It is estimated that most patients with pulmonary metastases have widespread disease (75%), and, traditionally, are not considered for surgical metastasectomy. On the other hand, there is a group of patients that will have disease confined to the lungs (25%), and may benefit from local surgical therapy.
The lungs are a common site of metastatic spread from almost all types of extrathoracic solid malignancies. Its capillaries work as a filter, where malignant metastatic cells can get trapped and proliferate locally.
Furthermore, there are some malignancies that metastasize preferentially to the lungs, such as most sarcomas.The majority of pulmonary metastases are asymptomatic. Most are detected incidentally during the initial staging workup of a primary cancer, or from routine post-treatment surveillance radiographic studies, typically chest computed tomography (CT). Symptoms of cough, pain, or hemoptysis may be present in patients with hilar involvement, particularly when the metastases abut or invade the bronchi. Rarely, patients with peripheral metastases present with a spontaneous pneumothorax due to tumor disruption of the visceral pleura.
The decision of operating a patient for metastasectomy is a complex one, and should be discussed in a multidisciplinary board, including surgeon, medical oncologist, radiation oncologist, pathologist, radiologist, pulmonologist, among others.
With the advent of computed tomography (CT), and its technological advances, more and more nodules can be detected in the preoperative period.
Thoracotomy with bi-manual palpation of the lung has been considered the gold standard method for pulmonary metastasectomy, since the fingers seem to find more nodules than expected with image studies.The major criticism to the use of VATS for the treatment of pulmonary metastases is the lack of manual palpation of the lung, which could detect more nodules than initially visualized in the CT. Most of the retrospective data in lung metastasectomy shows that complete resection of all disease is an important factor for long term survival.
Video-assisted thoracic surgery (VATS) emerged in the 1980s as a less invasive alternative to thoracotomy for the treatment of lung cancer, and is considered nowadays an equivalent oncologic option, with less morbidity and mortality in numerous comparative studies. Accordingly, it was expected that VATS could also be applied in the context of pulmonary metastasectomy.