ParticipantsAndrew M. Pagano, MD,MS, New York, NY (Abstract Co-Author) Nothing to Disclose
Maham Siddique, MD, New York, NY (Presenter) Nothing to Disclose
Michael Chung, MD, New York, NY (Abstract Co-Author) Nothing to Disclose
Rowena Yip, MPH, New York, NY (Abstract Co-Author) Nothing to Disclose
Mary Beth Beasley, New York, NY (Abstract Co-Author) Nothing to Disclose
Claudia I. Henschke, MD,PhD, New York, NY (Abstract Co-Author) Nothing to Disclose
David F. Yankelevitz, MD, New York, NY (Abstract Co-Author) Royalties, General Electric Company Stockholder, Accumetra Advisory Board, GRAIL
ms5270@cumc.columbia.edu
PURPOSEThe aim of this study is to use tumor volume doubling time (VDT) as a marker of tumor aggressiveness to determine if concurrent lung cancers in interstitial lung disease (ILD) demonstrate more rapid growth than non-ILD patients, and to determine if VDT is affected by tumor development in fibrotic versus non-fibrotic areas of the lung.
METHOD AND MATERIALSIn this retrospective study, a pool of potential patients with ILD and primary lung cancer was identified via radiology report search engine tool. This list was narrowed to identify 36 patients with pathology proven lung cancer and two chest CT scans separated by at least 4 weeks. Tumor size was measured using its largest axial diameter and the corresponding perpendicular axial dimension. Separate measurements performed by a radiology fellow and a cardiothoracic fellowship trained radiologist were averaged and the VDT of each nodule was calculated. Detterbeck et al. previously reported the mean VDT for lung cancers detected in the context of routine care: 169 days for adenocarcinoma and 104 days for squamous cell carcinoma. Differences in VDT were compared using Mann-Whitney U test.
RESULTSOf the 36 ILD patients diagnosed with lung cancer, 14 were adenocarcinoma, 16 were squamous cell, 4 small cell and 1 non-small-cell carcinoma. The cancer was located in the fibrotic area in 16 (51.6%) cases. Median VDTs for adenocarcinoma, squamous, small cell and non-small cell were 84.8, 69.3, 90.7 and 25.9 days, respectively. ILD patients had significantly faster tumor growth compared to patients without ILD. (84.8 vs. 169, p=0.03 for adenocarcinoma, 69.3 vs. 104, p=0.02 for squamous cell). When tumor was located in the fibrotic area, VDT was faster compared with those that were not (median 69.3 days vs. 84.8 days, p=0.40).
CONCLUSIONOur results suggest increased tumor aggressiveness of primary lung cancer in patients with concurrent ILD, particularly when the tumor is located in the ILD affected part of the lungs.
CLINICAL RELEVANCE/APPLICATIONThis study supports a need to review cancer screening guidelines in patients with interstitial lung disease and may warrant shorter screening intervals. In addition, the diagnostic workup of indeterminate pulmonary nodules in patients with ILD would also need to be reviewed to account for the shorter volume doubling times.