Author of

• 10974

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  P1.21 - Poster Session 1 - Diagnosis and Staging (ID 169)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Prevention & Epidemiology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 10982

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    P1.21-008 - Accuracy of nodal staging in early stage NSCLC in the modern era of PET-CT, EBUS-TBNA and multidisciplinary team approach (ID 2745)

    09:30 - 09:30  |  Author(s): L. Morgan
    • Abstract

    Background
    Accurate staging of NSCLC remains the most important step in predicting outcome. It has been proposed that PET-CT, as an addition to conventional work up, allows for more accurate pre operative detection of stage IIIa and IIIb disease. On the other hand, it appears to have limitations in reliably staging nodal involvement in early stage NSCLC. We aimed to compare pre-operative nodal staging (PET-CT and/or EBUS-TBNA findings) with post-operative histopathological results to determine the accuracy of PET- CT in a multi-disciplinary team setting.

    Methods
    This was a prospective, observational study of consecutive patients discussed through Nepean Lung Cancer MDT that underwent surgical resection for NSCLC from Jan 2010 until Feb 2013. PET-CT parameters of all patients, including FDG uptake in primary lesion(s) as well as hilar and mediastinal lymph nodes, were compared with post operative histopathology of the primary lesions and resected lymph nodes. Pre-operative nodal staging based on PET-CT +/- EBUS-TBNA was compared with post-operative histopathological staging. A PET-CT SUV (max) of equal or more than 2.5 was considered positive.

    Results
    74 patients (mean age 69 years, range 47-86, 45 M ) underwent surgical resection with lymph node dissection for NSCLC (65 lobectomies, 5 bi-lobectomies, 2 wedge resections and 2 pneumonectomies). The most common malignancy in this group was Adenocarcinoma (39 [52.7%]) followed by Squamous Cell Carcinoma (25 [33.7%]) and undifferentiated large cell carcinoma (10 [13.5%]). Most patients were post-operatively confirmed to be in early stages (32 stage I and 26 stage II) with other patients in stage III (12 IIIa and 1 IIIb) and stage IV (3). In 47% of cases, PET-CT nodal staging was concordant with final histopathological results. There was discordance in 39/74 cases with PET-CT being more likely to upstage (30/74) than to downstage (9/74) the mediastinum. Symmetrical FDG uptake in hilar lymph nodes was common amongst upstaged cases. Anthracosis/silicosis was reported in lymph node histopathology of 16/74 (%21.6) patients, with 8 upstaged by PET-CT. Overall, sensitivity of PET-CT mediastinal staging in our cohort was 31.25% with a specificity of 70.5%. This translates into accuracy of 70.2%. In 7 cases, EBUS-TBNA was performed to establish nodal staging. One case of micro-metastasis, confirmed on post-operative histopathology, was not detected on EBUS-TBNA.

    Conclusion
    Nodal staging by PET-CT in early stage NSCLC has reasonable specificity but poor sensitivity, tending to upstage rather than downstage. Benign inflammatory processes affecting intra-thoracic lymph nodes such as anthracosis/silicosis may cause false positive PET-CTs. Nodal staging based only on PET-CT is inadequate and discussion through a multidisciplinary panel as well as minimally invasive investigations such as EBUS-TBNA is recommended. This is consistent with current international guidelines.

• 11001

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  P1.24 - Poster Session 1 - Clinical Care (ID 146)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Supportive Care
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11031

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    P1.24-030 - A rare case of synchronous and metachronous lung cancers (ID 2238)

    09:30 - 09:30  |  Author(s): L. Morgan
    • Abstract

    Background
    Multiple primary lung tumours can be either synchronous or metachronous. Clarification between synchronous primary tumours and metastatic lesions is vital given the differing prognosis and therapeutic options. We present a case of a patient with a combination of synchronous and metachronous primary lung malignancies, who did well because she had careful multidisciplinary follow-up.

    Methods
    Not applicable

    Results
    A 63-year-old female ex-smoker, with history of moderately severe chronic obstructive pulmonary disease but good performance status, was found to have pulmonary nodules in the left upper and lower lobes that increased slightly in size over 2 years on serial thoracic CT scans. On FDG-PET, the lesion in the left upper lobe demonstrated marked FDG-avidity (SUVmax 7.5) while the left lower lobe nodule demonstrated much lower FDG uptake (SUVmax 2.5). These were considered synchronous early-stage lung tumours by consensus of our multidisciplinary lung cancer group. Intra-operatively, frozen sections confirmed malignancy in each lesion and the patient successfully underwent wide local excision of both nodules. Histopathology revealed infiltrating moderately differentiated adenocarcinoma in the left upper lobe (T1N0M0) and infiltrating undifferentiated large cell carcinoma in the left lower lobe with no hilar or mediastinal nodal involvement (T1N0M0). The patient remained disease-free until 6 years later, when new right lung opacities were found incidentally on a chest radiograph. Chest CT confirmed 2 new pulmonary nodules in the right upper lobe, one intensely FDG-avid (SUVmax 11.0) and the other poorly avid (SUVmax 1.2). No other FDG-avid foci suspicious of metastatic disease were detected elsewhere. Following multidisciplinary discussion, wedge resections of both lesions were performed. Histopathology revealed high-grade neuroendocrine carcinoma (small and large cell types) in the intensely FDG-avid lesion and adenocarcinoma in situ in the other lesion. The patient was subsequently offered adjuvant chemotherapy and prophylactic whole brain irradiation.

    Conclusion
    This rare case of synchronous and metachronous primary lung cancers illustrates the importance of long-term follow up of patients with previously treated non-small cell lung with curative intent. These patients may develop new metachronous early-stage lung tumours that would benefit from aggressive treatment. New lung opacities may not necessarily represent recurrent metastatic disease with poor prognosis.

• 11745

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  P2.11 - Poster Session 2 - NSCLC Novel Therapies (ID 209)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Medical Oncology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11753

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    P2.11-008 - High Proportion of Unusual EGFR Mutations in an Australian Population of Non-Squamous NSCLC (ID 935)

    09:30 - 09:30  |  Author(s): L. Morgan
    • Abstract

    Background
    EGFR mutations have previously been reported in 10-15% of non-squamous NSCLC in European populations. The rate of mutations and the proportion of mutations considered to be classical activating, known to confer resistance or unusual is yet to be determined in the Australian population. The influence of unusual mutations on disease progression is not yet clear.

    Methods
    We conducted a retrospective audit of cases of non-squamous NSCLC lung cancer presenting to two metropolitan multidisciplinary teams in Sydney, Australia. All had EGFR testing conducted between October 2010-March 2013. EGFR mutations were identified using PCR and DNA sequencing.

    Results
    134 patient samples were tested for EGFR mutation. Samples were obtained by surgical resection (n=50), FNA (n=31), Core Biopsy (n=31), pleural fluid aspirate (n=3) and EBUS FNA (19). Of these, 32 (24%) were positive for an EGFR mutation. 23/32 had classical activating mutations, with 16/32 Exon 19 deletions and 7/32 Exon 21 L858 substitutions. 4/32 had non-activating/resistance mutations, with 3 exon 20 insertions and 1 exon 20 T790M (L858 + T790M complex de novo mutation). The remaining 6/32 had unusual mutations (1 Exon 20 ala 767-Val769 duplication, 1 Exon 21 p. Pro848Leu, 2 Exon 18 p. G719x, 1 exon 20 S761, D770 insertion and 1 exon 20 deletion V774 insertion). 72 patients in the cohort were female. 8 were Asian, 8 were Pacific Islander, 1 was Indian and 15 were Caucasian. Smoking history was confirmed in all cases. 18/32 were non-smokers, 3/32 were Asian and 24/32 were female. Of the patients with EGFR mutation positive tumours, 16/32 received TKI as first-line therapy, 5/32 received TKI as second-line therapy, 6/32 did not receive TKI and 5/32 were lost to follow-up in other institutions. Of the 6 who did not receive TKI, 5 cases were early-stage treated surgically; the other case received palliative radiotherapy but co-morbidity prevented TKI therapy. Information regarding disease progression was available in 20/32 cases. Of these cases 11/20 had classical activating mutations, were treated with EGFR TKI and, to date have a mean (SD) progression free survival (PFS) of 315 (± 208) d. Those with other mutations had a PFS of 117 (±86) d. This difference was statistically significant at p<0.01(Mantel-Cox).

    Conclusion
    EGFR mutations occur more commonly in an Australian population of non-squamous NSCLC than previously reported in European populations. Most in this series have classical activating mutations. Almost one third of this series had a mutation other than classically activating and in all of these cases the PFS was significantly reduced. We report six unusual mutations of unclear clinical significance, which are also associated with poor PFS.