Objectives: Adjuvant immunotherapy is an innovative therapeutic option that might potentially improve outcome of early-stage non-small cell lung cancer. Melanoma associated antigen (MAGE)-A3 is a promising target for immunotherapy because it is exclusively presented on the cell surface of cancer cells and might be associated with an aggressive cancer phenotype. The present study was performed to determine the rate of MAGE-A3 expression in early-stage non-small cell lung cancer (NSCLC).
Patients and methods: Primary tumor samples from 204 patients with operable clinical Stages I or II NSCLC were collected between March and November 2001. Pathological Stage was determined by the local pathologist in each of the 16 participating institutions. Tissue samples were stored immediately after surgery in a RNA-stabilizing solution and were frozen at -20 degrees C. MAGE-A3 expression was analyzed by detection of MAGE-A3 transcripts using reverse-transcriptase polymerase chain reaction.
Results: MAGE-A3 expression was observed in 80 out of the 204 (39.2%) examined Stages I-II primary tumors. Stratification into UICC-Stages showed that 31 out of 105 (29.5%) Stage I non-small cell lung cancers and 49 out of 99 (49.5%) Stage II non-small cell lung cancers expressed MAGE-A3. In comparison to Stage I, the rate of MAGE-A3 positive tumors was significantly increased in Stage II (P=0.004; Chi-square test).
Conclusion: The MAGE-A3 expression rate showed that a promising proportion of operable patients with early-stage non-small cell lung cancers are possible candidates for trials investigating adjuvant therapy with MAGE-A3 immunization. Currently, a phase two trial of adjuvant MAGE-A3 vaccination is in progress.