# Case Report: Breast cancer in pregnancy with placental metastasis

## TL;DR

A young woman was diagnosed with breast cancer during pregnancy, and later found to have cancer metastasis to the placenta, a rare occurrence.

## Contribution

This case report highlights a rare instance of placental metastasis from breast cancer during pregnancy.

## Key findings

- Breast cancer was diagnosed at 31 weeks gestation and followed up until delivery.
- Post-delivery placenta examination revealed distant metastasis of breast cancer.
- The patient received multiple cycles of anti-tumour therapy after delivery.

## Abstract

With the increasing incidence of breast malignant tumours in the population, some rare cases of breast cancer have been reported. We would like to share with you a case of placental metastasis of a malignant tumour of the breast: the patient was a young woman who was diagnosed with a breast cancer at 31 weeks of gestation. After regular follow-up, a healthy baby girl was delivered by caesarean section at 37 weeks of pregnancy. In a subsequent placenta specimen, the pathologist found distant metastasis of breast cancer to the placenta. This is rare in distant metastases of breast cancer. The patient is currently undergoing further anti-tumour therapy. Through reviewing the relevant literature, we have compiled and discussed the mechanisms related to the possible use of placenta in preventing cancer invasion and how breast cancer in pregnancy can be followed up. We hope that sharing this case will help further clinical and experimental research.

A brief overview of the patient's diagnosis and treatment process.

Flowchart detailing medical procedures during pregnancy and treatment: At 31 weeks, diagnosis confirmed by biopsy. Followed by regular check-ups. Cesarean at 37 weeks. Post-surgery, treatment with trastuzumab, albumin-bound paclitaxel, and pyrotinib for eight cycles. Concludes with trastuzumab, capecitabine, and pyrotinib.