B16
Treatment of HER2+ breast cancer in routine practice review of testing and use of adjuvant trastuzumab across a cancer network
Samuel Coulson, Varadarajan Kumar, Robert Coleman
Cancer Research Centre, Sheffield, UK
Background
15% to 20% of patients with breast cancer over-express the human epidermal growth factor receptor 2 (HER2). Trastuzumab (Herceptin) is a recombinant monoclonal antibody against HER2, and has been shown to markedly improve disease outcomes including overall survival in women with early HER2+ breast cancer receiving adjuvant chemotherapy.
Aim
This retrospective review assessed all early breast cancer patients diagnosed in a 12-month period across the North Trent Cancer Network (NTCN). The review aimed to assess the frequency of HER2+ disease in our population, identify any differences in use of trastuzumab across the NTCN and investigate reasons why some patients had not received trastuzumab.
Method
Patients with histologically confirmed invasive early breast cancer in the NTCN have routine HER2 testing by immunohistochemistry (IHC) and fluorescent in situ hybridisation (FISH) for equivocal IHC results. Using the central histopathology database, HER2 results for all patients with early breast cancer between 09/07 and 08/08 were obtained, and the HER2+ group identified. Patients who received trastuzumab were identified from the electronic chemotherapy records, and the two lists compared. Case-notes for all HER2+ patients who did not receive trastuzumab were reviewed.
Results
HER2 testing was carried out on 1318 patients. 198 (15%) were HER2 positive (116 by IHC and 82 by FISH). 133 (67%) received adjuvant trastuzumab with similar proportions at each of the 5 breast units in the network treated. Of the remaining 65, 50 (77%) were deemed unfit for chemotherapy due to poor performance status and co-morbidities. 13 (20%) refused chemotherapy and therefore did not receive trastuzumab.
Conclusion
Only two-thirds of patients with early HER2+ breast cancer received trastuzumab. The combination of trastuzumab with hormone therapy or as a single agent without chemotherapy needs to be explored further in the adjuvant setting.
