TY - JOUR
TI - A Prospective Comparison of the 21-Gene Recurrence Score and the
PAM50-Based Prosigna in Estrogen Receptor-Positive Early-Stage Breast
Cancer
AU - Alvarado, Michael D.
AU - Prasad, Che
AU - Rothney, Megan
AU - Cherbavaz,
AU - Diana B.
AU - Sing, Amy P.
AU - Baehner, Frederick L.
AU - Svedman,
AU - Christer
AU - Markopoulos, Christos J.
JO - Advances in Therapy
PY - 2015
VL - 32
TODO - 12
SP - 1237-1247
PB - Springer-Verlag
SN - 0741-238X
TODO - 10.1007/s12325-015-0269-2
TODO - Adjuvant chemotherapy; Breast cancer; Oncotype DX; Oncology; PAM50;
Prosigna; risk assessment; Recurrence Score
TODO - The 21-gene Recurrence Score(A (R)) assay (Oncotype DXA (R), Genomic
Health, Inc.) is a validated predictor of recurrence risk/chemotherapy
benefit in patients with estrogen receptor-positive (ER+) early-stage
breast cancer treated with endocrine therapy. The Prosigna(A (R)) assay
(NanoString Technologies Inc.) is a validated prognosticator in
postmenopausal patients with low-risk ER+ early-stage breast cancer
treated with endocrine therapy. The assays were analytically/clinically
developed and validated differently. This study focused on comparing
recurrence risk estimates as determined by these assays and is the first
blinded comparison of these assays on matched patient samples.
Sequential breast cancer specimens from postmenopausal, node-negative,
ER+ patients treated at the Marin General Hospital were analyzed: first
by the 21-gene assay then by the Prosigna assay in an independent lab
blinded to the Recurrence Score results.
The final analysis included 52 patients. Correlation between the
Recurrence Score and the Prosigna assay results was poor (r = 0.08).
Agreement between risk classifications based on these assays was 54%;
4/7 of patients classified as high risk by the Prosigna assay had low
Recurrence Score results. Two tumors with high Recurrence Score results
had low ER expression (close to positivity threshold); both of which had
a low/intermediate Prosigna assay result. The Prosigna assay classified
73.1% and 23.1% of samples as luminal A and luminal B, respectively. A
range of Recurrence Score results was observed within the subtypes; 83%
of luminal B samples had a low Recurrence Score result.
Consistent with prior comparisons between the 21-gene and other genomic
assays, our study demonstrated substantial differences in the way
patients are risk stratified, suggesting that the different assays are
not interchangeable.
Genomic Health, Inc.
ER -