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
5747 - The routine use of sentinel lymph node biopsy in high risk DCIS lesions is not justified
Presenter: Fanny Preat
Session: Poster Display session 2
Resources:
Abstract
1837 - Oncological impact of re-excision for positive margin status after breast conserving surgery in invasive breast cancer
Presenter: Kenjiro Jimbo
Session: Poster Display session 2
Resources:
Abstract
4347 - Pneumonitis and fibrosis after breast cancer radiation.
Presenter: Jarle Karlsen
Session: Poster Display session 2
Resources:
Abstract
2280 - Prognosis of mastectomy with reconstruction after neoadjuvant chemotherapy: a nationwide study in Korean Breast Cancer Society
Presenter: Sungmin Park
Session: Poster Display session 2
Resources:
Abstract
804 - A negative prognosis of radiotherapy-induced lower lymphocyte to monocyte ratio in patients with breast cancer
Presenter: Chang-ik Yoon
Session: Poster Display session 2
Resources:
Abstract
2701 - Patient data to monitor clinical patterns in early and advanced breast cancer in Europe
Presenter: Francesco Giusti
Session: Poster Display session 2
Resources:
Abstract
1437 - A critical appraisal of quality indicators of breast cancer treatment in Belgium
Presenter: Didier Verhoeven
Session: Poster Display session 2
Resources:
Abstract
1534 - Predictors of adherence among post-menopausal women receiving adjuvant endocrine therapy for breast cancer in Ontario, Canada
Presenter: Phillip Blanchette
Session: Poster Display session 2
Resources:
Abstract
4363 - Evaluation of endocrine therapy and patients preferences in early breast cancer: results of Elena study
Presenter: Emilia Montagna
Session: Poster Display session 2
Resources:
Abstract
2679 - Baseline Quality of life (QoL) and chemotherapy related toxicities (CRT) in localized breast cancer (BC) patients (pts): the French multicentric prospective CANTO cohort study
Presenter: Idlir Licaj
Session: Poster Display session 2
Resources:
Abstract