Resection of pulmonary metastases from colorectal carcinoma

Abstract

Although pulmonary metastases from colorectal carcinoma (CRC) often represent systemic and uncontrolled tumour growth, in a number of patients lung disease is limited and the patient remains well. When the metastases can be removed, long term survival is a possibility, with 5- and 10-year survivals in the order of 44% and 25%. Chemotherapy, the only alternative treatment only very rarely leads to survival beyond 24 months. Pulmonary metastases which are suitable for resection are usually detected on chest radiography, especially when carried out during monitoring of patients. They are rarely a cause of symptoms and the majority of patients have otherwise healthy lungs. CT scans supplemented by PET scans usually confirm the diagnosis, but percutaneous biopsy is sometimes necessary to exclude a primary lung cancer. The criteria for resecting CRC pulmonary metastases are (1) the primary tumour is controlled or is controllable; (2) complete resection is possible; and (3) the patient has adequate pulmonary reserve to tolerate the planned resection. Surgical approaches include posterolateral thoracotomy, staged bilateral thoracotomies, median sternotomy, clamshell incision, and video-assisted thoracic surgery. Each has its advantages and disadvantages. The majority of patients having resection of pulmonary metastases from CRC recover well with very few post-operative complications. Following resection favourable prognostic factors include a long disease-free interval, small number and small size of metastases, a normal carcinoembryonic antigen level, and an absence of concomitant liver metastases and mediastinal lymph node spread. Surgery for pulmonary metastases of CRC remains the best means of local control and the best way to render the patient disease-free. Patients with complete resection of pulmonary metastases have an improved long-term survival when compared to patients with unresected metastases.