Repeated removal of lung metastases improves survival in certain patients with colorectal cancer

This study evaluated the survival benefits of repeated removal of lung metastases in patients with colorectal cancer. Additionally, the authors aimed to identify which patients would benefit the most from this treatment. 

Colorectal cancer is an abnormal growth of cells in the colon (large intestine) or rectum (last part of the large intestine before the anus). When colorectal cancer spreads, or metastasizes, one of the places it frequently goes is the lung tissue. Surgical removal of the cancer, when this is possible, gives patients the best chances of survival. When the primary site of cancer in the large intestine has been removed, surgeons consider whether removing the spread cancer (metastasis) will help the patient. This surgery is called a metastasectomy. Previous studies have shown that one lung metastasectomy improves survival for patients with colorectal cancer. However, sometimes lung metastases can reoccur. There is little information available regarding benefits after a second lung metastasectomy. Since each patient with cancer has a different experience, it is also important to identify which patients will benefit the most from repeat surgery to remove lung metastases.

This study evaluated data from 7 previous studies, including overall 759 colorectal patients. All patients received a first lung metastasectomy between 1983 and 2008, at different cancer clinics around the world. They were followed up for an average of 32 months after their first metastasectomy. Of these patients, 148 had a repeated lung metastasectomy.

Overall survival (the percentage of patients who survived a certain time after treatment) for all 759 patients 5 years after the first metastasectomy was 58.03%. For patients who had only one metastasectomy, the 5 year overall survival was 52%. For the 148 patients who had repeated lung metastasectomy, overall survival 5 years after the first metastectomy was 71.7% and 57.9% after the second metastasectomy. Patients with 3 or less lung metastases had higher overall survival (62.5%) compared to those who had more than 3 metastases (37.6%). Also, patients whose metastases were smaller than 3 cm had better survival (70.9%) than those with metastases larger than 3 cm (27%).

In summary, repeated lung metastasectomy was associated with very good survival rates in patients with metastatic colorectal cancer. Factors which influenced survival in these patients are number and size of metastases.

This study looked back at patients who were treated in the past (retrospective study) rather than following patients throughout their treatment and determining their outcomes. Retrospective studies are known to provide weaker statistical information. Also, this study did not include information regarding survival of patients without any sign of disease (disease free survival). Future studies are needed to evaluate this parameter in patients with repeated lung metastasectomy.

Talk to your doctor whether a first or repeated lung metastasectomy is a good treatment option in your situation.