A Story of Advanced Treatment, Remarkable Response, and Hope

In May 2021, a 51-year-old postmenopausal Chinese woman visited Yongchuan Hospital of Chongqing Medical University after noticing a painless, irregular mass in her left breast. She had no prior medical history or co-morbidities. Imaging tests, including ultrasound and mammography, revealed two connected masses in the lower inner quadrant of the breast, alongside a low-density liver lesion detected on an abdominal CT scan. While no lymph node abnormalities were observed, biopsies of both the breast and liver confirmed invasive carcinoma with liver metastasis. The cancer was classified as HER2-positive, meaning it could potentially respond well to targeted therapies.

The Treatment Journey

Given the HER2-positive status, a treatment plan incorporating dual-targeted therapy and chemotherapy was initiated. The patient received six cycles of nab-paclitaxel combined with trastuzumab and pertuzumab, followed by an additional 11 cycles of dual-target therapy alone. She tolerated the regimen well, with no significant adverse effects.

After six cycles of treatment, follow-up imaging showed a significant reduction in the liver metastasis, shrinking from 4.6 cm × 3.0 cm to just 0.8 cm × 0.5 cm. The primary breast tumor had completely disappeared on imaging. Encouraged by this progress, the patient opted for surgery.

A thorough preoperative evaluation, including MRI and CT scans, confirmed the complete disappearance of liver metastases and no new evidence of disease progression. In response to these findings and retrospective studies suggesting improved survival with tumor resection, a simple mastectomy of the left breast was performed. The postoperative pathology report revealed a complete pathological response—an extraordinary outcome.

The Outcome

Since surgery, the patient has been on trastuzumab maintenance therapy every three weeks. She continues to do well, with no evidence of disease recurrence during routine follow-ups. Given the uncertainty around the optimal duration of maintenance therapy, ongoing observation remains crucial to balance effectiveness with potential side effects and treatment burden.