At 3 years, there was no difference in disease-free survival, with an 85% rate in the combination group and 84% in the ibandronate-only group. At 5 years, disease-free survival was 79% and 75%, respectively. Nor was there any difference in overall survival at 3 years; in fact, survival was quite good, Dr. von Minckwitz said, with 95% still alive in the combination group and 94% in the ibandronate-only group. At 5 years, patients continued to do very well, with an overall survival of 90% in the combination group and 88% in the ibandronate-only group.
There were no significant between-group differences in any subgroup analyzed, including separation by age; pN status; hormone-receptor status; hemoglobin, albumin, and creatinine clearance; comorbidity status; or body mass index.
Adverse events of grades 3 or 4 were significantly more common in the combination group (31% vs. 9%). Two individual events drove that finding – gastrointestinal problems (6.7% vs. 1%), and skin disorders, especially hand-foot syndrome (14.6% vs. 0.6%).
Other adverse events more common in the combination group included blood and lymphatic disorders (1.2% vs 0.7%); neuropathy and dizziness (2.5% vs. 0.7%) arrhythmias and cardiac ischemia (1.8% vs. 0.4%); and thromboembolic events (2.8% vs.1.3%).
Ibandronate completion was virtually identical – about 76% in each group. Most patients in the combination group (83%) also completed the treatment.
A quarter of patients in each group experienced a bone-related adverse event, excluding metastasis. These included fractures, surgery, and new osteoporosis. Because these were so frequent, Dr. von Minckwitz suggested that bisphosphonates should be part of any treatment regimen for this population.
The ICE survival curves are so good, Dr. Minckwitz said, that they raise a bit of a question, which only time can answer. “Due to the excellent survival data, we need longer follow-up to observe any potential late effect of capecitabine.”
He had no relevant financial disclosures. The German Breast Group has no financial ties with any pharmaceutical company.
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