Author of

• 10962

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  P1.20 - Poster Session 1 - Early Detection and Screening (ID 172)

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

  • 10972

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    P1.20-010 - A Prospective Study of Annual CT Screening for Lung Cancer in HIV Smokers (ID 3367)

    09:30 - 09:30  |  Author(s): A. Hulbert
    • Abstract

    Background
    Of all the non-AIDS associated malignancies, lung cancer is the most deadly because of its advanced stage of presentation. Within the HIV population, the incidence of non-small cell lung cancer (NSCLC) is estimated to be 2-4 times that of the general population. Despite this growing burden of NSCLC in HIV-infected smokers, no data exist regarding early detection of lung cancer in this population since screening trials, such as the U.S. National Lung Cancer Screening Trial, excluded HIV-infected participants. Preliminary data have highlighted the ineffectiveness of chest x-rays in diagnosing lung cancer early, and waiting for HIV-positive individuals to develop symptoms is misguided. These facts provide a compelling argument for the use of helical CT as a screening tool for lung cancer in HIV-infected patients.

    Methods
    From 2006-2013, a prospective feasibility study was conducted to determine the prevalent and incident CT detection rates in HIV-infected smokers of lung cancer. The secondary objective was to determine if CT screening could change the stage distribution of HIV lung cancer to that of an early stage disease. Annual CT screening was conducted for lung cancer in current or former smokers over age 25 years old with ≥20 pack-years history and a confirmed HIV diagnosis. To determine markers of lung cancer risk, we also analyzed from trial participants, clinical data, sera, and CT scans using quantitative, densitometry imaging as an estimate of emphysema, and compared these variables to similar parameters from 130 HIV patients at our institution with known lung cancer.

    Results
    Of the 224 individuals enrolled, 72% were males, 90% African-Americans, 9.5% Caucasian, and 0.5% Hispanic. The median age was 48 years and the median number of smoking pack-years was 34. No prevalent lung cancers were detected by CT screening and only lung cancer was found on incident screening. There were no interim diagnoses of lung or extrapulmonary cancers. Eighteen deaths occurred but none were cancer-related. Of 29 nodules detected at baseline screening, fifteen were further imaged, five biopsied, but none progressed to cancer at study end. Emphysema was commonly observed and its heterogeneity across the entire lung as measured by CT densitometry was significantly higher in HIV subjects with lung cancer than in those without (p≤0.01). On multivariate regression, increased age, higher smoking pack-years, low CD4 nadir, and increased heterogeneity of emphysema on quantitative CT imaging were all significantly associated with lung cancer in HIV individuals.

    Conclusion
    This pilot feasibility study is the world’s first reported annual lung cancer CT screening trial in HIV-positive smokers. During 4 years of CT screening of 224 HIV subjects with a median age of 48 years, only one incident lung cancer was found. This suggests that until the median age of the worldwide HIV population increases, the ability of annual CT screening to detect lung cancers in HIV-infected smokers will be low. Immunologic and radiographic differences that exist between HIV patients with and without lung cancer may serve as biomarkers of lung cancer risk.