What is consolidation therapy ... Instead of understanding this term with regard to therapy, understand it with regard to timing: consolidation therapy is a therapy administered to a cancer patient immediately after induction therapy (this just means the first therapy received), for the purposes of 'mopping up' any remaining, wayward, hard-to-find cancer cells lurking in the body.
If a person goes in for breast cancer surgery (induction therapy), they might receive radiation afterwards (consolidation therapy).
Follicular lymphoma patients sometimes undergo combination chemotherapy (induction) followed by rituximab (consolidation).
A third step, maintenance therapy, is sometimes involved in treatment plans. However, not all treatment approaches are the same and they will differ depending on cancer type, among other factors.
Perhaps the most complete example of consolidation therapy comes from pediatric cancers.
Children with acute lymphoblastic leukemia (ALL), the most commonly diagnosed pediatric cancer, first undergo an induction phase, consisting of two to four chemotherapy drugs and perhaps a steroid. This phase is designed to put the leukemia into remission by killing over 99 percent of the cancer cells in the child's body.
Back in the 1970s, kids with ALL received the induction phase, which lasts about one month, then they entered the maintenance phase, which lasts as long as two years. But kids kept relapsing. They were relapsing because induction therapy was putting them into what their tests told them was complete remission, when in fact cancer cells remained. When testing for the leukemia cells became more sensitive, it became clear that induction therapy wasn't achieving complete remissions.
Consolidation therapy was added to the protocol, and now kids with ALL have an excellent chance of achieving full and lasting remission.
As is very typical in cancer terminology, consolidation therapy is sometimes referred to using other terms, including:
They mean the same thing; the central idea behind it remains the same. As MedicineNet puts it, consolidation therapy "consolidates the gains obtained [from induction therapy, to] further reduce the number of cancer cells and enhance the likelihood of a durable complete remission."
It's important to remember that induction therapy can mean many things—surgery, chemotherapy, radiation, even a stem cell transplant, or even chemotherapy AND a transplant—and that consolidation can too—immunotherapy, chemotherapy, radiation, antibody drug conjugates and more. So there's no one single treatment that means 'consolidation', it is simply going to be a therapy that follows closely behind a prior therapy and is meant to chase remaining cancer cells in the body.
You can see the term at work in this video of Dr. Paul Richardson discussing consolidation for multiple myeloma.
Sources: NCI, ACS