"About three years ago international guidelines relating to Human Epidermal Growth Factor 2 (HER2) hit the headlines (Journal of Clinical Oncology 2007; 25: 118-45). I was on the panel that determined these guidelines and it is this and previous experience that has led to my involvement in the new set of recommendations that will have an even greater impact in terms of the numbers of patients with ER/PgR positive tumours.  It is known that Herceptin is an effective treatment in approximately 25% of patients who show positive results for HER2 and these guidelines had considerable impact globally in helping to standardize the clinical tests that predict the likely response to Herceptin therapy.

"However, a lot more breast tumours (around 70%) are driven by oestrogen which acts as a powerful growth stimulant when it binds to receptors in the tumour cells. The new guidelines relate to the most appropriate testing regimes for oestrogen receptors and progesterone receptors for predicting response to therapies such as tamoxifen. The new guidelines include recommendations for standardised tests for specimen handling, proper use of controls, and interpretive and reporting criteria.

"The key is to reliably identify those patients whose cancers are driven by oestrogen - patients who fall into this category are likely to benefit from the drug tamoxifin, or similar drugs such as aromatase inhibitors. In cases where oestrogen is not driving the tumours growth other drugs are more appropriate."

The full report is published today in the Journal of Clinical Oncology.

SOURCE Journal of Clinical Oncology