The gist: New research shows that knowing whether a patient has one of two different subtypes of lung cancer—adenocarcinoma in-situ (AIS) or minimally invasive adenocarcinoma (MIA)—may not actually be helpful. Both AIS and MIA are subtypes of a type of lung cancer called bronchioloalveolar carcinoma. They both affect the cells lining the small air sacs of the lungs. The difference is that MIA tumors grow past the lining. The new research found that people with AIS have similar survival rates as people with MIA.
“Lung cancer patients with minimally invasive adenocarcinoma (MIA) have similar, positive five-year disease-free survival (DFS) and overall survival (OS) rates as patients with adenocarcinoma in-situ (AIS), according to research presented today at the 2014 Chicago Multidisciplinary Symposium in Thoracic Oncology. The Symposium is sponsored by the American Society of Clinical Oncology (ASCO), the American Society for Radiation Oncology (ASTRO), the International Association for the Study of Lung Cancer (IASLC) and The University of Chicago Medicine.
“Lung adenocarcinoma accounts for 60 percent of all non-small cell lung cancers and is the most common form of lung cancer in both smokers and non-smokers and patients younger than 45 years old. Bronchioloalveolar carcinoma is a type of adenocarcinoma that affects the cells lining the alveoli (small air sacs) of the lungs. Invasion occurs when the tumor extends beyond the alveolar lining and evokes a fibroblastic stromal response. These types of tumors, if ≤3 cm in size, are reclassified as AIS (no tumor invasion) or MIA (≤0.5 cm of tumor invasion), according to the 2011 IASLC/American Thoracic Society /European Respiratory Society (IASLC/ATS/ERS) International Multidisciplinary Classification of Lung Adenocarcinoma. This study examines the difference in DFS and OS rates for patients with diseases classified as AIS and MIA and determines if it is beneficial to categorize tumors according to additional sub-types…
” ‘Some researchers have advocated that AIS and MIA should have separate categorization,’ said lead author Madhusmita Behera, PhD, associate director of research in the Department of Hematology and Medical Oncology at Winship Cancer Institute of Emory University in Atlanta. ‘Our analysis demonstrates that these carcinomas, especially when the tumor is 3 centimeters or less in size, are associated with excellent survival outcomes; therefore, tumor sub-classification into AIS and MIA may not provide additional prognostic information.’ “