Complete response after treatment of breast cancer with isolated liver metastasis: a case report.

BACKGROUND

Breast cancer has a high incidence and is prone to metastasis, while isolated liver metastasis is rare. A growing body of evidence supports the effectiveness of treating breast cancer with anti-human epidermal growth factor receptor-2 (HER2) therapy in combination with chemotherapy. However, little is known about its impact on metastatic liver disease. There is also a lack of consensus on managing liver metastases from breast cancer, and no studies have been conducted on managing the disappearance of liver metastases after treatment.

CASE DESCRIPTION

In May 2021, a 51-year-old female patient with HER2-positive breast cancer with isolated liver metastases had immunohistochemistry of estrogen receptor (ER) (-), progesterone receptor (PR) (-), and HER2 (3+) for both her primary lesion and liver metastases. After undergoing 17 cycles of anti-HER2 therapy and chemotherapy, the patient expressed a desire for surgery. Then a preoperative examination was performed, which revealed the disappearance of both the primary breast lesion and the liver metastases. Immediately afterwards, a left mastectomy was performed, and postoperative pathology showed a complete response to the breast tumor. As for the liver, where the metastatic lesions disappeared, no relevant study has reported how to deal with this situation. Finally, after a hospital-wide discussion, the patient was given trastuzumab maintenance therapy. Until now, no obvious signs of recurrence or metastasis have been observed during regular follow-ups.

CONCLUSIONS

This case suggests that maintenance therapy may be the best option for patients with breast cancer whose liver metastases disappear by medication. Also, it can be inferred that in HER2-positive metastatic breast cancer (MBC), patients with isolated liver metastases may be more likely to achieve a cure-like outcome. Nevertheless, more cases and follow-up information are needed to support these views.