to develop new genomics technologies that can generate a comprehensive genetic profile of tumor specimens in a time- and cost-effective manner.