Expression of Cancer-Testis Antigens in Non-Hodgkin’s Lymphomas

Cancer-testis (CT) antigens are expressed in a variety of malignant tumors but in normal adult tissues solely in testicular germ cells. Based on this tumor-associated expression pattern, CT antigens are considered valuable targets for immunotherapy. While CT antigens have been studied in many solid tumors, much less is known about their presence in neoplasms of the hematopoetic system such as Non Hodgkin’s Lymphoma (NHL).

Aims: To analyze the expression of 10 CT antigens in NHL by immunohistochemistry (IHC) using tissue microarray (TMA) technology, and to correlate its expression with histologic subtypes.

Patients and Methods: Formalin-fixed paraffin-embedded tissues of 116 NHL cases dating from June 2003 to June 2007 were retrieved from the archives of the Department of Pathology, Federal University of São Paulo, Brazil. Two TMA blocks were generated comprising three cores/NHL case, as well as positive (testis) and negative (reactive lymph nodes) control tissue cores. The following monoclonal antibodies (mAbs) (to the following antigens) were used for IHC analysis: MA454 (MAGE-A1), M3H67 (MAGE-A3), 57B (MAGE-A4), CT7-33 (CT7/MAGE-C1), CT10#5 (CT10/MAGE-C2), E978 (NY-ESO-1), 219-510-23 (LAGE-1 and NY-ESO-1), #26 (GAGE) and SSX-2#7 (SSX-2). Two observers scored all slides independently and cases with loss of all three punches and/or missing tumor tissue were excluded from analysis.

Results: The number of cases which could not be evaluated due to loss of tissue core and/or missing tumor differed, ranging between 8 for mAb #26 to 12 for mAbs MA454, CT10#5 and 219-510-23. 7/116 NHL cases were missing in all slides. 14/109 (12.8%) NHL cases expressed at least one CT antigen: diffuse large B-cell lymphoma (DLBCL) 9/58 (15.5%); anaplastic large cell lymphoma (ALCL) 1/3; follicular lymphoma (FL) 1/10 (10%); lymphoplasmacytic lymphoma (LPL) 1/3; peripheral T-cell lymphoma (PTCL) 1/9 and histiocytic lymphoma (HL) 1/1. No CT antigen expression was present in lymphoblastic lymphoma (5), mantle cell lymphoma (2), small lymphocytic lymphoma (6), marginal zone lymphoma (4), MALT lymphoma (5) and mycosis fungoides (3). The most frequently expressed CT antigens were: GAGE 6/108 (5.5%), NY-ESO-1 5/105 (4.7%), CT7 5/106 (4.7%), MAGE-A1 4/104 (3.8%) and MAGE-A3 4/107 (3.7%). According to cell origin, positivity of CT antigens was more prevalent in B-cell NHL (11/91; 12.1%) than in T-cell NHL (1/15; 6.7%). NY-ESO1 5/91(5.5%) was the most frequently expressed CT in B-cell NHL, followed by GAGE 4/91 (4.4%), MAGE-A1 3/91 (3.3%), MAGE-A3 3/91 (3.3%), CT7 3/91 (3.3%) and LAGE 3/91 (3.3%). The only positive T-cell lymphoma case expressed MAGE-A1 and GAGE.

Conclusions: Expression of CT antigens in NHL is limited. In the present TMA-based IHC analysis, only 12% of NHLs express at least one CT antigen, with DLBCL showing the highest incidence and NY-ESO-1 being the most prevalent antigen. In spite of the low incidence, presence of CT antigens could offer the opportunity of vaccine-based immunotherapy in selected cases of NHL.