Combination Chemotherapy Shrinks HER2 Positive Breast Cancer

Combination Chemotherapy Shrinks HER2 Positive Breast Cancer

Take-Home Message:

Preoperative treatment with trastuzumab and lapatinib holds promise as highly effective therapy for HER2 positive breast cancer.



Effects of Perioperative Lapatinib and Trastuzumab, Alone and In Combination, in Early HER2+ Breast Cancer – the UK EPHOS-B Trial (CRUK/08/002)

Authors: Bundred N, Cameron D, Armstrong A, et. al.

Source: European Journal of Cancer 57, suppl 2 (2016)S1-S8

There are multiple treatments available for HER2+ breast cancer.  Currently, efforts are being made to determine which therapies, in which combinations, are best for specific breast cancer scenarios.

This preliminary study randomized women with operable HER2+ breast cancer into four groups.  Each group received a different treatment for 11 days prior to surgery.  The first group received no therapy. The second group received trastuzumab on days 1 and 8 before surgery. The third group received lapatinib daily.  The fourth group received a combination of trastuzumab and lapatinib.

Tumor features at biopsy were compared to features at definitive excision (surgery). Only the group that received both lapatinib and trastuzumab showed a complete disappearance of cancer at the time of operation: almost 11% of patients in this group had a pathologic complete response. No such response was observed in the group that received trastuzumab alone. The combination group also demonstrated the greatest reduction of detectable disease: almost 17% of subjects had less than 5mm of invasive cancer present at operation. Only 3.1% of subjects who received trastuzumab alone had such a response.

This study showed a significant reduction or disappearance of HER2+ cancer after 11 days of preoperative treatment with both lapatinib and trastuzumab. This surprising data creates opportunities for more studies that will allow providers to individualize cancer care according to tumor details.