Pregnancy and breast cancer: a population-based study

Area of Science:

• Oncology
• Reproductive Medicine
• Pathology

Background:

• Increasing maternal age at childbirth is linked to a rise in pregnancy-associated breast cancer (PABC).
• Limited large-scale studies exist on PABC, encompassing cancers diagnosed during pregnancy or lactation, and subsequent pregnancies post-diagnosis.
• This study addresses the need for more data on PABC outcomes and prognostic factors.

Purpose of the Study:

• To evaluate the outcomes and identify prognostic factors in patients with PABC.
• To compare PABC diagnosed during pregnancy versus lactation.
• To analyze outcomes for women with breast cancer diagnosed before subsequent pregnancies.

Main Methods:

• A population-based study involving 173 breast cancer patients.
• Categorization into three groups: PABC during pregnancy (n=20), PABC during lactation (n=102), and pregnancy subsequent to breast cancer (n=51).
• Analysis of histopathological parameters, including hormone receptors (oestrogen, progesterone), c-erbB-2, and c-erbB-4, alongside survival data.

Main Results:

• PABC tumors (pregnancy and lactation groups) exhibited high histological grade, low hormone receptor expression, and high c-erbB-2 expression.
• Tumors in PABC groups were larger with more lymph node involvement compared to the subsequent pregnancy group.
• Survival rates for PABC were lower than for subsequent pregnancies; 5-year survival ranged from 50-62% for PABC vs. 80-86% for subsequent pregnancies.

Conclusions:

• PABC, whether during pregnancy or lactation, presents with aggressive tumor characteristics and poorer survival outcomes.
• Tumor size, lymph node status, histological grade, and receptor status (progesterone, oestrogen, c-erbB-2) are significant prognostic indicators for PABC.
• Women diagnosed with breast cancer prior to subsequent pregnancies have significantly better survival rates.