Abstract P1-14-02: Breast cancer in pregnancy: A retrospective clinical study in a single large tertiary cancer center in the United Arab Emirates
Authors: Hourani Mohammad , Bdair Rawan , Hussein Mawada , Yousif Ali , Wahba Lina , AlAgha Abla , Shoqeir Alaa , Alkindi Fatima , Alawadhi Aydah 
Published: March 2023

Abstract
Introduction: Pregnancy associated breast cancer (PABC) is defined as any breast cancer (BC) diagnosed during pregnancy or one year postpartum. BC considered the most common type of malignancy in pregnant women, occurring approximately once in every 3000 pregnancies. In view of the fact that PABC is a relatively rare event surrounded by multiple variables, few studies address the best management and treatment options.
Objectives: The aim of this study is to report the incidence, clinicopathological characteristics and treatment outcomes of PABC diagnosed over 20 years period treated in Tawam hospital. This will help clinician, researchers shed the light of the unmet needs for this entity of BC.
Method: We reviewed all BC patients ≤ 40 years of age diagnosed between 2000 -2020 in Tawam hospital and identified those with PABC as the definition above. Information was obtained from the Tawam Cancer Registry and analyzed. A retrospective data analysis was conducted. The data analyzed using the SPSS software. The study was approved by the hospital Research Ethics Board.
Results: a total of 67 patients were identified in the study with pregnancy associated BC among all BC patients age ≤ 40 years old which compromised 7.4% (67/911) from year 2000 till 2022. The clinical and the pathological characteristics of these patients are provided in table 1. Around 22 (32.8%) of the patients were diagnosed at the second trimester. Only 6 (8.6%) patients found to have inflammatory breast cancer diagnosis. 31(42%) patients had hereditary genetic testing done of which 5 (16.1%) patients found to have pathogenic genetic mutations. Pathogenic mutations identified including 3 (9.7%) patients with BRCA2 mutation, 1 patient had BRCA1 mutation, and 1 patient had TP53 mutation. Out of these 67 patients, 36 (65.5%) underwent modified radical mastectomy, 19 (34.5%) had lumpectomy, 37 (55.2%) had axillary lymph node dissection, 14 (20.8%) had sentinel lymph node biopsy, 13 (19.4%) had the surgery during the pregnancy and 45 (67.1%) had adjuvant radiation therapy post delivery. Regarding the chemotherapy, 29 (43.2%) patients received Neoadjuvant chemotherapy, 24 (35.8%) received Adjuvant chemotherapy, 11 (16.4%) were pregnant when they received chemotherapy. Only 7 (10.4%) patients had termination of their pregnancies, while 3 (4.4%) patients had spontaneous miscarriage. 47 (70.1%) patients delivered at our facility and 9 (13.4%) patients delivered at other facilities (unknown delivery details). In terms of delivery type, 24 (35.8%) patients had C-section surgery, and 23 (34.3%) patients had spontaneous vaginal delivery. All of the patients who had delivery in Tawam hospital, delivered healthy baby with no complications. Survival analysis and treatment outcome to be presented in the meeting.
Conclusion: Our study showed that significant proportion of the patients with PABC diagnosed with HER2neu + disease, stage II-III disease, high grade tumors and nodal involvement on initial presentation. Patients were treated according to the standard of care with trend of favorable delivery outcomes. PABC is a unique entity of BC that requires careful planning and multidisciplinary approach with consideration of factors related to feral, pregnancy and maternal outcomes.
Table 1: Clinical and Pathological Characteristics of Pregnancy Associated Breast Cancer (N=67)
Citation Format: Mohammad Hourani, Rawan Bdair, Mawada Hussein, Ali Yousif, Lina Wahba, Abla AlAgha, Alaa Shoqeir, Fatima Alkindi, Aydah Alawadhi. Breast cancer in pregnancy: A retrospective clinical study in a single large tertiary cancer center in the United Arab Emirates [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-14-02.