In certain aspects, the present invention provides methods for determining whether a Her-2 positive cancer is likely to respond to treatment with a Her2-acting agent and/or whether a patient with a Her-2 positive cancer is likely to have a slow disease progression. In other aspects, the present invention is drawn to methods for determining whether a subject with a Her-2 positive cancer is unlikely to respond to treatment with at least one chemotherapeutic agent in addition to a Her2-acting agent and/or whether a patient with a Her-2 positive cancer is likely to have a fast disease progression.