Incidence of non-breast cancer neoplasms (non-BCN) diagnosed prior and subsequent to breast cancer (BC): Single institution experience.

Abstract

e13689 Background: The risk for developing subsequent non-BCN in BC patients is recognized as growing problem hence more patients are long term survivors. Limited data are available for non-BCN developed prior to BC. Better defining of types and frequency of non-BCN might be important for recognition of cancer predisposing factors. We aim to evaluate incidence, type, and time of development for all non-BCN in BC patients at the Institute for Oncology and Radiology of Serbia (IORS). Methods: During 2019, 2384 BC patients were seen at the IORS for treatment or follow up, all medical records have been evaluated for potential non-BCN diagnosis. Results: 230 (9.7%) patients also had variety of histologically confirmed non-BCN: in 78 (34%) as prior to BC, median 5 years (1-42); as synchronous with BC in 12 (5%) median 4 months (0 < 12 months) and in 140 (61%) as subsequent to BC, median 8 years (≥1-33). Six most frequent non-BCNs are presented in table. Conclusions: Amongst 230 BC patients 34 different non-BCN were identified. All non-BCNs were more frequently developed subsequently to BC, representing 61% of all non-BCN cases, with expected exception of HL hence 12/13 (92%) occurred prior to BC. EC,TC, OC, CRC and LC, represents 54 % of all non-BCN and were diagnosed more frequently as subsequent to BC while TC had similar incidence as prior and subsequent to BC. Subsequent development might be related solely to genetic factors, but at least in some cases, influence of BC treatment (tamoxifen, cyclophosphamide, radiotherapy) cannot be excluded.[Table: see text]