Ki67 as Proliferative Marker in Patients with Early Breast Cancer and Its Association with Clinicopathological Factors

<b><i>Introduction:</i></b> Ki67 as a proliferative marker has prognostic and therapeutic relevance in early breast cancer (EBC). However, standard cutoffs for distinguishing low and high Ki67 do not exist. <b><i>Material and Methods:</i></b> Data from all patients treated at the University Hospital Ulm for EBC between January 2013 and December 2015 with documented results for internal Ki67 assessment of the primary (<i>n</i> = 917) tumor were retrospectively analyzed evaluating the associations between Ki67 and other clinicopathological factors. <b><i>Results:</i></b> 595 (64.9%) patients had a Ki67 &#x3c;20% and 322 (35.1%) a Ki67 ≥20%. The median Ki67 was 10% (range 1–90%). Median Ki67 values according to the hormone receptor (HR)/ human epidermal growth factor receptor 2 (HER2) subtypes were 10% for HR-positive/HER2 negative (HR+/HER2−) disease (<i>n</i> = 717), 20% for HR+/HER2+ (<i>n</i> = 76), 30% for HR−/HER2+ (<i>n</i> = 45), and 60% for HR−/HER2− (<i>n</i> = 75). 75.2% or 89.3% of all patients with HER2-positive or triple-negative disease had a Ki67 ≥20%, respectively. Using a multivariable logistic regression with Ki67 (&#x3c;20% vs. ≥20%) as binary dependent variable, younger age, positive nodal status, higher grading, histological nonspecific type carcinoma, negative HR status, and positive HER2 status were shown to be significantly associated with a higher proliferative index (Ki67 ≥20%). <b><i>Conclusion:</i></b> This analysis described Ki67 in different subtypes in EBC and its association with clinicopathological factors. According to more aggressive tumor biology, the respective subgroups also showed higher median Ki67 levels. However, definition of low and high proliferation index itself is difficult. It is essential to interpret Ki67 indices carefully with regard to the own institutional values and other clinicopathological factors.

Immunohistochemical Expression of Ki-67 and p53 in Surface Epithelial Ovarian Tumour

BACKGROUND Surface epithelial ovarian tumour (SEOT) develops from the outer surface of ovary. It accounts for more than 90 % of all the ovarian tumours. Most of the SEOT are benign. Few SEOT are of low malignant potential or high malignant potential. The purpose of this study was to assess the rate of expression of proliferative marker Ki-67 and staining pattern of p53 in various histological types of SEOT. METHODS It was a randomised type of study carried out in the Department of Pathology, GSVM Medical College, Kanpur, for 2 years. It included 100 random patients with surgically resected specimens of SEOT. Ki-67 immunohistochemistry (IHC) was performed on all malignant cases and few random benign cases; and the percentage of immunopositive cells in each case was expressed as Ki-67 labelling index (Ki-67 LI). p53 expression was interpreted as positive when cells showed diffuse and intense nuclear staining in malignant cases. RESULTS Out of 100 cases, 70 were benign and 30 were malignant. Cases comprised of serous and mucinous histological subtypes. In all malignant cases, Ki-67 expression was found to be positive (Ki-67 LI > 1 %). Highest Ki-67 LI of 52 % was associated with high grade serous cystadenocarcinoma. High grade serous carcinoma (HGSC) had higher p53 positivity. 88.8 % of HGSC were p53 positive. CONCLUSIONS Ki-67 is a cost-effective proliferative marker; therefore, its assessment can be included in routine histopathological report of SEOT for better understanding of the biologic behaviour and aggressiveness of the tumour. p53 expression was more common in HGSC and can help in discriminating between HGSC and lowgrade serous carcinoma (LGSC). KEYWORDS p53, Ki-67, Ovarian Tumour, Serous, Mucinous, SEOT