On June 26, Time magazine ran a story about molecular targeted therapy for treating cancer, characterizing these drugs as the promising future of cancer treatment. These therapies target cancer cells bearing one or more specific mutations. While general medical opinion suggests these molecular drugs are less damaging to healthy cells than conventional chemotherapies, other views suggest that targeted therapies are more likely than standard chemotherapy drugs to cause certain types of severe side effects that are typically experienced by small numbers of patients.
Whichever is correct, because these drugs work by interfering with the specific molecules involved in tumor growth and progression, they do represent an advance in treatment. At the Block Center, we employ certain ones with individual patients whenever they are indicated. We are finding, however, that they’re not entirely the “miracle drugs” that we’d like them to be.
For one thing, while targeted therapies don't share the same side effects as chemotherapy drugs, they are not totally free of problematic side effects, and many can be quite significant. Another myth circulating among both clinicians and patients is that patients will not develop a resistance to these drugs as they do with chemotherapies. This is simply not accurate. Individual patients do develop drug resistance. In fact, this can occur even more quickly than with chemotherapy, often with a full return of disseminated disease. And once cancer cells develop resistance to a specific drug, treatment must be halted.