In most cases, metastatic cancer to the lung is a sign that the cancer has spread into the bloodstream. Usually cancer will be present even in places not seen by CT scans. In these circumstances, removing the visible tumors by surgery is usually not beneficial. Chemotherapy is usually the treatment of choice.

Cure is unlikely in most cases. However, patients with testicular cancer or lymphoma have a higher likelihood of long-term survival than those with most other cancers.

In some circumstances in which the primary tumor has been removed and cancer has spread to only limited areas of the lung, the lung metastases can be removed surgically with the goal of cure. This is more likely to happen with certain types of primary cancers.

Radiation therapy, the placement of stents inside the airways, or laser therapy are sometimes used but are less common than surgery or chemotherapy.

Living more than five years with metastatic cancer to the lungs is uncommon. In some circumstances, patients with certain types of cancer (sarcoma, renal cell carcinoma, bladder cancer, colon cancer, or melanoma) that has only spread a limited amount to the lung can be cured with surgery.

Some types of cancer, particularly lymphoma or testicular cancer, that have spread to the lung can be cured with chemotherapy. However, this is the exception rather than the rule. In general, lung metastases are a sign of widespread cancer with a poor survival rate.

• Side effects of chemotherapy and radiation therapy
• Further spread of the cancer
• Pleural effusions (fluid between the lung and chest wall), which can cause shortness of breath