Patients diagnosed with a specific form of breast cancer may have a new treatment option to look out for, as it shows promise in shrinking tumors. The drug duo trastuzumab (Herceptin ®) and lapatinib (Tyverb ®), when used after diagnosis and before other treatments, can shrink breast cancer tumors in just 11 days.
About a quarter of women diagnosed with human epidermal growth factor receptor 2 or HER2-positive breast cancer saw their tumors shrink or disappear after using the drugs, according to the results of a clinical trial conducted by researchers from the Institute of Cancer Research (ICR) in London.
"This has ground-breaking potential because it allows us to identify a group of patients who, within 11 days, have had their tumors disappear with anti-HER2 therapy alone and who potentially may not require subsequent chemotherapy," said Nigel Bundred, surgical oncology professor at the University of Manchester. "This offers the opportunity to tailor treatment for each individual woman."
The clinical trial involved 257 women newly diagnosed with HER2-positive breast cancer in England between November 2010 and September 2015. They were treated with the drug combination or nothing for 11 days after diagnosis and before any treatment, such as surgery or chemotherapy, was initiated.
The trial consisted of two parts. For part one, 130 women were grouped into three: one group received trastuzumab only, the second received lapatinib only and the last received no treatment at all after diagnosis.
The initial finding showed the medicines both have efficacy against the tumor. As a result, the researchers changed the second part of the trial, where 127 women were divided into three groups and were each given trastuzumab only, a combination of trastuzumab and lapatinib, and nothing.
The researchers then took samples of tumor tissues from the women's first biopsy and analyzed the levels of Ki67 protein, an indicator of tumor cell spread. They also took into consideration the rise in apoptosis or programmed cell death.
Findings of the second part revealed that 87 percent of women who took the drug duo have gone through biological changes where the number of cancer cells decreased. In about 11 percent of those women, no active cancer cells were found. Seventeen percent had tumor cells that decreased to less than 5 millimeters in diameter.
The results of the clinical trial suggest that medical experts can assess patients' pathological response as early as 11 days in comparison to previous trials that were able to do so only after several months. However, the researchers said they still need to confirm what they called an astonishing breakthrough in cancer treatment.
"Clearly these results need further confirmation, but I suspect the excitement from seeing the speed of disappearance of the tumors will mean that several trials will attempt to confirm these results," said Professor Judith Bliss, lead researcher from the ICR.
The EPHOS-B clinical trial was presented at the 10th European Breast Cancer Conference on March 10.
Photo : Ed Uthman | Flickr