In a patient with primary mediastinal seminoma with normalization of biomarkers s/p EPx4 and residual non-FDG avid mass, would you consider resection of residual tumor vs surveillance?

Patients with a primary mediastinal seminoma will have > 90% cure rate with chemo alone, but will ALWAYS have a residual mass. Assuming the initial serum AFP was normal and pathology was definitive that this was ONLY seminoma, we would not even do a PET scan but just observe with serial CT scans, H and P and tumor markers. PET scans are not helpful, as many patients have granulomatous disease such as histoplasmosis in the mediastinum that is PET positive. Finally, in the near future, elevated serum micro RNA 371 might help to detect the very rare patient that one could consider further intervention such as resection.

This should be a good risk situation assuming there is no extra-mediastinal disease and the cure rate with primary therapy should be high. My own opinion is that such patients should receive standard therapy for this setting which is BEP X 3 (Based on the French randomized trial of BEP X 3 vs EP X 4 in which twice as many patients died on the EP X 4 arm and the toxicity advantage went to BEP X 3 with no difference in pulmonary toxicity but more neuropathy in EP X 4). In the setting of this case, you have a non avid residual mass in seminoma which favors a pathological finding of fibrosis/necrosis. I would watch such a patient with intermittent chest CT and regular HCG determination. I probably would do a repeat CT at the 4-6 month mark to m...