Abstract PS9-72: Fertility preservation in breast cancer patients

Fertility preservation in breast cancer patients. Aims. - Study in breast cancer patients whether fertility preservation (FP) can affect the onset of the oncological treatment and the pathological response in those patients who underwent neoadjuvant chemotherapy (NAC). Methods. - Patients with breast cancer who underwent fertility preservation and NAC are matched 1:2.45 to non-FP controls by age and date al diagnosis and are studied: -Timing between the diagnosis of breast cancer and the onset of oncological treatment was performed. The following variables were chosen: 1.- Confirmation (pathologic result), 2.- FP visit, 3.- Onset FP, 4.- Final FP, 5. - Onset oncological treatment. The periods analyzed (median in days) were: 1.- Period of FP visit (AP result-FP visit), 2.- Period of FP (FP beginning -FP ending), 3.- Period of onset of oncological treatment (FP ending-onset of oncological treatment), 4.- Overall period (AP result-onset of oncological treatment). -Studying the pathological complete response (Miller Payne scale) among patients with FP compare to non-FP control group was also performed.Results. - 20 patients with FP and NAC are studied between 2010-2019 and were compared to 49 non-FP patients. The median age at diagnosis was 36 years (28-39). The oncological characteristics of the patients are shown in Table 1.The time analysis in FP group was: 1.- Period of FP visit was 4 days (1-26), 2.- the period of FP (start of the stimulation treatment until the recovery of the oocytes) 12 days (7-20), 3.- the Period of onset of oncological treatment 7 days (1-27). The overall period took 26 days (18-51) compared to 17.5 days (1-60) in non-FP group (NS). Pathological complete response (Miller Payne 5): The pathological complete response was 80% (16/20) in FP group versus 40.8% (20/49) in non-FP group. Analyzed by tumor subtype in FP group, a MP5 was achieved in 72.7% luminal tumor (8/11), 75% positive-HER2 (3/4), 100% triple negative (5/5) versus 19% luminal tumor (4/21), 41.6% (5/12) positive-HER2 and 68.7% triple negative (11/16) in non-FP group. Conclusion. - FP does not delay the onset of oncological treatment and our data do not suggest an adverse impact of FP on pathological complete response to NAC. Citation Format: Sonia Baulies, Maxim Izquierdo, Marta Devesa, Ignacio Rodriguez, Francesc Tresserra, Rafael Fabregas. Fertility preservation in breast cancer patients [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS9-72.