EBCC Glasgow 2014 Bisphosphonate debate

one of the  highlights was the debate between Robert Coleman (Sheffield UK) who has led this area and Gabriel Hortobagyi (MD Anderson, Tx,US). Robert reiterated data presented at SABCS 2013 , a metaanalysis of 36 studies and > 18000 patients showing an  reduction in the development of bone metastases and a 3% improvement in overall mortality for post menopausal women with ER+ve breast cancers.

Hortobagyi’s concerns were statistical, but relevant. There was tremendous heterogeneity amongst the studies, none of the studies met their individual primary endpoint (let alone the metaanalysis), the study outcome  was inversely proportional to size, and there was no interaction between schedule type of agent.

Certainly on the basis of no real data Coleman was recommending a 6 monthly schedule of zoledronic acid as per the Austrian study 12 and also the later part of the schedule of ZA in Coleman’s own AZURE study.

(SW) This is contentious and no bisphosphonate is TGA approved for this indication, nor funded on the PBS. Its use would  need to be case by case and i think logically, related to the absolute  risk of relapse of the individual patient. The toxicities of osteonecrosis of the jaw (albeit low 1-2%) need to be considered also.