Shrinking Triple Negative Breast Tumors

A small clinical trial conduced at Massachusetts General Hospital Cancer Centre found that a drug that uses an antibody to target cancer cells shrank tumours in women with triple negative breast cancer that has spread. The therapy used a drug made by fusing a chemotherapy treatment to an antibody that targets Trop-2, a molecule found at high levels on the surface of many cancer cells. Although the trial is still at an early stage, the 69 women who were part of the original study showed strong benefits. Almost 7 out of 10 participants saw their tumours shrink to some extent. 21 of the 69 women found that their tumours shrank by 30% and two patients saw their tumour disappear completely.

Around 15 out of 100 breast cancers are defined as triple negative and this disease often affects younger people. Triple negative breast cancers lack the HER2 molecule and receptors that sense the hormones oestrogen and progesterone on their surface which affect the growth of cancer cells and result in an aggressive cancer.

This therapy needs to be investigated further to understand why it’s efficient in reducing tumours in 70 percent of women and why it is ineffective in the other 30 percent. The next step in this study is to study the drug’s effects in patients with earlier stage disease to see if it can be used in combination with other drugs and whether it can treat patients with other forms of breast cancer.

“The response to this treatment, and how long they lasted, are promising. And the side effects of the treatment seem manageable” – Professor Peter Schmid