Abstract: The present invention relates to methods for detecting antibodies, methods for diagnosing lung cancer and kits for lung cancer diagnosis. The methods of the invention are based on a blood or serum sample of a subject. According to a preferred embodiment, the invention uses a combination of different peptides comprising an amino acid stretch of BARD1, short peptides and/or larger fragments thereof. In preferred embodiments, the methods of the invention comprise measuring the amount of autoimmune antibodies in the sample binding to each of the different peptides and applying a statistically determined assessment for making the diagnosis.