HER2-Positive Metastatic Breast Cancer: Response After Four Cycles of ADC Treatment

A 47-year-old woman presented with HER2-positive metastatic breast cancer involving the liver and extensive areas of bone. Her biopsy showed that the cancer was oestrogen receptor and progesterone receptor positive (ER/PR positive), with HER2 scored as 3+.

HER2-positive metastatic breast cancer: achieving an early response

Because we wanted a rapid response, I started treatment with an antibody-drug conjugate (ADC). After four cycles, her PET/CT scans showed a very good treatment response.

Understanding the scan comparison

The images on the left show her scans before treatment. Orange areas associated with cancer deposits are visible in the liver and multiple bones.

The images on the right show her scans after four cycles of ADC treatment. Activity in these cancer deposits has markedly reduced, demonstrating a very good response.

PET/CT colours represent tracer uptake, which can also occur in normal organs. Reduced colour alone does not establish that every cancer cell has disappeared.

Adapting treatment to support affordability

Following this response, financial constraints became an important consideration in planning her ongoing care.

I therefore de-escalated her treatment, moving to a second-generation anti-HER2 therapy alongside oral targeted therapy, oral hormonal therapy and hormonal injections.

The aim was to preserve the benefit of treatment while reducing costs and making continued care more sustainable.

Treatment tolerance

She tolerated treatment very well, with few side effects.

Personalised care throughout treatment

For this patient, personalising treatment involved selecting therapy based on her ER/PR and HER2 results, then adapting the plan to her response, tolerability and financial circumstances.

The focus was on achieving a strong initial response and developing an ongoing treatment plan she could sustain.