Side effects and Risks of tamoxifen
Tamoxifen acts like an anti-estrogen in some tissues and acts like estrogen in other tissues.
- Hot flashes and night sweats
- Cancer of the uterus (most were endometrial cancer, a few were uterine sarcoma). The risk is not present in those patients who have had a hysterectomy.
- Blood clots (DVT, PE, and stroke)
Tamoxifen is contraindicated in patients who continue to smoke due to the increased risk of thromboembolic disease.
- Trastuzumab has a trade name of Herceptin.
- It is a monoconal antibody that interferes with the HER2/neu receptor.
- Her proteins stimulate cell proliferation. In certain types of breast cancers, HER2 is over expressed and causes the cancer cell to reproduce uncontrollably.
- Trastuzumab is associated with cardiac dysfunction in 2-7% of cases. Regular cardiac screening with an echocardiogram or MUGA scan is commonly undertaken during the trastuzumab treatment duration.
- Optimal treatment duration of Herceptin isn’t known but one year of treatment is generally accepted as the optimum length of therapy based on clinical trials.
- FDA approval was received in 1998 by Genentech with UCLA.
HER2 positive breast cancers vs. HER-2 negative
HER2 positive breast cancers have a worse prognosis. HER2 positive breast cancers are likely to have high proliferative rate, positive axillary lymph nodes, and decreased expression extrogen and progesterone receptors.
Of invasive breast cancers what percentage are HER2 positive?
15-20% of invasive breast cancers are HER2 positive.