This study evaluated the benefit of radiation therapy in high-risk breast cancer patients who have received immediate transverse rectus abdominis myocutaneous (TRAM) flap reconstruction. The evaluation involved examining the effect of radiation therapy on postmastectomy flap fat necrosis and tumor recurrence.

A retrospective review was performed on 102 patients who underwent mastectomy and immediate TRAM flap reconstruction between 1996 and 2001 at the Asan Medical Center (Seoul, Korea). The mean patient age was 41 years, and the median follow-up time was 33 months. Skin-sparing mastectomy was con ducted in 82 patients (80.4%) and classical mastectomy in 20 patients (19.6%). Of the 21 high-risk patients needing postmastectomy radiation therapy, nine received it.

Moderate or severe TRAM flap fat necrosis occurred more frequently in patients receiving radiation therapy than those not receiving radiation therapy (55.6% vs. 19.4%, P=0.026). In the group with high-risk patients, two tumor recurrences occurred (one-locoregional and one- systemic). Among the 102 patients, thirteen had recurrences, including only two high-risk patients, with almost of them being systemic recurrences except four locoregional recurrences.

Our findings showed that radiation therapy increased flap fat necrosis in high-risk patients underwent immediate TRAM flap reconstruction. Such necrosis can result in poor outcomes for reconstruction. We recommend careful consideration prior to using radiation therapy on highrisk breast cancer patients after immediate TRAM flap reconstruction, where clinicians need to balance the possible positive effects on recurrence with the possible negative effects on flap tissue.