WASHINGTON (AP) â€” Many women should consider taking a combination of chemotherapy drugs after surgery for localized breast cancer because the additional treatment improves long-term survival, a panel of experts said Friday.
Three to six months of treatment with two or more chemotherapy drugs is optimal, and can benefit even women whose cancer has not spread to their lymph nodes, concluded the panel, convened by the National Institutes of Health.
Another top recommendation: Most women whose tumors may be fueled by estrogen should receive hormonal treatment, typically by taking the drug tamoxifen for five years, not just one or two years, the panel said.
The main treatment for localized breast cancer â€” a tumor not yet believed to have spread to other organs â€” is surgery to remove either the tumor alone or the cancerous breast. But many women also undergo post-surgery treatment, called ``adjuvant therapy,'' that helps kill remaining cancer cells floating in the body.
Each case of breast cancer is different, so doctors must tailor post-surgery treatment. But with a variety of options, and new discoveries in recent years of genes and other factors that may influence survival, it's hard to know just which therapy to pick.
So the NIH convened breast cancer experts for a three-day conference to hear the latest research and determine which adjuvant therapies are best proven to work in different circumstances.
``There have been significant advances,'' with some studies showing adjuvant therapy improves survival even 15 years after breast cancer first surfaces, said committee chair Dr. Patricia Eifel, a radiation oncologist at Houston's M.D. Anderson Cancer Center.
But at the same time, picking a treatment ``has become a more complex process,'' she explained. So the NIH panel's recommendations should alert doctors and patients to which therapies are state-of-the-art, and which need more research to know how best to use them, she said.
Among the findings:
â€”Adjuvant chemotherapy substantially improves long-term survival in both premenopausal and postmenopausal women up to age 70, and in women with both cancer-free and cancer-positive lymph nodes. The biggest benefit occurs when the tumor is larger than 1 centimeter.
â€”Using at least two chemotherapy drugs together, for three to six months, is better than one drug. Combinations that include at least one anthracycline, a type of chemotherapy drug, work best. Anthracyclines can cause serious cardiac toxicity, but studies show that is a minimal risk if the breast cancer patient does not have significant pre-existing heart disease, the panel added.
â€”Drugs in the Taxol family are good treatments for metastatic, or spreading, breast cancer. But there is no proof yet that Taxol and related drugs are a good adjuvant therapy for localized breast cancer, and thus they shouldn't be used outside of clinical trials.
â€”More study is needed before women select a specific chemotherapy based on newly discovered genetic risk factors, such as the HER2-neu gene.
â€”But, most women who have ``hormone receptors'' on their cancer cells â€” a long-known risk factor that signals estrogen could fuel the cancer's growth â€” should receive hormone therapy. The standard treatment is five years of tamoxifen; it can be added to chemotherapy if needed. Alternative drugs such as raloxifene are not yet proven. Women who do not have hormone receptors should not get tamoxifen.
â€”High-dose chemotherapy followed by a bone-marrow transplant is not a proven therapy and should be restricted to clinical trials.
â€”Radiation is a necessary for all women who undergo a lumpectomy, where just the tumor is removed. But radiation can help some mastectomy patients, too â€” those with very large primary tumors or when cancer has spread to four or more lymph nodes. Additional studies are needed to see if radiation helps when cancer has spread to fewer lymph nodes.
On the Net:
NIH Consensus Development Program: http://consensus.nih.gov