HER2 positive early breast cancers: tumour demographics and trastuzumab therapy in the real-world.

Abstract

Abstract Abstract #3159 Background: Various trials have shown substantial benefits of addition of Trastuzumab (Herceptin®) to adjuvant chemotherapy in Early Breast Cancer (EBC). We analysed our breast cancer population to determine the incidence of HER2 positive Early Breast Cancers, the tumour demographics and the number of patients eligible for and receiving trastuzumab therapy in this group.
 Methods: Data for all patients diagnosed with EBC in 2006 was recorded prospectively in a database. Case notes were consulted where the HER2 positive patients, determined by a combination of IHC and FISH, had not received trastuzumab, to ascertain the reasons.
 Results: A total of 951 patients were diagnosed with Breast Cancer in 2006. 417 (43.9%) of these were screen-detected cancers.
 There were 123 (12.9%) HER2 positive newly diagnosed Breast Cancers of whom 117 were EBCs. The HER2 positivity rate in the screen detected cancers (n=417) was 9% and 17% in the symptomatic cancers (n=433).
 1. Demographics of the HER2 positive Early Breast Cancer Population:
 The median age at diagnosis was 61 yrs (range: 30-92).
 
 2. Fifty nine (50.4%) of the HER2 positive EBCs received trastuzumab therapy.
 
 Conclusions: The HER2 positivity rate is lower than that previously reported suggestive of changing demographics secondary to a high screen detected cancer population. A third of the HER2 positive tumours are screen detected. The percentage of ER positive, node negative and low grade tumours was higher than anticipated.
 Only 50% of HER 2 positive EBC patients received trastuzumab therapy. Of those who did not receive trastuzumab, the commonest reason was low risk status or age and co-morbidities precluded chemotherapy.
 HER 2 positivity alone confers high risk irrespective of pathological stage. Further trials are required to evaluate whether the substantial number of patients who are at present not eligible for trastuzumab therapy might also benefit. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3159.