title: Recurrence Patterns and Second Primary Lung Cancers After Stereotactic Body Radiation Therapy for Early-Stage Non-Small-Cell Lung Cancer: Implications for Surveillance.
abstract: Patients treated with stereotactic body radiation therapy (SBRT) for early-stage non-small-cell lung cancer (NSCLC) are subject to locoregional and distant recurrence, as well as the formation of second primary lung cancers (SPLCs). The optimal surveillance regimen for patients treated with SBRT for early-stage NSCLC remains unclear; we therefore investigated the posttreatment recurrence patterns and development of SPLCs.
  
  
  
  Three hundred sixty-six patients with pathologically proven inoperable early-stage NSCLC treated with SBRT between 2006 and 2013 were assessed. Patients underwent a computed tomographic (CT) scan of the chest every 3 months during years 1 and 2, every 6 months during years 3 and 4, and annually thereafter. Competing risk analysis was used for all time-to-event analyses.
  
  
  
  With a median follow-up of 23 months, the 2-year cumulative incidence of local, nodal, and distant treatment failures were 12.2%, 16.1%, and 15.5%, respectively. In patients with disease progression after SBRT (n = 108), 84% (n = 91) of cases occurred within the first 2 years. Five percent (n = 19) of patients experienced SPLCs. The median time to development of an SPLC was 16.5 months (range, 6.5-71.1 months), with 33% (n = 6) of these patients experiencing SPLCs after 2 years. None of the never smokers, but 4% of former tobacco smokers and 15% of current tobacco smokers, experienced an SPLC (P = .005).
  
  
  
  Close monitoring with routine CT scans within the first 2 years after SBRT is effective in detecting early disease progression. In contrast, the risk for the development of an SPLC remains elevated beyond 2 years, particularly in former and current smokers.
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY; Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Spratt
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Abraham J
authors.initials: AJ
authors.lastname: Wu
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Victoria
authors.initials: V
authors.lastname: Adeseye
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Shaun U
authors.initials: SU
authors.lastname: Din
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Fauzia
authors.initials: F
authors.lastname: Shaikh
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Kaitlin M
authors.initials: KM
authors.lastname: Woo
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Amanda
authors.initials: A
authors.lastname: Foster
authors.affiliation: Department of Radiation Oncology, Mount Sinai Medical Center, New York, NY.
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Rosenzweig
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Richard
authors.initials: R
authors.lastname: Gewanter
authors.affiliation: Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: James
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY. Electronic address: rimnera@mskcc.org.
authors.forename: Andreas
authors.initials: A
authors.lastname: Rimner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000453:epidemiology / Q000473:pathology / Q000532:radiotherapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008168:Lung / Q000000981:diagnostic imaging*; D008175:Lung Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000473:pathology / Q000532:radiotherapy*; D016634:Radiosurgery; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
keywords: Computed tomography; Early stage; Non–small-cell lung cancer; Stereotactic body radiation therapy (SBRT); Surveillance