Author of

• 11595

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  P2.07 - Poster Session 2 - Surgery (ID 190)

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

  • 11608

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    P2.07-013 - Risk factors for locoregional failure in completely resected N1 non-small cell lung cancer without postoperative radiotherapy (ID 1316)

    09:30 - 09:30  |  Author(s): S.W. Yeom
    • Abstract

    Background
    N1 disease is a subset of non-small cell lung cancer (NSCLC) with a different prognosis than other subsets. Although the NCCN guideline recommends adjuvant chemotherapy alone in completely resected N1 disease, locoregional failure, which could have been prevented by postoperative radiotherapy (PORT), may not be uncommon. Using PORT with modern techniques has resulted in significantly higher rates of local control, disease-free survival, and overall survival. Therefore, this study aimed to evaluate the actuarial rates of locoregional failure in patients with pathologic N1 NSCLC and to identify the risk factors associated with an increased risk of locoregional failure, which could have been potentially prevented by PORT after complete resection.

    Methods
    Between 2003 and 2010, we enrolled 136 patients who underwent complete resection with pathologically confirmed N1 disease through the prospective lung cancer database of Seoul National University Bundang Hospital. Patients who underwent neoadjuvant therapy, adjuvant radiotherapy, or operative mortality were excluded. Multiple factors potentially related to outcomes including patient-related factors, surgery-related factors, and pathologic factors were extensively evaluated. Locoregional failure, which could have been potentially prevented by PORT, was defined as recurrence at either a bronchial stump, or a resected margin of the lung, hilum, and mediastinum. Other failures were ipsilateral lung recurrence, pleural seeding, and metastasis of distant organs. Univariate analysis by a log rank test and multivariate analysis by the Cox proportional hazards model were performed to identify risk factors independently associated with a higher risk of locoregional failure.

    Results
    The median follow-up duration was 45 months (6-114) and recurrence developed in 54 (40%) patients. The actuarial 5-year rates of disease-free survival and overall survival were 56% and 66%, respectively. From the perspective of first site recurrence, 23 (17%) locoregional failures, which could have been potentially prevented by PORT, included recurrence in the mediastinum in 10, bronchial stump in 5, regional lymph nodes in 4, and mediastinum + others in 4. The 31 (23%) other failures included a distant organ in 17, ipsilateral lung in 12, and pleural seeding in 2. The median survival time from locoregional failure and other failures was 41 and 57 months, respectively; however, there was no significant difference. Risk factors of locoregional failure were squamous cell carcinoma, number of involved node (>1), pathologic stage (IIIA), interlobar node involvement, more than 2 node stations of involvement, and a lymph node ratio greater than 10% by univariate analysis. Pathologic stage (HR=4.768, 95% CI=1.641-13.859, p=0.01), interlobar node involvement (HR=2.783, 95% CI=1.057-7.327, p=0.04), and squamous cell carcinoma (HR=2.449, 95% CI=0.929-6.454, p=0.07) were independent risk factors by multivariate analysis.

    Conclusion
    Locoregional failure was more common than expected, and pathologic stage, interlobar node involvement, and cell type were independent risk factors for locoregional failure after complete resection of N1 NSCLC. A prospective clinical trial may be necessary to evaluate the effectiveness of adjuvant radiotherapy in patients with these risk factors.