For decades, the early detection of common cancers has been advocated to attempt to improve the chance for long-term cancer survival and cure. Breast, colon, cervical and prostate cancer all have established screening programs that are covered by insurers, embraced by physicians and the public, endorsed by professional societies and policy-makers, and touted as critical public health measures as the U.S. healthcare system strives to prevent rather than treat disease. Yet, in the midst of this enthusiasm for early diagnosis, lung cancer has lagged behind, with no approved, endorsed, or supported screening modality, in spite of the fact that lung cancer causes more cancer deaths than breast, colon, and prostate cancer combined.
The National Lung Screening Trial (NLST) now provides Level I evidence that high risk patients undergoing screening by low-dose computed tomography (LDCT) have a 20% reduction in lung cancer mortality.1 Clearly this is a major advance for patients, perhaps the most significant advance in lung cancer treatment in a generation. Payors, policy-makers, and guidelines groups will need to make major policy changes as a result. However, this enthusiasm, although deserved, must be tempered with caution. Another view of the NLST data reveals that it is necessary to screen 320 individuals for each lung cancer death avoided, so many patients will be exposed to the emotional and physical risks of lung cancer screening to achieve the desired benefit. A careful, measured approach is important for the institution of lung cancer screening nationwide.
The NLST enrolled only patients at high risk of lung cancer. Although it would be naïve and narrow-minded to not recognize that additional patients, outside of the NLST criteria, may have substantial risk of lung cancer that warrants screening, one must be very cautious in extrapolating the NLST results to other patient populations and recognize the unintended consequences of screening these patients. In the NLST 96% of lung nodules found were ultimately determined to be false positives and 39% of patients had at least one positive result during the study. A highly organized and disciplined approach to management is the only way to mitigate the potential harms caused to patients by excessive and unnecessary testing and the morbidity of invasive procedures. The margin between net benefit and net harm in lung cancer screening is likely small, and the benefit to patients could easily be lost if a higher percentage of the patients with false positive findings undergo unnecessary workup and invasive testing. Successful implementation of lung cancer screening will require the following: (1) pragmatic and thoughtful guidelines that define patients eligible for screening (not limited to NLST criteria yet reasonably narrow in scope); (2) experienced radiologists to interpret screening studies and minimize false positives; (3) a protocolized approach for the management of screen detected nodules; (4) diagnostic and therapeutic surgical procedures performed by board-certified thoracic surgeons in order to optimize staging and minimize morbidity; and (5) experienced multidisciplinary oncology management with thoracic surgery, medical and radiation oncology to optimize oncology treatment and outcomes.
The development of lung cancer screening guidelines is underway, with the first being published by the National Comprehensive Cancer Network (NCCN) in November 2011.2 Most notable in the NCCN guidelines is the extrapolation of high risk patients beyond the inclusion criteria of the NLST. The NCCN also recommended a highly protocolized approach to the followup, workup, and invasive testing of positive findings, similar to those recommended by the Fleischner Society3 and others. Of note, surveys of compliance with the Fleischner Society guidelines have shown only 35% to 60% compliance by members of the RSNA,4 and 27% compliance by members of the Society of Thoracic Radiology,5 with an overall trend towards over management. It will be important for the successful application of screening programs to assure an algorithmic and disciplined approach to nodule workup and followup in order to minimize the serious potential harms from excessive and invasive testing in these patients undergoing screening.
Once a nodule has been identified, the involvement of an experienced thoracic surgeon will help the multidisciplinary team refine a strategy for further workup, including biopsy and/or resection. The Non-Small Cell Lung Cancer Panel of the NCCN recommends assessment and management of presumed or proven lung cancer by “Board certified thoracic surgeons who perform lung cancer surgery as a prominent part of their practice.”6 This recommendation is based on the data that as much as 50% of lung cancer surgery in the United States continues to be performed by general surgeons, and that surgical outcomes (morbidity and mortality), as well as oncology outcomes (correct staging, extent of resection, cancer survival) are better when performed by specialists in thoracic surgery.7,8 There are multiple potential adverse consequences of non-specialist surgery, which are even more profound for recipients of lung cancer screening: unnecessary surgery in cases where followup or other diagnostic testing may have been preferred, inadequate staging before and/or during lung cancer surgery, underutilization of minimally invasive surgery for both diagnostic and resection procedures, and lack of advanced techniques (segmentectomy, sleeve resection) to minimize the extent of pulmonary resection. Specialist thoracic surgeons, working in a multi-disciplinary lung cancer team, are best equipped to help maximize the benefit of early detection. They are an important part of avoiding the adverse consequences of unnecessary procedures or substandard cancer outcomes that potentially could result in more harm than good from lung cancer screening programs applied without adherence to guidelines and necessary specialty expertise.
1. . Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011;365:395–409
2. Wood DE, Eapen GA, Ettinger DS, et al. Lung cancer screening. J Natl Compr Canc Netw. 2012;10:24–65
3. MacMahon H, Austin JHM, Gamsu G, et al. Guidelines for management of small pulmonary nodules detected on CT scans: a statement from the Fleischner Society. Radiol. 2005;237:395–400
4. Eisenberg RL, Bankier AA, Boiselle PM. Compliance with Fleischner Society guidelines for management of small lung nodules: a survey of 834 radiologists. Radiology. 2010;255:218–224
5. Esmaili A, Munden RF, Mohammed TLH. Small pulmonary nodule management: a survey of the members of the Society of Thoracic Radiology with comparison to the Fleischner Society guidelines. J Thorac Imaging. 2011;26:27–31
6. Ettinger DS, Akerley W, Bepler G, et al. Non-small cell lung cancer. J Natl Compr Canc Netw. 2010;8:740–801
7. Wood DE, Farjah F. Surgeon specialty is associated with better outcomes: The facts speak for themselves. Ann Thorac Surg. 2009;88:1393–1395
8. Farjah F, Flum DR, Varghese TK, et al. Surgeon specialty and long-term survival following resection for lung cancer. Ann Thorac Surg. 2009;87:995–1006