Researchers from the Dana Farber Cancer Center have confirmed that starting radiation therapy as soon as possible after beast conserving therapy in older women with localized breast cancer decreases the risk of local recurrence. The details of this study were published in the March 13, 2010 issue of the British Medical Journal.[1]

Previous studies have suggested that it is important not to delay radiotherapy beyond two to three months in women with localized breast cancer receiving breast conserving surgery.

These authors used data from the Surveillance, Epidemiology and End Results Program- Medicare to evaluate the impact of radiotherapy delay in 18,050 women over the age of 65 years with localized Stage 0-II breast cancer. The median time from surgery to start of radiotherapy was 34 days. Approximately 30% of women started radiotherapy after six weeks. The local relapse rate for the entire group of patients was 4%.

• Radiation therapy initiated beyond six weeks increased the risk of local recurrence by 19%.
• The risk of local recurrence was time dependent; risk of recurrence increased with increasing delay of radiotherapy.
• Factors associated with delayed administration of radiotherapy included: positive lymph nodes, co-morbidity, low income, Hispanic ethnicity, non-White race, later year of diagnosis, and residence outside the southern states of the United States.
• They also observed: “Regions of the US known to have increased rates of breast conserving surgery had longer intervals before radiotherapy, suggesting limitations in capacity.”

These authors suggest, “Given the known negative impact of local recurrence on survival, mechanisms to ameliorate disparities and policies regarding waiting times for treatment might be warranted.”

Comments: These data are consistent with other studies suggesting that adjuvant radiation therapy needs to be carried out in a timely manner for optimal treatment of localized breast cancer.

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