In which clinical situations, if any, would you use imiquimod for treatment of breast cancer skin metastases?

Imiquimod is synthetic toll-like receptor (TLR)7 agonist that has immunostimulatory effects when applied topically. Topical application can enhance clearance of human papillomavirus (HPV)-​related genital warts, and might lower cancers associated with HPV, and is approved for that purpose. It has been tested in cutaneous metastases of breast cancer alone or in combination with chemotherapy, showing transient responses in 20-30% of patients, but only in Phase I/II and not in controlled trials that I am aware of (1, 2). It can cause skin irritation and rarely systemic allergic/immune reactions as might be expected with any immune stimulator.

In my opinion, it would be reasonable to discuss this with a patient with cutaneous symptomatic metas...