Clinicopathological Features of Pregnancy-Associated Breast Cancer at Chris Hani Baragwanath Academic Hospital

Abstract

Background: Pregnancy-associated breast cancer (PABC), defined as cancer diagnosed during pregnancy or up to one year postpartum, is typically associated with tumours displaying more adverse prognostic pathological features. It is unclear if this is due to the more aggressive tumour biology associated with early-onset breast cancer or influenced by the pregnancy itself. Given the existing paucity of data, especially in an African context, the aim of this study was to compare the clinicopathological features of patients presenting with PABC to their age- matched non-PABC controls in a high volume urban breast unit. Methods: Records of reproductive age females diagnosed with breast cancer from 1 October 2006 to 31 October 2020 were retrospectively reviewed using the Chris Hani Baragwanath Academic Hospital Breast Unit electronic database. Cases of PABC were then identified, and non-PABC cases were selected as age-matched controls at a 2:1 ratio to each PABC case. Results: A total of 1056 patients were eligible for inclusion, with 63 patients meeting criteria for PABC. After excluding 10 cases, 53 PABC cases were age-matched to 106 controls. The incidence of PABC was 1.5% with a median age of 36 years. Over 90% of patients presented with palpable breast masses. Pregnancy-associated breast cancer patients presented with significantly larger tumours (5.5 cm vs. 4.0 cm) at diagnosis with higher nuclear grades compared to age-matched controls. PABC patients also demonstrated more Oestrogen (40%vs.23%) and Progesterone Receptor (47%vs.28%) negativity compared to controls. Conclusions: Pregnancy-associated breast cancer patients from our population presented with more adverse clinicopathological tumour characteristics than their age-matched controls.These findings align with existing literature and would more likely contribute to a worse prognosis in this patient group.