Abstract
Patients with breast carcinomas of the invasive cribriform (IC) histological type often have excellent prognosis. Nevertheless, prognostic markers such as CD44v3, v4, and v6 isoforms have never been evaluated in this histological type. Cases seen between 1996 and 2006 at two major public hospitals in Kuwait were reviewed. We selected the cases which still had enough tissue in the paraffin blocks, had pure rather than mixed typical histological type, did not receive hormonal or any other type of therapy prior to or at the time the tumour was excised, and which were grade I and stage IIA (T2 NO MO). This is to control for confounding factors that could affect the degree of tumour expression of the above isoforms. Sections were immunostained using a highly sensitive peroxidase-anti-peroxidase kit, and scoring of immunostaining was performed in a semi-quantitative manner as established in the literature. An extensive expression of the CD44v3 and v6 isoforms was seen in 83.3% of the IC tumours, while 83.3% lacked the expression of the v4 isoform. A significant association between the histological type and degree of expression of CD44 isoforms was only found with the v3 isoform. The degree of expression of the Q isoform was significantly different in the IC tumours as compared to the papillary, invasive lobular, and invasive ductal (NOS) ones. There was a significant negative correlation (r(s)= - 0.201) between the expression of the v4 and v6 isoforms. In conclusion, IC tumours seem to have a strong expression of the prognostic markers v3 and v6 isoforms of the transmembrane molecule CD44, and to lack the expression of the v4 isoform.