BMT for Breast Cancer
It is becoming more widely accepted that BMT is inferior to Peripheral Blood Stem Cell transplantation from a standpoint of safety and efficacy for both autologous and allogeneic indications. It is also cheaper and less painful to patients (I've been on the BMT registry for over a decade and didn't really look forward to a call!)
In the case of breast cancer, for many years two debates went on- whether HDC was more effective than conventional chemo and 2. If it was whether BMT/stem cell rescue re-infused tumor cells into the patient leading to relapse.
The BMT and later PBSC transplants were always part of the HDC- it was the only way to make HDC feasible without killing the patient.
While studies have shown that tumor depletion from stem cell transplants are effective at removing circulating tumor cells, the effect on disease free survival has not been established. It is the subject of current clinical trials by at least one group.
Further, the presumed advantage of HDC has been seriously called into question, by the NEJM article among others, and many who were once staunch advocates of HDC are rethinking it and doing less. This is also been driven by the introduction of Herceptin and the development of other BC vaccines.
But I don't think it's fair to cast this as a "Huge industry has grown up doing the (untested) bone marrow transplants, and exerts big-time political pressure to stay in business". The transplantation is a necessary part of HDC, which is itself a response to the very poor therapeutic ratio of many chemotherapeutic agents (i.e. the minimum effective dose is close or greater than the maximum tolerated dose). Hence HDC was a logical therapy to obtain a safe way to administer the minimum effective dose and transplantation was a logical way to rescue the hematopoetic system.
As you pointed out, BMT is a messy process, very expensive and unpleasant. While it is currently under question as to efficacy, I know that for many years physicians truly believed it was giving the patient the best possible chance.
Hopefully current therapies will offer simpler, more effective and less costly alternatives.
Disclosure: I do work in the stem cell transplantation area but not in BMT or PBSC for autologous stem cell transplantation for HDC.
RWR |
