- Search tips Researchers Investigate Combination Herceptin/Iressa Treatment for Breast Cancer Patients (dateline February 28, 2002) Format for Printing The results of a preliminary study find that combining the drugs Herceptin and Iressa may be effective in treating some breast cancer cases. Both drugs work by targeting certain growth factors on the surface of breast cancer cells, which are ...www.imaginis.com/breasthealth/news/news2.28.02.asp