What To Expect from a Pulmonary Metastasectomy

The rationale of lung resection

Patients with untreated metastatic disease have a 5-year survival rate of less than 5-10% on average. For a patient with isolated metastatic disease to the lungs (i.e., with no metastases to other parts of the body), pulmonary metastasectomy (surgical removal of the lung tumors) is the best hope for cure. Numerous studies have demonstrated 5-year survival rates of 30 to 50% for a variety of primary tumors when they spread to the lungs but then are surgically removed. These survival rates are far superior to any other treatment currently available. Regardless of the primary tumor, completeness of resection is the key to achieving long-term survival/cure. Since these operations can be performed with very low morbidity and mortality rates, and offer a chance for cure in otherwise incurable patients, surgery is very often recommended.

Number of tumors

The number of tumors found in the lung is a factor when determining whether or not to undergo surgery. In general, the presence of fewer, or solitary, tumors occurring at a remote time from the primary cancer diagnosis will factor favorably into the decision to offer a lung operation. However, the presence of multiple metastatic tumors does not preclude lung resection, and even if the metastases are present at the time of (synchronous with) identification of the primary tumor, resection can be considered.

Our group favors a relatively aggressive approach, and we do not consider the number of metastases per se to be limiting. What is more important is the feasibility of resecting all sites of disease in the context of leaving adequate lung function in reserve.

Use of minimally invasive techniques

The newest surgical approach to pulmonary metastasectomy is by video-assisted thoracoscopic surgery (VATS). This minimally invasive approach provides excellent exposure of the lung surface, and by palpation nodules below the surface. It reduces surgical trauma, minimizes postoperative pain, provides earlier patient mobilization, and decreases hospital length of stay. Pulmonary metastases are often small nodules located in the periphery of the lung, well suited for wedge resection by stapler and the VATS approach when they are limited in number (generally 3 or less). In case of recurrence of pulmonary disease, and if the patient fulfils the initial criteria for pulmonary metastasectomy, repeat surgery can be performed.

When more nodules are present, or more complex resections are required, thoracotomy may be recommended. This allows the surgeon to carry out bimanual palpation of the entire lung, and it likely reduces the chance of tiny, more difficult-to-find nodules being missed. This comes at the cost, however, of greater patient discomfort and greater difficulty if later reoperation is required.