Breast cancer returning years later in the biceps muscle

What happened, in summary

A 60-year-old woman was first treated for left breast cancer in 1990. The tumour was a grade 2 ductal carcinoma, ER-positive, with 6 of 10 axillary lymph nodes involved. The original cancer was Stage II. She underwent wide local excision and axillary clearance, followed by chemotherapy with 5-fluorouracil, epirubicin and cyclophosphamide and then radiotherapy. Hormone therapy was not given at that time.

In March 2001, 11 years later, she developed a 2 × 2 cm lump in the left axilla. Testing showed breast cancer in the subcutaneous tissue that matched her original tumour. The recurrence was removed surgically, followed by another course of 5-fluorouracil, epirubicin and cyclophosphamide and then tamoxifen for 5 years.

By January 2015, she had experienced 6 months of worsening numbness, pain, coldness and pins-and-needles sensations in her left forearm and hand. The later work-up established a rare metastasis involving the left biceps muscle, making her disease Stage IV. Surgery was considered but carried a high risk of injury to nearby nerves and blood vessels.

She chose non-surgical treatment. Letrozole 2.5 mg daily was started, together with palliative radiotherapy delivered in 15 fractions to a total dose of 40.05 Gy. Her symptoms improved considerably. MRI 6 months after radiotherapy showed a significant decrease in the size of the biceps tumour.