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L. Renfro

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    P1.06 - Poster Session 1 - Prognostic and Predictive Biomarkers (ID 161)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Biology
    • Presentations: 1
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      P1.06-014 - A nomogram for predicting 5-year RFS in patients with pulmonary carcinoid tumors incorporating Ki-67 and clinical variables (ID 1567)

      09:30 - 16:30  |  Author(s): L. Renfro

      • Abstract

      Evaluation of prognostic factors in carcinoid tumors of the lung is limited due to the rarity of disease. This study assessed Ki-67 expression and other clinical variables as prognostic factors in cohort of 262 patients seen at Mayo Clinic, and subsequently developed a nomogram for predicting recurrence-free survival (RFS).

      A systematic search of Mayo Clinic lung cancer epidemiology and tumor registry databases from 1997 to 2009 identified 448 consecutive patients, with 262 having available tissue blocks [40 atypical carcinoids (AC) and 222 typical carcinoids (TC)]. Clinical data were collected by chart review. Tissue blocks were reviewed by 1 of 3 pathologists using WHO criteria. Tumors were tested for the Ki-67 index using digital image analysis (tumor tracing) by two operators. The associations of the factors with RFS were explored using multivariable Cox proportional Hazards models, including concordance (c) index. A nomogram was developed using the variables from the final multivariate model.

      Age, smoking history, lymph node (LN) involvement, tumor size, and Ki-67 index were significant prognostic factors for RFS from a multivariate model (Table 1). Median follow-up on alive-patients was 5.6 years (0.008-16.2). Median percentage of Ki-67 index of AC and TC were 1.61% and 0.56% (P<0.0001), respectively. The multivariable model with Ki-67 index showed a c-index of 0.79 which was identical to a multivariable model with pathological diagnosis (c-index 0.79). The nomogram showing the probability of 5-year RFS estimates is shown in Figure 1. Figure 1

      Variables Adjusted by Ki-67 and Clinical Variables HR; 95% CI (P) Adjusted by Pathological Diagnosis and Clinical Variables HR; 95% CI (P)
      Ki-67 1.25; 1.11-1.41 (0.0016) --
      AC vs. TC -- 2.01; 1.05-3.88 (0.0436)
      Age 1.05; 1.03-1.08 (<0.0001) 1.06; 1.03-1.09 (<0.0001)
      Smoking Never Former Current (<0.0001) -- 3.11; 1.68-5.74 4.34; 1.94-9.74 (0.0003) -- 2.86; 1.56-5.24 3.74; 1.67-8.40
      Size of Tumor 1.42; 1.20-1.67 (0.0002) 1.33; 1.13-1.56 (0.0012)
      Metastatic LN Negative Positive (0.0007) -- 3.05; 1.66-5.59 (0.0068) -- 2.51; 1.33-4.76

      Ki-67 index is a valuable prognostic biomarker for pulmonary carcinoids based on this large cohort. The nomogram based on Ki-67 index, age, smoking history, LN involvement, and tumor size is a useful clinical tool for predicting the 5-year RFS rate. Updating this nomogram with additional clinical follow-up, as well as external validation of this nomogram is critical before routine clinical use.