title: Adenocarcinoma in situ, minimally invasive adenocarcinoma, and invasive pulmonary adenocarcinoma--analysis of interobserver agreement, survival, radiographic characteristics, and gross pathology in 296 nodules.
abstract: The International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society and 2015 World Health Organization classifications of lung adenocarcinoma recommend designating tumors showing entirely lepidic growth as adenocarcinoma in situ (AIS) and lepidic tumors with invasion less than or equal to 5 mm as minimally invasive adenocarcinoma (MIA), both of which have superior outcome to conventional invasive adenocarcinoma (IA). Data on interobserver variability within this classification are limited, and further validation of the superior survival of AIS and MIA is needed. A total of 296 surgically excised pulmonary adenocarcinomas were reviewed from 254 patients (1997-2009). Slides were independently reviewed by 2 pulmonary pathologists who categorized tumors as AIS, MIA, or IA. Of 296 nodules, 244 (82.4%) were agreed upon by both observers: 10 AIS, 61 MIA, and 173 IA (κ = 0.63, good agreement). In 6 cases (2%), there was disagreement between AIS and MIA; in 45 cases (15%), there was disagreement between MIA and IA; and in 1 case, there was disagreement between AIS and IA. Overall survival was significantly different among categories as determined by both observers. Cases with disagreement between MIA and IA had similar survival to agreed MIA. Disease-specific 10-year survival was 100% for AIS (both observers) and 97.3% and 97.6% for MIA, although this did not reach statistical significance compared to IA for either observer. Good agreement was present between observers when classifying tumors as AIS, MIA, and IA. Significant differences in overall survival were present between the 3 groups for both observers, and interobserver variability was evident. Patients with AIS and MIA experienced excellent DSS.
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, 55905. Electronic address: boland.jennifer@mayo.edu.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Boland
authors.affiliation: Department of Radiology, Mayo Clinic, Rochester, MN, 55905.
authors.forename: Adam T
authors.initials: AT
authors.lastname: Froemming
authors.affiliation: Department of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, 55905.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Wampfler
authors.affiliation: Department of Pulmonology and Critical Care Medicine, Mayo Clinic, Rochester, MN, 55905.
authors.forename: Fabien
authors.initials: F
authors.lastname: Maldonado
authors.affiliation: Department of Pulmonology and Critical Care Medicine, Mayo Clinic, Rochester, MN, 55905.
authors.forename: Tobias
authors.initials: T
authors.lastname: Peikert
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, 55905.
authors.forename: Courtney
authors.initials: C
authors.lastname: Hyland
authors.affiliation: Department of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN, 55905.
authors.forename: Mariza
authors.initials: M
authors.lastname: de Andrade
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, 55905.
authors.forename: Marie Christine
authors.initials: MC
authors.lastname: Aubry
authors.affiliation: Department of Epidemiology, Mayo Clinic, Rochester, MN, 55905.
authors.forename: Ping
authors.initials: P
authors.lastname: Yang
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, 55905.
authors.forename: Eunhee S
authors.initials: ES
authors.lastname: Yi
mesh_terms: D000230:Adenocarcinoma / Q000145:classification* / Q000000981:diagnostic imaging / Q000473:pathology*; D065311:Adenocarcinoma in Situ / Q000145:classification* / Q000000981:diagnostic imaging / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000145:classification* / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D016016:Proportional Hazards Models; D011859:Radiography; D055815:Young Adult
keywords: AIS; Agreement; MIA; Minimally invasive adenocarcinoma; Survival