Formal discussant Peter Albers, MD, of University Hospital, Düsseldorf, Germany, praised the design and goal of the study. “This type of cancer occurs in otherwise healthy, young people in whom a risk-stratified approach to reduce long-term toxicity is our goal,” he said.

“From these results, we can conclude that ¹⁸F-fluorodeoxyglucose (FDG)–positron-emission tomography (PET), in this indication, is a very helpful marker to guide treatment, especially because the main goal is achieved. Patients have less neuropathy and less toxicity,” Dr. Albers noted. “The positive predictive value rate of FDG-PET is very low, so there are a high number of false-positives, which means that patients are unnecessarily treated, and it means that a low positive predictive value for FDG-PET is dangerous for patients,” he continued.

Dr. Albers took issue with the design of the trial, which called for one cycle of carboplatin in PET-negative patients. “I don’t understand why carboplatin should be given to a patient with FDG-PET–negative seminoma. In my view, there is no reason to add another chemotherapy to treatment in this population. Carboplatin is known to be inferior to cisplatin in seminoma and it results in recurrences in 28% of patients. It is not a good drug, and it didn’t get better in the last 20 years,” Dr. Albers continued.

Another issue he had with the trial design was that SEMITEP selected for low-volume disease, with more than 60% of enrolled patients having tumors < 5 cm. “This is not representative of all metastatic seminoma patients,” he noted.

Dr. Albers concluded: “The study is not yet practice-changing. We need a clear comparison to standard treatment before we introduce FDG-PET. We can risk-stratify within the context of clinical trials, but we need more evidence from properly randomized trials [before changing practice],” Dr. Albers said. 

DISCLOSURE: Dr. Albers has received honoraria from MSD Oncology and Sanofi and has served in a consulting or advisory role for MSD Oncology and Roche/Genentech.