This form of lung cancer accounts for more than 30 percent of all lung cancers and about half of all non-small cell lung cancers.
Lung adenocarcinoma is a sub-type of non-small cell lung cancer (NSCLC). It is categorized as such by how the cancer cells look under a microscope, and starts in glandular cells, which secrete substances such as mucus, and tends to develop in smaller airways, such as alveoli. Lung adenocarcinoma is usually located more along the outer edges of the lungs.
Other than the lungs, adenocarcinoma is most prevalent in cancers found in the prostate, pancreas, esophagus, colon and rectum. In the lungs, adenocarcinoma tumors most often form in the alveoli, the tiny balloon-like sacs that help pump air in and out of the lungs.
Current and former heavy smokers are high-risk patients. Lymph node metastasis occurs in peribronchial lymph nodes before moving to mediastinal or subcarinal nodes and then the contralateral lung. Distant metastasis includes extension to a contralateral lobe, pleural nodules, malignant pleural or pericardial effusion, or any distant site such as the brain, bones, or liver.
If a lung nodule is found, the next step depends on the and imaging characteristics of the lung nodule. If a nodule is suspicious for lung cancer, PET/CT may be performed followed by biopsy or surgical excision. Lobectomy or a pneumonectomy are often performed.