Virtual Library

Start Your Search

Letícia Ferro Leal



Author of

  • +

    EP1.04 - Immuno-oncology (ID 194)

    • Event: WCLC 2019
    • Type: E-Poster Viewing in the Exhibit Hall
    • Track: Immuno-oncology
    • Presentations: 1
    • Now Available
    • Moderators:
    • Coordinates: 9/08/2019, 08:00 - 18:00, Exhibit Hall
    • +

      EP1.04-11 - Frequency of Microsatellite Instability (MSI) in Brazilian TKI Non-Treatable Non-Small Cell Lung Cancer (NSCLC) Patients  (Now Available) (ID 2304)

      08:00 - 18:00  |  Author(s): Letícia Ferro Leal

      • Abstract
      • Slides

      Background

      Lung cancer is the most common cause of cancer deaths worldwide. Personalized medicine based on driver mutations has improved tailored treatment for patients with non-small cell lung cancer (NSCLC). However, only a subset of patients is benefited with tyrosine kinase inhibitors. Non-treatable advanced NSCLC patients may be eligible for treatment with immunotherapies. Recently, microsatellite instability (MSI) phenotype was reported as a predictive biomarker of response to immunotherapy, making it a crucial biomarker for clinical management for NSCLC patients. This study aimed to determine MSI frequencies in Brazilian NSCLC patients who are not eligible for TKi therapy.

      Method

      522 patients diagnosed with NSCLC patients at Barretos Cancer Hospital (Brazil) were evaluated. All samples were molecularly analyzed for EGFR (exons 18, 19, 20 and 21), KRAS (codons 12/13) and BRAF (exon 11 and 15) mutations by PCR followed by Sanger direct sequencing. The molecular MSI evaluation was performed using a hexa-plex marker panel by PCR followed by fragment analysis.

      Result

      The mean age of the patients was 61y (22-87) and 54% were male. EGFR, KRAS, and BRAF wild-type status were identified in 62.6% (327/522) of cases. In 297 EGFR/KRAS/BRAF wild-type cases, MSI analysis was performed and we observed the presence of MSI-H in only three (1%) cases. Overall, two out of these three patients were female and one was male, the age at the diagnosis ranged from 55 to 76 years old, they were current or former smokers and all three cases were diagnosed at stage IV. Of note, one of the patients with MSI-high status received treatment with immune checkpoint inhibitor, and he is the only one out of the three patients that remains alive with 51-months survival.

      Conclusion

      The frequency of MSI-high status is low in Brazilian NSCLC patients, in accordance with other population literature. Nevertheless, these MSI-positive patients are eligible for immunotherapy approaches.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.

  • +

    EP1.11 - Screening and Early Detection (ID 201)

    • Event: WCLC 2019
    • Type: E-Poster Viewing in the Exhibit Hall
    • Track: Screening and Early Detection
    • Presentations: 1
    • Now Available
    • Moderators:
    • Coordinates: 9/08/2019, 08:00 - 18:00, Exhibit Hall
    • +

      EP1.11-06 - Design and Implementation of an Integrated Lung Cancer Prevention and Screening Program Using a Mobile CT in Brazil (Now Available) (ID 1031)

      08:00 - 18:00  |  Author(s): Letícia Ferro Leal

      • Abstract
      • Slides

      Background

      Lung cancer is a high-ranking cause of cancer deaths in Brazil. Low dose computerized tomography screening national guidelines has not yet been established, and public primary prevention and tobacco control programs have an inconsistent coverture, especially among the most deprived. The Cancer Prevention Department of Barretos Cancer Hospital has a large tradition in the use of mobile units to reach out and conduct cancer screening in underserved Brazilian populations. This study aims to design an integrated lung cancer prevention and early detection program using a mobile CT unit to reach high-risk lung cancer population.

      Method

      The study is placed in Barretos, Brazil, with an estimated population of 120,000 inhabitants. Tobacco cessation intervention and LDCT screening will be offered in partnership between the municipal health system and Barretos Cancer Hospital. Every smoker seeking health assistance and those identified in active surveys in the community would be offered tobacco cessation support. High-risk individuals matching USPTF criteria will be offered LDCT using a mobile CT unit.

      Result

      Nineteen tobacco cessation teams were formed in different public primary health unities throughout the city. Patient information are stored in a web-based databank (RedCap) and shared between teams. Screening flow was coordinated by municipal health office and Barretos Cancer Hospital. The CT mobile unit is intended to be placed near primary health care centers. It was estimated 3,376 eligible participants. A comprehensive epidemiological questionnaire will be asked, in addition with blood and sputum samples collection for further cancer biomarker studies. Those with symptoms of suspected lung malignancy or poor clinical condition would be excluded from screening. Nodules detected in LDCT screening will be managed under ACR Lung-Rads criteria. A multidisciplinary team will be available to discuss doubtful cases, diagnosis and treatment strategies. Two reports are generated for each LDCT screening exam and sent back to primary care teams, one with educational purposes and another with technical information. Primary care teams were trained, being responsible to manage non-cancer conditions eventually detected on screening. A direct line of communication was set between primary care teams, radiologists and multidisciplinary team.

      Conclusion

      Tobacco cessation and lung cancer screening in high-risk individuals have to be integrated. Since Brazilian health assistance in public system is fragmented, it is imperative to design a coordinated flow and establish communication channels between primary care teams, radiologists and multidisciplinary team. There was good feedback by primary care teams and patients about the impact of screening in the tobacco cessation process.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.

  • +

    P1.03 - Biology (ID 161)

    • Event: WCLC 2019
    • Type: Poster Viewing in the Exhibit Hall
    • Track: Biology
    • Presentations: 2
    • Moderators:
    • Coordinates: 9/08/2019, 09:45 - 18:00, Exhibit Hall
    • +

      P1.03-13 - Genomic Landscape of Brazilian Non-Small Cell Lung Cancer (ID 1296)

      09:45 - 18:00  |  Presenting Author(s): Letícia Ferro Leal

      • Abstract

      Background

      Non-Small Cell Lung Cancer (NSCLC) is the most common type of lung cancer with low survival rates. Therefore, NSCLC patients may be benefited by tailored treatment based on genomic profiling. However, the genomic landscape of Brazilian NSCLC remains unknown. Thus, our aim was to evaluate the genomic profiling of NSCLC of a Brazilian series.

      Method

      We analyzed 96 NSCLC patients from Barretos Cancer Hospital, Brazil. Exome sequencing of paired tumor/blood DNA was performed by Illumina HiSeq2500 and VarScan was applied for germline alterations exclusion, variant calling, and annotation. Cancer Genome Interpreter was employed for identification of driver genes. Mutational Signatures were performed using Somatic Signature. Copy Number Variations (CNV) were determined using Circular Binary Segmentation. Gene expression analysis was assessed by NanoString and pathway enrichment was performed using KEGG.

      Result

      Overall, 61 cases were adenocarcinomas, 34 squamous cell carcinomas and 1 was adenosquamous (I, n=19; II, n=14; III, n=23; IV, n=40). Regarding smoking, 82 patients were current/former smokers and 12 patients were never smokers and most of the cases presented the mutational signature 4. More than 30,000 mutations were identified and 733 were classified as drivers (known: 90; predicted: 643). TP53 gene was the most recurrently mutated gene (56% of the cases). Besides of TP53 gene, recurrent mutations were found in KRAS (23%), EGFR (12.5%), NFE2L2 (9%), HERC2 (9%), STK11, ROS1, PIK3CA and CDKN2A (8%). KRAS, EGFR, STK11 and ROS1 mutations were mutually exclusive. CNV gain was observed in 1q21.3, 1q22, 3q26, 31q29, 7q11.21, 7p11.1-q11.1, 8p11.1-q11.1, 19q13. Downregulation of DKK1, IBSP, LAMC2, NGFR and LAMB3 and upregulation of LAMC3, MAPK8IP1, IL5RA, NR4A1, AXIN2, PLA2G4E, COL6A6, CACNA2D2, LRP2, NR4A3, FOS, BMP5, and FGFR2 were observed in disease stages I/II indicating enrichment of PI3K-Akt, MAPK, Ras, Rap1 and Wnt signaling pathways. Downregulation of MCM2, VEGFA, E2F1, HMGA1, CCNE1, CHEK1, RAD51, FOSL1, CCNB1, GNG4, IL11 and IL8 and upregulation of WNT10B, MAPK10, GNG7, WNT4, IL7R, PIK3CG, and FGFR2 were observed in never smokers indicating enrichment of Cell cycle, Pathways in cancer and PI3K-Akt signaling. Differential expression of KRAS-mutated tumors indicated enrichment of ECM-receptor interaction, Focal adhesion, and PI3K-Akt pathway and TP53-mutated tumors indicated enrichment of Cell Cycle.

      Conclusion

      The genomic profiling of Brazilian NSCLC indicated remarkable driver mutations and genomic amplifications. Gene expression profiling indicates the enrichment of key pathways enrolled in TP53- and KRAS-driven tumors. Our results may contribute for improving the knowledge about the molecular pathogenesis of Brazilian NSCLC.

    • +

      P1.03-36 - Cell-Free DNA Levels in Liquid Biopsy from Patients with Non-Small Cell Lung Cancer and Association with Clinical Parameters and Disease Outcome (ID 2468)

      09:45 - 18:00  |  Presenting Author(s): Letícia Ferro Leal

      • Abstract

      Background

      Patients with non-small cell lung cancer (NSCLC) are constantly submitted to invasive biopsies for clinical management and for guiding tailored treatment based on molecular targets. The liquid biopsy is a minimally invasive collected sample that contains cell-free circulating DNA (cfDNA), which may reflect clinical conditions and outcome based on their levels. Thus, the aim of this study was to assess the cfDNA levels in liquid biopsy samples from NSCLC patients and to correlate with the clinical parameters, overall survival, and disease outcome.

      Method

      cfDNA was manually isolated from the liquid biopsies NSCLC patients (n=38) employing MagMax Cell-free cfDNA Isolation Kit. The cfDNA levels were checked by fluorometry and fragments size were evaluated by TapeStation. The cfDNA levels were associated with clinical parameters from NSCLC patients and disease outcome.

      Result

      Overall, 18 cases were adenocarcinomas and 20 squamous cell carcinomas. Regarding smoking, 34 patients were current or former smokers and 4 patients were never smokers. cfDNA was successfully isolated from 31 cases, whose presented detectable levels of cfDNA (median: 0.862 ng/μL; range 0.144– 4.36 ng/μL), and 7 cases presented undetectable levels of cfDNA. All cfDNA fragments were successfully confirmed by TapeStation. Of note, patients with detectable levels of cfDNA were diagnosed at stages I (n=2), II (n=4), III (n=10), IV (n=14). However, disease staging at diagnosis was not associated with cfDNA levels (Kruskal-Wallis p=0.54). cfDNA levels were not associated with overall survival (Log-Rank p=0.86). Nonetheless, detectable levels of cfDNA were associated with unfavorable outcome (Qui-Square test p=0.03).

      Conclusion

      Our results may reassure the use of liquid biopsy in personalized medicine, although these results should be confirmed in a larger series. Our results show that liquid biopsy is a useful non-invasive tool for prognostication of NSCLC patients.

  • +

    P2.03 - Biology (ID 162)

    • Event: WCLC 2019
    • Type: Poster Viewing in the Exhibit Hall
    • Track: Biology
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/09/2019, 10:15 - 18:15, Exhibit Hall
    • +

      P2.03-07 - Frequency of Driver Genes (EGFR, KRAS, BRAF, ALK, RET and ROS1) Alterations in Brazilian Patients with Lung Adenocarcinoma (ID 1841)

      10:15 - 18:15  |  Presenting Author(s): Letícia Ferro Leal

      • Abstract

      Background

      Lung cancer is the deadliest cancer in the world. Several oncogenic drivers are observed in non-small cell lung cancer (NSCLC) and they have been used as therapeutic targets. The frequency of the major driver genes in lung adenocarcinoma varies based on ethnicity and the impact in the Brazilian admixture population has not been explored. Thus, we aimed to investigate the presence gene mutations of EGFR, KRAS, and BRAF, and ALK, RET and ROS1 rearrangements in Brazilian lung adenocarcinoma and to associate the presence of these alterations with clinicopathological characteristics and genetic ancestry.

      Method

      We evaluated 444 patients diagnosed with lung adenocarcinoma at Barretos Cancer Hospital. The presence of EGFR, KRAS and BRAF mutations in hotspot regions were evaluated by direct sequencing. For EGFR/KRAS/BRAF wild-type samples, we investigated the presence of ALK, RET and ROS1 rearrangements by the NanoString platform. Genetic ancestry was assessed by a multiplexed 46-ancestry informative markers panel. Stats: X2 test and Cox regression model.

      Result

      Overall, 232 were male (52%) and 212 female (48%) and the average mean at diagnosis was 61 years. The majority of the patients were self-reported as white (77%), smokers (68%) and most patients were diagnosed at stage IV (74%). The median overall survival in patients at stage IV was 8.8 months. The frequency of EGFR mutations was 22.7% (n=101) and they were independently associated with never-smokers and Asian ancestry. KRAS mutations were found in 20.4% (n=91) of cases and were independently associated with smoking. The frequency BRAF mutations was of 1% (n=4), being all of them non-V600 BRAF. The frequency of ALK rearrangements was 2.25% (n=10) and was associated with younger age, the presence of metastases and advanced disease stage at diagnosis. RET and ROS1 rearrangements were only observed in 0.2% each (n=1/each) of cases. All the alterations identified in the oncogenic drivers were mutually exclusive.

      Conclusion

      The evaluation of the major driver genes for NSCLC, EGFR, KRAS, BRAF, ALK, RET and ROS1 can guide better clinical strategies for Brazilian lung adenocarcinoma, and the frequencies observed of these genes are in line with reported in other populations.