Abstract 125P
Background
Adjuvant endocrine therapy (ET) with exemestane combined with LHRH analog (LHRHa) is standard of care for premenopausal women with hormone receptor-positive breast cancer. However, LHRHa may not always achieve complete ovarian suppression in these patients.
Methods
The PREFER-Fertility (NCT02895165) and GIM 23-POSTER (NCT05730647) are prospective, observational studies that enrolled premenopausal women eligible to receive (neo)adjuvant chemotherapy and/or ET. We conducted an exploratory analysis of patients achieving suboptimal suppression of ovarian function enrolled at the coordinating center of both studies, defined as estradiol levels greater than 25.1 ng/L or resumption of menstruation at least 3 months after the start of exemestate plus LHRHa.
Results
As of February 2024, a total of 1616 patients were enrolled (766 in the PREFER and 850 in the GIM 23), of whom 528 patients included from the main center. Among them, 26 (4.9%) had a suboptimal ovarian suppression. Median age of these patients was 39 (interquartile range (IQR) 36-46). Median body mass index was 21.8 kg/m2 (84.6% <25). Main histopathological characteristics are summarised in the table. 65.4% of these patients received chemotherapy, mainly anthracycline plus taxane (93.8%), and 3 patients received adjuvant abemaciclib. Median time from last chemotherapy to suboptimal ovarian suppression was 7 months, with 17 patients already on LHRHa during chemotherapy. Monthly leuprorelin was given in 65% of the cases, while the others received monthly triptorelin. Median time to suboptimal ovarian suppression was 7 months (IQR: 5-20). At median follow-up of 5 years (IQR: 2-6), 3 patients had a relapse of disease. Table: 125P
| Characteristics | N of patients (%) |
| TNM - Stage | |
| IA | 14 (53.9) |
| IB | 3 (11.5) |
| IIA | 5 (19.2) |
| IIB | 2 (7.7) |
| IIIA | 2 (7.7) |
| Grading | |
| 1 | 1 (3.8) |
| 2 | 18 (69.3) |
| 3 | 5 (19.2) |
| NA | 2 (7.7) |
| Histology | |
| Ductal | 21 (80.8) |
| Lobular | 1 (3.8) |
| Other | 4 (15.4) |
| Ki67 | |
| <20 | 12 (46.2) |
| ≥20 | 14 (53.8) |
| HER2 status | |
| 0 | 12 (46.1) |
| 1+ | 5 (19.2) |
| 2+ | 2 (7.7) |
| 2+ FISH amplified or 3+ | 7 (27) |
Conclusions
In our cohort, almost 5% of premenopausal patients did not achieve ovarian suppression with LHRHa. Oncologists should be aware that serial monitoring of estradiol levels should be performed to address this.
Clinical trial identification
NCT02895165; NCT05730647.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
L. Del Mastro: Financial Interests, Personal, Invited Speaker, Educational meeting: Novartis, Symposia, Andromeda E20, Vyvamed S.r.l.; Financial Interests, Personal, Invited Speaker, Lecture: Ipsen; Financial Interests, Personal, Advisory Board, Her2+ and TN breast cancer: Roche; Financial Interests, Personal, Invited Speaker, Consultancy for TNBC text: Roche; Financial Interests, Personal, Advisory Board, denosumab: Amgen; Financial Interests, Personal, Advisory Board, Early and metastatic BC: Eli Lilly; Financial Interests, Personal, Invited Speaker, CDK4-6 inhibitors: Eli Lilly; Financial Interests, Personal, Advisory Board, tucatinib: Seagen Int; Financial Interests, Personal, Advisory Board, Oncotype dx: Exact sciences, Havas life; Financial Interests, Personal, Advisory Board, Neratinib: Pierre Fabre; Financial Interests, Personal, Invited Speaker, Internal training: MSD; Financial Interests, Personal, Invited Speaker, Educational meetings: Accademia Nazionale Medicina; Financial Interests, Personal, Invited Speaker, Author for BC text: Pensiero Scientifico Editore; Financial Interests, Personal, Advisory Board, Breast cancer: Uvet; Financial Interests, Personal, Other, Author slide kits and interviews: Think2it; Financial Interests, Personal, Advisory Board, Palbociclib: Pfizer; Financial Interests, Personal, Invited Speaker, Breast cancer: Aristea, Meeting S.r.l.; Financial Interests, Personal, Other, Author slide kits: Forum service; Financial Interests, Personal, Other, Author text about biosimilars: Edizioni Minerva Medica; Financial Interests, Personal, Other, consultant: Kardo S.r.l.; Financial Interests, Personal, Invited Speaker, Breast cancer meetings: Delphi international, Over S.r.l.; Financial Interests, Personal, Invited Speaker: Prex S.r.l., Editree; Financial Interests, Personal, Advisory Board: Uvet, Collage SpA, Daiichi Sankyo, AstraZeneca, Agendia, Gilead, GSK, Eisai, Stemline Menarini; Financial Interests, Personal, Other, Interview: Infomedica S.r.l.; Financial Interests, Personal, Other, Consultant: Sharing progress in cancer care - Switzerland; Financial Interests, Personal, Other, Consultancy: Eli Lilly, Gilead; Financial Interests, Institutional, Funding, National coordinating PI: Roche; Financial Interests, Institutional, Funding, Local PI: AstraZeneca, Roche, Eli Lilly, Daiichi Sankyo, Novella Clinical, Novartis; Financial Interests, Institutional, Invited Speaker: Gilead, Seagen; Financial Interests, Institutional, Research Grant: Pfizer; Non-Financial Interests, Institutional, Product Samples, Genomic Test: FoundationOne. M. Lambertini: Financial Interests, Personal, Advisory Board: Roche, AstraZeneca, Lilly, Novartis, Pfizer, Exact Sciences, MSD, Seagen, Gilead; Financial Interests, Personal, Invited Speaker: Takeda, Sandoz, Ipsen, Libbs, Knight, Daiichi Sankyo, Lilly, Pfizer, Novartis, Roche; Financial Interests, Personal, Other, Travel grant to attend ASCO 2022: Gilead; Financial Interests, Institutional, Invited Speaker, 2-year research grant paid to my Institution: Gilead. F. Poggio: Financial Interests, Personal, Advisory Board: AstraZeneca; Financial Interests, Personal, Invited Speaker, Speaking and travel expenses: Eli Lilly, Novartis, Daiichi Sankyo, Gilead. All other authors have declared no conflicts of interest.