Abstract 243P
Background
Breast cancer is the leading cause of death in women aged 35-54 years, with 15% of cases diagnosed in women of reproductive age. Older maternal age at first pregnancy and increasing rates of breast cancer in premenopausal women have seen an increase in pregnancy associated breast cancers (PABC). We report the largest UK patient series for PABC management.
Methods
PABC cases (January 2010-2020) were identified and demographic, tumour characteristic, treatment and obstetric data were collected retrospectively. Hospitals were recruited via collaborative research and trainee networks. Descriptive statistics were used to describe the treatment received and then compared between sites in / outside of London.
Results
Data for 57 patients from 8 NHS Trusts was included. Patient characteristics are described in the table. Table: 243P
| Age | Median age at diagnosis (range) | 34 (24-43) years |
| Gestation at diagnosis | Mean (range) | 19 (2-38) weeks |
| Staging | Early (localised) breast cancer | 97 % (55) |
| Metastatic breast cancer | 3 % (2) | |
| Receptor status | ER positive % (n) | 58 % (33) |
| Her2 positive % (n) | 34 % (19) | |
| Triple negative % (n) | 32 % (18) |
Surgery was performed in 95% of cases. All 57 patients received chemotherapy (23 (40%) neo-adjuvant, 29 (51%) adjuvant, 5 (9%) metastatic). All patients, except one who had a termination of pregnancy shortly afterwards, received chemotherapy after the first trimester of pregnancy, with standard regimens being used with GSCF support in 22 (39%). No patients received radiotherapy whilst pregnant and 38 (67%) received it post-partum. All ER+ patients received hormonal therapy and 15/19 Her2+ patients received anti-Her2 targeted therapy. In this UK data series 18 (32%) underwent a preterm delivery, though complete obstetric data was missing in 37%. Patients treated outside of London were more likely to receive radiotherapy (80 Vs. 65%), were more likely to deliver at term (48 Vs.19%) and less likely to have a caesarean (24 Vs.40%).
Conclusions
PABC management included all modalities in keeping with standard practice. Although there was little variation in the management; the use of radiotherapy and obstetric outcomes varied geographically within the UK. Further prospective work is required to explore national variation in PABC management and patient outcomes.
Clinical trial identification
Editorial acknowledgement
Adam Heaton, Timothy Robinson, Vinton Cheng, Tze-en Ding, Caroline Michie, Ellen Copson and all members of the Breast Cancer Trainees Research Collaborative.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.