Role of Ki67 in predicting resistance to adjuvant tamoxifen in postmenopausal breast cancer patients

• Published in: Journal of Egyptian National Cancer Institute Vol. 25; no. 4; pp. 181 - 191
• Main Authors: Elzawahry, Heba M., Saber, Magdy M., Mokhtar, Nadia M., Zeeneldin, Ahmed A., Ismail, Yahia M., Alieldin, Nelly H.
• Format: Journal Article
• Language: English
• Published: Cairo, Egypt Elsevier B.V 01.12.2013; Cairo University, National Cancer Institute
• Subjects: Adjuvant hormonal therapy; Aged; Antineoplastic Agents, Hormonal - therapeutic use; Breast; Breast cancer; Breast Neoplasms - drug therapy; Breast Neoplasms - genetics; Breast Neoplasms - metabolism; Breast Neoplasms - mortality; Breast Neoplasms - pathology; Cancer; Chemotherapy, Adjuvant; Drug resistance; Drug Resistance, Neoplasm - genetics; Egypt; Female; Follow-Up Studies; Humans; Immunohistochemistry; Ki-67 Antigen - genetics; Ki-67 Antigen - metabolism; Ki67; Middle Aged; National Cancer Institute; Neoplasm Grading; Neoplasm Staging; Patients; Postmenopausal; Postmenopause; Prospective Studies; Recurrence; Tamoxifen; Tamoxifen - therapeutic use; Therapeutic use; الثدي; السرطان; المرضى; Postmenopausal; Egypt; National Cancer Institute; Breast cancer; Adjuvant hormonal therapy; Tamoxifen; Ki67
• ISSN: 1110-0362; 1687-9996; 2589-0409
• DOI: 10.1016/j.jnci.2013.02.001

Breast cancer (BC) is a major health problem in Egypt and worldwide. Its prognosis depends not only on tumor stage but also on tumor biology. To correlate the expression of Ki67 with the clinical outcomes of early hormone-receptor positive postmenopausal BC patients who are receiving tamoxifen. This cohort study included 70 patients. They were followed up for a minimum of 2years. Ki67 was assessed on paraffin-embedded blocks using immunohistochemistry methods. The median Ki67 value was 22.5% (IQR, 10%–50%). Ki67 was significantly higher in patients with HER2 positive tumors compared to HER2 negative tumors. After a median follow up period of 53months, 22 patients (31%) developed disease recurrence either loco-regional or distant in 5.7% and 30%, respectively. Recurrent patients had significantly higher tumor stage, nodal stage and Ki67 values compared to non-recurrent cases. The 2-, 3- and 5-year overall survival (OS) and disease-free survival (DFS) rates were 100% & 91%, 98% & 84% and 77% & 59%, respectively. DFS was significantly worse with higher TNM stage, lower ER expression and higher Ki67 values. OS was significantly worse in patients with Ki67 values ⩾30%. Ki67 ⩾30% was an independent predictor of recurrence, poor DFS and OS. High Ki67 expression is predictive of poor prognosis and of resistance to adjuvant tamoxifen therapy in postmenopausal BC. We recommend considering Ki67 as one of the risk factors that guide adjuvant treatment decisions.