Background
Breast cancer incidence was 114 cases on 100.000/year.
Bone is the most frequent site of metastases (mts) from breast and the presence of Skeletal Related Events (SRE) increases morbidity. The treatment is based on chemotherapy, endocrine therapy, radiotherapy and recently also target therapy agents (trastuzumab, lapatinib, bevacizumab, everolimus). These therapies are frequently associated with antiresorptive agents, such as Bisphosphonates (BPs), including Pamidronate, Zoledronic Acid, Ibandronate, or an anti-RANKL agent, Denosumab. All these agents are able to reduce the risk of SRE and to delay SRE onset. However they are associated with adverse events, including Osteonecrosis of Jaw (ONJ) that can occur in 1.1–9.9 % of breast cancer pts. Preventive (risk reduction) measures before BP and Denosumab treatment (dental visit, dental RX, eventual teeth extractions, dental and denture care) have been recommended.
Materials and methods
We reviewed all breast cancer patients affected by bone mts observed by our team at the Oncology Unit in years 2005–2013. They were classified as: a) Hystoric group (pts already under BP treatment on 2005); b) Prevention group (pts undergoing preventive measures before BP therapy start); c) Screening group (pts treated with BP, not receiving prevention due to several reasons, on years 2006–2013).
Results
We followed 168 pts treated with BPs and/or Denosumab. ONJ was observed in 10/168 pts (5.9%). In the Historic group we observed ONJ in 6/60 pts (10%); in the Screening group in 3/24 pts (12.5%); in the Prevention group in 1/84 (1.2%).
Conclusions
The preventive measures can minimize the rate of ONJ and could potentially reduce the impact on Quality of Life in case of ONJ onset. Breast cancer pts that start BP and Denosumab without pre-treatment assessment (due to clinical emergency, etc.) are at higher ONJ risk. Our experience data reinforce the literature recommendations about implementing preventive protocols.
References
- AA VV. Linee Guida AIOM Associazione Italiana Oncologia Medica. 2013. available at www.aiom.it.
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