According to a new study, a gel containing tamoxifen and applied to the skin was as effective in reducing the growth of breast cancer cells in women with noninvasive cancer.
The gel was as effective as the pill form of the medication and it caused fewer side effects.
Tamoxifen is used to treat women with estrogen receptor- positive cancer. Estrogen receptor-positive cancer relies on estrogen to grow. When taken for 5 years, the drug can cut the risk of recurrence of this type of cancer in half.
The study was published Tuesday in Clinical Cancer Research, a journal of the American Association for Cancer Research.
In the study, the gel was applied to the breasts of women diagnosed with ductal carcinoma in situ or DCIS. All the women had DCIS that was sensitive to estrogen.
After 6 to 10 weeks of gel application, the reduction in a marker for cancer cell growth in the breast tissue was similar to that of the orally ingested tamoxifen.
According to researchers the findings could have broad implications. The gel could be used to reduce the risk of a recurrence of breast cancer to prevent the disease in the first place.
The usual side effects of tamoxifen range from hot flashes and vaginal dryness to potentially fatal blood clots and uterine cancer.
Because the gel has fewer side effects, it will most likely be used more widely. The gel causes fewer side effects because the drug is concentrated in the breast tissue. The drug does not circulate much in the blood which should avoid potential blood clots as well as an elevated risk of uterine cancer.
Researchers are further investigating the effectiveness of the gene signature in predicting whether women at risk would respond to tamoxifen therapy. The investigation uses data from about 680 patients.
