Author of

• 20195

  +

  P3.16 - Surgery (ID 732)

  • Event: WCLC 2017
  • Type: Poster Session with Presenters Present
  • Track: Surgery
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/18/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)

  • 24636

    +

    P3.16-025 - Tumor Doubling Time Is the Most Important Predictor of Survival and Pathological Diagnosis in Metachronous Lung Cancer (ID 9101)

    09:30 - 09:30  |  Author(s): Y. Yoshida
    • Abstract

    Background:
    Good prognosis following surgery for metachronous second primary lung cancer has been reported. However, distinguishing pulmonary metastasis from metachronous second primary lung cancer is difficult.
    
    Method:
    Patients who underwent multiple pulmonary resections for metachronous lung cancer at our institution between 2000 and 2014 were retrospectively analyzed. Metachronous lung cancer was defined as non-small cell cancer regardless of disease-free interval or histologic concordance.
    
    Result:
    The retrospective chart review identified 86 patients. The median patient age at the time of second resection was 72 years, and 53 out of 86 patients (62%) were male. The median time interval between first and second resection was 1540 days. The mean tumor size was 19 ± 8 mm, the mean tumor doubling time was 316 ± 305 days, and 71 out of 86 patients (83%) had concordant histology. Upon postoperative pathological examination, the metachronous lung cancer was diagnosed as second primary lung cancer in 72 patients (84%), and pulmonary metastasis in 4 patients (5%). In the remaining 10 patients (12%), second primary lung cancer was indistinguishable from pulmonary metastasis. In second primary lung cancer, pulmonary metastasis, and indistinguishable tumors, the 5-year overall survival rates were 82%, 50%, and 53%, respectively. Factors significantly associated with improved overall survival included: tumor doubling time >180 days; pathological diagnosis of second primary lung cancer; pathological stage IA; >2 year interval between first and second surgery; and a consolidation/tumor ratio of ≤0.5. A tumor doubling time of >180 days was significantly associated with pathological diagnosis of second primary lung cancer. Using multivariate analysis, we also found that tumor doubling time >180 days was the only independent predictor of superior overall survival.
    
    Conclusion:
    This study found that tumor doubling time is the most important preoperative predictor of survival and pathological diagnosis of second primary lung cancer in metachronous lung cancer. The classic criteria for the diagnosis of a metachronous primary lung cancer were defined by Martini and Melamed. A tumor was considered to be metachronous primary lung cancer if the histologic type was discordant, or if the disease-free interval was at least 2 years for tumors with a histologic type similar to that of the primary cancer. However, due to the rising incidence of adenocarcinoma, earlier detection by computed tomography, and later recurrence due to adjuvant chemotherapy, Martini and Melamed’s criteria should be modified. We propose that tumor doubling time of >180 days should be a new criterion among Martini and Melamed’s criteria.