Role of Ki-67 index in predicting adjuvant chemotherapy response in node positive luminal cancers (Poster presentation)

Abstract

<p>Background: Being node-positive is one of the indications for adjuvant chemotherapy for breast cancers. However, its role in luminal cancers, especially in those with low proliferative index (e.g. Ki-67), is less wellestablished. This territory-wide cancer registry study aims to evaluate the role of adjuvant chemotherapy in node-positive breast cancers with low- and high- proliferative index.<br></p><p>Methods: A territory-wide breast cancer database was reviewed. The database contained prospectively maintained data of all breast cancer patients treated in Hong Kong between 1996 and 2006. Analysis of 10-year local relapse rate of node positive luminal breast cancer patients with or without adjuvant chemotherapy was performed.<br></p><p>Result: 3072 patients were treated for node-positive luminal breast cancer. Of which 237 were found to have low Ki-67 ( < 12%), 269 had high Ki-67 index, while 59 (24.9%) patients in the low Ki-67 group did not receive adjuvant chemotherapy, 171 (72.2%) patients in the low Ki-67 group received adjuvant chemotherapy. 52 (19.3%) patients in the high Ki-67 group did not receive adjuvant chemotherapy, while 213 (79.2%) in the high Ki-67 group received chemotherapy. Background demographic characteristics between all four groups (i.e. Low KI-67 / No Chemotherapy, Low Ki-67 / Chemotherapy, High Ki-67 / No Chemotherapy, High Ki-67 / Chemotherapy) were comparable (p> 0.05) 10-year relapse free survival in the low Ki-67 group who received chemotherapy was 89.5%, and was 72.9% in those who did not receive adjuvant chemotherapy (p = 0.002). 10-year relapse free survival in the high Ki-67 group who received chemotherapy was 75.6%, and was 63.5% for those who did not receive chemotherapy.<br></p><p>Conclusions: Significant survival benefit is observed in node-positive breast cancers treated with adjuvant chemotherapy, irrespective of the Ki-67 level.<br></p>