A lower dose and shorter course of adjuvant radiation for localized breast cancer cuts down on toxicity without raising recurrence risk, researchers reported at the San Antonio Breast Cancer Symposium.
The UK authors studied whether delivering a reduced radiation dose 40 grays or Gy, a standard unit of radiation provided the same degree of prevention of recurrence or spread of cancer as the prior standard dose, 50 grays. Further, the lower dose was delivered in a 15-fraction regimen over a three week period, and calls for 10 fewer doses of radiation and removes 2 weeks from the conventional 5-week, 5-days-a-week regimen. Previous studies have led many British caregivers to adopt the shorter, lower-dose regimen as standard.
The report showed that, indeed, local or regional tumor recurrence was no different over 10 years with 40 Gy administered in 15 fractions compared with the standard 50 Gy in 25 fractions, John R. Yarnold, MBBS, of the Institute of Cancer Research in London, and colleagues found in the START trial
Furthermore, a second portion of the trial showed a significant 8 percent reduction in moderate or marked effects on normal breast tissue at 10 years, and a 20 percent reduction in 10-year risk of adverse effects, compared with the standard regime.
Although these data and conclusions should be considered preliminary, and only apply to women who have had a lumpectomy, this is definitely exciting news. This is definitely more convenient for women, says Dr. Elizabeth Whelan, since not all cancer patients live near their treatment facilities.
Furthermore, states ACSH s Dr. Ruth Kava, the lower overall radiation dose is an important facet of this altered regimen women will be pleased to hear of this change if these results are borne out by future studies.