Human epidermal growth factor receptor 2 (HER-2) is a protein which promotes the growth of cancer cells. If the protein is found on the cancer cells of a tumour, the tumour is said to be HER-2 positive. Trastuzumab (Herceptin®) treats HER-2 positive cancer by attaching to this protein to control unnecessary cell growth.
In 2007 recommendations were developed advising that patients who are treated for HER-2 positive cancers should receive trastuzumab with chemotherapy (National Breast and Ovarian Cancer Centre). This applies when patients have cancer cells found in lymph nodes in the armpit (node-positive), or have tumours larger than one centimetre.
National Breast Cancer Audit data shows that by 2008:
- Testing to determine HER-2 status had increased.
- Trastuzumab treatment for HER-2 positive patients had increased.
- The proportion of cases in which surgeons followed the recommendations had increased for node-positive patients (from 67% to 84%) and node-negative patients with tumours larger than 1 cm (from 40% to 71%).
- Trastuzumab treatment had also increased for node-negative, HER-2 positive patients with tumours smaller than 1 cm (from 16% to 43%), although there were no recommendations for the use of the drug in this group.
- Breast cancer patients over 70 years were less likely to receive the treatment as recommended (33%) compared with patients under 70 (75%).
In conclusion, the treatment of early breast cancer has changed in line with recommendations for the use of trastuzumab, although the effect has been less for node-negative patients and patients over 70 years of age.