RESUMO
BACKGROUND: In a significant percentage of advanced non-small-cell lung cancer (NSCLC) patients, tumor tissue is unavailable or insufficient for genetic analyses. We prospectively analyzed if circulating-free DNA (cfDNA) purified from blood can be used as a surrogate in this setting to select patients for treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). PATIENTS AND METHODS: Blood samples were collected in 119 hospitals from 1138 advanced NSCLC patients at presentation (n = 1033) or at progression to EGFR-TKIs (n = 105) with no biopsy or insufficient tumor tissue. Serum and plasma were sent to a central laboratory, cfDNA purified and EGFR mutations analyzed and quantified using a real-time PCR assay. Response data from a subset of patients (n = 18) were retrospectively collected. RESULTS: Of 1033 NSCLC patients at presentation, 1026 were assessable; with a prevalence of males and former or current smokers. Sensitizing mutations were found in the cfDNA of 113 patients (11%); with a majority of females, never smokers and exon 19 deletions. Thirty-one patients were positive only in plasma and 11 in serum alone and mutation load was higher in plasma and in cases with exon 19 deletions. More than 50% of samples had <10 pg mutated genomes/µl with allelic fractions below 0.25%. Patients treated first line with TKIs based exclusively on EGFR positivity in blood had an ORR of 72% and a median PFS of 11 months. Of 105 patients screened after progression to EGFR-TKIs, sensitizing mutations were found in 56.2% and the p.T790M resistance mutation in 35.2%. CONCLUSIONS: Large-scale EGFR testing in the blood of unselected advanced NSCLC patients is feasible and can be used to select patients for targeted therapy when testing cannot be done in tissue. The characteristics and clinical outcomes to TKI treatment of the EGFR-mutated patients identified are undistinguishable from those positive in tumor.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/genética , Neoplasias Pulmonares/genética , Mutação , Inibidores de Proteínas Quinases/uso terapêutico , Adulto , Idoso , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Tomada de Decisões , Receptores ErbB/antagonistas & inibidores , Feminino , Testes Genéticos , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Resultado do TratamentoRESUMO
BACKGROUND: In advanced-stage (IIIB or IV) non-small-cell lung cancer (NSCLC), combination chemotherapy has demonstrated response rates of 20% and a 1-year survival rate of 30%. We conducted a multicentre, open-label, nonrandomised phase II trial to determine the efficacy and tolerability of sequential monotherapy with gemcitabine followed by paclitaxel in chemotherapy-naïve patients with advanced NSCLC. MATERIALS AND METHODS: Between December 2002 and July 2004, the Spanish Lung Cancer Group (SLCG) conducted a study in which 34 patients with advanced (stage IIIB or IV) NSCLC received 1200 mg/m(2) of i.v. gemcitabine on days 1, 8 and 15 of each 28-day cycle for a total of 3 cycles followed by 100 mg/m(2) of weekly i.v. paclitaxel for a maximum of 8 weeks. If objective response or stable disease was achieved, 70 mg/m(2) of weekly i.v. paclitaxel was maintained until disease progression was evident or toxic effects were intolerable. Lung Cancer Symptom Scale (LCSS) analysis was performed. Baseline levels of serum VEGF, EGFR, telomerase reverse transcriptase (hTERT) and K-ras mutations were analysed. The primary endpoint was the objective response rate. RESULTS: The median age of the 34 patients who were enrolled was 67 years (range 46-77), but later 8 patients were excluded; 78.8% were men, 81.8% had performance status 1 and also 81.8% had metastatic disease at diagnosis. The objective response rate was 28% (95% CI, 14.2-47.8); the median overall survival was 7.2 months (95% CI, 2.1-12.3) and the median time to progression (TTP) was 3.1 months (95% CI, 2.5-5.3). Grade 3 or 4 drug-related haematological toxicities were observed in 6 patients. Patients with lower baseline serum VEGF levels had significantly longer survival. CONCLUSIONS: Sequential therapy with gemcitabine followed by paclitaxel was well tolerated with a low proportion of grade 3 or 4 adverse events, the absence of unexpected toxicity and with an improvement in quality of life. Unfortunately, the response rate did not meet the minimally required rate of 20% and the study was prematurely closed. VEGF was identified as a poor prognostic factor for TTP and survival (AU)
