Advances in Drug Therapies for Breast Cancer - Imaginis.com (dateline May 17, 2001)
At the annual meeting of the American Society of Clinical Oncology (ASCO) held this May in San Francisco, California, physicians and healthcare professionals discussed a variety of advances in drug therapies for breast cancer. In addition, several recently published studies have also helped shed new light on the advantages and disadvantages of treating breast cancer with drugs. This article summarizes recent research on drug therapy for breast cancer:
Tamoxifen: Recent studies, including a study by the University of Pennsylvania's National Adjuvant Breast and Bowel Project (NSABP), show that women do not receive any additional benefit from taking the drug tamoxifen (brand name, Nolvadex) for more than five years. When taken immediately after breast cancer surgery (lumpectomy or mastectomy) for a period up to five years, tamoxifen has been shown to increase patient survival and reduce the risk of a cancer recurrence. Since tamoxifen does slightly increase the risk of endometrial cancer (cancer of the uterine lining) and other conditions, researchers of these studies suggest limiting tamoxifen use to five years unless further research shows a clear benefit to taking tamoxifen for a longer period of time.
Aromasin: A study presented at the ASCO conference found that the drug Aromasin (generic name, exemestane) may be associated with a higher rate of tumor response than tamoxifen when given to advanced breast cancer patients as a first treatment option. The study involved 122 advanced breast cancer patients and showed that treatment with Aromasin resulted in tumor shrinkage in 44.6% of the patients compared with 14.3% of patients who were given tamoxifen.
The early results also showed that Aromasin had no negative effect on blood lipid levels, including HDL ("good") cholesterol. The researchers say this is good news for post-menopausal women who take Aromasin because the drug is unlikely to increase their risk of heart disease. Based on the results of this study, the researchers are planning a Phase III clinical trial that will allow for a formal comparison of tamoxifen and Aromasin in breast cancer patients.
Femara: Another study presented at the ASCO conference showed that the drug Femara (generic name, letrozole) may be more effective than tamoxifen in treating post-menopausal women with large localized or locally advanced, hormone dependent breast cancers who are not candidates for breast-conserving surgery (lumpectomy). According to the researchers, Femara may be a viable alternative to chemotherapy for some older women who would like to avoid having a mastectomy (surgical breast removal)
In the study, researchers compared the effectiveness of Femara and tamoxifen in patients with invasive breast cancer to see if the therapies could reduce the size of the tumors before surgery. The results revealed that Femara was significantly more effective at reducing tumor size than tamoxifen, and as a result, more women who took Femara were eligible for breast-conserving surgery (lumpectomy). Further research will continue to compare Femara and tamoxifen.
Gemzar: The drug Gemzar (generic name, gemcitabine hydrochloride) used alone or in combination with the drug Taxotere (generic name, docetaxel) may be beneficial for advanced breast cancer patients who have become resistant to chemotherapy with classes of drugs called taxanes or anthracyclines. Examples of anthracyclines include the drugs Adriamycin (generic name, doxorubicin) and Ellence (generic name, epirubicin). Examples of taxanes include Taxol (generic name, paclitaxel) and Taxotere. Based on these study results, further research will be conducted. Gemzar is currently used to treat pancreatic cancer and non-small-cell lung cancer.
Paxil: A new study showed that the anti-depressant drug Paxil (generic name, paroxetine HCl) is not an effective treatment for fatigue in cancer patients. The study, which was also presented at the ASCO conference, involved 738 patients being treated at 18 private oncology practices across the United States. While the drug did help treat depression in the cancer patients, Paxil did not relieve fatigue. According to the researchers, cancer-induced fatigue differs from normal fatigue because it is not alleviated with rest. Approximately 80% of cancer patients experience fatigue. Researchers will continue to explore other treatment options for cancer fatigue, including psycho-stimulants and compounds used in the transfer of energy from the muscles. Lead researcher Dr. Gary Morrow said that exercise has been shown to prevent cancer fatigue but it does not relieve it.
Anti-angiogenesis drugs: At the ASCO conference, a panel of cancer experts discussed the disappointing results of so-called anti-angiogenesis drugs in treating cancer. These drugs are designed to work by cutting off the blood supply to cancerous tumors, which prevents the tumors from growing larger. Media coverage devoted to the discovery of two compounds, angiostatin and endostatin, by Judah Folkman, MD in 1998 sparked widespread interest in angiogenesis inhibitors. In animal studies, the drugs have had a significant impact on the progression of cancer, but similar results have not yet been produced in humans. However, the panel of experts said that anti-angiogenesis drugs still show promise, especially when combined with standard chemotherapy or drugs that target the COX-2 enzyme (an enzyme that plays a role in pain and inflammation) such as the arthritis drug Celebrex.
- The March 27, 2001 Imaginis report, "No Need for Women to Take Tamoxifen Longer Than Five Years, Study Finds," is available at http://www.imaginis.com/breasthealth/news/news3.27.01.asp
- The May 12, 2001 Eli Lilly and Company news release, "Eli Lilly and Company: New Data Presented at ASCO Demonstrate the Activity of Gemzar Alone and in Combination with Taxotere in Patients with Metastatic Breast Cancer" is available within 30 days of publication at http://biz.yahoo.com/bw/010512/2007.html
- The May 13, 2001 Novartis Oncology news release, "Femara (letrozole tablets) Demonstrates Superiority Over Tamoxifen in Advanced Breast Cancer," is available within 30 days of publication at http://biz.yahoo.com/prnews/010513/nysu001.html
- The May 14, 2001 Pharmacia Corporation news release, "Aromasin Demonstrates High Tumor Response Rate Versus Tamoxifen in First-Line Treatment of Advanced Breast Cancer," is available within 30 days of publication at http://biz.yahoo.com/prnews/010514/cgm046.html
- The May 13, 2001 Reuters Health report, "Drug Aids Cancer Patients' Depression, Not Fatigue," is available within 30 days of publication at http://www.reutershealth.com/archive/2001/05/14/eline/links/20010514elin024.html
- To learn more about drugs used to treat breast cancer, please visit http://www.imaginis.com/breasthealth/drugs.asp