Breast Cancer Therapy Shows Long-Term Benefits

Researchers found significant improvements in overall survival and in disease-free survival in patients who received trastuzumab in addition to chemotherapy.

Adding trastuzumab to chemotherapy improved overall survival by 37%, and reduced the risk of cancer recurrence by 40% in patients with early stage HER2-positive breast cancer, compared to chemotherapy alone, according to a recent study.

The researchers found no increase in secondary cancer incidence and only minor increases in heart problems, confirming trastuzumab’s long-term safety, the study noted.

“This long follow-up of patients shows that we have really altered the natural history of this disease,” Edith A. Perez, MD, lead author and deputy director at large of the Mayo Clinic Cancer Center, said in a press release. “Herceptin works and it works for a long period of time. The drug has impacted the lives of many women in the US and worldwide.”

The study, published in the Journal of Clinical Oncology, reports long-term findings from 2 randomized phase III studies that led to trastuzumab’s approval. The examination included a combined 4046 participants, and tested the addition of trastuzumab to chemotherapy after surgery.

All participants received doxorubicin plus cyclophosphamide. A control group that included half of all participants received paclitaxel alone, whereas the remaining half received trastuzumab and paclitaxel.

Researchers saw improvement in overall and disease-free survival in all subgroups, including older and younger patients, patients with node-positive and node-negative cancers, and estrogen-positive and estrogen-negative cancers.

HER-2 positive breast cancer accounts for 15 to 20% of invasive breast cancers, and prior to trastuzumab’s approval, women with early stage HER-2 positive breast cancer faced quicker relapse, higher incidence of metastasis, and shorter survival.