Analysis confirms benefits of combining trastuzumab and chemotherapy

At the ESMO Conference Lugano, Issa Dahabreh from the University of Athens reported the results of a meta-analysis of 5 trials involving more than 13,000 women whose breast cancer was amenable to surgery.

All the trials compared disease-free survival, overall survival and the risk of locoregional and distant recurrence of breast cancer in women given adjuvant chemotherapy alone or chemotherapy plus trastuzumab, after breast surgery.

Up to a quarter of all breast cancers express large amounts of the HER2 protein or carry multiple copies of the HER2 gene. Those cancers tend to be associated with aggressive disease, a higher likelihood of recurrence and a decreased response to treatment. Trastuzumab is a monoclonal antibody that directly targets part of the HER2 tyrosine kinase receptor.

The results showed that combining trastuzumab with chemotherapy results in a -34% reduction in mortality and a 38% increase in disease-free survival, Dahabreh said. Those survival benefits were accompanied by decreases in the risk of both locoregional and distant recurrences of the cancer.

“Taken together, these results confirm that the administration of trastuzumab in combination with chemotherapy should be the standard choice for the treatment of women with HER2 positive early stage disease, especially those with limited cardiovascular comorbidities”, Dahabreh said.

This is the first meta-analysis of current published trials on the adjuvant use of trastuzumab. The results are of great clinical value since they indicate that treatment with trastuzumab results in major survival benefit in women with an aggressive disease subtype.

The level of effectiveness demonstrated by this analysis is largely unprecedented in the treatment of solid tumors, the authors say, and highlights the potential of implementing targeted agents with cytotoxic chemotherapy.