Abstract: The invention concerns kits and methods for the diagnosis, prognosis and monitoring of cancer. In one aspect, there is provided a method for identifying whether or not a mammal is suffering from cancer, wherein the method comprises the steps of: (a) measuring a signal due to a non-IgG immunoglobulin binding to a carbohydrate-containing antigen in a sample from the mammal; and (b) comparing the signal measured in step (a) with a signal due to the non-IgG immunoglobulin binding to the carbohydrate-containing antigen in one or more samples from one or more mammals known to have cancer and/or with a signal due to the non-IgG immunoglobulin binding to the carbohydrate-containing antigen in one or more samples from one or more healthy mammals.