Autologous transplantation. Purging and the impact of minimal residual disease.
Without a randomized trial any benefit of purging on patient survival will remain theoretical. Although molecular techniques may document that the autograft tumor burden is substantial when compared with the patient tumor load following conditioning therapy, a theoretical benefit may not be sufficient to persuade third-party payers to expend additional money for the purging procedure. For insurers, the equation to determine product usefulness does not consider risk as the only negative component, but a combination of risk and cost. When the amount that can be spent is limited, a demonstration that these additional costs will garner a true patient benefit becomes more important. Because it is difficult to assign a dollar amount for a theoretical benefit, third-party payers may be unwilling to accept the potential but unproven benefit from a purging procedure. Nevertheless, if the time to engraftment remains unchanged, the added costs of the purging procedure should be relatively minimal and, in the authors' view, should not be a major impediment to its widespread use. Educated patients and physicians will probably demand that these procedures be performed in cases where autograft purging adds little if any risk and provides at least a significant potential for benefit.