Abstract 261P
Background
TNBC is a subtype of Breast Cancer (BC) associated with an overall survival (OS) of around 19 months (ms). Before immunotherapy, no specific systemic treatment apart from chemotherapy (CT) was available. ER low disease is characterized by low ER and PgR staining (both <10%) and negative Her2. It’s considered as having a survival and a biological behavior comparable to that of TNBC. Deleterious germline BRCA mutations were the only predictive biomarker available in the past years for TNBC.
Methods
Patients (pts) were identified within the GIM-14 study, an ambispective multicenter Italian study including pts with metastatic breast cancer diagnosed from 2000 to 2020. TNBC and ER low pts were eligible to this analysis. Pts demographics, disease characteristics and treatment patterns were obtained for each patients. OS and 1st line Time to Treatment Failure (TTF) were calculated. Statistical analysis was performed with SAS v 9.4.
Results
Overall, 195 pts were eligible (158 TNBC and 37 ER low pts). BRCA mutation was assessed in 35 pts (18%), of whom 16 were pos and 19 neg. Pts’ characteristics are summarized in the table. Median (m) OS was 22.6 ms (95% CI: 18.6-26.8); 84% and 57% of pts were alive at 1 and 2 years respectively. M TTF was 4.4 ms (95% CI: 3.8-5.1). MOS of TNBC pts was 20.2 ms (95% CI: 16.9-24.9) while for ER low pts was 26.8 ms (17.4-73 ms); p 0.07. First line mTTF was 4.3 ms (95% CI: 3.7-4.9) for TNBC and 5.5 ms (95% CI: 3.7-9.3) for ER low pts, p 0.1. mOS in BRCA pos pts was 35 ms (19.6-NR) while for BRCA neg 16.3 was ms (95 CI%: 9-32), p 0.03. TTF was 6.9 ms (95%CI: 2.1-8) for BRCA pos pts and 3.9 ms for BRCA neg pts (95%CI: 1.4-6.6), p 0.44. Table: 261P
| Variable | N=195 |
| Age (mean) | 58 |
| Menopause No Yes NA | 47(24%)131(67%)17(9%) |
| Disease Subtype TNBC ER low | 158(61%)37(39%) |
| BRCA BRCA + BRCA – NA | 16(8%)19(10%)160(82%) |
| De novo metastatic YesNoNA | 43(16%)121(62%)21(22%) |
| Metastatic Sites Non visceralBoneVisceral (liver,lung, brain)NA | 53(27%)31(16%)105(54%)6(3%) |
| N° of metastatic sites 123NA | 94(48%)48(25%)48(25%)5(2%) |
| N°of CT lines 12≥3NA | 61(31%)42(22%)87(44%)5(3%) |
| 1st line CT AnthraTaxane (without beva)Taxane + bevaPlatinumCapecitabineOtherMissing | 22(11%)26(13%)37(19%)21(11%)16(8%)44(23%)29(15%) |
| Stage at localized disease IIIIIINA | N=12123(19%)55(46%)33(27%)10(8%) |
| Adjuvant CT YesNoNA | N=121110(91%)7(6%)4(3%) |
Conclusions
In this analysis OS of TNBC pts was comparable to that previously reported in literature. BRCApos pts showed a better OS when compared to BRCAneg pts. A trend towards a better OS in ER low pts was found. Further prospective investigation in this subgroup of pts is warranted.
Clinical trial identification
NCT02284581.
Editorial acknowledgement
Legal entity responsible for the study
Consorzio Oncotech.
Funding
Has not received any funding.
Disclosure
M. De Laurentiis: Financial Interests, Personal, Speaker’s Bureau: Novartis, Roche; Financial Interests, Personal, Advisory Role: Amgen; Celgene; Eisai; Genomic Health; Lilly; MSD Oncology; Novartis; Pfizer; Pierre Fabre; Roche; Financial Interests, Institutional, Funding: Eisai; Italfarmaco; Roche; Financial Interests, Personal, Other: Amgen; Celgene; Eisai; Genomic Health; Lilly; MSD Oncology; Novartis; Pfizer; Pierre Fabre; Roche . G. Arpino: Financial Interests, Personal, Other: Roche, Pfizer, AstraZeneca, Novartis, Celgene, Eli Lilly, Amgen, Eisai. A. Fabi: Financial Interests, Personal, Other: Roche, Celgene, AstraZeneca, Eli Lilly, Novartis, Pfizer, Eisai. C. Mulinelli: Non-Financial Interests, Personal, Other, honoraria: Novartis. M. Lambertini: Financial Interests, Personal, Advisory Board: Roche; Financial Interests, Personal, Advisory Board: Novartis; Financial Interests, Personal, Advisory Board: Eli-Lilly; Financial Interests, Personal, Advisory Board: AstraZeneca; Financial Interests, Personal, Speaker’s Bureau: Theramex; Financial Interests, Personal, Speaker’s Bureau: Takeda; Financial Interests, Personal, Speaker’s Bureau: Pfizer; Financial Interests, Personal, Speaker’s Bureau: Roche; Financial Interests, Personal, Speaker’s Bureau: Lilly; Financial Interests, Personal, Speaker’s Bureau: Sandoz; Financial Interests, Personal, Speaker’s Bureau: Novartis. C. Bighin: Financial Interests, Personal, Invited Speaker: Roche; Financial Interests, Personal, Invited Speaker: Novartis; Financial Interests, Personal, Invited Speaker: Lilly; Financial Interests, Personal, Invited Speaker: Pfizer. L. Del Mastro: Financial Interests, Personal, Invited Speaker: Roche, Novartis, Eli Lilly, MSD, Pfizer, Ipsen; Financial Interests, Institutional, Invited Speaker: Novartis; Financial Interests, Personal, Advisory Board: Roche, Novartis, Eli Lilly, MSD, Genomic Health, Pierre Fabre, Daiichi Sankyo, Seagen, astraZeneca, EIsai. All other authors have declared no conflicts of interest.