Pre-Surgical Lapatinib Treatment Reduces HER2+ Breast Cancer Growth
Posted Jul 01 2011 11:31am
HER2-positive (HER2+) breast cancers express an excess of the human epidermal growth factor receptor 2. Overexpression of this receptor causes the breast cancer tumors to be more aggressive, which results in greater risk for breast cancer recurrence and poorer outcomes.
Previous research has suggested that breast cancer treatments that take place between diagnosis and surgery can help improve surgical success and breast cancer outcomes. Therefore, the development of breast cancer treatments that can slow breast cancer growth during this time is an important area of research.
A recent research study explored the potential benefits of treating breast cancer patients with lapatinib, a HER2-specific breast cancer treatment. For this study, 60 breast cancer patients were treated with lapatinib for the 3 weeks between breast biopsy and surgery. Breast tissue samples after surgery were examined for differences in breast cancer growth compared to women treated with a placebo. The study investigators reported
Cell growth decreased by about 9% in patients treated with lapatinib, while cell growth increased by 15% in placebo-treated patients.
The decrease in breast cancer cell growth was greater in estrogen receptor-negative tumors (35% decrease) than in estrogen receptor-positive tumors (12% decrease).
Breast tumor size was smaller after lapatinib treatment (18 mm) than after placebo treatment (24 mm).
Breast cancer tumor progression was only 27% on lapatinib compared to 56% growth on placebo treatment.
Lapatinib treatment resulted in a 14% partial response, while placebo treatment was associated with only a 4% partial response.
These results clearly show that breast cancer treatment with lapatinib during the 3 weeks between diagnosis and surgical treatment is an effective way to slow tumor growth. This is an important finding because slowing tumor growth before surgery can help improve surgical success. This, of course, can lead to decreased changes of breast cancer recurrence and might lead to better overall outcomes. Additional studies with larger numbers of breast cancer patients appear to be planned to confirm these initial results.