PO-341 The role of cancer/testis antigens from MAGE-A family and NY-ESO-1 in ductal carcinoma in situ (DCIS)

Abstract

IntroductionCancer/testis antigens (CTA) are a large family of tumor-associated antigens expressed in human tumours of different histological origin, but not in normal tissues except for testis and placenta. Several immunohistochemical studies confirmed the association of CT antigen expression and ER negativity in breast tumours and demonstrated their frequent expression in tumours with higher nuclear grade. The expression of cancer/testis antigens in ductal carcinoma in situ is not studied so extensively as in invasive breast cancer.Material and methodsThis retrospective study included archived paraffin-embedded specimens from 83 patients diagnosed with DCIS in the period between 2007. and 2014, a mean follow up time for local recurrence was 6.5 years. Antigens multi-MAGE-A, MAGE-A1, MAGE-A10 and NY-ESO-1 and were demonstrated by immunostaining. TILs were determined on all sections together with the histopathological variables of DCIS.Results and discussionsAll tested antigens showed association (positive or negative) with histopathological parameters. Expression of MAGE-A1 was significantly associated with cytoplasmic staining (p=0,007). Simultaneously cytoplasmic and nuclear staining was in statistically significant positive correlation with local recurrence (p=0,005) and central necrosis (p=0,016) and in negative correlation with expression of ER receptors (p=0,003) and PR receptors (p=0,009). Antigen MAGE-A10 was significantly associated with tumor-infiltrating lymphocytes (p=0.05). The additional analysis of TILs showed statistically significant positive correlation with grade (p=0.023), and central necrosis (p<0.001), and negative with tumour size (p=0.623), ER receptors (p=0.003) and PR receptors (p=0.027).ConclusionCancer/testis antigens from MAGE family (MAGE-A1, multi-MAGE-A and MAGE-A10) and NY-ESO-1 correlate with histopathological predictive variables of DCIS. The expression of antigen MAGE-A10 could have an important role in treatment of patients with negative histopathological predictive variables, but further analysis is required. Simultaneous cytoplasmic and nuclear protein expression of MAGE-A family and NY-ESO-1 cancer-testis antigens represent an independent marker for local recurrence. Cancer/testis antigens are not perfect indicators of invasiveness for DCIS, but in combination with others histopathological predictive variables they can be used as a guidance for better treatment of this patients. But, this is the small study and further larger studies are necessary to confirm our findings.