Up to 50% of patients with soft tissue sarcoma (STS) develop lung metastases. Effective systemic therapies for metastatic STS are currently limited; when possible, surgical removal of the lung metastases (known as pulmonary metastasectomy, PM) is the preferred treatment. However, guidelines for the performance of PM for STS do not exist and decisions to operate are often made on an individual basis. In a presentation at the 96th AATS Annual Meeting, researchers from Memorial Sloan Kettering Cancer Center share the results of their experience with more than 500 patients with pulmonary metastases from STS and describe prognostic factors associated with improved survival.
Baltimore, MD, May 16, 2016 – Approximately 12,000 new cases of soft tissue sarcoma (STS) are diagnosed in the U.S. annually, resulting in nearly 5,000 deaths. Up to half of STS patients develop one or more lung metastases. Without effective systemic therapies, doctors often rely on pulmonary metastasectomy (PM), surgical removal of the pulmonary metastases, although current data for the practice specific to STS are limited. In a presentation at the 96th AATS Annual meeting, Neel P. Chudgar, MD, from the Department of Surgery at Memorial Sloan Kettering Cancer Center (New York) presents survival data and prognostic factors based on a large, single-institution database of STS patients who have undergone pulmonary metastasectomy.
"The present study differs from previous publications in that we used a larger single-institution cohort, which increases the power to potentially identify significant differences, and we focused on STS exclusively to enhance the homogeneity of the study population," explained Dr. Chudgar. The database included 803 patients who underwent PM for sarcoma between September 1991 and June 2014. After excluding patients who had primary bone sarcomas, underwent diagnostic resection, underwent PM at another hospital, or did not undergo resection of their primary tumor, 539 patients who underwent 760 curative-intent PMs were studied.
The investigators found that the median overall survival after the first PM was 33.2 months and the median disease-free survival was 6.8 months. Thirty-four percent of patients were alive after 5 years and 23% were alive after 7 years.
The researchers then analyzed the data to see if they could identify factors associated with prolonged survival. They found that leiomyosarcoma histologic subtype, primary tumor size less than or equal to 10 cm, increasing time from primary tumor resection to development of pulmonary metastases, and less than or equal to three initial lung metastases, were all significantly associated with longer overall survival. Minimally invasive resections were also associated with longer overall survival (median, 44.3 months), compared with open surgery (median, 29.9 months). However, the authors attribute the reduced risk associated with minimally invasive surgery to patient selection, since 81% of these patients had only one or two pulmonary metastases.
"Our results indicate that the preoperative determination of disease characteristics can assist surgeons in selecting patients who may achieve longer survival with PM," commented senior author David R. Jones, MD, Professor and Chief of the Thoracic Surgery Service at Memorial Sloan Kettering Cancer Center. "Until there is an improved understanding of the underlying biologic mechanisms of metastases and further identification of druggable targets, PM remains the best available treatment for metastatic STS."