Tumors from 3,807 patients were centrally tested for HER2 status: this centralization ensures reliable assessment, quality control, and accurate response and survival rates given that only HER2 patients were recruited.
The tumor tissues were centrally tested and classified.
All samples were centrally tested in London in duplicate, including positive and negative control standard sera.
Histo-clinical features of patients whose tumor samples were and were not centrally tested were similar (data not shown).
We centrally tested serum GAD antibodies (GADAs), interleukin-6 (IL-6), lipocalin 2 (LCN2), high-sensitivity C-reactive protein (hs-CRP), and adiponectin.
Table 1 gives the patient characteristics, the demographic and prognostic features and the 7-year MFS and OS of patients whose tumor samples had been centrally tested and were found to be similar to those that had not been centrally tested (data not shown) [ 17].
Retesting of HR-tested tumors, included in the Eastern Cooperative Oncology Group (ECOG) study E2197, showed a concordance of 90 and 84 %, respectively, between locally tested and centrally tested ER and PR results [ 10].
These were centrally tested at baseline and Week 52 of CN04E1 study period, namely Year 5 or Year 6 of long-term antiviral treatment, using standard commercially available assays.
At the time of this analysis 85.7% of patients in the T-DM1 arm and 85.9% of patients in the HT arm had confirmed centrally tested HER2-positive primary tumors.
Additional analyses of data from BIG 1-98 to determine the predictive value of centrally tested ER, PgR, and HER2 status on the response to letrozole and tamoxifen indicate that there is no difference in subgroups by ER/PR or HER2 status regarding the superiority of upfront letrozole versus tamoxifen [ 106].
