A recent study entitled “Adjuvant Paclitaxel and Trastuzumab for Node-Negative, HER2-Positive Breast Cancer” shows combining paclitaxel and trastuzumab reduces the risk for cancer recurrence in women with stage I HER2-positive breast cancer. The study was published in the journal New England Journal of Medicine.
Previous large Phase 3 randomized clinical trials showed that combining trastuzumab with chemotherapy resulted in an overall increase in survival and a 50% reduction of cancer recurrence among patients with stage I and stage II HER2-positive breast cancer (breast cancer that is positive for the protein Human epidermal growth factor receptor 2 (HER2) that promotes the growth of cancer cells). However, patients with stage I HER-positive breast cancer – these patients have small HER2-positive breast tumors that have not reached the lymph nodes – were excluded from these trials since recurrence risk is considered low and trastuzumab, a humanized monoclonal antibody that binds HER2, was still undergoing clinical investigation.
In this study, a team of researchers from the Dana-Farber Cancer Institute investigated if stage I HER-positive breast cancer patients benefited from a combined therapy of paclitaxel, a lower-intensity chemotherapy agent, and trastuzumab. The authors studied 406 patients with HER2-positive, node-negative breast tumors (size inferior to 3 cm). Patients were treated for 12 weeks with paclitaxel and trastuzumab (administered weekly) and subsequent monotherapy of trastuzumab for 9 months. In the third year after therapy, the majority of patients (98.7 percent) had survived and was negative for invasive breast cancer. Moreover, the side effects registered with the combination of paclitaxel and trastuzumab resulted in less severe side effects, when compared to traditional therapies.
Currently, women with stage I HER-positive breast cancer have no single standard regiment. The combined therapy resulted in a lower risk of cancer recurrence (less than 2 percent measure at the third year after therapy completion) and thus poses a potential new treatment for these patients.
Eric Winer, MD, director of the Breast Oncology Program at the Susan F. Smith Center for Women’s Cancers at Dana-Farber and study leading author commented in a press release, “Women with small, HER-2 positive, node-negative [no sign of spread to adjacent lymph nodes] breast tumors have a low, but still significant, risk of recurrence of their disease. This study demonstrates that a combination of lower-intensity chemotherapy and trastuzumab – which is associated with fewer side effects than traditional chemotherapy regimens – is an appealing standard of care for this group of patients.”
Sara Tolaney, MD, MPH, of the Susan F. Smith Center for Women’s Cancers at Dana-Farber and study first author added, “We’re committed to identifying treatment regimens that are geared not only to the specific biological features of a woman’s cancer, but also to the stage of the cancer – the size of the tumor and how far it has advanced. This study is a prime example of the value of that approach”.