Sarcoma Lung Metastases
Dr. Jean Yves-Blay: It is clear that the majority of metastases in sarcoma are acting in the lung. The reasons for that are not so clear, but the theory is that these metastases occur through what we call ematogenic spreading, which means that the cells go in the blood flow and are stopped at the next stop in the capillaries of the lung. Now this is a simple mechanical explanation, probably not the only explanation. And we now know for other tumors that some factors expressed at the surface of the cell may explain why some lesions establish themselves in the lung, others in the liver, others in the brain and so on. So it's still under exploration.
Regarding the treatment, basically we have two types of strategy. The first one is to give systemic treatment to the patient, treating all of the body including the lungs, and this is often proposed in situations where the lesions are multiple and/or aren't resectable for some reason. And the second strategy, which is used less frequently because not a lot of people can comply with this strategy because of the number of metastases, their site or age, is to try to remove the metastases. And this is possibly useful in a subset of patients with 1,2,3...actually a small number of metastases (less than five is generally what is recommended).
The final point is that it is not known whether we should combine, if a complete resection of metastasis has been done, if we should combine that with chemotherapy. This is a question which is still not completely answered at this stage. A randomized trial was attempted some years ago but failed to recruit a sufficient number of patients.