Introduction: Breast cancer is one of the most frequently occurring cancers during pregnancy and its incidence is increasing. Many studies have shown poor outcomes, the causes of which remain unclear.
Objectives: To analyze radiologic characteristics, histology, and prognosis factors of breast cancer during pregnancy.
Methods: A total of 42 patients with breast cancer diagnosed during pregnancy (BCP) were matched with 84 patients with breast cancer of similar age who were not pregnant. Sensitivity of radiology, tumor characteristics, prognosis factors, disease-free survival, and overall survival were analyzed.
Results: The sensitivity of breast ultrasound was higher than that of mammography for both groups. Ultrasound sensitivity for cancer was 95.7% in patients with BCP versus 98% in the not pregnant group, with non-statistically significant differences. Mammography sensitivity for cancer was 56.5% in patients with BCP versus 61% in the not pregnant group, with non-statistically significant differences. The stage at diagnosis according to the TNM staging system was significantly higher in patients with BCP with stage IV cancer: 16.7% in patients with BCP versus 3.7% in the not pregnant group (p = 0.03). No statistically significant differences were observed in histologic grade, Ki-67 index, or molecular subtype. Disease-free survival and overall survival were significantly lower in patients with BCP (p = 0.002 and p = 0.04). Multivariate analysis showed no difference when adjusting for stage and surrogate molecular subtype.
Conclusion: Breast ultrasound shows a high sensitivity to detect breast cancer during pregnancy. BCP is diagnosed at a higher stage than in nonpregnant women. In our series, patients with BCP had poorer outcomes than the not pregnant group. These results were not observed when adjusting for stage.
Keywords: Breast cancer; pregnancy; radiology.