A new meta-analysis of studies investigating the impact of bisphosphonate treatment in early breast cancer has concluded that such treatment does not prevent disease progression. Bisphosphonates are used to treat osteoporosis and metastatic bone disease. The authors conducted a search of both published and unpublished randomized controlled trials available as of January 2009. The 13 trials included in the meta-analysis all compared patients with early stage breast cancer who received treatment with a bisphosphonate (a total of 3,414 patients) with those who did not receive such treatment (3,472 patients).

Adjuvant breast cancer treatment with bisphosphonates was not found to decrease the overall number of deaths, bone metastases, or recurrences (local or distant) compared to no use. When examining particular bisphosphonates, zoledronic acid was found to be associated with a statistically significant lower risk of disease recurrence. However, the authors comment that these results should be interpreted with caution because the statistical significance was weak. In addition, use of zoledronic acid was not associated with any significant difference in death or bone metastases. The currently available evidence does not support the use of bisphosphonates in adjuvant treatment of early breast cancer, according to the authors. However, nonsignificant trends were apparent in the data that suggested better outcomes in patients undergoing bisphosphonate treatment. The authors conclude that until further evidence from new clinical trials becomes available, adjuvant bisphosphonate treatment should not be recommended routinely.