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
5063 - Does Nutritional Status Affect Treatment Tolarability, Response and Survival in Metastatic Gastric Cancer Patients? Results of Prospective Multicenter Study
Presenter: Senem Karabulut
Session: Poster Display session 2
Resources:
Abstract
2717 - Ramucirumab use in patients with Advanced Gastric Cancer (AGC) or gastro-oesophageal junction (GEJ) adenocarcinoma in Spain: RAMIS observational study
Presenter: Federico Longo Munoz
Session: Poster Display session 2
Resources:
Abstract
3187 - Gastrectomy plus chemotherapy versus chemotherapy alone for advanced gastric cancer with a single non-curable factor: Exploratory analysis in the patients who were enrolled in JCOG0705/KGCA01 phase III trial (REGATTA) and could continue chemotherapy
Presenter: Takaki Yoshikawa
Session: Poster Display session 2
Resources:
Abstract
4765 - A prospective observational study on the optimal maintenance strategy in HER2-positive advanced gastric cancer treated with trastuzumab based therapy
Presenter: Qian Li
Session: Poster Display session 2
Resources:
Abstract
3500 - Randomised phase 2 trial of first-line docetaxel, carboplatin, capecitabine (CTX) and epirubicin, oxaliplatin, capecitabine (EOX) in advanced esophagogastric adenocarcinoma (SEED)
Presenter: Peter Petersen
Session: Poster Display session 2
Resources:
Abstract
5197 - Ramucirumab in the treatment of refractory metastatic gastric cancer: results from the RamSelGa trial.
Presenter: Alexey Tryakin
Session: Poster Display session 2
Resources:
Abstract
2011 - Regorafenib in combination with Paclitaxel for beyond first-line treatment of advanced esophagogastric cancer (REPEAT): a phase Ib trial with expansion cohort
Presenter: Mohammed Khurshed
Session: Poster Display session 2
Resources:
Abstract
2117 - The relationship between the survival and fixed dosing of S-1 in advanced gastric cancer patients by pooled analysis using individual data from four Japanese randomized phase III trials
Presenter: Wataru Ichikawa
Session: Poster Display session 2
Resources:
Abstract
2669 - A Phase 1b Study of Oraxol in Combination with Ramucirumab in Patients with Gastric or Esophageal Cancers who failed previous chemotherapy
Presenter: Ming Huang Chen
Session: Poster Display session 2
Resources:
Abstract
3240 - Efficacy and safety of trifluridine/tipiracil (FTD/TPI) in European patients with heavily pretreated metastatic gastric cancer (mGC): an analysis of the TAGS study
Presenter: Maria Alsina
Session: Poster Display session 2
Resources:
Abstract