Bronchoalveolar carcinoma (BAC), also referred to as bronchioalveolar carcinoma, is a rare type of lung cancer. It grows and spreads mostly in the walls of the alveolar sacs of the lungs, with no tendency to metastasize to other parts of the body. The alveoli are tiny sacs found at the end portion of the lungs where oxygen exchange usually takes place. This type of cancer is generally fatal, and mortality is often high. Incidence of bronchoalveolar carcinoma is frequently seen in non-smokers and middle-aged women, particularly of Asian origin.
The precise cause of bronchoalveolar carcinoma remains unknown, but studies suggest that exposure to harmful substances may contribute to its development. Examples of these substances are radon, a naturally occurring radioactive gas, and asbestos, a mineral containing fibers that can penetrate deep into the lungs when inhaled. Asbestos has also been implicated in many cases of mesothelioma, a cancer that grows on the lining of the lungs and other organs as a result of asbestos exposure. Infection with certain viruses and bacteria may also lead to bronchoalveolar carcinoma.
Coughing is the most noted symptom of bronchoalveolar carcinoma. As the cancer advances, coughing can turn from mild to severe and to intensely violent, which may be accompanied by blood in the sputum. Weakness, anemia, seizures, and vision changes may also be observed in some patients. Other common manifestations of the disease include persistent chest pain, weight loss, shortness of breath, and repeated lung infections such as bronchitis and pneumonia. Bronchitis is the inflammation of the airways' mucous membranes, and pneumonia is inflammation of the lung tissues.
During the early stage of the cancer, patients may not have any noticeable symptoms. This is why most of them are diagnosed at the later stage of the disease, resulting in delayed medical intervention. Diagnosis of bronchoalveolar carcinoma can be done through the use of several diagnostic imaging tools. These include a chest X-ray and computer tomography (CT) scan of the chest.
Possible treatment alternatives for bronchoalveolar carcinoma are chemotherapy, radiation therapy, and surgery. Surgery is frequently an option to remove affected regions of the lungs. Due to the aggressiveness of this type of cancer, however, formation of new growths is often difficult to prevent. A lung transplant may also be considered to prolong one’s life. Compared with other types of lung cancer, the survival rate of most patients with bronchoalveolar carcinoma in the late stage, is generally poor.