Author of

• 16751

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  P1.05 - Poster Session with Presenters Present (ID 457)

  • Event: WCLC 2016
  • Type: Poster Presenters Present
  • Track: Early Stage NSCLC
  • Presentations: 1
  • Moderators:
  • Coordinates: 12/05/2016, 14:30 - 15:45, Hall B (Poster Area)

  • 16817

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    P1.05-066 - Impact of Micropapillary Pattern in Nodal Upstaging of Lung Adenocarcinoma 2cm or Less (ID 5189)

    14:30 - 14:30  |  Author(s): Y. Kondo
    • Abstract

    Background:
    Clinical and pathological determinations of lymph node staging are critical in the treatment of lung cancer. However, upstaging of nodal status frequently is necessitated by postoperative findings. It is now being recognized that lung adenocarcinoma (LAC) with tumor cells arranged in a micropapillary pattern (MPP) is more malignant than those without such pattern. Thus, this study was conducted to evaluate clinicopathologic features that impact nodal upstaging in patients with small-sized(≦2cm) LACs with MPP(LAC-MPP).
    
    Methods:
    We retrospectively reviewed the 182 radically resected lung adenocarcinomas at the Kitasato University Hospital, Japan, from January 2005 to December 2015. MPP was defined as a small papillary tumor cell tuft without an obvious fibrovascular core. Tumors with ≧1% of their tumor cells arranged in a MPP were diagnosed as LAC-MPP, while the remainders were diagnosed as conventional LAC. The histological subtypes and differentiation grade of LAC were determined according to the 4th WHO classification. The registry date of the patients with LAC and LAC-MPP were analyzed, and the clinicopathologic profiles and surgical outcomes of the patients were evaluated.
    
    Results:
    One hundred and sixty (88%) of the total 182 were LAC whereas 22(12%) were LAC-MPP. Among the two groups, there is no significant difference in age, sex, smoking habit, preoperative serum CEA level, or surgical procedures. Compared with the LAC, the LAC-MPP had worse statuses for lymphatic invasion (p=0.0096), pleural invasion (p=0.002), postoperative lymph node metastases (p<0.001) and postoperative recurrence (p=0.002). On the other hand in clinical stages, pleural lavage cytology, and postoperative stages, there is not significant deference statistically. Median follow up time was 48 months. The five-year overall survival rates were 92% in LAC group and 85% in LAC-MPP, statistically not significant deference (p=0.98). Also with regarding to the median relapse free survival rates, no significant difference was found between two groups (p=0.14).
    
    Conclusion:
    The follow-up term of patients was limited in this study. But, we concluded that LAC-MPP should be considered as an aggressive disease showing nodal upstage. Although lymph node metastasis and lymphatic infiltration should be usually reported in LAC-MPP patients, these are difficult to detect by preoperative imaging tools such as CT and PET canning. Therefore, MPP could be important factor to determine the indications for limited resection for LAC patients even if small-sized(≦2cm) LAC- MPP.