Trial investigates multiparametric prognostic score in early HR+/HER2- breast cancer

Dr Oleg Gluz – Krankenhaus “Bethesda“ Klinik, Mönchengladbach, Germany

We have looked at the data from the ADAPT trial that was a large phase III trial performed in Germany in about eighty centres several years ago.  In this trial we saw a major difference to other trials in early hormone receptor positive, HER2 negative breast cancer once we have combined static assessment by recurrence score, by genomic assay, with a functional test by Ki67 response to preoperative endocrine treatment given for 2-4 weeks before the surgery. This was done in patients with clinical intermediate to high risk disease and after this risk assessment patients were allocated to endocrine therapy or to chemotherapy based on this three-step approach based on clinical assessment and genomic risk and response to endocrine treatment.

Now we have looked at the prognostic assessment from this trial and we have shown that the use of a genomic assay like OncotypeDX may be useful for the prognostic assessment to be done combined with clinical markers, for example, tumour size, nodal stage, also expression of progesterone receptor at the immunohistochemical level. So it’s not simply the genomic signature, it’s also additional factors which may be used here.

One novel thing which was shown in our analysis was that in patients with high risk, so treated by chemotherapy in the trial, we know that patients with lobular breast cancer have rather more favourable biology but there is a small group of these patients with high risk features. We have shown for the first time that this small group with high risk features may be treated very differently and very carefully because these patients have a real risk for relapse. This is something new. So we have to take histology also into account to understand how many residual risk, we all have these patients, for example after chemotherapy up front. This is something which may be used also in the clinical team also on Monday next week.

These results point out that we have to take into account, as well as histology subtype and also tumour biological factors, for example progesterone receptor expression, and genomic signature and clinical factors, for example tumour size and nodal status, all these factors should be taken together into account so we have some more precise information for our patients for their reasonable risk after chemotherapy and standard endocrine therapy.