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Some Breast Cancer Patients Could Benefit From Shorter Radiation and Chemotherapy Regimens (dateline May 31, 2000)

Two studies presented at the annual meeting of the American Society of Clinical Oncology (ASCO) this May reveal that radiation and chemotherapy regimens can be shortened for many women with early- stage breast cancer without increasing health risks.  Shorter treatment regimens pose fewer inconveniences to breast cancer patients and can reduce the overall cost and duration of treatment.

The study on shorter radiation therapy regimens was presented by Canadian researchers at the ASCO meeting.  In Canada, the United States, and several other countries, women with early stage breast cancer whose cancer has not spread to the axillary (underarm) lymph nodes typically receive five to six weeks of radiation following breast-conserving surgery ( lumpectomy). In the study, researchers found that the five-year survival rate in women who received only three weeks of radiation was the same as women who received five weeks of radiation after lumpectomy (nearly 90%). 

Radiation therapy helps reduce the chances that breast cancer will recur (return) by destroying any remaining breast cancer cells after surgery.  The researchers noted that the risk of breast cancer recurrence was not significantly different among women who received three weeks of radiation compared to women who received five weeks of radiation: 2.5% of women who had three weeks of radiation experienced a local recurrence of breast cancer within five years compared with 3.3% of women who had five weeks of radiation.  

All 1,234 women in the radiation therapy study received the same amount of radiation, regardless of whether they were treated for three weeks or five weeks.  Researchers had previously thought that women who receive higher doses of radiation would experience visible side effects, such as thicker breast tissue or the appearance of small blood vessels near the breast skin.  However, all women in the study were closely monitored three years and five years after radiation therapy, and no significant differences in side effects were noted. 

The Canadian researchers believe the results of the study show that radiation therapy delivered to early-stage breast cancer patients (with no evidence of cancer in the lymph nodes) in three weeks time will reduce the cost of radiation therapy while making the therapy more convenient to patients.

Some early-stage breast cancer patients choose to have their breast(s) surgically removed ( mastectomy) instead of having a lumpectomy because the five to six weeks of radiation therapy after surgery is inconvenient with their work or personal schedules. 

Shorter Chemotherapy Regimen Effective As Well

Another study presented at the ASCO meeting shows that a three-month regimen of chemotherapy with AC (adriamycin and cyclophsophamide) provides the same benefits to early-stage breast cancer patients as a six-month chemotherapy regimen of CMF (cyclophosphamide, methotrexate, and flurouracil).  Both AC and CMF are common chemotherapy regimens

The five-year survival rate was not significantly different among the 2,008 women with early-stage breast cancer (with no evidence of cancer in the lymph nodes) regardless of which chemotherapy regimen they received. Side effects noted in the study were similar among all of the women.

Lead researcher Bernard Fisher, MD of the National Surgical Adjuvant Breast and Bowel Project study believes the findings show that early-stage breast cancer patients who need chemotherapy could be spared months of treatment if physicians substitute AC for CMF.  Dr. Fisher noted that there has already been a trend to prescribe the AC chemotherapy regimen instead of the CMF regimen and believes this study will accelerate the trend.      

The cost of the two chemotherapy regimens is approximately the same, but for women who hold jobs, the three-month AC regimen will allow them to get back to work sooner, costing them less in lost pay. 

Researchers from both the radiation and chemotherapy studies caution that shorter treatment regimens are not appropriate for all breast cancer patients.  All of the patients in the radiation and chemotherapy studies had early-stage breast cancer that had not spread to the axillary (underarm) lymph nodes.  Further clinical trials may help to confirm the results of the studies presented at the ASCO meeting. 

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