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S. Maehara



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    P1.01 - Advanced NSCLC (ID 757)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Advanced NSCLC
    • Presentations: 1
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      P1.01-041 - Role of Re-Biopsy During Disease Progression Non-Small Cell Lung Cancer for Acquired Resistance Analysis and Directing Oncology Treatments (ID 10340)

      09:30 - 16:00  |  Author(s): S. Maehara

      • Abstract

      Background:
      It is not possible to properly target treatments in cases of relapse without knowing the nature of new lesions. Third-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKI) can overcome T790M-mediated resistance in non-small-cell lung cancer (NSCLC). But the re-biopsy to confirm T790M status is occasionally difficult. In Japan, transbronchial lung tissue biopsy (TBLB / TBB) is the most common sampling method used for re-biopsy to confirm patients eligible for treatment. We aimed to investigate the success rate of re-biopsy and re-biopsy status of patients with advanced or metastatic NSCLC completing either 1st line chemotherapy or EGFR-TKI therapy.

      Method:
      We initially screened 39 consecutive patients with NSCLC harboring EGFR-sensitive mutations who had experienced PD after any chemotherapy at Tokyo Medical University Hospital January 2014 and December 2016.

      Result:
      38 patients who had experienced PD after EGFR-TKI treatment were eligible. Among 30 patients, tumor progression sites included 3 pleural effusion, 9 thoracic primary/metastatic lesions, 2 hepatic metastases, 15 lymph node metastases. Of the 38 patients, 47.3% underwent rebiopsy sucessfully. Of the 38 biopsied patients, 18 (47.3%) were analyzed for EGFR mutation, using tissue or cytology samples; T790M mutations were identified in 10 (55%) of the 18 patients. Of the 38 biopsied patients, 18 (47.3%) were analyzed for EGFR mutation, using tissue or cytology samples; T790M mutations were identified in 10 (55%) of the 18 patients.

      Conclusion:
      Most re-biopsy samples were diagnosed with malignancy. T790M mutations were identified as much as same in previous studies. However, tissue samples were less available in previous studies. Skill and experience with re-biopsy and noninvasive alternative methods will be increasingly important.

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    P1.16 - Surgery (ID 702)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Surgery
    • Presentations: 1
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      P1.16-010 - Development of a Novel Surgical Marking Method Using Low Power Laser Light (ID 8992)

      09:30 - 16:00  |  Author(s): S. Maehara

      • Abstract
      • Slides

      Background:
      Small lung nodules which appear to be ground glass opacity in peripheral lung are difficult to identify during surgery. In order to identify the site of such lesions, various types of preoperative or intraoperative marking methods have been reported. However all of them have advantages and disadvantages, so there is no definitive way. Therefore, we developed a new safe and reliable intraoperative marking method using a thin laser fiber. This is a method to confirm a low power laser light from lung surface irradiated from a small diameter laser fiber inserted into or close to the lesion transbronchoscopically using a navigation system. In this study, we conducted an animal experiment to confirm whether the laser light can actually be observed safely from lung surface.

      Method:
      Bronchoscopy was performed to a hybrid dog under general anesthesia. A plastic laser probe was inserted into a peripheral bronchus from the biopsy channel of the bronchoscope. The plastic laser probe was a very thin (0.8 mm diameter) and flexible cylindrical-type probe. Therefore, it can be inserted into the peripheral lung. It was developed jointly with Keio University. The probe was induced just below the pleura and 50 mW low power laser irradiation was performed. We examined whether laser light could be confirmed from lung surface under thoracotomy. We also examined the difference in appearance from direct-type laser irradiation.

      Result:
      When the probe was guided to just below the pleura, laser light could be clearly observed from the lung surface. After that, the probe was gradually withdrawn. The laser light could be observed until the depth of 2.0 cm from the pleura. Moreover, laser irradiation was able to be performed safely without any damage around the laser irradiated area. The laser light was observed consistent with laser irradiation site by the cylindrical probe. On the other hands, it was observed on the pleura ahead of laser irradiation by the direct-type probe. Therefore, it is suggested that cylindrical probe might indicate the target area more accuracy.

      Conclusion:
      It might be possible to confirm the localization of small nodules in peripheral lung using low power laser light during surgery.

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    P2.02 - Biology/Pathology (ID 616)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Biology/Pathology
    • Presentations: 1
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      P2.02-009 - Metabolomic Analysis in Lung Cancer (ID 8521)

      09:30 - 16:00  |  Author(s): S. Maehara

      • Abstract
      • Slides

      Background:
      Metabolomics measures low weight molecules, generally called metabolites, and it is an effective technique to understand how metabolism is changed by various factors, including environment and disease, particularly malignant disease. Body fluids, for example sputum or urine, harvested non-invasively havebeen used in remarkable recent developments of omics analysis technology, yielding highly precise results for diagnosis of oral cancer, breast cancer, and pancreatic cancer. Metabolomic analysis has begun to be reported based on the pattern information of metabolites. It can be used for practical clinical early detection of carcinoma of various organs. However, practical metabolomic analysis regarding lung cancer has not been repored yet. We used surgically resected specimen of lung cancer to analyze and clarify metabolomics as an aspect of lung cancer.

      Method:
      We obtained resected specimens from patients with lung cancer after obtaining informed consent for this study, and compared the metabolism profile of the normal tissue portion with carcinoma tissue in 80 patients in terms of various clinical aspects. Metabolomic analysis was performed by capillary electrophoresis / time-of-flight mass spectrometry (CE-TOFMS) of metabolites of the lung tissue and analysed ionized tissue which contained the most main metabolites.

      Result:
      Analysis of serum and metabolite organization by CE-TOFMS revealed that the intermediate metabolite levels of several pathways changed markedly in lung cancer tissue. We can identify a characteristic metabolic marker in advanced lung cancer tissue with metabolomic clinical information by analysing the association with the overall metabolism profile.

      Conclusion:
      We identified metabolomic biomarkers which were characteristic of lung cancer using resected tissue in this study. At present, we are analysing various body fluids for analysis of lung cancer cases including prognostic implications. Applications to non-invasive, simple, easy and cheap cancer screening are expected in the future.

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    P3.02 - Biology/Pathology (ID 620)

    • Event: WCLC 2017
    • Type: Poster Session with Presenters Present
    • Track: Biology/Pathology
    • Presentations: 1
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      P3.02-012 - Liquid Based Cytology (LBC) Specimens Were Useful for EGFR Mutation Test (ID 10305)

      09:30 - 16:00  |  Author(s): S. Maehara

      • Abstract
      • Slides

      Background:
      Reliable EGFR mutation testing techniques are required to identify eligible patients for EGFR-TKI treatment. Nowadays, surgically resected tissues or biopsy specimens are mainly used for the molecular testing. However, the biopsy samples sometimes have a certain limitation and so the cytology specimens are chosen for EGFR testing instead. Plasma sample has also become an option in EGFR-TKI resistant cases in which often have difficulties to obtain the inadequate tumor yield. In this study, we evaluated the feasibilities of using cytology samples and plasma specimens the EGFR molecular testing.

      Method:
      Cytology samples were obtained from biopsy and cells were suspended into liquid-based cytology (LBC) media. Tumor contents in the samples were confirmed with Papanicolaou stained slides. Plasma samples were also collected from patients shortly before the tissue biopsy. EGFR mutations in these samples were analyzed by cobas EGFR Mutation Test v2. Also, EGFR testing result of tissue specimens of the patients corresponded were collected from the medical records measured by cobas EGFR Mutation Test v2 as references.The feasibilities of both cytology and plasma specimen were evaluated comparing the results with the tissue samples.

      Result:

      EGFR mutation rate of tissue, plasma and LBC
      Tissue Plasma LBC
      EGFR mutation + 18 9 14
      EGFR mutation - 42 51 43
      Invalid 0 0 3
      Total 60 60 60
      Positive rate (%) 30.0 15.0 23.3
      One-hundred seven patients were registered to this study. 60 patients were enrolled to this study. EGFR mutation rates in tissue, cytology, and plasma were 30.0, 23.3 and 15.0 %, respectively. Concordance analysis was performed comparing cytology specimens and plasma specimens to the tissue samples. Overall concordance EGFR mutation status was 85.0 and 81.7%, respectively. A total 7 cytology specimens had discordances and 3 were invalid results. For plasma samples, discordants were found in11 samples but no invalids.

      Conclusion:
      Plasma was easy to obtain sample, but rate of detection was low. If a cancer cell is detected enough, LBC is useful for the examination for EGFR. Preservation of sample is easy, and re-useful for the examination, repeatedly.

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