Safety of alternative treatments for menopausal symptoms after breast cancer: a qualitative systematic review

Aim This qualitative review analyzes systematically the safety of drugs used to alleviate menopausal symptoms, other than hormone replacement therapy, in breast cancer patients. Methods We searched systematically studies using tibolone, serotonin reuptake inhibitors, clonidine, veralipride, gabapentin, black cohosh and phytoestrogens in breast cancer patients. We selected five studies for which we evaluated the methodology, characteristics of the studied populations, outcomes in terms of mortality and recurrence rates. Results Four trials were conducted using tibolone in breast cancer patients: one double-blind, randomized trial, one prospective controlled study, and two uncontrolled studies. They considerably lack power to detect any difference in breast cancer recurrence or mortality between the treated and control patients. Similar conclusions have to be drawn from the only controlled retrospective study analyzing the safety of antidepressants and antihistamines. We were unable to find studies reporting the safety of the other drugs in breast cancer patients. Conclusions There are no valuable data indicating the absence of a harmful effect of drugs used to alleviate climacteric symptoms in breast cancer patients. There is a need for randomized trials to assess the safety of these drugs. In the meantime, patients should be informed about the absence of safety data.