Stem Cell Transplants

There have been some interesting items in the NHL universe lately about Stem Cell Transplants. There's a nice article from CNN on the Stem Cell/Bone Marrow donation, and another one this week on the same subject in our local paper (but the link is broken so I can't post it for you). All of which comes on the heels of an interesting article about Stem Cell Transplants for Follicular NHL patients.

It's from the most recent issue of The Oncologist, and is titled "Role of Hematopoietic Stem Cell Transplant in the Management of Follicular Lymphoma." The abstract gives an overview of the past and future for SCT in fNHL. According to the article, Auto SCT, in which the patient's own stem cells are harvested prior to chemo, was first developed before Rituxin came about, so there's some question now as to whether an Auto SCT is worth the risk, given the other treatment options available. Allo SCT, in which a donor's cells are used, can be more effective (since the donated cells are guaranteed to be cancer-free), but also comes with the kinds of rejection issues that come with any transplant, and can be especially dangerous for patients with very weak immune systems to begin with.

The authors seem to be advocating a Reduced Intensity SCT, also called a "mini-Allo" transplant. With a "regular" Allo SCT, the patient receives heavy chemo to essentially wipe out the immune system, which is then replaced and regenerated by the donated cells. But that heavy chemo can still be present when the donated cells are introduced, and the chemo can damage those new cells, causing the transplant to fail. The "mini Allo" takes care of that by using less-intensive chemo (or even RadioImmunoTherapy) before introducing the donated cells. The theory is that any cancer cells that haven't been wiped out by the treatment will be taken care of by the donated cells, which will do their job in a normal way -- killing invaders (including cancer cells).

There has been some success with mini Allos. It's often used in patients who are over 70, or who are weakened by multiple chemo treatments, and couldn't handle a full Allo SCT. The authors of the article are encouraging more participation in clinical trials for the procedure (which is what everyone is encouraging, really).