Relation of CD117 immunoreactivity and microvascular density in invasive breast carcinoma.

Background and Objective: In breast cancer, the expression of CD117 represents a highly controversial subject but the majority of studies have found decreased c-kit expression in malignant breast epithelium. A number of studies have reported that increased intratumoral microvessel density (MVD) is associated with poor prognosis in breast cancer. The aim of the study was to assess the relation of CD117 and MVD with other clinicopathological parameters in invasive breast carcinomas using the tissue microarray technique. Materials and Methods: A total of 126 cases of invasive breast carcinoma of different histological types and grades were collected from files of a pathology department during 2010. Clinicopathological and histological parameters were evaluated. Sections from formalin-fixed, paraffin-embedded tumor tissues microarray blocks were immunostained with CD117 and CD34. Statistical analysis of data was done using SPSS, version 16.0. Results: About 29% of invasive breast carcinomas were CD117 positive. There were significant differences between expression of CD117 in the tumor epithelial cells and age of the patient; tumor grade; tumor size, and LN metastasis. Also, there was significant relation between expression of CD117 in the tumor epithelial cells and MVD, expression of estrogen, and progesterone receptors. On multivariate analysis, the most important predictors of negativity of CD117 were tumor size and positive lymph node involvement. Conclusion: Lack of CD117 immunoreactivity in invasive breast carcinoma was associated with features of more aggressive tumor behavior as higher microvessel density, larger size, higher tumor grade, more lymph node metastasis, and negative estrogen and progesterone receptors.

Gastrointestinal stromal tumour--a paradigm shift in management of solid tumours.

Gastrointestinal stromal tumour (GIST) till recently were non-responsive to all chemotherapy agents. With the advent of c-kit, diagnosis of GIST has become more specific. STI-571, a tyrosine kinase, has become one of the first targeted therapeutic agent tobe active in solid tumour. At present it is the only agent with substantial activity in GIST.