Endometrial cancer associated with an increase of CA 15 3 and CA 125 in tamoxifen treated patients with breast cancer

: The study presents a case of endometrial cancer in a breast cancer patient treated with tamoxifen. The disease occured with elevated values of CA 125 and CA 15_3 tumour markers without any other signs. Additional diagnostic analyses were performed showing a "de novo" endometrial cancer rather than metastatic breast cancer. The patient underwent surgery and radiotherapy. Thereafter, the values of tumour markers were in the reference values.