When it comes to Herceptin for HER2 positive breast cancer, does tumor size matter? What if the tumor is very small? Should Herceptin still be considered? Today we'll share the latest research on Herceptin (trastuzumab) for women with small, node-negative, HER2 positive breast cancer.
Clinical Breast Cancer: HER2 positive breast cancer has a higher risk of recurrence than other breast cancers
A July 15 Clinical Breast Cancer study from MD Anderson compared the risk of recurrence for women with different breast cancer subtypes. All of the women had small (less than 2cm), node-negative breast cancer. None were treated with chemotherapy or Herceptin.
The study found that women with HER2 positive breast cancer had a greater risk of recurrence than women with hormone-receptor positive breast cancer. Triple-negative breast cancer also had a greater risk than hormone-receptor positive breast cancer, but the difference was not as high as with the HER2 group.
Cancer (6/16): Herceptin plus chemotherapy beneficial for tumors 2cm or less
A June 16 study in Cancer from the Memorial Sloan-Kettering Cancer Center compared recurrence rates for women treated with and without Herceptin plus chemotherapy for small (2cm or less), node-negative, HER2 positive breast cancer. Based on their comparison, the authors concluded, "Women with small, node-negative, HER2+ primary breast cancers likely derive significant benefit from adjuvant trastuzumab with chemotherapy."
Cancer (9/1): Herceptin reduces recurrence after lumpectomy for tumors 5cm or less
A September 1 study in Cancer from the Memorial Sloan-Kettering Cancer Center compared localregional recurrence rates (LRR) for women treated with or without Herceptin after lumpectomy (breast conserving surgery) and radiation. All women had node-negative, HER2 positive breast cancer measuring 5cm or less.
According to the conclusion, "Even among women with lower risk breast cancer, the relatively high locoregional failure rates associated with positive HER2 status could be reduced markedly with adjuvant trastuzumab chemotherapy." Within 3 years, there was a 10% recurrence rate for women not treated with Herceptin compared to a 1% rate with Herceptin.
Internal Medicine News: Uncertainty for tumors less than 1cm
An August 16 Internal Medicine News article discussed the uncertainty about Herceptin for women with very small (less than 1cm), node-negative, HER2 positive breast cancer.
Although studies such as the July 15 Clinical Breast Cancer study above suggest a higher risk of recurrence for small, HER2 positive breast cancer, an American Society of Clinical Oncology (ASCO) presentation suggested that for women with very small tumors (1cm or less), the risk of recurrence may be so low that the benefit of Herceptin may not be worth the risk of cardiovascular disease.
Nonetheless, Dr. Gabriel Hortobagyi from MD Anderson was quoted to say he discusses Herceptin and chemotherapy with anyone with HER2 positive breast cancer, regardless of tumor size.
For more on Herceptin for HER2 positive breast cancer, including two-years worth of news, research and overviews, please visit the Hercetpin (trastuzumab) page of our website. From the home page of our site, click the "Treatments" tab and search for "Herceptin" in the box in the top right corner.