Luis Chirinos

Real-World Treatment Patterns, Survival, and Prediction of CNS Progression in ALK-Positive Non-Small-Cell Lung Cancer Patients Treated with First-Line Crizotinib in Latin America Oncology Practices

Objective: This study describes the real-world characteristics, treatment sequencing, and outcomes among Hispanic patients with locally advanced/metastatic ALK-positive non-small-cell lung cancer (NSCLC) treated with crizotinib. Methods: A retrospective patient review was conducted for several centers in Latin America. Clinicians identified ALK-positive NSCLC patients who received crizotinib and reported their clinical characteristics, treatments, and survival. Overall survival and progression-free survival (PFS) were described. A Random Forest Tree (RFT) model was constructed to predict brain progression. Results: A total of 73 patients were included; median age at diagnosis was 58 years, 60.3% were female, and 93.2% had adenocarcinoma. Eighty-nine percent of patients were never smokers/former smokers, 71.1% had ≥2 sites of metastasis, and 20.5% had brain metastases at diagnosis. The median PFS on first-line crizotinib was 7.07 months (95% CI 3.77–12.37) and the overall response rate was 52%. Of those who discontinued crizotinib, 55.9% progressed in the central nervous system (CNS). The RFT model reached a sensitivity of 100% and a specificity of 88% for prediction of CNS progression. Conclusions: The overall response rate and the PFS observed in Hispanic patients with ALK-positive NSCLC treated with first-line crizotinib were similar to those in previous reports. An RFT model is helpful in predicting CNS progression and can help clinicians tailor treatments in a resource-limited practice.

EGFR exon 20 insertion in lung adenocarcinomas among Hispanics (geno1.2-CLICaP)

OBJECTIVES Contrasting other EGFR mutations (EGFRm) in lung adenocarcinomas, insertions in exon 20 (exon20ins) are generally associated with resistance to targeted therapy, limiting therapeutic options and impoverishing the prognosis compared to other EGFRm. We sought to extensively characterize exon20ins from a large cohort of lung adenocarcinomas in Hispanic patients. MATERIALS AND METHODS This was a region-wide, observational longitudinal cohort study to evaluate characteristics and outcomes of patients with exon20ins in lung adenocarcinoma, based on a secondary analysis of electronic records from the Geno1.2-CLICaP Platform and extended genotype testing. Patients from six Latin-American countries were included (Argentina, Colombia, Costa Rica, Ecuador, Panama, and Mexico). Data obtained included the molecular spectrum (extended genotyping for mutations in BRAF, NRAS, PIK3CA, Her2 and MEK1, as well as for EGFR amplification, ALK and PD-L1 protein expression), clinic-pathologic characteristics, prevalence and outcomes to therapeutic approach. RESULTS AND CONCLUSIONS 4.005 patients diagnosed with stage III/IV lung adenocarcinoma from 2011 to 2016 were initially screened. Among these, 88 patients had a confirmed exon20 in. and were included; median age was 66-years, 62.5% were females, 64% were never smokers and 39% presented with brain metastases. The H773insH variant was the most frequent, making up 21.6% of cases. A common EGFRm was concomitantly found in 36.4% (del19/L858R), and 8% (G719X/L861Q/S768I) of cases. Five cases had additional mutations in PI3K, KRAS and MEK1, 26% had EGFR amplification and 81.7% had PD-L1 expression 1-50%. Overall response rate to first-line therapy was 28% and overall survival was 16.4 months. Prognosis was positively influenced by the concomitant presence of common EGFRm and response to first-line. Our results suggest that patients with EGFR exon20ins have similar clinical characteristics to those with common EGFRm but a poorer prognosis. Last, the mean PD-L1 expression in this population seems higher than for patients with common EGFRm.

P2.03: Treatment of Malignant Pleural Mesothelioma Beyond First-Line Among Hispanics (MeSO-CLICaP): Track: SCLC, Mesothelioma, Thymoma

Background: Thymoma and thymic carcinoma are rare malignancies, despite being amongst the most common tumors of the anterior mediastinum. The incidence in the United States (US) is 0.13 per 100.000 habitants per year. Patients with thymoma can be asymptomatic during the diagnosis in 30% to 50% of the cases. The optimal treatment is complete resection. There are two types classification for Thymoma: Masaoka-Koga’s Classification, which assess the degree of invasion, and World Health Organization (WHO) that organize the histologic subtypes. Little information regarding thymic malignancies is available in Latin America. Method: Retrospective service database review of patients with thymoma treated at Hospital São Lucas between 2006-2016. Inclusion criteria were age 18 or older with histologically confirmed thymoma. Thymomas were classified according toWHO criteria andMasaoka staging. Results: In eligible 10 patients there were 80% males and 20% females. The mean age was 62 years and 40% were over 65 years. A complete R0 resection was achieved in all cases. No in hospital mortality or morbidity was verified. Conventional open approach was used in 90% and minimally invasive (VATS) in 10%. WHO AB type was the most common with 40% patients, followed by 30% A type, 20% B1 and 10% B2. Masaoka-Koga classification: 70% Type I, 20% IIA and 10% III. The body mass index was normal in half of patients. Myasthenia Gravis was present in 30% and all achieved at least partial response. CKAE1/3 markers were positive in 60%. Conclusion: Thymoma was most frequent in middle age men. Complete resection was achieved in all cases; predominately Masaoka I stage and WHO AB and type. CKAE1/3 markers were positive in most cases. Multicenter studies in Latin America should be performed for better understanding of this rare disease.

P2.04: Characteristics and Long Term Outcomes of Advanced Pleural Mesothelioma in Latin America (MeSO-CLICaP): Track: SCLC, Mesothelioma, Thymoma

(HR 0.72; p1⁄40.02), and FL-TTP 12 months (HR 0.48; p<0.001). OS was significantly related to ECOG 0-1 (HR 0.43; p1⁄40.011) and to FL-TTP 12 months (HR 0.66; p1⁄40.05). Fifty-two patients (42%) receive a TL achieving a disease control rate of 62% with a PFS of 5.9 months (95%CI 5.0-6.8). Conclusion: SL-chemotherapy appears to be active in Hispanic MPM-patients, particularly in younger patients with good PS and prolonged disease control with FL chemotherapy. Considering the important limitations of this study, due to retrospective nature and the possible selection bias, prospective clinical trials are warranted to clarify these issues.