Author of

• 10923

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  P1.18 - Poster Session 1 - Pathology (ID 175)

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

  • 10928

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    P1.18-005 - Clinicopathological features and prognostic significance of tumor invasion into the interlobular septal area and perivascular area (ISA/PA) in lung adenocarcinoma (ID 1049)

    09:30 - 09:30  |  Author(s): K. Kamiya
    • Abstract

    Background
    Lung interstitium is composed of the interlobular septal area (ISA), perivascular area (PA), and visceral pleural area. Tumor invasion into the visceral pleural area is recognized as a prognostic factor in lung cancer, whereas invasion into the ISA/PA has not been clearly examined. The aim of this study was to evaluate the clinicopathological features and prognostic significance of invasion into the ISA/PA in lung adenocarcinoma.

    Methods
    A total of 132 patients with pathological stage I lung adenocarcinoma who were treated with surgical complete resection from 2000 to 2006 in the Yokohama Municipal Citizen’s Hospital were retrospectively evaluated (mean follow-up period 79.1 months). Tumor invasion into the ISA/PA was defined as the existence of tumor cells in that area or septum discontinuity around the area due to tumor cells. Hematoxylin-eosin and Victoria-blue stained slides for each case were reviewed by two investigators. The correlation between a presence of the feature and clinicopathological characteristics or prognosis was analyzed using the chi-square test, log-rank test, and Cox proportional hazards regression model.

    Results
    In 53 cases, we were unable to identify the ISA/PA area adjacent to the tumor or the existence of the septum itself, particularly in those with small sized tumors or poorly differentiated cases; therefore, they were excluded from the analysis. We subsequently divided the remaining 79 cases into the following two groups: invasion in the ISA/PA-positive (n = 36) and ISA/PA-negative group (n = 43). Lymphatic and venous invasion was identified significantly more frequently in the positive than negative group (p = 0.012/0.001). No significant difference between the two groups in gender, age, smoking habit, tumor size, or visceral pleural invasion was observed. Disease-free and overall survival rates for the positive were significantly worse than those for the negative group (p = 0.002/0.012). Multivariate analysis demonstrated an independent prognostic effect of the feature (p = 0.04). Further, when we limited the analysis to lymphatic and venous invasion-negative cases (n = 42), we found that every relapsed case (n = 4) had the feature but no visceral pleural invasion.Figure 1

    Conclusion
    It is believed that invasion into the ISA/PA is a feature predictive of tumor invasiveness and may be a prognostic factor in stage I lung adenocarcinoma. This finding may portray the previous phase of lymphatic or venous invasion. Unfortunately, we were unable to evaluate the feature in many cases of this study. Further studies are needed to elucidate the clinical significance of this finding.