PURPOSE: Lung cancer is the leading cause of cancer deaths worldwide. Early detection is difficult given the lack of an easy, inexpensive screening method and insensitivity and nonspecificity of current imaging methods. We report that testing for autoantibodies (AAbs) to tumor antigens using the EarlyCDT-LungTM test can help with identification of malignant lung nodules.
METHODS: A 69 year old female with a 30 pack-year smoking history was found to have a spiculated non-calcified, 14 mm nodule in the left upper lobe suspicious for malignancy or an inflammatory process, and was treated with antibiotics. Repeat CT showed stable findings after 3 months. A third CT, performed three months later, revealed decreased size from 15x13 mm to 12x11 mm. PET/CT revealed the nodule to have an SUV of 2.2. Because of the decreasing size and low FDG avidity, continued imaging follow-up was recommended. Due to our high suspicion for malignancy, we performed the EarlyCDT-Lung assay to better characterize the risk for malignancy. EarlyCDT-Lung is a blood test that was released by Oncimmune USA LLC in May 2009 that detects a panel of six AAbs (Annexin 1, CAGE, GBU4-5, NY-ESO-1, p53 and SOX-2) specific for tumor-associated antigens known to have implications in lung cancer.
RESULTS: EarlyCDT-Lung showed an elevated AAb level above cut-off for GBU4-5, suggesting the patient is at high risk of having a lung malignancy. A left upper lobectomy revealed a 23 mm well-differentiated adenocarcinoma. All margins were clear by >10 mm. Hilar and mediastinal nodes were negative (stage Ia). The patient is currently doing well with no evidence of disease.
CONCLUSION: A physician must be highly suspicious of malignancy before deciding to biopsy the lung. In this case, despite benign appearance on imaging, the EarlyCDT-Lung result increased our confidence that the lesion was malignant, leading to resection.
CLINICAL IMPLICATIONS: EarlyCDT-Lung can improve on the predictive value of CT and PET, and lead to earlier resection of malignant nodules.
DISCLOSURE: Keith Kelly, No Financial Disclosure Information; No Product/Research Disclosure Information