Clinicopathological features of pregnancy-associated breast cancer at Chris Hani Baragwanath Academic Hospital, South Africa

Abstract

Background. Pregnancy-associated breast cancer (PABC), defined as cancer diagnosed during pregnancy or up to 1 year postpartum, tends to present with tumours displaying more adverse prognostic pathological features compared with those diagnosed outside of pregnancy. It is unclear if this is due to the more aggressive tumour biology associated with early-onset breast cancer, or influenced by the pregnancy independently. Objectives. To compare the clinicopathological features of patients presenting with PABC with their age-matched non-PABC controls. Methods. Records of females of reproductive age 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 identified, and non‑PABC cases were selected as age-matched controls at a 2:1 ratio to each PABC case. Results. A total of 1 056 patients were eligible for inclusion, with 63 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. PABC patients presented with significantly larger tumours (5.5 cm v. 4.0 cm) and higher nuclear grades compared with age-matched controls. PABC patients also demonstrated more oestrogen (40% v. 23%) and progesterone receptor (47% v. 28%) negativity compared with controls. Conclusion. PABC patients from our population presented with more adverse clinicopathological tumour characteristics than their age-matched controls. These findings align with existing literature, and would likely contribute to a worse prognosis in this patient group