The method of the present invention can rapidly identify with expected accuracy those that are likely to respond to farnesyl transferase inhibitors and etoposide, teniposide, tamoxifen, sorafenib, paclitaxel, temozolomide, topotecan AML patients, including elderly AML patients, who respond to a combination of one or more of , trastuzumab, and cisplatin. In one embodiment, the improvement includes using whole blood instead of the usual bone marrow sample, making the test more accurate, faster, less intrusive, less expensive and less painful. The method includes evaluating the expression ratio of the two genes (RASGRP1:APTX) in combination with corresponding thresholds, which provides sufficient precision for the prediction of response to combination therapy. A preferred embodiment is the combination therapy of tipifarnib (R1 15777,) combined with etoposide. Further, elderly AML patients identified as likely to respond to the combination of tipifarnib and etoposide had full recovery rates comparable to younger patients under optimal treatment conditions.