Skipping Chemo to Treat a Breast Cancer

HER2 positive breast cancer responses to combination therapy of Tykerb and Herceptin

(RxWiki News) Aggressive breast cancer requires aggressive treatment. The therapy for one menacing type of breast cancer – HER2-positive – almost always involves chemotherapy.  Maybe not for everyone, though.

Medical researchers are turning the page on treating this cancer.

Women with HER2-positive breast cancer may no longer need chemotherapy. Instead, they could begin receiving two targeted therapies that knock out the cancer cells themselves, according to a new study.

Two existing medications – Tykerb (lapatinib) and Herceptin (trastuzumab) – were shown in a recent study to attack the cancer on multiple fronts. This powerful drug combination delivered fatal blows to the cancer cells.

"Research your cancer treatment options."

Mothaffar Rimawi, MD, medical director of the Lester and Sue Smith Breast Center at Baylor College of Medicine and first study author, said, "This study really epitomizes the whole new era of cancer medicine, using effective targeted treatments against selected subsets of patients resulting in high efficacy."

The goal of this study was to see if the combination therapy could not only shut down tumor growth, but also prevent the tumors from becoming resistant to treatment.

This clinical trial involved 64 women with HER2-positive breast cancer, an aggressive form of the disease in which the protein HER2 is overexpressed. Some of the women also had cancers that were driven by estrogen, or estrogen receptor positive (ER+) cancer.

The medications attack the HER2 from different angles.

This team of researchers has been working with these two medications for years. Previous laboratory and animal studies strongly suggested these medications were more powerful together than was either drug separately.

Study members had large tumors and a median age of 40. They received the combination therapy for 12 weeks before surgery.

Researchers found that the combination of lapatinib and trastuzumab effectively eliminated evidence of the disease in 21 percent of ER+ patients and 36 percent of ER– (estrogen receptor negative) cancers.

That these results were achieved – without what the authors call the "sledgehammer" of chemotherapy – could be a huge advancement.

“Our data support the hypothesis that selected patients with HER2-positive tumors may not need chemotherapy, and more-complete blockade of HER receptors and ER is an effective strategy worthy of further study,” the authors concluded.

“This is interesting data which suggest that a subset of women with HER2-positive breast cancer may not need chemotherapy to treat their disease,"  Adam Brufsky, MD, PhD, professor of medicine at the University of Pittsburg School of Medicine, told dailyRx News.

"The issue is, at this point, we are not 100 percent sure who these women with HER2-positive breast cancer are.”

This study was published April 8 in the Journal of Clinical Oncology. This study was supported by GlaxoSmithKline and the Translational Breast Cancer Research Consortium. Several authors reported having financial relationships with Genentech (maker of Herceptin), GlaxoSmithKline (maker of Tykerb), NanoString Technologies, Novartis and Pfizer.

Review Date: 
April 8, 2013