Treatment repeats every 3 weeks in the absence of disease progression or unacceptable toxicity. Blood samples are collected at baseline and periodically during treatment for pharmacogenetic studies. Tumor tissue samples that are available are also collected for laboratory studies. Samples are analyzed for number of circulating tumor cells, levels of intracellular targets (e.g., CDK4, akt, phospho-akt, Hsp90, Hsp70, and CHK1), single nucleotide DNA polymorphisms, and Vav1 expression. Samples are analyzed by reverse transcriptase-polymerase chain reaction, immunofluorescence, and immunohistochemistry.