Dear Editor, The paper by Henry et al published by Supportive Care in Cancer comparing efficacy of denosumab versus zoledronic acid in patients with bone metastases of advanced solid tumours
[1] comes to integrate the original reports of three pivotal large randomized phase 3 trials
[2][3][4], the publication by Saad et al about osteonecrosis of the jaw (ONJ) in those three trials
[5], and the combined outcome analysis by Lipton et al
[6].Henry et al[1] reported outcomes of the single trial conducted on patients with solid tumours (except breast or prostate cancers, object of other two trials)
[2,3], excluding patients with multiple myeloma: This ad hoc analysis confirmed the superiority of denosumab in delaying or preventing skeletal-related events
[1]. Amongst side effects, after a median (Q1, Q3) time on study of 6.7 (3.2, 13.0) and 6.4 (3.1, 12.9)months in the two groups, ONJ was reported in six denosumab arm patients (0.8 %) and in nine zoledronic acid arm patients (1.1 %).
We wish to underline some sparse data reported in the cited papers, focusing attention on occurrence of ONJ in patients with renal cell cancer (RCC) included in the trial.
In the summary ONJ analysis [5] of the above-mentioned three randomized trials comparing zoledronic acid and denosumab in patients with several cancer types and conducted between 2006 and 2009, it appears that an "Oral Event Identified as Potential ONJ" was registered in 276 patients out of 5,723 (4.8 %).