Safety and Efficacy of Long-Term Zoledronic Acid in Advanced Breast Cancer with Bone Metastasis in South China

Table 2

Long-term adverse effects of ZA in advanced breast cancer with bone metastasis.

Parameter		Group A (ZA 6–24 months); n = 293	Group B (ZA > 24 months); n = 273	value
ONJ	No	284 (96.9%)	267 (97.8%)	0.606
	Yes	9 (3.1%)	6 (2.2%)
Renal impairment	No	291 (99.3%)	270 (98.9%)	0.676
	Yes	2 (0.7%)	3 (1.1%)
Hearing impairment	No	293 (100.0%)	273 (99.7%)	0.482
	Yes	0 (0.0%)	1 (0.4%)

ONJ: osteonecrosis of jaws; AE: adverse effect. In the safety analysis, the enrolled cases included cases without SRE before the initiation of ZA, mentioned previously, and cases with SRE before the initiation of ZA. All were compared by Fisher’s exact test.