Landmark events in the field of lung cancer in the past year have the potential to significantly alter the practice of pathology. Three key events are (1) approval of payment for low-dose computed tomography screening for lung cancer, (2) publication of an extensively revised World Health Organization classification of lung cancers, and (3) approval of immunohistochemistry based companion diagnostics by the US Food and Drug Administration. We briefly review these milestones in the context of their impact on the practice of pathology.( Arch Pathol Lab Med. 2016;140:322-325; doi: 10.5858/ arpa.2015-0535-SA) L andmark events in the field of lung cancer in the past year have the potential to significantly alter the practice of pathology. We briefly review 3 important milestones: (1) approval of payment for low-dose computed tomography (LDCT) screening for lung cancer, (2) publication of an extensively revised World Health Organization (WHO) classification of lung cancers, and (3) approval of immunohistochemistry (IHC) based companion diagnostics by the US Food and Drug Administration (FDA).
LUNG CANCER SCREENINGIn February 2015, the Centers for Medicare and Medicaid Services (CMS) decided ''to add a lung cancer screening counseling and shared decision-making visit, and for appropriate beneficiaries, annual screening for lung cancer with LDCT, as an additional preventive service benefit under the Medicare program.'' 1 This decision was accompanied by mandated private insurance coverage for LDCT beginning in 2015, based on the US Preventive Services Task Force's ''B'' rating, given to LDCT screening in late 2013.2 The LDCT screening is likely to increase the number of fine-needle biopsies, cytology specimens, and other pathology specimens requiring diagnosis, as an increased number of pulmonary nodules are discovered during the screening process. After histologic or cytologic diagnosis, there may be follow-up studies such as biomarker testing for samples that are positive for lung cancer to say nothing of possible follow-up resection specimens.The recommendations for lung cancer LDCT screening are based largely on the results of the National Cancer Institute's National Lung Screening Trial (NLST), 3-5 which was preceded by the International-Early Lung Cancer Action Project (I-ELCAP).6,7 Beginning in 1993, the I-ELCAP enrolled asymptomatic persons, 60 years of age or older, with at least 10 pack-years smoking history and no prior cancer and compared LDCT screening to chest radiograph screening. For LDCT versus radiograph, noncalcified nodules were detected in 23% versus 7% of individuals (3 times as often), cancer in 2.7% versus 0.7% (4 times as often), and stage I cancers in 2.3% versus 0.4% (6 times as often). In 2001, the authors of this study concluded that ''baseline CT screening for lung cancer provides for detecting the disease at earlier and presumably more commonly curable stages in a cost-effective manner. '' 6,7 The NLST enrolled participants at high risk for lung cancer at 33 US medical centers fro...