That two distinct tumor profiles emerged was, in fact, of little surprise. Clinicians have long recognized at least two major courses DLBCL can take. Brown and his colleagues went further to match which tumor group was behind which prognosis: they found that patients with tumors expressing genes involved in later stages of B-cell development in general fared much worse after standard chemotherapy.
There may well be other subtypes of DLBCL, Brown points out. Indeed, only 40 percent of the 25,000 cases that occur each year respond well to treatment. But all subtypes--of all cancers, perhaps--stand to benefit from further gene expression analysis. "The differences we are seeing are at the level of the molecules and regulatory systems that are the targets of present and future anticancer drugs," Brown says. And the more clearly scientists can see this bull's-eye, the better they can take aim.