(HealthDay News) – Accelerated partial breast irradiation (APBI) yields five-year clinical outcomes and patterns of failure similar to those achieved with whole breast irradiation (WBI), with excellent three-year survival for women who develop an ipsilateral breast tumor recurrence (IBTR).

Chirag Shah, MD, of the William Beaumont Hospital in Royal Oak, MI, and colleagues conducted a five-year study involving 1,440 patients with early-stage breast cancer (1,255 with invasive breast cancer [IBC], 194 with ductal carcinoma in situ [DCIS]) who underwent breast-conserving therapy (BCT) using ABPI.

The researchers found that 3.5% of patients developed an IBTR, for a five-year actuarial rate of 3.61%. Of the 50 recurrences, 36 were new primary cancers and 14 were recurrences of the index lesion. The vast majority of recurrences (78%) were IBC, and 22% were DCIS. After recurrence, 74% of women underwent a salvage mastectomy and 26% underwent a second BCT procedure. Tamoxifen was given as adjuvant therapy in 16%, and 12% received systemic chemotherapy. Three years after IBTR, the disease-free survival rate was 58.7%, cause-specific survival was 92.1%, and overall survival was 80.5%.

“In conclusion, with five years of follow-up in a large group of selected patients, APBI produced clinical outcomes and patterns of failure comparable to those reported with WBI,” the authors write. “Those patients who developed an IBTR after APBI had excellent three-year survival outcomes after salvage treatment, which, again, was similar to the outcomes of those who developed an IBTR after WBI.”

One author disclosed financial ties to Hologic Inc.

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