Abstract 3093
Background
Tumor phenotype may change during breast cancer (BC) progression and discordance between primary and metastases ranges between 16% and 21% for Hormone Receptor (HR) expression in some series. The impact of this change on patient (pts) management and outcome is not yet clear, even though preliminary data indicate that the molecular characterization of recurrent breast cancer may induce clinicians to modify the treatment choice in ∼14% of the cases and that a change in the receptor status is associated with poorer survival. This analysis evaluates the prognostic impact of receptor discordance between paired primaries and recurrences.
Methods
We used data of 879 pts of the longitudinal cohort AMBRA study, identifying 3 different groups: Group A: HR+ BC remaining HR+ at relapse; Group BHR+ BC becoming TNBC; Group C:TNBC remaining TNBC. Change in HR status was evaluated on the biopsy done at the moment of relapse. Time to event was evaluated by Cox-Mantel Hazard Ratio and Logrank Test; Mean/median by Wilcoxon Rank-Sum Test.
Results
Pts who underwent biopsy at the time of relapse were 545/879 (62%), of those 462 (84.4%) were classified as Luminal tumors and 83 (15.2%) TNBC on primary. Change in tumor phenotype occurred in 31 (6.7%) of Luminal BC and 16 (19.3%) TNBC, probably due to a higher genomic instability (p = 0.021). Median DFS between Luminal BC was not different: HR+àHR+: 74.56 months (95%CI 66.8-82.1) vs HR+àTNBC: 89.73 months (95%CI:44.73-103.46). Table summarizes main data in time to event in the 3 identified groups. *PFS at 1strelapse; **PFS at 2nd relapse; ***Time to Treatment Change at 1strelapse; °OS at 1strelapse; §OS from 1stPDTable:
325P
HR+/HR + (range) Group A | HR+/TNBC (range) Group B | p value Group A vs C | TNBC/TNBC (range) Group C | |
---|---|---|---|---|
PFS1* (months) | 13.65 (0,77-162,03) | 9.45 (3,97-52,73) | 0.36 | 8.13 (6.3-10.9) |
PFS2** (months) | 6.83 (0,00-57,13) | 6.12 (2,67-26,30) | 0.84 | 4.20 (0,33-22,17) |
TTC1*** (months) | 12.43 (0,13-163,10) | 8.88 (0,00-48,40) | 0.50 | 7.88 (0,23-27,80) |
TTC2**** (months) | 7.45 (0,00-55,97) | 6.73 (3,77-26,80) | na | na |
OS1° (months) | 23.1 (20-26) | 15 (8.7-26.3) | 0.031 | 3.60 (0,60-25,38) |
OS (years) | 8.52 (0,26-115,92) | 7.86 (0,19-30,67) | 0.43 | 3.58 (2.91-2.39) |
OS from PD1§ (months) | 25.8 (0,00-207,53) | 17.23 (2,67-104,30) | 0.82 | 17.90 (2,37-53,57) |
Conclusions
Change in tumor phenotype has a significant impact on OS; BC pts who become TNBC at relapse should be treated in the same way as TNBC pts at diagnosis. Anyway, OS of Luminal BC who change phenotype seems to be better than TNBC.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
GIM - Gruppo Italiano Mammella.
Funding
Celgene.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
5203 - Novel fusion genes identified from matched primary and recurred breast cancers by RNA-sequencing
Presenter: Soojeong Choi
Session: Poster Display session 2
Resources:
Abstract
5873 - Association between PIK3CA mutation status and development of brain metastases in HR+/HER2- metastatic breast cancer
Presenter: Donna Fitzgerald
Session: Poster Display session 2
Resources:
Abstract
3588 - The role of AXL as mechanism of resistance to trastuzumab and a prognostic factor in breast cancer HER2 positive: a translational approach.
Presenter: Anna Adam-Artigues
Session: Poster Display session 2
Resources:
Abstract
5640 - Untargeted assessment of tumor fractions in plasma for monitoring and prognostication from metastatic breast cancer patients undergoing systemic treatment
Presenter: Marija Balic
Session: Poster Display session 2
Resources:
Abstract
2616 - Clinical application of mutational analysis in breast cancer patients: the relevance of PIK3CA analysis for precision medicine.
Presenter: Juan Miguel Cejalvo
Session: Poster Display session 2
Resources:
Abstract
3870 - A retrospective gene expression analysis of surgically-removed Breast Cancer Brain Metastasis (BCBM)
Presenter: Meritxell Mallafré-Larrosa
Session: Poster Display session 2
Resources:
Abstract
1240 - Endocrine therapy alone versus targeted combination strategy as first line treatment in elderly patients with hormone receptor-positive advanced breast cancer: meta-analysis of Phase II and III randomized clinical trials
Presenter: Claudia Omarini
Session: Poster Display session 2
Resources:
Abstract
5535 - Alpelisib (ALP) + fulvestrant (FUL) for patients with hormone receptor–positive (HR+), HER2− advanced breast cancer (ABC): management and time course of key adverse events of special interest (AESIs) in SOLAR-1
Presenter: Hope Rugo
Session: Poster Display session 2
Resources:
Abstract
1378 - MONARCH 3: Updated time to chemotherapy and disease progression following abemaciclib plus aromatase inhibitor (AI) in HR+, HER2- advanced breast cancer (ABC)
Presenter: Miguel Martín
Session: Poster Display session 2
Resources:
Abstract
3536 - Palbociclib plus an aromatase inhibitor as first-line therapy for metastatic breast cancer in US clinical practices: Real-world progression-free survival analysis
Presenter: Mylin Torres
Session: Poster Display session 2
Resources:
Abstract