Assessment of the treatment results in patients with breast cancer coexisting with pregnancy: A single-center observational study.

Abstract

e12566 Background: This study discusses the analysis of the prospectively collected material on pregnant patients treated for breast cancer at the Department of Breast Cancer and Reconstructive Surgery of the Maria Skłodowska-Curie National Oncology Institute - National Research Institute (until 2020: Oncology Center - Institute) in Warsaw, in the years 1995 - 2020. 84 patients were included into the final analysis and 72 children were assessed simultaneously. Methods: The paper summarizes information on the diagnosis and treatment of breast cancer during pregnancy, the course of pregnancy and childbirth and the birth parameters of children i.e. weight, length and Apgar score, as well as the dependencies between them, mainly the impact of some breast cancer, diagnosis and treatment process features on the newborns. The patietnt’s survavial - DFS ( disease free survival) and OS ( overall survival) - was also analyzed. The course of breast cancer diagnosis and treatment data were obtained from the patients’ medical documentation (medical records) and from information provided by the mothers during follow-up visits and read in the children's health books. In order to answer the research questions, statistical analyzes were conducted using the IBM SPSS Statistics 26 package. Results: In the analyzed period, the disease recurrence was recognized in 34 (40.5%) patients, and 24 (28.6%) patients died. The median disease-free survival (DFS) was 12.3 years (147.5 months), and the median overall survival (OS) was not reached during the follow-up period. The estimated 5-year survival rates for DFS and OS were 57.9% and 74.5% respectively, and for 10-year survival - 51.4% and 64.5%. The study showed a statistically significant relationship between the baseline clinical advancement and DFS. It has been also analyzed how the diagnosis, treatment and method of pregnancy termination changed in two time periods (1995-2012 and 2013-2020). There were no statistically significant differences in survival - both DFS and OS - between the group of patients treated before and after 2012. In the assessment of the impact of some factors on the birth children parameters (weight and length), statistically significant results were obtained for: pregnancy advancement at diagnosis, breast cancer stage at diagnosis, pregnancy advancement at the start of chemotherapy, the chemotherapy regimen (classic or dose-dense), the number of cycles of chemotherapy given during pregnancy, and the number of drugs used in supportive treatment. Conclusions: The entire analysis has become not only an insightful characteristic of the studied group, but also these results may be important in everyday clinical practice and may help to optimize the management of an extremely complex and difficult situation, which is the coexistence of pregnancy with a malignant disease that threatens the mother’s life.