MicroRNA-based methods and compositions for the diagnosis, prognosis and treatment of solid cancers

A method of diagnosing whether a subject has a solid cancer, comprising

• measuring in a test sample from the subject a level of miR-21 gene product and miR-191 gene product,
• comparing the level of the miR-21 gene product and miR-191 gene product in the test sample to a control level of miR-21 gene product and miR-191 gene product;
• and
• diagnosing whether a subject has a solid cancer selected from the group consisting of colon, lung, pancreas, prostate, and stomach cancer,
• wherein an increase in the level of miR-21 gene product and miR-191 gene product in the test sample, relative to the control level of miR-21 gene product and miR-191 gene product, is indicative of the subject having a solid cancer selected from the group consisting of colon, lung, pancreas, prostate, and stomach cancer.