The use of R-CHOP, given every two weeks, will be associated with improvements in response rate, and progression-free survival, when compared to R-CHOP given every three weeks. The addition of sargramostim will allow safer adminIstration of the dose-intensified R-CHOP, while at the same time, improving the functional capability of the macrophages, and thus increasing the likelihood of improved clinical response and disease-free survival.