Ki 67: a Promising Prognostic Marker in Early Breast Cancer-a Review Article.

Ki67 index is considered to be a reliable indicator of the proliferative activity of breast cancer. Additionally, the Ki67 proliferative marker may play a role in assessing response to systemic therapeutic strategies and can act as a prognostic biomarker. But its limited reproducibility which stems from a lack of standardization of procedures, inter-observer variability, and preanalytical and analytical variabilities all have hampered the use of the Ki67 index in clinical practice. Currently, clinical trials have been evaluating Ki67 as a predictive marker for needing adjuvant chemotherapy in luminal early breast cancer patients receiving neoadjuvant endocrine therapy. But the inconsistencies existing in the estimation of the Ki67 index limit the utility of Ki67 in standard clinical practice. The purpose of this review is to evaluate the benefits and drawbacks of utilizing Ki-67 in early-stage breast cancer to prognosticate the disease and predict the risk of recurrence.

Unchartered waters: Significance of fall in Ki67 index after short-term preoperative endocrine therapy in early breast cancers.

BACKGROUND: Endocrine treatment for breast cancer acts largely by inhibiting tumor cell proliferation. The biomarker Ki67 is linked to the proliferative index of the tumour. OBJECTIVE: To identify the factors affecting the fall in Ki67 value in early-stage hormone receptor (HR) positive breast cancer patients receiving short-term preoperative endocrine therapy in an Indian cohort. METHODS: Women with hormone receptor positive, invasive, nonmetastatic, and early breast cancer (4 week) did not affect the fall in Ki67. CONCLUSION: Preoperative therapy with Letrozole resulted in a more significant fall in Ki67, as compared to therapy with Tamoxifen. Determining the fall in Ki67 value in response to preoperative endocrine therapy could provide an insight into the response to endocrine therapy in luminal breast cancer.

Fall in Ki67 Index After Short-Term Preoperative Letrozole: a Gateway to Assess the Response in Hormone-Positive Early Breast Cancers.

Endocrine treatment for breast cancer acts largely by inhibiting tumor cell proliferation. The study aimed to explore the fall in proliferative marker Ki67 in patients receiving preoperative endocrine therapy and the factors associated with it. A prospective series of hormone receptor-positive postmenopausal women with early N0/N1 breast cancer were enrolled. Patients were requested to take letrozole OD while they await surgery. The fall in Ki67 after the endocrine therapy was defined as the percentage of the difference between the pre-and postoperative Ki67 value with the preoperative Ki67. Sixty cases matched the criteria of which 41 (68.3%) of women showed a good response to preoperative letrozole (fall in Ki67 > 50%; p-value < 0.001). The average mean fall in Ki67 was 57.083 ± 37.97. Postoperative Ki67 after the therapy was less than 10% in 39 (65%) patients. Ten patients (16.6%) had a low Ki67 index at baseline, which continued to remain low after preoperative endocrine therapy. The duration of the therapy did not affect the percentage of Ki67 fall in our study. Short-term changes in the Ki67 index in the neoadjuvant settings may predict outcomes during adjuvant use of the same treatment. Proliferation index on residual tumor holds prognostic importance, and our results reflect that greater attention should be given to the percentage of reduction of Ki67, rather than focusing purely on a fixed value. This could help predict patients who respond well to endocrine therapy, while those who respond poorly may require further adjuvant treatment.