Ipsilateral in-breast tumor recurrence after breast conserving therapy: true recurrence versus new primary tumor.

Purpose: To classify ipsilateral in-breast cancer recurrences (IBCR) in patients treated with conservative surgery and radiation therapy, either as new primary tumor (NP) or true recurrence (TR) and to assess the prognostic and therapeutic importance of this classification.

Methods: The records of 107 patients treated for local tu- mor recurrence after breast-conserving therapy (BCT) at the National Cancer Center, Sofia, between March 1999 and May 2011 were retrospectively analysed. The patients'primary tumors were up to 2 cm in size.