Six months of breast cancer treatment ‘could be as effective as 12’ in some women with early stage disease

Six months of targeted treatment could be as effective as 12 months for women with a type of early stage breast cancer, according to unpublished clinical trial results. 

Around 9 in 10 women taking trastuzumab (Herceptin) for 6 months were cancer-free 4 years after treatment. This figure was the same in those taking the standard 12-month course. 

The shorter treatment time also came with less severe side effects.

All the women taking part in the study had HER2-positive breast cancer, which means their cancer cells can be targeted by Herceptin.

The results will be presented at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago. Professor Helena Earl, lead researcher from the University of Cambridge, said the findings were very exciting. 

“We are confident that this will mark the first step towards a reduction of Herceptin treatment to six months in many women with HER2-positive breast cancer.”

What did the study show?

The UK trial involved over 4,000 women with HER2-positive breast cancer that hadn’t spread to other parts of the body. They were given either 6 or 12 months of Herceptin, as well as chemotherapy. 

Researchers found that the 6-month course was as effective as 12 months at preventing the cancer coming back or death.  

The shorter course also reduced side effects. Only 4 in 100 women taking 6 months of Herceptin stopped the drug early because of heart problems, compared to 8 in 100 women on a 12-month course. 

Professor Charles Swanton, Cancer Research UK’s chief clinician, said the results of this study had been eagerly awaited by breast cancer researchers. 

He added that reducing treatment time could help make expensive targeted drugs more cost effective. 

Next steps 

Although the trial results show the potential benefits of taking Herceptin for 6 months, Earl said that changing treatment guidelines can be complex and very challenging.

The results are also a preliminary look at the trial, and are yet to published in a scientific journal. 

Earl urged women taking Herceptin not to change their treatment without speaking to their doctor. 

 “By analysing tumour and blood samples, the researchers will now try to understand which patients can stop Herceptin at 6 months and which patients need extended therapy,” said Swanton.