European Journal of Biomedical and Pharmaceutical Sciences

EFFICACY OF CDK4/6 INHIBITOR IN TREATMENT OF METASTATIC BREAST CANCER AND COLON CANCER

J. Raycheva, M.D.*1 and M. Taushanova-Hadjieva M.D. Ph.D2

ABSTRACT

Background: Efficacy of CDK4/6 inhibitors in treatment of metastatic breast cancer and colon cancer. Case report: A 52-y.o. woman was diagnosed with an invasive left-sided ductal breast cancer, G3 - T2N0M0; ER (3+), PR (+), HER2 (-), Ki67-11%. She underwent a radical mastectomy, followed by adjuvant chemotherapy and hormone treatment with Tamoxifen. A year later she was diagnosed with a colorectal cancer-low grade, G1; adenocarcinoma - T3N1M1 with liver metastases. After a biopsy, which revealed that the metastases are coming from the breast (ER+/HER 2(-) Breast cancer - (GATA (3+)), she was restaged as T3N1M0. The patient started treatment with Ribociclib 600mg/d + Letrozole 2,5mg/d with a complete response of the disease after three months of treatment. Due to G3 neutropenia, the dose was adjusted to 400 mg/d. Last restaging: July 2019 – stable disease and a good quality of life. This case approves that the CDK 4/6 inhibitors are able to manage visceral metastases and to provide long-term survival without worsening the quality of life. Conclusion: Her disease is successfully managed with CDK4/6 inhibitor together with hormonal therapy, which proves the effect of the CDK 4/6 inhibitors in treatment not only to breast cancer. Six months after there are no signs of relapse of the colon cancer. Despite the stage of the second cancer – T3N1M0, the patient did not undergo adjuvant treatment for the colon cancer.

Keywords: Metastatic breast cancer; colon cancer; hormone therapy; efficacy; safety profile.