Effect of Pulmonary Metastasectomy on Sarcoma Survival Unclear, Unproven

Despite its place in standard practice, the performance of pulmonary metastasectomy in patients with sarcoma and lung metastases may not improve the survival rate of these patients, according to information from a systematic review of studies investigating the procedure in this patient population.

High magnification micrograph of Ewing sarcoma in lung; PAS stain; source: Nephron, Wikimedia Commons

Patients diagnosed with sarcoma frequently have disease metastasize to their lungs. For many years patients with these metastases have undergone surgical resection, or pulmonary metastasectomy, to remove the metastases. However, recent data from a survey conducted by the European Society of Thoracic Surgeons Lung Metastasectomy Project showed that thoracic surgeons varied considerably in their practice of removing these metastases when it came to considering things such as time from diagnosis of the primary tumor, and the number of metastases seen. This led the society to conclude that too little evidence exists regarding lung metastasectomy to issue firm recommendations.

Given this conclusion, Tom Treasure, MD, of the Clinical Operational Research Unit of the department of mathematics, University College London, United Kingdom, and colleagues conducted a systematic review of published literature to determine if in fact pulmonary metastasectomy improves survival in patients with sarcoma and lung metastases. The results of the review were published in BMJ.

A literature search was conducted and included all eligible articles on the topic from 1990 to June 2011 that contained at least 20 patients who had undergone pulmonary metastasectomy for sarcoma of any type and had data on surgical outcomes. Ultimately the researchers used data from 18 articles, none of which were randomized controlled trials.

Overall, data did indicate that those patients who had undergone pulmonary metastasectomy had increased 5-year survival rates. Those patients with bone sarcoma had a 34% 5-year survival after first metastasectomy compared to historical data from the Thames Cancer Registry that showed a 20% to 25% survival rate for all patients with metastatic sarcoma. Similarly, those with soft-tissue sarcoma had a 25% 5-year survival rate after first metastasectomy compared to a historical rate of 13% to 15% for all patients with metastatic sarcoma.

However, the researchers point out that these data cannot be directly compared as “patients destined to survive longer are more likely to be selected for surgery.”

Among the selection criteria found for patients recommended to undergo surgery were having fewer metastases, and a longer interval between the diagnosis and treatment of the primary tumor and the pulmonary metastasectomy.

The researchers concluded that there “is no evidence that survival difference is attributable to metastasectomy.”

Although the researchers did admit that a true study of pulmonary metastasectomy would be challenging, they wrote that “a randomized controlled trial is now necessary if we are to see the signal from the noise in this area of clinical practice.”

This article has been revised to reflect the following change:

Correction: November 8, 2012

An earlier version of this article used the following quote from the BMJ study: “it is the process of selection, rather than the effect of pulmonary metastasectomy, which is responsible for any survival difference perceived.” While the quote does appear in the study, it is a hypothesis the authors refer to and does not represent their findings.