S1823/GCC.1is a prospective cohort study. It was designed to fill an unmet need in active surveillance in patients with early-stage germ cell tumour. We do manage these patients with active surveillance because we don’t have a reliable biomarker to predict relapse. Therefore we use CT scans mainly and secondary tumour markers for an active surveillance schedule but these tests lack sensitivity and specificity, especially for very small nodules at the time of relapse and expose these young patients to radiation that comes from the CT scan that we mainly use for active surveillance. Therefore, there is a need for a better, more accurate biomarker that can be used for the surveillance but also hopefully to predict relapse of the patients who are managed with active surveillance.

Could you outline the methodology?

This was a prospective cohort trial and it’s a real-world investigator-initiated clinical trial sponsored by the Southwest Oncology Group and the Canadian Cancer Trial Group with the support of many funding agencies within Canada and in the United States. The study targeted 150 relapses in clinical stage 1 and stage 2a germ cell tumour patients on active surveillance and the primary endpoint was to define the operating characteristics of miR371 checked and dosed in the plasma of these patients to detect relapse while they were followed and managed on active surveillance.

It is a real-world study so it was open to [??] in the United States, therefore we did not dictate any active surveillance schedule. The eligibility criteria were purposely made very broad to allow a very easy recruitment.

What did you find?

Our main finding for this first interim analysis that was conducted in 224 patients, including 69 relapses and 155 no relapses, was that miR371 has a very high specificity – 94%, a very high negative predictive value – 90%, but the sensitivity and the positive predictive value was lower than the specificity and negative predictive value and did increase with the higher stage at relapse which was what we already observed in our longitudinal cohort study from BC Cancer and what we expected on the basis of the known association between miR371 and tumour burden correlation.

Regardless, one of the most compelling data was the relapse free survival difference. When we measured miR371 post-orchiectomy it was much shorter if the miR371 was positive immediately post-orchiectomy compared to miR371 negative post-orchiectomy, suggesting that there is a lot of enthusiasm to use this in the future as a tool to predict relapse and to mould our active surveillance schedule on the basis of miR371 status.

What impact could these findings have?

I don’t think this data is going to inform our clinical decision making as yet for many reasons. This is the first interim analysis, we didn’t analyse all correlative patients that contributed to the primary endpoint that was 630 patients. We are going to present the whole cohort study later this year.

We didn’t present the longitudinal sample analysis, again we are going to do it later this year. Also this was a real-world study to understand whether or not this is feasible and could be done in even rural, peripheral clinical settings. This confirms what we already saw with a retrospective and smaller study. But we need specific miR371 inform the clinical trial to understand and learn how to best integrate this m