From the San Antonio Breast Conference in December, new data shows a higher than predicted rate of breast cancer recurrence even with very small breast cancers that are HER2 positive. The data is from the first large study to analyze early-stage breast cancer patients with HER2 positive tumors one centimeter or smaller. All these women would benefit from adjuvant Trastuzumab, also known as Herceptin, (for one year, the standard in America) - along with adjuvant chemotherapy. This represents a shift in the way women with early-stage HER2 positive breast cancer should be assessed for risk of recurrence and considered for treatment, according to the study's author.
Overall, twenty percent of women with breast cancer have HER2-positive cancer.
While I had read a 12-page case presentation debating this in a woman with a small breast cancer, where the authors recommended against therapy, a trumpet has been sounded. Further details to follow but for now HER2 positivity will likely change the recommendation regarding adjuvant chemotherapy/Trastuzumab - even for smaller node negative cancers.