De novo malignancies are one of the current problems in patients with organ transplantation. The incidence has been considered to be higher as a result of increases of oncogenic viruses in immunosuppressed organ recipients. Published reports have shown increased incidence of de novo tumors such as malignant lymphomas and cutaneous neoplasms but decreased incidence of breast cancer. A variety of factors affect de novo breast cancer development in organ recipients, including immunosuppression, viruses, and underlying disease. The aims of this review are to evaluate the incidence and management of patients with de novo breast cancer by giving the University of Pittsburgh's data, and to evaluate the incidence of de novo breast cancer in published reports in light of an age-adjusted rate. According to age-adjusted rates presented by the National Cancer Institute's Surveillance, Epidemiology and End Results data, we found increased incidence rate of de novo breast cancer in the previously published series. The University of Pittsburgh's incidence rate of de novo breast cancer was determined in a fashion similar to that for the Surveillance, Epidemiology and End Results data. Eighty-three percent of all patients were diagnosed at early stages, and it appeared to take longer for de novo breast cancer to develop in patients treated with tacrolimus than in patients treated with cyclosporine. In conclusion, surgical treatment of breast cancer in liver recipients is the same as treatment of breast cancer in patients without transplantation. However, the effects of chemotherapy, radiotherapy, and/or tamoxifen remain unclear in transplanted patients and need to be evaluated in larger studies. (Liver Transpl 2004;10:1-6.)